US 8106153 B2
Cytotoxic T lymphocytes (CTLs) specific for antigenic peptides derived from IgE molecule can be generated in vitro by stimulating resting naive CD8 T cells with IgE peptides presented by artificial antigen presenting cells. The IgE specific CTLs lyse the target cells loaded with IgE peptides in vitro and inhibit antigen specific IgE response in vivo. In addition, adoptive transfer of the IgE specific CTL to an asthmatic mouse model can inhibit the development of lung inflammation and airway hypersensitivity. IgE specific CTL provides a treatment for allergic asthma and other IgE-mediated allergic diseases. Antigenic peptides identified from non-tumor self-antigens induce specific cytotoxic T lymphocyte (CTL) in vitro. The CTL induced by peptides identified from CD40L can kill activated CD4 T cells. In vitro generated CTL specific for CD40L inhibit CD4-dependent antibody responses of all isotypes in vivo. In contrast, CTL induced by antigenic peptides derived from IgE specifically inhibit IgE responses, and adoptive transfer of CD40L-specific CTL to NOD mice at early age delay the development of diabetes in NOD mice. In vitro generated CTL specific for non-tumor self-antigens expressed on activated CD4 T cells regulate immune responses in vivo.
1. An isolated antigenic peptide selected from the group consisting of:
This application is a divisional application of U.S. application Ser. No. 11/935,486 filed Nov. 6, 2007 now U.S. Pat. No. 7,842,501, which is a continuation of U.S. application Ser. No. 11/580,358 filed Oct. 13, 2006 now abandoned which is a divisional of U.S. application Ser. No. 10/144,188 filed May 13, 2002 now U.S. Pat. No. 7,811,816, which claims priority to U.S. Provisional application No. 60/291,300 filed May 15, 2001, the entire disclosures of which are hereby incorporated in their entirety.
This application claims priority from U.S. provisional application Ser. No. 60/291,300, filed May 15, 2001, the contents of which are hereby incorporated by reference.
Immune responses to foreign antigens such as those found in bacteria and virus protect from and eliminate infections. However, aberrant immune responses can cause allergic diseases and autoimmune diseases. Immune responses to foreign, sometimes innocuous, substances such as pollen, dust mites, food antigens and bee sting can result in allergic diseases such as hay fever, asthma and systemic anaphylaxis. Immune responses to self-antigens such as pancreatic islet antigens and cartilage antigens can lead to diabetes and arthritis, respectively. The hallmark of the allergic diseases is activation of CD4 T cells and high production of IgE by B cells, whereas the salient feature of autoimmune diseases are activation of CD4 T cells and over production of inflammation cytokines. The current therapies have been focused on the treatment of symptom of allergy and autoimmune diseases and do not prevent the development and progression of the diseases.
CTLs are derived from resting naïve CD8 T cells and recognize antigenic peptides presented by Major Histocompatibility Complex (MHC) class I molecules. When resting CD8 T cells encounter antigenic peptides/MHC complex presented by professional antigen presenting cells, CD8 T cells will be activated and differentiated into armed CTL. Upon recognition of peptide/MHC complexes on the target cells, the antigen specific CTL will deliver a lethal hit and lysis the antigen-expressing target cells, such as virus infected target cells or tumor cells.
Activation of naive T cells in vivo is controlled by multiple receptor-ligand interactions between T cells and professional APC such as dendritic cells (R. M. Steinman, Annu. Rev. Immunol. (1991) 9:271-296). It is generally accepted that two signals are required for activation of naive T cells (C. A. Janeway and K. Bottomly, Cell (1994) 76:275-285). Signal 1 is induced by the interaction between TCR and MHC/peptide complexes (R. N. Germain, Cell (1994) 76:287-299) and is aided by binding of CD4/CD8 co-receptors to non-polymorphic regions of MHC class II/I molecules, respectively (M. C. Miceli and J. R. Parnes, Adv. Immunol. (1993) 53:59-122). Signal 2 is qualitatively different from Signal 1 and is delivered via T cell costimulatory molecules interacting with complementary ligands on APC, e.g. through CD28 interaction with B7 (P. S. Linsley and J. A. Ledbetter, Annu. Rev. Immunol. (1993) 11:191-212; Lenschow et al., Annu. Rev. Immunol. (1996) 14:233-258). Signals 1 and 2 function synergistically and trigger a series of signaling events which ultimately induce T cells to proliferate, produce cytokines and differentiate into effector cells (Mueller et al., Annu. Rev. Immunol. (1989) 7:445-480; A. Weiss and D. R. Littman, Cell (1994) 76:263-274). The relationship between Signals 1 and 2, however, is unclear.
Although a variety of molecules have been reported to have costimulatory function, particular attention has been focused on costimulation delivered via CD28-B7 interaction (R. H. Schwartz, Cell (1992) 71:1065-1068). CD28 is a molecule with a single Ig like domain and is constitutively expressed as a homodimer on T cells (P. S. Linsley and J. A. Ledbetter, (1993) supra). Through its interaction with either B7-1 or B7-2 molecules on APCs, CD28 molecules are thought to transduce unique signals that stimulate T cell to produce growth-promoting cytokines such as IL-2 (June et al., Immunol. Today (1994) 15:321-331), to upregulate expression of survival factors such as Bcl-XL (Boise et al., Immunity (1995) 3:87-98) and to prevent anergy induced by Signal 1 alone (R. H. Schwartz, Curr. Opin. Immunol. (1997) 9:351-357).
Another pair of molecules that has an important role in T cell activation is LFA-1/ICAM-1 (Van Seventer et al., J. Immunol, (1990) 144:4579-4586). ICAM-1 belongs to the Ig gene superfamily and has five Ig C like domains in the extracellular regions; it is expressed on both hemapoietic and nonhemapoietic cells. The receptor for ICAM-1 on T cells is LFA-1 (CD11/CD18), which belongs to the b2 integrin family (T. A. Springer, Cell (1994) 76:301-314). The interaction of LFA-1 with ICAM-1 has potent costimulatory function on T cells (Shimizu et al., Immunol. Rev. (1990) 114:109-143), although opinions vary on whether this function reflects a separate signaling pathways or increased adhesion between T cells and APC (Damle et al., J. Immunol. (1993) 151:2368-2379; Bachmann, et al., Immunity (1997) 7:549-557).
In addition to B7 and ICAM-1 molecules, several other molecules on APCs, including CD70 (Hintzen et al., J. Immunol. (1995) 154:2612-2623) and heat-stable antigen (HSA) (Liu et al., J. Exp. Med. (1992) 175:437-445), can exert quite potent costimulatory function through their interaction with their respective ligands on T cells. The implication is that T-APC interaction is highly complex and involves multiple interactions between complementary sets of molecules on T cells and APCs. The interaction of each set of molecules could trigger specific signals which induce different cellular events. The combination of the different signals may act synergistically for optimal T cell activation and determine the final fate of T cells. Alternatively, the function of costimulation molecules may be redundant and the signals induced by each set of costimulation molecules are additive. The requirement for each set of costimulation molecules will be influenced by the strength and characteristics of Signal 1.
In considering these two possibilities, it is important to understand the minimal requirements for stimulating naive T cells. Studies with CD28−/− mice indicated that CD28-B7 interaction is highly important in some situations, but not in others (Shahinian et al., Science (1993) 261:609-612). Likewise, the requirement for LFA-1/ICAM interaction in primary responses is not an invariable finding (Shier et al., J. Immunol. (1996) 157:5375-5386).
CD8 T cells recognize antigenic peptides derived mainly from virus proteins and proteins expressed on tumor cells. However, it has recently been reported that newly synthesized proteins are preferentially processed by antigen-processing machinery (Schubert et al., Nature, (2000) 404:770-774). Upon activation, immune cells have acquired the ability to synthesize a number of new proteins, it is possible that IgE producing B cells and activated CD4 T cells would present a different sets of peptide/MHC complexes than the non-IgE producing cells and resting CD4 T cells. These peptides/MHC complexes presented on IgE producing B cells and activated CD4 T cells would be able to be recognized by CD8 T cells. Thus, CTL specific for these peptides/MHC complexes would be able to treat allergy and autoimmune diseases. However, a number of tolerance mechanisms have been able to prevent the activation the CD8 T cells towards self-antigens in vivo.
CD8 lymphocytes (CTLs) are the arm of adaptive immunity responsible for the recognition and elimination of infected cells, tumor cells, and allogeneic cells. Once primed, CTL can recognize their target antigen on a wide variety of cells and accomplish their function by lysing the target cell and/or secreting cytokines like TNF-alpha, or IFN-gamma.
Presentation of antigen to CD8+ CTL (cytotoxic T lymphocytes) occurs in the context of MHC class I molecules (MHC-I), while presentation of antigen to CD4+ HTL (helper T lymphocytes) occurs in the context of MHC class II molecules.
Efficient induction of CD4+ T cell requires that the T cells interact with antigen presenting cells (APC) i.e. cells that express MHC class II and co-stimulatory molecules. APC are dendritic cells, macrophages and activated B cells. Although nearly all nucleated cells express MHC-I, naive CTL also require presentation of antigen (Ag) by bone marrow-derived APC for efficient priming (Dalyot-Herman et al., J. Immunol., 165(12):6731-6737). Dendritic cells are highly potent inducers of CTL responses (J. Bancherean and R. M. Steinman, Nature, (1998) 392:245-252) and are thought to be the principal APC involved in priming CTL. Once primed, CTL can recognize their cognate Ags on a wide variety of cells and respond by lysing the target cell and/or secreting cytokines.
Although bone marrow-derived APC are required to efficiently prime CTL responses (P. J. Fink and M. J. Bevan, Exp. Med. (1978) 148:755-766) activated CTL are readily able to recognize and respond to Ag presented by a wide variety of cells. Induction of tumor- or viral-specific CTL immune responses in vivo have been shown to be dependent on bone marrow derived antigen-presenting cells (Paglia et al., J. Exp. Med. (1996) 183(1):317-322; Labeur et al., J. Immunol. (1999) 162(1):168-175). It is generally accepted that bone marrow derived APC, through mechanisms unique to these cells, take up cellular antigens either in the form of soluble antigen, associated with chaperone molecules or by phagocytosis.
It has long been demonstrated that responses to cellular antigens are dependent on help delivered by CD4+ T cells. It has also been shown that the cellular antigen had to be presented on the same APC for recognition by the CTL and the HTL. The nature of this help has been interpreted as a need of IL-2 necessary for CTL expansion. Recent studies have shown that this help results from the activation of dendritic cells by HTL and is mediated via CD40-CD40L interaction (S. R. Clarke, J. Leukocyte Bio. (2000) 67(5):607-614).
A likely scenario for the induction of a CD8 mediated immune response to a cellular antigen (derived from a tumor cell or an infected cell) is therefore the following: dendritic cells acquire antigens derived from tumor or infected cells. Interaction of DC-antigen with CD4 cells enable the DC to activate the CD8 cells.
Immune cells, such as IgE producing B cells and activated CD4 T cells play a central role in the pathogenesis of allergic diseases and autoimmune diseases. The present invention utilizes cytotoxic T lymphocytes (CTLs) to eliminate or inhibit the immune cells that cause the allergy and/or autoimmune diseases. Thus, the development and progression of diseases can be prevented or interrupted by the methods of the present invention.
The present invention provides a method for producing CTL specific for one or more non-tumor self antigen T cell epitopes, comprising:
The present invention also provides CD8+ T cells that are specifically cytotoxic for a disease causing target cell, wherein the target cell has on its surface one or more non-tumor self antigen T cell epitopes associated with Class I MHC molecules, and wherein the CD8+ T cells have been selectively activated by interaction with Class I MHC molecules associated with the non-tumor self antigen T cell epitopes.
The present invention also provides a method for treating a disease mediated by a disease causing target cell, wherein the target cell has on its surface one or more non-tumor self antigen T cell epitopes associated with Class I MHC molecules, comprising administering to a patient in need of such treatment, activated CD8+ T cells wherein the CD8+ T cells have been selectively activated by interaction with Class I MHC molecules associated with the non-tumor self antigen T cell epitopes.
The present invention demonstrates that by making and using artificial antigen presenting cells, tolerance of CD8 T cells to self antigens was broken and CTLs specific for antigenic peptides identified from IgE or CD40L proteins were generated. Adoptive transfer of the in vitro generated CTLs specific for CD40L to NOD mice dramatically delayed the development of diabetes, and CTLs specific for IgE peptides inhibited the production of IgE and reduced lung inflammation in an asthmatic mouse model. The above system is potentially applicable to human diseases that are caused by CD4 T cells and by IgE producing B cells. Autoimmune diseases that caused by CD4 T cells are diabetes, rheumatoid arthritis, SLE, multiple sclerosis and psoriasis. Whereas allergic diseases mediated by IgE are systemic anaphylaxis caused by drugs, venoms and peanuts, allergic rhinitis, food allergy, and allergic asthma. In addition other self-antigens that expressed on immune cells can also be used for generation of CTLs in vitro as well in vivo for treatment of autoimmune diseases and allergic diseases. Antigenic peptides, proteins or RNA and DNA encoding the non tumor antigens expressed in non tumor cells can also be used to develop vaccines for treatment or prevention of allergy and autoimmune diseases.
CD8+ T cells were purified from lymph nodes of CBF1/J mice (A, B and D) or from B6, interferon γ knock out mice (IFNγ−/−) or perform (PF−/−) knock out mice (C). The purified CD8 T cells were cultured with indicated IgE peptides presented by SC2 cells transfected with Db MHC class I, B7-1 (CD80) and ICAM-1 (CD54) molecules. Low dose of recombinant IL-2 (20 units/ml) was added to the culture at Day 3 and every other day thereafter. On Day 9, CTL activity was measured against 51Cr labeled RMAS cells loaded with or without indicated IgE peptides. In
CBF1/J mice were immunized as in
CBF1/J mice were immunized with OVA/Alum at Day 1 and Day 14. Two weeks after the second immunization, mice were injected every other day for three treatments with PBS, anti-IgE CTL or a control CTL (anti-influenza CTL) as indicated. Three weeks after the last treatment, mice were challenged with OVA intranasally every other day for three treatments. One day after the last challenge with OVA, airway responsiveness to methacholine for each mouse was measured by whole body plethrography. Two independent experiments were shown in Panels A and B respectively.
Adult CBF1/J mice (8 to 12 weeks) were immunized intraperitoneally with 50 μg ovalbumin (OVA) precipitated with Alum Hydroxide on Day 1 and Day 14 respectively. Two weeks after the second immunization, the mice were given IgE-specific CTLs (5×106) or PBS intravenously. Three weeks after the last treatment, mice were challenged with OVA intranasally every other day for two to three treatments. One day after the last challenge with OVA, the BAL was prepared from each mouse and the lung from each mouse was fixed and stained with HE. A representative HE staining of lung tissue from mice received PBS (Panel A) or from mice received anti-IgE CTL (Panel B) was shown.
CD8 T cells were purified from individual donors and cultured with Drosophila cells transfected with HLA-A2, h137-1, hB7-2, hICAM-1 and hLFA-3 molecules in the presence of indicated peptides. After being cultured for six days, low doses of hIL-2 was added to the culture and re-stimulated with peptides loaded autologous adherent cells for an additional seven days. The CTLs were then harvested and the specific killing activities were tested with 51Cr labeled T2 cells that loaded with indicated peptides by a standard chromium release assay.
Purified CD4 or CD8 T cells were activated with plate-bound anti-CD3 and anti-CD28 for forty hours (top panel) or for indicated time (bottom panel) and were stained with indicated mAb.1
B10.D2 mice were immunized with OVA+CFA on Day 1. Anti-CD40L CTL or anti-CD40L Ab were given at Days 1, 3, 5. Serum was collected on Day 14 and OVA-specific immunoglobulins were measured by ELISA.
CD8 T cells were purified from C57BL/6 mice and cultured with Drosophila cells transfected with Db, B7-1 and ICAM-1 in the presence of IgE.44 peptide (A), IgE.366 peptide (B) and IgE.125 (C). IL-2 (20 units/ml) was added to the culture on Day 3 and 5. CTLs were harvested on Day 7 and their specific killing activity was measured against 51Cr labeled RMA.S target cells in the presence or absence of indicated peptides.
The present invention provides in one embodiment, a method for treating a subject with non-tumor self-antigen T cell epitopes comprising:
Another embodiment of the present invention provides a method for treating a subject comprising,
Another embodiment of the present invention provides a method for treating a subject with autoimmune disease, including, but not limited to, rheumatoid arthritis, lupus, psoriasis, autoimmune nephritis, multiple sclerosis, insulin dependent diabetes, autoimmune thyroiditis, Crohn's disease, inflammatory bowel disease, graft versus host disease and transplant rejection, and/or allergic diseases, including, but not limited to, food allergy, hay fever, allergic rhinitis, allergic asthma and venom allergy, comprising:
Another embodiment of the present invention is a method of treating allergic and/or autoimmune diseases wherein the nnAPC presents the following peptides, SEQ ID NO:15 to SEQ ID NO: 49.
Another embodiment of the present invention is a method of treating a non-cancer disease or disease condition that results in an insufficient or inadequate immune response that is normally associated with Class I HLA molecules, wherein the treatment eliminates infected or transformed cells wherein said elimination has been demonstrated to be mediated by CTLs.
Another embodiment of the present invention is a method of treating a non-cancer disease or disease condition that results in an insufficient or inadequate immune response that is normally associated with Class I HLA molecules, wherein infected or transformed cells that have been shown to be susceptible to elimination by CTL are treated by the method comprising:
The present invention provides a non-naturally occurring antigen-presenting cell (nnAPC) derived from Drosophila melanogaster cells transfected with DNA for expression, wherein the nnAPC is capable of simultaneously presenting up to fifteen different peptide molecules associated with allergic and/or autoimmune disease, preferably ten peptide molecules that are encoded by the DNA.
The present invention provides a non-naturally occurring antigen-presenting cell (nnAPC) derived from Drosophila melanogaster cells transfected with human class I HLA, binding, and co-stimulatory molecule's DNA for expression, wherein the nnAPC is capable of presenting up to fifteen different peptide molecules associated with allergic and/or autoimmune disease, preferably ten peptide molecules that are encoded by the DNA simultaneously.
Another embodiment of the present invention provides a nnAPC that presents peptides that are associated with various desired functions that enhance the treatment of the subject. For example, in addition to peptides associated with the disease or disease condition being treated, the nnAPC can present peptides associated with accessory molecules such as, lymphocyte function antigens (LFA-1, LFA-2 and LFA-3), intercellular adhesion molecule 1 (ICAM-1), T-cell co-stimulatory factors (CD2, CD28, B7) enhance cell-cell adhesion or transduce additional cell activation signals.
Another embodiment of the present invention provides a nnAPC that presents peptides that are associated with allergic and/or autoimmune diseases. For example, the peptides associated or derived from IgE may be presented with peptides associated or derived from an allergen, or further in combination with CD40L peptides.
Another embodiment of the present invention provides a method for manufacturing non-naturally occurring antigen-presenting cell (nnAPC) capable of presenting up to ten different peptide molecules associated with allergic and/or autoimmune disease simultaneously, said method comprising of the step:
Professional antigen presenting cells, such as dendritic cells and macrophages, can be loaded with IgE peptides (Dalyot-Herman et al. (2006) supra) or IgE recombinant proteins (Paglia et al. (1996) supra) or transduced with virus encoding IgE or fragments of IgE (Yang et al., Cellular Immunology (2000) 204:29-37). These modified professional antigen-presenting cells can then be used to activate IgE specific CD8 T cells and generate IgE specific CTLs in vitro. Alternatively, non-professional antigen presenting cells can also be transfected or transduced with a number of genes that encode costimulation molecules plus the genes that encode IgE and a fragment of IgE. The modified non-professional antigen presenting cells thus can be used to stimulate IgE specific CD8 T cells for generation of IgE specific CTLs.
The insect cells of the present invention are grown in a media suitable for growing insects, hereinafter referenced to as “insect growth media”. Insect growth media are commercially available from a number of vendors, such as, Schneider™'s Drosophila Medium, Grace's Insect Media, and TC-100 Insect Media. Alternatively, insect growth media can be prepared by one of ordinary skill in the art. Typically, the media will include components necessary to promote and sustain the growth of insects cells, such as, inorganic salts (for example, calcium chloride, magnesium sulfate, potassium chloride, potassium phosphate, sodium bicarbonate, sodium chloride, and sodium phosphate), amino acids various carbohydrate and chemical species (Imogene Schneider, Exp. Zool. (1964) 156(1):91-104). Alternatively, the media can also include vitamins, minerals, and other components that aid in the growth of insect cells.
Following is a list of abbreviations and definitions used in the present specification.
Following is a list of abbreviations used in the present specification for various peptide epitopes. The individual amino acid residues are identified according to a single letter code that is readily known and used by those of ordinary skill in the art.
As used herein the term IgE 11 refers to the amino acid sequence KPCKGTASM (SEQ ID NO: 1).
As used herein the term IgE 209 refers to the amino acid sequence IPPSPLDLY (SEQ ID NO: 2).
As used herein the term IgE 366 refers to the amino acid sequence GSNQGFFIF (SEQ ID NO: 3).
As used herein the term IgE 29 refers to the amino acid sequence FPNPVTVTW (SEQ ID NO: 4).
As used herein the term IgE 105 refers to the amino acid sequence HSSCDPNAF (SEQ ID NO: 5).
As used herein the term IgE 114 refers to the amino acid sequence HSTIQLYCF (SEQ ID NO: 6).
As used herein the term IgE 363 refers to the amino acid sequence KSNGSNQGF (SEQ ID NO: 7).
As used herein the term IgE 307 refers to the amino acid sequence RSAPEVYVF (SEQ ID NO: 8).
As used herein the term IgE 44 refers to the amino acid sequence MSTVNFPAL (SEQ ID NO: 9).
As used herein the term IgE 411 refers to the amino acid sequence TSLGNTSLR (SEQ ID NO: 10).
As used herein the term IgE 16 refers to the amino acid sequence TASMTLGCL (SEQ ID NO: 11).
As used herein, the term IgE 159 refers to the amino acid sequence of ASTCSKLNI (SEQ ID NO: 12).
As used herein, the term IgE 125 refers to the amino acid sequence of GHILNDVSV (SEQ ID NO: 13).
As used herein the term CD40L 17 refers to the amino acid sequence LPASMKIFM (SEQ ID NO: 15).
As used herein the term CD40L 186 refers to the amino acid sequence RPFIVGLWL (SEQ ID NO: 16).
As used herein the term CD40L 118 refers to the amino acid sequence DPQIAAHVV (SEQ ID NO: 17).
As used herein the term CD40L 220 refers to the amino acid sequence QSVHLGGVF (SEQ ID NO: 18).
As used herein the term CD40L 9 refers to the amino acid sequence SPRSVATGL (SEQ ID NO: 19).
As used herein the term CD40L 195 refers to the amino acid sequence KPSIGSERI (SEQ ID NO: 20).
As used herein the term CD40L 252 refers to the amino acid sequence FSSFGLLKL (SEQ ID NO: 21).
As used herein the term CD40L 7 refers, to the amino acid sequence QPSPRSVAT (SEQ ID NO: 22).
As used herein the term CD40L 181 refers to the amino acid sequence EPSSQRPFI (SEQ ID NO: 23).
As used herein the term CD40L 79 refers to the amino acid sequence LSLLNCEEM (SEQ ID NO: 24).
As used herein, the term CD40L 152 refers to the amino acid sequence of VMLENGKQL (SEQ ID NO: 25).
As used herein, the term CD40L 146 refers to they amino acid sequence of TMKSNLVML (SEQ ID NO: 26).
As used herein, the term CD40L 235 refers to the amino acid sequence of SVFVNVTEA (SEQ ID. NO: 27).
As used herein, the term CD40L 38 refers to the amino acid sequence of GSVLFAVYL (SEQ ID NO: 28).
As used herein, the term CD40L 19 refers to the amino acid sequence of ASMKJFMYL (SEQ ID NO: 29).
As used herein the term CD40L 24 refers to the amino acid sequence FMYLLTVFL (SEQ ID NO: 30).
As used herein the term CD40L 167 refers to the amino acid sequence GLYYIYAQV (SEQ ID NO: 31).
As used herein the term CD40L 22 refers to the amino acid sequence KIFMYLLTV (SEQ ID NO: 32).
As used herein the term CD40L 36 refers to the amino acid sequence MIGSALFAV (SEQ ID NO: 33).
As used herein the term CD40L 58 refers to the amino acid sequence NLHEDFVFM (SEQ ID NO: 34).
As used herein the term CD40L 170 refers to the amino acid sequence YIYAQVTFC (SEQ ID NO: 35).
As used herein the term CD40L 26 refers to the amino acid sequence YLLTVFLIT (SEQ ID NO: 36).
As used herein the term CD40L 231 refers to the amino acid sequence LQPGASVFV (SEQ ID NO: 37).
As used herein the term CD40L 45 refers to the amino acid sequence VLHRRLDKI (SEQ ID NO: 38).
As used herein the term CD40L 147 refers to the amino acid sequence TMSNNLVTL (SEQ ID NO: 39).
As used herein, the term CD40L 229 refers to the amino acid sequence of FELQPGASV (SEQ ID NO: 40).
As used herein, the term CD40L 160 refers to the amino acid sequence of QLTVKRQGL (SEQ ID NO: 41).
As used herein, the term CD40L 35 refers to the amino acid sequence of QMIGSALFA (SEQ ID NO: 42).
As used herein, the term CD40L 185 refers to the amino acid sequence of SQAPFIASL (SEQ ID NO: 43).
As used herein, the term CD40L 19 refers to the amino acid sequence of ISMKIFMYL (SEQ ID NO: 44).
As used herein, the term CD40L 153 refers to the amino acid sequence of VTLENGKQL (SEQ ID NO: 45).
As used herein, the term CD40L 126 refers to the amino acid sequence of VISEASSKT (SEQ ID NO: 46).
As used herein, the term CD40L 227 refers to the amino acid sequence of GVFELQPGA (SEQ ID NO: 47).
As used herein, the term CD40L 20 refers to the amino acid sequence of SMKIFMYLL (SEQ ID NO: 48).
As used herein, the term CD40L 165 refers to the amino acid sequence of RQGLYYIYA (SEQ ID NO: 49).
As used herein, the term IgE 47 refers to the amino acid sequence of SLNGTTMTL NO: 50).
As used herein, the term IgE 96 refers to the amino acid sequence of WVDNKTFSV (SEQ ID NO: 51).
As used herein, the term IgE 185 refers to the amino acid sequence of WLSDRTYTC (SEQ ID NO: 52).
As used herein, the term IgE 309 refers to the amino acid sequence of ALSDRTYTC (SEQ ID NO: 53).
As used herein, the term IgE 876 refers to the amino acid sequence of SLLTVSGAWA (SEQ ID NO: 54).
As used herein, the term IgE 883 refers to the amino acid sequence of WLEDGQVMDV (SEQ ID NO: 55).
As used herein, the term IgE 884 refers to the amino acid sequence of TLTVTSTLPV (SEQ ID NO: 56).
As used herein, the term IgE 887 refers to the amino acid sequence of QMFTCRVAHT (SEQ ID NO: 57).
As used herein, the term IgE 890 refers to the amino acid sequence of YATISLLTV (SEQ ID NO: 58).
As used herein, the term IgE 895 refers to the amino acid sequence of TLACLIQNFM (SEQ ID NO: 59).
As used herein, the term IgE 898 refers to the amino acid sequence of QVMDVDLSTA (SEQ ID NO: 60).
Terms and Definitions
As used herein, the term “adoptive immunotherapy” refers the administration of donor or autologous T lymphocytes for the treatment of a disease or disease condition, wherein the disease or disease condition results in an insufficient or inadequate immune response that is normally associated with Class I HLA molecules. Adoptive immunotherapy is an appropriate treatment for any disease or disease condition where the elimination of infected or transformed cells has been demonstrated to be achieved by CTLs. For example, disease or disease conditions include but are not limited to cancer and/or tumors, such as, melanoma, prostate, breast, colo-rectal, stomach, throat and neck, pancreatic, cervical, ovarian, bone, leukemia and lung cancer; viral infections, such as, hepatitis B, hepatitis C, human immunodeficiency virus; and bacterial infections, such as, malaria; tuberculosis, and lysteria monocytogenesis.
As used herein, the term “B7.1” refers to a co-stimulatory molecule associated with antigen-presenting cells.
As used herein, the term “BCNU” refers to carmustine, also known as, 1,3-bis (2chloroethyl)-1-nitrosourea.
As used herein, the term “BSE” refers to bovine spongiform encephalitis.
As used herein, the term “CD” refers to clusters of differentiation, T lymphocytes (originally), B lymphocytes, monocytes, macrophages, and granulocytes grouped by antigen epitopes and function.
As used herein, the term “DTIC” refers to dacarbazine, 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide.
As used herein, the term “ex vivo” or “ex vivo therapy” refers to a therapy where biological materials, typically cells, are obtained from a patient or a suitable alternate source, such as, a suitable donor, and are modified, such that the modified cells can be used to treat a pathological condition which will be improved by the long-term or constant delivery of the therapeutic benefit produced by the modified cells. Treatment includes the re-introduction of the modified biological materials, obtained from either the patient or from the alternate source, into the patient. A benefit of ex vivo therapy is the ability to provide the patient the benefit of the treatment, without exposing the patient to undesired collateral effects from the treatment. For example, cytokines are often administered to patients with cancer or viral infections to stimulate expansion of the patient's CTLs. However, cytokines often cause the onset of flu like symptoms in the patients. In an ex vivo procedure, cytokines are used to stimulate expansion of the CTLs outside of the patient's body, and the patient is spared the exposure and the consequent side effects of the cytokines. Alternatively under suitable situations, or conditions, where appropriate and where the subject can derive benefit, the subject can be treated concurrently with low level dosages of α interferon.
As used herein, the term “HEPES” refers to N-2-hydroxyethylpiperazine-N′2-ethanesulfonic acid buffer.
As used herein, the term “HLA-A2.1” refers to a HLA Class I molecule found in approximately 45% of Caucasians.
As used herein, the term “MPC-10” refers to a magnetic particle concentrator.
As used herein, the term “NK cells” refers to natural killer cells.
As used herein, the term “OKT3” refers to ORTHOCLONE OKT3, muromonab-CD3, anti-CD3 monoclonal antibody.
As used herein, the term “TAP-1, 2” refers to Transporter Associated with Antigen Processing-1, 2.
As used herein, the term “Th cells” refers to Helper T cells, CD4+.
As used herein, the term “C-lectin” refers to a peptide of the sequence that has been found to be associated with ovarian cancer.
As used herein, the term “major histocompatibility complex” or “MHC” is a generic designation meant to encompass the histocompatibility antigen systems described in different species including the human leucocyte antigens (HLA).
As used herein, the terms “epitope,” “peptide epitope,” “antigenic peptide” and “immunogenic peptide” refers to a peptide derived from an antigen capable of causing a cellular immune response in a mammal. Such peptides may also be reactive with antibodies from an animal immunized with the peptides. Such peptides may be about five to twenty amino acid in length preferably about eight to fifteen amino acids in length, and most preferably about nine to ten amino acids in length.
As used herein, the term “analog” includes any polypeptide having an amino acid residue sequence substantially identical to the polypeptide sequence of the present invention in which one or more residues have been conservatively substituted with a functionally similar residue and which displays the functional aspects of the present invention as described herein. Examples of conservative substitutions include the substitution of one non-polar (hydrophobic) residue such as isoleucine, valine, leucine or methionine for another, the substitution of one polar (hydrophilic) residue for another such as between arginine and lysine, between glutamine and asparagine, between glycine and serine, the substitution of one basic residue such as lysine, arginine or histidine for another, or the substitution of one acidic residue, such as aspartic acid or glutamic acid or another.
As used herein, the term “conservative substitution” also includes the use of a chemically derivatized residue in place of a non-derivatized residue.
As used herein, the term “chemical derivative” refers to a subject polypeptide having one or more residues chemically derivatized by reaction of a functional side group. Examples of such derivatized molecules include for example, those molecules in which free amino groups have been derivatized to form amine hydrochlorides, p-toluene sulfonyl groups, carbobenzoxy groups, t-butyloxycarbonyl groups, chloroacetyl groups or formyl groups. Free carboxyl groups may be derivatized to form salts, methyl and ethyl esters or other types of esters or hydrazides. Free hydroxyl groups may be derivatized to form O-acyl or O-alkyl derivatives. The imidazole nitrogen of histidine may be derivatized to form N-im-benzylhistidine. Also included as chemical derivatives are those proteins or peptides which contain one or more naturally-occurring amino acid derivatives of the twenty standard amino acids. For example, 4-hydroxyproline may be substituted for proline; 5-hydroxylysine may be substituted for lysine; 3-methylhistidine may be substituted for histidine; homoserine may be substituted for serine; and ornithine may be substituted for lysine. Proteins or polypeptides of the present invention also include any polypeptide having one or more additions and/or deletions or residues relative to the sequence of a polypeptide whose sequence is encoded is the corresponding nucleic sequence of the present invention, so long as the requisite activity is maintained.
Cytolytic T cells (CD8+) are the main line of defense against viral infections. CD8+ lymphocytes specifically recognize and kill host cells that are infected by a virus. Theoretically, it should be possible to harness the immune system to combat other types of diseases including cancer. However, few in vitro/ex vivo procedures have been available for specifically activating CTLs. The identification of key allergic and/or autoimmune antigens noted herein and a method for specific in vitro activation CTLs described below now allow testing of the concept of adoptive immunotherapy of allergic and/or autoimmune diseases.
All naive T cells require two signals for activation to elicit an immune response. For CD8+ lymphocytes (CTLs), the first signal, which imparts, specificity, consists of presentation to the CD8+ cell of an immunogenic peptide fragment (epitope) of the antigen bound to the Class I MHC (HLA) complex present on the surface of antigen-presenting cells (APCs). This complex is recognized specifically by a T cell antigen receptor (TCR), which communicates the signal intracellularly.
Binding to the T cell receptor is necessary but not sufficient to induce T cell activation, and usually will not lead to cell proliferation or cytokine secretion. Complete activation requires a second co-stimulatory signal(s), these signals serve to further enhance the activation cascade. Among the co-stimulatory molecules on antigen-presenting cells, B7 and cell adhesion molecules (integrins) such as ICAM-1 assist in this process by binding to CD28 and LFA-1, respectively, on the T cell. When a CD8+ cell interacts with an antigen-presenting cell bearing an immunogenic peptide (epitope) bound by a Class I MHC molecule in the presence of appropriate co-stimulatory molecule interactions, the CD8+ cell becomes a fully activated cytolytic T cell.
Lymphocyte-mediated cell killing involves a sequence of biological events beginning with the binding of the CD8+ CTL to an antigen-bearing target (tumor) cell by means of the recognition process described above for T cell activation. The interaction begins with the binding of antigen in association with an MHC Class I molecule on the APC or target cell to the T cell antigen receptor (TCR). Accessory molecules such as lymphocyte function antigens (LFA-1, LFA-2 and LFA-3), intercellular adhesion molecule 1 (ICAM-1), T cell co-stimulatory factors (CD2, CD28, B7) enhance cell-cell adhesion or transduce additional cell activation signals.
After cell-cell interaction, the CTL kills the target cell through the action of soluble cytolytic mediators (perforin and granzymes stored in cytoplasmic granules in the T cell) and a CTL surface molecule (FAS ligand). After the cytolytic attack, target cells die by necrosis (membrane perforation and organelle destruction) or apoptosis (chromatin condensation, DNA fragmentation and membrane blebbing).
The mechanisms of lymphocyte-mediated cytolysis is graphically depicted in
It is possible to use naturally-occurring antigen-presenting cells, for example, dendritic cells, macrophages, autologous tumor cells for in vitro CD8+ activation. However, the efficiency of activation following this approach is low. This is because the Class I molecules of native APCs contain many other types of peptide epitopes besides tumor epitopes. Most of the peptides are derived from normal innocuous cell proteins, resulting in a dilution of the number of active native APCs that would actually be effective against a tumor (Allison et al., Curr. Op. Immunol. (1995) 7:682-686).
A more direct and efficient approach to this problem is to, specifically activate CD8+ cells only with those epitopes relevant to combating a specific disease, (such as allergic and/or autoimmune disease). To this end, an artificial antigen presenting cell is created by expressing MHC Class I molecules in Drosophila melanogaster (fruit fly) cells. Since Drosophila does not have an immune system, the TAP-1,2 peptide transporters involved in loading peptide epitopes onto class I molecules are absent. As a result, the class I molecules appear on the Drosophila cell surface as empty vessels. By incubating these transfected Drosophila cells with exogenous peptides that bind to the class I molecules, such as, cancer or tumor specific epitopes, including but limited to, melanoma specific epitopes, it is possible to occupy every class I molecule with the same peptide. High density expression of class I molecules containing a single peptide in these Drosophila APCs permit generation of cytotoxic CD8+ T cells in vitro which are completely specific for the antigen peptide. Methods and procedures for preparing Drosophila cells are taught in U.S. Pat. No. 5,529,921 issued Jun. 25, 1996 entitled “In Vitro Activation of Cytotoxic T-Cells Using Insect Cells Expressing Human Class I MHC and β2-Microglobulin”, and U.S. Pat. No. 5,314,813 issued May 24, 1994 entitled “Drosophila Cell Lines Expressing Genes Encoding MHC Class I Antigens And β2-Microglobulin and Capable of Assembling Empty Complexes and Methods of Making Said Cell Lines”. In particular, U.S. Pat. No. 5,529,921 discloses at column 26, line 56 to column 28, line 22 various methods of separating out and/or enriching cultures of precursor cells.
Additionally, this feature eliminates the need for in vivo stimulation of the immune system with various cytokines. Thereby resulting in a treatment that fore goes the side effects caused by cytokines. Alternatively under suitable situations, or conditions, where appropriate and where the subject can derive benefit, the subject can be treated concurrently with low level dosages of α interferon.
Eliminating the need for in vivo stimulation with cytokines provides an improvement to the quality of patient care. Treatment regimes that include the administration of cytokines to patients often result in the patient developing flu-like symptoms, such as nausea, vomiting, and fever. These side reactions are generally not life threatening, although a particularly severe reaction occurring in a patient who is already in a weaken condition could result in a life endangering situation. Another consideration is the adverse impact such side reactions have on patient acceptance and compliance of an otherwise beneficial treatment regime. Removing the need for in vivo stimulation with cytokines results in a treatment regime that improves the comfort of the patient, and provides the clinician with an effective method of treatment that his or her patient is more likely to comply with.
The utility of this method for adoptive immunotherapy has been demonstrated in mice using transfected Drosophila cells as APCs and CD8+ cells from the 2C line of T cell receptor (TCR) transgenic mice. In this system, purified CD8+ 2C cells are highly responsive to in vitro peptides presented by MHC Class I (Ld)-transfected Drosophila cells also bearing the co-stimulatory molecules B7-1 and ICAM-1. Transfected Drosophila cells as a probe for defining the minimal requirements for stimulating unprimed CD8+ T cells (Cai et al., P.N.A.S. USA (1996) 93:14736-14741). Alternatively, when un-separated mouse spleen cells are used as responders in place of purified 2C cells, the need for co-stimulatory molecules does not apply. In this instance, the CD8+ cells in the spleen population receive “bystander” co-stimulation from activated B cells. Utilizing this finding, it has been possible to show that MHC Class I (Ld)-transfected Drosophila cells are able to induce normal DBA/2 mouse spleen cells to respond to syngeneic P815 mastocytoma tumor-specific peptides in vitro in the absence of added lymphokines. Injection of these CTLs into DBA/2 mice bearing P815 mastocytoma led to rapid tumor regression (Sun et al., Immunity (1996) 4:555-564).
The use of any natural, or artificial, antigen presenting cell (APC) system to generate cytotoxic T lymphocytes in vitro is limited by the antigen specificities these systems are capable of generating.
The following APC systems have been utilized to generate antigen-specific CTL's to single epitopes:
Dendritic cells (DCs) are considered the primary antigen presenting cell system in humans because of their wide application in presenting primary antigen cells. Self or foreign proteins are processed within a DC. The resultant peptide epitopes are presented by HLA molecules, and are transported to the surface of the DC. However, it was found that DCs would not consistently generate in vitro, CTLs directed against four different peptides. This would have provided CTLs having activity corresponding to each of the four peptides. In addition, it was also found that the phenotype of the DC at the time of peptide pulsing, mature or immature, did not effect the outcome.
Alternatively, Drosophila cell stimulation usually resulted in CTLs directed against up to ten different types of peptides. This provides CTLs that are active to each of the ten peptides.
The ability of Drosophila cells and DC to elicit CTL responses were evaluated, initially to a single peptide epitope, following the standard stimulation protocols for each, in order to compare DCs and transfected Drosophila cells. Immature DCs were generated by culturing for one week autologous monocytes in the presence of IL-4 and GM-CSF. Mature DCs were obtained from immature DCs by addition of TNF α to the culture medium twenty-four hours prior to harvesting. DCs (immature and mature) were harvested, pulsed with peptides and mixed with purified CD8 cells following the procedure used for the stimulation of CD8 cells and peptide-pulsed Drosophila cells. Drosophila cells were found to be generally better stimulators than DC. Further, DCs displaying either the immature or mature phenotype were not as efficient as Drosophila cells in eliciting specific CTL responses when defined peptides were used to pulse the APCs. This is particularly surprising, because of the dominant role played by DCs in the immune system.
Preparation of Cytotoxic Lymphocytes
CD8+ cells isolated from leukapheresis samples by positive selection with anti-CD8 antibody are stimulated against IgE and/or CD40L associated peptides presented by Drosophila cells expressing Human Class I molecules (HLA-A2.1), B7.1, ICAM-1, LFA-3 and B7.2. CD8+ cells are re-stimulated for two rounds with autologous monocytes loaded with the peptide epitope in the presence of IL-2 and IL-7. CTLs are non-specifically expanded with OKT3 and IL-2. CTL activity is measured against cells and purity of CD8+ T cells is assessed by flow cytometry.
The manufacturing processes and protocols are done according to Good Laboratory Practices and Good Manufacturing Practices. “Good Laboratory Practices” and “Good Manufacturing Practices” are standards of laboratory and manufacturing practices, which are set by United States Food and Drug Administration, and are readily known to those of skill in the art. The CTLs are monitored for identity, viability, CTL activity, sterility, and endotoxin content.
The following examples are intended to illustrate but not limit the present invention.
The Schneider S2 cell line was prepared from Drosophila melanogaster (Oregon-R) eggs according to published procedures and has been deposited with the American Type Culture Collection (CRL 10974). S2 cells are gown in commercial Schneider's Drosophila medium supplemented with 10% fetal bovine serum.
The pRmHa-3 plasmid vector for expressing MHC Class I and co-stimulatory proteins in S2 cells was derived from the pRmHa-1 expression vector constructed as described in the literature. It contains a metallothionein promoter, metal response consensus sequences and an alcohol dehydrogenase gene bearing a polyadenylation signal isolated from Drosophila melanogaster.
Complementary DNAs for Transfection were Prepared as Follows:
Complementary DNAs were individually inserted into the pRmHa-3 vector. S2 cells were transfected with a mixture of HLA-A2.1, B7.1 and ICAM-1 plasmid DNAs and the phshneo plasmid using the calcium phosphate precipitation method. Stably transfected cells were selected by culturing in Schneider's medium containing geneticin. Twenty-four hours before use, expression of the transfected genes was induced by addition of CuSO4. The level of expression was assessed by flow cytometry using anti-HLA-A2.1, anti-B7.1 and anti-ICAM-1 antibodies. HLA expression by greater than 30% of the cells is necessary for efficient in vitro activation of CD8+ lymphocytes.
Isolation of Human CD8+ Cells
CD8+ cells are isolated from leukapheresis samples by positive selection using the Dynabeads™ isolation procedure (Dynal). An anti-human CD8 mouse monoclonal antibody (50 μg/ml in human gamma globulin [Gammagard®]) is added to washed cells in Dulbecco's PBS supplemented with 1% human serum albumin (Baxter-Hyland) and 0.2% Na citrate. After incubation at 4° C. for forty-five minutes with gentle mixing, the cells are washed and re-suspended in the same buffer containing Dynal magnetic beads (Dynabeads™) coated with sheep anti-mouse IgG at a bead to cell ratio of 1:1. The cells and beads are placed into a sterile tube and gently mixed at 4° C. for forty-five minutes. At the end of this time, the antibody-bound cells are removed magnetically using the MPC-1® separator according to the manufacturer's instructions (Dynal). Dissociation of the CD8 cell-bead complex is achieved by incubation at 37° C. for forty-five minutes in the presence of CD8 peptide59-70 (AAEGLDTQRFSG, SEQ. ID. NO.:52). Free beads are removed magnetically and the CD8 cells are counted and analyzed by flow cytometry to evaluate purity. Recovery of CD8+ cells is typically greater than 80%. Table I summarizes the cell composition of fourteen separate CD8+ preparations from normal human PBMC preparations by positive selection with anti-CD8 antibody.
Primary Stimulation: Transfected Drosophila S2 cells are incubated in Schneider's medium (106 cells/ml) supplemented with 10% fetal calf serum and CuSO4 at 27° C. for twenty-four hours. Cells are harvested, washed and re-suspended in Insect X-press medium (BioWhittaker) containing 100 μg/ml human tyrosinase369-377 (RWJPRI). Following incubation at 27° C. for three hours, the S2 cells are mixed with CD8+ cells at a ratio of 1:10 in RPMI medium (Gibco) supplemented with 10% autologous serum. The cell mixture is incubated for four days at 37° C. during which the Drosophila cells die off. On Day 5, IL-2 (20 U/ml) and IL-7 (30 U/ml) are added with a media change to selectively expand the tyrosinase-specific CTL population.
Re-stimulation: Frozen, autologous, CD8-depleted PBMCs, obtained at the time of leukapheresis, are thawed, washed and re-suspended at 106 cells/ml in RPMI medium containing 10% autologous serum (as a source of β2 microglobulin) and 20 μg/ml of peptide epitope. Following γ-irradiation (5,000 rads), the cells are incubated at 37° C. for two hours.
Non-adherent cells are removed by washing with Dulbecco's PBS. Adherent monocytes are loaded with the tyrosinase epitope by incubation for 90 minutes in Hepes-buffered RPMI medium containing 10% autologous serum and 10 μg/ml of peptide epitope. The supernatant is removed and the Drosophila-activated CD8+ cell suspension (3×106 cells/ml in RPMI medium with 10% autologous serum) is added at a ratio of ten CD8+ cells to one adherent monocyte. After three to four days of culture at 37° C., IL-2 (20 U/ml) and IL-7 (30 U/ml) are added with a medium change to selectively expand the epitope-specific CTL population.
Non-specific Expansion: CD8's non-specifically expanded and culturing them in RPMI medium supplemented with autologous serum, anti-CD3 monoclonal antibody (OKT®3), IL-2 and γ irradiated autologous PBMCs.
Assays for Activity and Purity
CTL Assay: Epitope-bearing (target) cells are used as target cells in a 51Cr release assay. 5×106 target cells in RPMI medium containing 4% fetal calf serum, 1% HEPES buffer and 0.25% gentamycin are labeled at 37° C. for one hour with 0.1 mCi 51Cr. Cells are washed four times and diluted to 105 cells/ml in RPMI with 10% fetal bovine serum (HyClone). In a 96-well microtiter plate, 100 μl effector CTLs and 100 μl peptide-loaded, 51Cr-labeled target cells are combined at ratios of 100:1, 20:1 and 4:1 (effector: target). K562 cells are added at a ratio of 20:1 (K562) to reduce natural killer cell background lysis. Non-specific lysis is assessed using cells labeled with 51Cr as described above, but not bearing the epitope cell line. Controls to measure spontaneous release and maximum release of 51Cr are included in duplicate. After incubation at 37° C. for six hours, the plates are centrifuged and the supernatants counted to measure 51Cr release. Percent specific lysis is calculated using the following equation:
Flow Cytometry: CD8+ cells, before and after in vitro activation, were analyzed for a number of cell surface markers using fluorescent monoclonal antibodies and FACS analysis. Results from a typical activation protocol using cells from a healthy donor is shown in Table 2.
In addition to activity and purity, CTL preparations will be assayed for sterility and endotoxin content.
Purpose of Trial
This example teaches the effectiveness of cytotoxic T Cell infusions in the treatment of allergic diseases as assessed according to the following factors:
All patients will receive, at least, a single infusion of autologous CTLs. The number of cycles and the dose of cells administered to each patient are summarized in Table 1. The number of cells generated in vitro is dependent on patient-related factors such as the numbers of PBMCs isolated from the aphaeresis procedure and the number of CD8+ T cells present in each PBMC preparation. Since all of the cells generated in vitro are re-infused into the donor, doses administered to each patient are necessarily varied. In an attempt to normalize the doses between patients, a calculated “potency” score is recorded for each dose. The value is obtained by multiplying the total number of cells by the lytic activity obtained with peptide-loaded target cells. Patients are entered into a second, third or fourth cycle of treatment based on their clinical status at the end of each cycle. The total number of naïve CD8+ T cells isolated is dependent on its percentage in each of the PBMC preparations. The percent of CD8+ T cells varies among the patients. The procedure for generating CTLs ex vivo is taught in the Specification and Example 1, above.
Up-Regulation of Class I and Melanoma-Associated Antigens in Response to IFNα-2b
In an attempt to enhance the ability of the antigen-specific CTLs to lyse IgE producing cells in vivo, low dose IFNα-2b is administered for five consecutive days prior to the CTL infusion, and thrice weekly for an additional four weeks. One way to measure an in vivo response to the cytokine is to evaluate biopsies obtained at serial time points by immunohistochemical analysis for positive staining with specific antibodies.
Antigenic Specificity of Ex Vivo-Generated CTLs
CTLs generated from all patients are evaluated on the day of release against peptide-loaded T2 targets, an HLA-A2 IgE producing M-14 clone 4 cell line and an autologous M-14 cell line, if biopsy material was available to establish a line. Each prepared dose of cells is evaluated for its cytolytic activity. Peptide-loaded T2 cells, presenting either each peptide alone, or all peptides simultaneously, are used to determine the specificity of the CTL response generated for each patient. The ability to lyse endogenously-expressed, HLA-A2-associated, antigen-bearing cells is assessed with an HLA-A2 matched line or an autologous cell line. In addition to cytolytic activity, antigen-specificity is evaluated with an established method for detecting intracellular gamma interferon production, made in response to a specific peptide stimulus. The CTLs generated at the end of the ex vivo protocol are evaluated by this method. The percent of cells specific for each of the peptides is recorded individually. The total number of specific cells in each bulk CD8 culture from a patient is calculated by adding each of the peptide specificities detected in that population of T cells. An increase in the total number of specific cells is detected with each successive treatment cycle.
Presence of Anergic State Did not Preclude Ability to Generate CTLs or Prevent a Clinical Response
Most of the patients treated under this protocol receive previous medical intervention. A pretreatment skin test is performed to determine if an anergic response to a panel of seven common antigens correlates with either an inability to generate CTLs ex vivo, or prevent a documented clinical response. The ability to generate CTLs ex vivo does not correlate with the patient's pretreatment skin test results.
IgE plays an essential role in the pathogenesis of allergic asthma. Here, we show that cytotoxic T lymphocytes (CTLs) specific for antigenic peptides derived from IgE molecule can be generated in vitro by stimulating resting naive CD8 T cells with IgE peptides presented by artificial antigen presenting cells. The IgE specific CTLs lyse the target cells loaded with IgE peptides in vitro and inhibit antigen specific IgE response in vivo. In addition, adoptive transfer of the IgE specific CTL to an asthmatic mouse model can inhibit the development of lung inflammation and airway hypersensitivity. Thus, IgE specific CTL may provide a treatment for allergic asthma and other IgE-mediated allergic diseases.
Cytotoxic T lymphocytes are derived from resting naïve CD8 T cells. In the present of antigens and co-stimulations, resting naive CD8 T cells can be activated and differentiated into armed cytotoxic T cells, which can destroy the target cells that express the antigens. CTLs play an essential role in immunity against virus and intracellular pathogens by lysis the infected cells and/or through the effect of cytokines CTL produced.
Identification of Antigenic Peptides from IgE Protein Sequence:
Two alleles of mouse IgE (IgEa and IgEb) have been described previously (P06336). The alignment of the amino acid sequences of the IgEa and IgEb shown that 95% of the amino acid sequences are identical. A fourteen amino acids differences are located at the junction region between CH1 and CH2 region and another five amino acid differences are located at the junction region between the CH3 and CH4 region. The amino acid sequence of IgEb was analyzed for 9 mer peptide sequences that contain binding motifs for Ld and Db MHC class I molecules by using the software of the Bioinformatics & Molecular Analysis Section available at http://bimas.dcrt.nih.gov/molbio/hla_bind/. This program ranks potential nonapeptides based on a predicted half-time of dissociation to MHC class I molecules. Based on the ranking analysis, eight peptides with Ld binding motifs and five peptides with Db binding motifs were selected for synthesis (Table 1).
The binding capacity of these synthetic peptides to Ld and Db class I molecules were tested in an MHC class I stabilization assay (Cai et al. (1996) supra). Antigen-transporting deficient (TAP−) RMAS cells (H-2b) or Ld transfected RMAS (RMAS-Ld) cells were cultured in the presence of a titrated concentration of peptides at 27° C. After overnight culturing at 27° C., these cells were further cultured for two hours at 37° C. and the surface expression of Ld or Db on the cells were analyzed by flow cytometry. As shown in Table 1, two IgE peptides, IgE 11 and IgE366 bind to Ld strongly, whereas IgE 114 binds Ld weakly. Of the five peptides predicted bind to Db, only IgE44 binds Db strongly and two peptides, IgE16 and IgE125, bind Db weakly. Interestingly, IgE366 originally predicted binding Ld binds both Ld and Db. Thus, a total of six peptides were identified that bind to either Ld or Db MHC class I molecules.
The ability of these IgE peptides in eliciting CTL responses was evaluated in vitro. As previously described, Drosophila cells transfected with MHC class I plus B7-1 and ICAM-1 are potent antigen presenting cells (APC) in activation of resting naïve CD8 T cells in vitro. Resting naïve CD8 T cells were purified from mouse lymph nodes and cultured with peptide loaded Drosophila cells transfected with Ld or Db plus B7-1 and ICAM-1 in the absence of cytokines. IL-2 (20 units/ml) was added at Day 3 and every other day thereafter. The CTL activity towards peptides loaded RMAS (Kb, Db) cells or RMAS-Ld cells were measured on Day 9. As shown in
No specific CTL activity was induced by IgE16 or IgE 125 peptides, which have been show to bind Db. IgE366 was originally identified as Ld binding peptide, interestingly, in addition to inducing Ld restricted CTLs by IgE366, IgE366 also induce Db restricted CTLs (
Inhibition of IgE Responses by Anti-IgE Specific CTLs.
Because CTLs induced by IgE peptides kills the target cell specifically in vitro, we were interested in seeing if these CTLs could inhibit the IgE responses in vivo. Mice have very low serum IgE and do not develop allergic response spontaneously. Ovalbumin precipitated with Alum Hydroxyde has been used to induce antigen specific IgE responses in mice. As shown in
In the presence of specific antigen and constimulation, resting CD8 T cells can be activated and differentiated into CTL, which plays an essential role in anti-virus immune response. Recently, it has also been shown that tumor associated antigens specific CTL generated in vitro can be used in treating cancer patients. Here we show that antigenic peptides identified from non-tumor self-antigens can induce specific cytotoxic T lymphocyte (CTL) in vitro. The CTL induced by peptides identified from CD40L, a self antigen transiently expressed on activated CD4 T cells, can kill activated CD4 T cells and the killing can be blocked either by the antibody (Ab) specific for the restricting class I molecule or by the Ab recognizing CD8 molecule. In addition, neither activated CD4 T cells generated from CD40L−/− mice nor from 2 m−/− mice are killed by the CD40L specific CTL, demonstrating that the killing of activated CD4 T cells by CD40L specific CTL is antigen-dependent and MHC restricted. Importantly, in vitro generated CTL specific for CD40L inhibit CD4-dependent antibody responses of all isotypes in vivo. In contrast, CTL induced by antigenic peptides derived from IgE specifically inhibit IgE responses and adoptive transfer of CD40L-specific CTL to NOD mice at early age delay the development of diabetes in NOD mice. Thus, in vitro generated CTL specific for nor-tumor self-antigens expressed on activated CD4 T cells can regulate immune responses in vivo.
Allergic diseases, such as hay fever, asthma and systemic anaphylaxis, are immune responses to innocuous substances. The hallmark of the diseases is activation of CD4 cells and over production of IgE by B cells. The current therapies have been focused on the treatment of symptoms and do not prevent the development and progression of the diseases. Because allergen-activated CD4 cells and IgE producing B cells play a central role in the pathogenesis of allergy, our strategy is to use autologous CTL to eliminate activated CD4 T cells and IgE producing B cells, thus preventing the development and progression of the diseases. Two molecules, CD40 ligand (CD40L) and IgE, were selected as target antigens for CTL therapy. Three antigenic peptides from CD40L and two antigenic peptides from IgE were identified. CTLs specific for these peptides have been generated and the function of these CTLs has been evaluated both in vitro and in vivo.
Three antigenic epitopes from CD40L and two epitopes from IgE molecules were identified. Synthetic peptides of the antigenic epitopes were able to bind to class I molecules and to activate resting naive CD8 T cells in vitro.
CTLs were generated by stimulation of CD8 T cells with CD40L or IgE peptides presented by Drosophila cells expressing MHC class I, B7-1 and ICAM-1 molecules. The CTLs thus generated in vitro killed peptide-loaded target cells specifically. CD40L-peptide specific CTL killed activated CD4 T cells and the recognition was dependent on the expression of CD40L and MHC class I molecules.
The function of CD40L-specific CTL were also evaluated in vivo. Antigen-specific antibody response was inhibited by anti-CD40L CTL. The effect of anti-CD40L CTL and anti-IgE CTL on allergy and autoimmune diseases will be investigated in animal models.
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