Abstract:
CTLA-4 biomarkers useful in a method for predicting the likelihood that a mammal that will respond therapeutically to a method of treating cancer comprising administering an CTLA-4 antagonist, wherein the method comprises (a) measuring in the mammal the level of at least one biomarker s, (b) exposing a biological sample from the mammal to the CTLA-4 antagonist, and (c) following the exposing of step (b), measuring in the biological sample the level of the at least one biomarker, wherein an increase in the level of the at least one biomarker measured in step (c) compared to the level of the at least one biomarker measured in step (a) indicates an increased likelihood that the mammal will respond therapeutically to the method of treating cancer.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 60/892,916, filed Mar. 5, 2007, and U.S. Provisional Application No. 60/923,117, filed Apr. 12, 2007, whose contents are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of pharmacogenomics. More specifically, the invention relates to methods and procedures to determine drug sensitivity and insensitivity in patients, which allows the identification of individualized genetic profiles which will aid in treating diseases and disorders including cancer. The invention also relates to methods for predicting the likelihood a mammal will respond therapeutically to a method of treating cancer. 
       BACKGROUND OF THE INVENTION 
       [0003]    Cancer is a disease with extensive histoclinical heterogeneity. Although conventional histological and clinical features have been correlated to prognosis, the same apparent prognostic type of tumors varies widely in its responsiveness to therapy and consequent survival of the patient. 
         [0004]    New prognostic and predictive markers, which would facilitate an individualization of therapy for each patient, are needed to accurately predict patient response to treatments, such as small molecule or biological molecule drugs, in the clinic. The problem may be solved by the identification of new parameters that could better predict the patient&#39;s sensitivity to treatment. The classification of patient samples is a crucial aspect of cancer diagnosis and treatment. The association of a patient&#39;s response to a treatment with molecular and genetic markers can open up new opportunities for treatment development in non-responding patients, or distinguish a treatment&#39;s indication among other treatment choices because of higher confidence in the efficacy. Further, the pre-selection of patients who are likely to respond well to a medicine, drug, or combination therapy may reduce the number of patients needed in a clinical study or accelerate the time needed to complete a clinical development program (Cockett et al., Current Opinion in Biotechnology, 11:602-609 (2000)). 
         [0005]    The ability to predict drug sensitivity in patients is particularly challenging because drug responses reflect not only properties intrinsic to the target cells, but also a host&#39;s metabolic properties. Efforts to use genetic information to predict drug sensitivity have primarily focused on individual genes that have broad effects, such as the multidrug resistance genes, mdr1 and mrp1 (Sonneveld, J. Intern. Med., 247:521-534 (2000)). 
         [0006]    The development of microarray technologies for large scale characterization of gene mRNA expression pattern has made it possible to systematically search for molecular markers and to categorize cancers into distinct subgroups not evident by traditional histopathological methods (Khan et al., Cancer Res., 58:5009-5013 (1998); Alizadeh et al., Nature, 403:503-511 (2000); Bittner et al., Nature, 406:536-540 (2000); Khan et al., Nature Medicine, 7(6):673-679 (2001); and Golub et al., Science, 286:531-537 (1999); Alon et al., P. N. A. S. USA, 96:6745-6750 (1999)). Such technologies and molecular tools have made it possible to monitor the expression level of a large number of transcripts within a cell population at any given time (see, e.g., Schena et al., Science, 270:467-470 (1995); Lockhart et al., Nature Biotechnology, 14:1675-1680 (1996); Blanchard et al., Nature Biotechnology, 14:1649 (1996); U.S. Pat. No. 5,569,588). 
         [0007]    Recent studies demonstrate that gene expression information generated by microarray analysis of human tumors can predict clinical outcome (van&#39;t Veer et al., Nature, 415:530-536 (2002); Sorlie et al., P. N. A. S. USA, 98:10869-10874 (2001); M. Shipp et al., Nature Medicine, 8(1):68-74 (2002): Glinsky et al., The Journal of Clin. Invest., 113(6):913-923 (2004)). These findings bring hope that cancer treatment will be vastly improved by better predicting the response of individual tumors to therapy. 
         [0008]    The vertebrate immune system requires multiple signals to achieve optimal immune activation (see, e.g., Janeway, Cold Spring Harbor Symp. Quant. Biol. 1989; 54:1-14; Paul William E., ed. Raven Press, N.Y., Fundamental Immunology, 4th edition (1998), particularly chapters 12 and 13, pages 411 to 478). Interactions between T lymphocytes (T cells) and antigen presenting cells (APC) are essential to the immune response. Levels of many cohesive molecules found on T cells and APC&#39;s increase during an immune response (Springer et al., A. Rev. Immunol. 1987; 5:223-252; Shaw and Shimuzu, Current Opinion in Immunology, 1988 Eds. Kindt and Long, 1:92-97; and Hemler, Immunology Today 1988; 9:109-113). Increased levels of these molecules may help explain why activated APC&#39;s are more effective at stimulating antigen-specific T cell proliferation than are resting APC&#39;s (Kaiuchi et al., J. Immunol. 1983; 131:109-114; Kreiger et al., J. Immunol. 1985; 135:2937-2945; McKenzie, J. Immunol. 1988; 141:2907-2911; and Hawrylowicz and Unanue, J. Immunol. 1988; 141:4083-4088). 
         [0009]    T cell immune response is a complex process that involves cell-cell interactions (Springer et al., A. Rev. Immunol. 1987; 5:223-252), particularly between T and accessory cells such as APC&#39;s, and production of soluble immune mediators (cytokines or lymphokines) (Dinarello, New Engl. J. Med 1987; 317:940-945; Sallusto, J. Exp. Med. 1997; 179:1109-1118). This response is regulated by several T-cell surface receptors, including the T-cell receptor complex (Weiss, Aim. Rev. Immunol. 1986; 4:593-619) and other “accessory” surface molecules (Allison, Curr. Opin. Immunol. 1994; 6:414-419; Springer, 1987, supra). Many of these accessory molecules are naturally occurring cell surface differentiation (CD) antigens defined by the reactivity of monoclonal antibodies on the surface of cells (McMichael, Ed., Leukocyte Typing III, Oxford Univ. Press, Oxford, N.Y., 1987). 
         [0010]    CD28 antigen, a homodimeric glycoprotein of the immunoglobulin superfamily (Aruffo and Seed, Proc. Natl. Acad. Sci. 1987; 84:8573-8577), is an accessory molecule found on most mature human T cells (Damle et al., J. Immunol. 1983; 131:2296-2300). Current evidence suggests that this molecule functions in an alternative T cell activation pathway distinct from that initiated by the T-cell receptor complex (June et al., Mol. Cell. Biol. 1987; 7:4472-4481). Monoclonal antibodies (MAbs) reactive with CD28 antigen can augment T cell responses initiated by various polyclonal stimuli (reviewed by June et al., supra). These stimulatory effects may result from MAb-induced cytokine production (Thompson et al., Proc. Natl. Acad. Sci. 1989; 86:1333-1337; and Lindsten et al., Science 1989; 244:339-343) as a consequence of increased mRNA stabilization (Lindsten et al., 1989, supra). 
         [0011]    CTLA-4 is a negative regulator of CD28′ dependent T cell activation, and acts as an inhibitory checkpoint for the adaptive immune response. Various preclinical studies have shown that CTLA-4 blockade by monoclonal antibodies enhances the host immune response against immunogenic tumors, and can even reject established tumors. Currently, ipilimumab (MDX-010) and CP-675206, both fully human anti-human CTLA-4 monoclonal antibodies (mAbs), are under clinical development to treat various types of solid tumors. 
         [0012]    CTLA-4 (cytotoxic T lymphocycte-associated antigen-4) is accepted as opposing CD28 activity and dampening T cell activation (Krummel, J. Exp. Med. 1995; 182:459-465; Krummel et al., Int&#39;l Immunol. 1996; 8:519-523; Chambers et al., Immunity. 1997; 7:885-895). CTLA-4 deficient mice suffer from massive lymphoproliferation (Chambers et al., supra). It has been reported that CTLA-4 blockade augments T cell responses in vitro (Walunas et al., Immunity. 1994; 1:405-413) and in vivo (Kearney, J. Immunol. 1995; 155:1032-1036), exacerbates antitumor immunity (Leach, Science 1996; 271:1734-1736), and enhances an induced autoimmune disease (Luhder, J. Exp. Med. 1998; 187:427-432). It has also been reported that CTLA-4 has an alternative or additional impact on the initial character of the T cell immune response (Chambers, Curr. Opin. Immunol. 1997; 9:396-404; Bluestone, J. Immunol. 1997; 158:1989-1993; Thompson, Immunity 1997; 7:445-450). This is consistent with the observation that some autoimmune patients have autoantibodies to CTLA-4. It is possible that CTLA-4 blocking autoantibodies play a pathogenic role in these patients (Matsui, J. Immunol. 1999; 162:4328-4335). 
         [0013]    Non-human CTLA-4 antibodies have been used in the various studies discussed above. Furthermore, human antibodies against human CTLA-4 have been described as immunostimulation modulators in a number of disease conditions, such as treating or preventing viral and bacterial infection and for treating cancer (e.g., PCT Publication WO 01/14424 and PCT Publication WO 00/37504). U.S. Pat. No. 5,855,887 discloses a method of increasing the response of a mammalian T cell to antigenic stimulation by combining a T cell with a CTLA-4 blocking agent. U.S. Pat. No. 5,811,097 discloses a method of decreasing the growth of non-T cell tumors by administering a CTLA-4 blocking agent. U.S. Pat. No. 6,984,720 and U.S. Patent Publication No. 2002/0086014 disclose human CTLA-4 antibodies. Each of these patents and applications is hereby incorporated by reference. 
         [0014]    Needed are new and alternative methods and procedures to determine drug sensitivity in patients to allow the development of individualized genetic profiles which are necessary to treat diseases and disorders based on patient response at a molecular level. 
       SUMMARY OF THE INVENTION 
       [0015]    The invention provides methods and procedures for determining patient sensitivity to one or more CTLA-4 antagonists. The invention also provides methods of determining or predicting whether an individual requiring therapy for a disease state such as cancer will or will not respond to treatment, prior to administration of the treatment, wherein the treatment comprises administration of one or more CTLA-4 antagonists. The one or more CTLA-4 antagonists are compounds that can be selected from, for example, one or more small molecule CTLA-4 inhibitors or one or more CTLA-4 binding monoclonal antibodies. 
         [0016]    In one aspect, the invention provides a method for predicting the likelihood a mammal will respond therapeutically to a method of treating cancer comprising administering an CTLA-4 antagonist, wherein the method comprises: (a) measuring in the mammal the level of at least one biomarker; (b) exposing a biological sample from the mammal to the CTLA-4 antagonist; (c) following the exposing of step (b), measuring in the biological sample the level of the at least one biomarker, wherein an increase in the level of the at least one biomarker measured in step (c) compared to the level of the at least one biomarker measured in step (a) indicates an increased likelihood that the mammal will respond therapeutically to the method of treating cancer. 
         [0017]    In another aspect, the invention provides a method for predicting the likelihood a mammal will respond therapeutically to a method of treating cancer comprising administering an CTLA-4 antagonist, wherein the method comprises: (a) measuring in the mammal the level of at least one biomarker selected from the biomarkers of Table 1 and Table 3; (b) exposing a biological sample from said mammal to the CTLA-4 antagonist; (c) following the exposing of step (b), measuring in said biological sample the level of the at least one biomarker, wherein an increase in the level of the at least one biomarker measured in step (c) compared to the level of the at least one biomarker measured in step (a), indicates an increased likelihood that the mammal will respond therapeutically to said method of treating cancer when said at least one biomarker is from Table 1, and indicates an increased likelihood that the mammal will not respond therapeutically to said method of treating cancer when said at least one biomarker is from Table 3. 
         [0018]    The biological sample can comprise, for example, at least one of whole fresh blood, peripheral blood mononuclear cells, frozen whole blood, fresh plasma, frozen plasma, urine, saliva, skin, hair follicle, bone marrow, or tumor tissue. In one aspect, the biological sample is tumor tissue. In another aspect, the biological sample can be, for example, a tissue sample comprising cancer cells and the tissue is fixed, paraffin-embedded, fresh, or frozen. 
         [0019]    A difference in the level of the biomarker that is sufficient to predict the likelihood that the mammal will or will not respond therapeutically to the method of treating cancer can be readily determined by one of skill in the art using known techniques. The increase or decrease in the level of the biomarker can be correlated to determine whether the difference is sufficient to predict the likelihood that a mammal will respond therapeutically. The difference in the level of the biomarker that is sufficient can, in one aspect, be predetermined prior to predicting the likelihood that the mammal will respond therapeutically to the treatment. In one aspect, the difference in the level of the biomarker is a difference in the mRNA level (measured, for example, by RT-PCR or a microarray), such as at least a two-fold difference, at least a three-fold difference, or at least a four-fold difference in the level of expression. In another aspect, the difference in the level of the biomarker is determined by IHC. In another aspect, the difference in the level of the biomarker refers to a p-value of &lt;0.05 in Anova (t test) analysis. In yet another aspect, the difference is determined in an ELISA assay. 
         [0020]    As used herein, respond therapeutically refers to the alleviation or abrogation of the cancer. This means that the life expectancy of an individual affected with the cancer will be increased or that one or more of the symptoms of the cancer will be reduced or ameliorated. The term encompasses a reduction in cancerous cell growth or tumor volume. Whether a mammal responds therapeutically can be measured by many methods well known in the art, such as PET imaging. 
         [0021]    The mammal can be, for example, a human, rat, mouse, dog, rabbit, pig sheep, cow, horse, cat, primate, or monkey. 
         [0022]    The method of the invention can be, for example, an in vitro method wherein the step of measuring in the mammal the level of at least one biomarker comprises taking a biological sample from the mammal and then measuring the level of the biomarker(s) in the biological sample. In one aspect, the biological sample is tumor tissue. In another aspect, the biological sample can comprise, for example, at least one of serum, whole fresh blood, peripheral blood mononuclear cells, frozen whole blood, fresh plasma, frozen plasma, urine, saliva, skin, hair follicle, bone marrow, or tumor tissue. 
         [0023]    The level of the at least one biomarker can be, for example, the level of protein and/or mRNA transcript of the biomarker. The level of the biomarker can be determined, for example, by RT-PCR or another PCR-based method, immunohistochemistry, proteomics techniques, or any other methods known in the art, or their combination. 
         [0024]    In another aspect, the invention provides a method for identifying a mammal that will respond therapeutically to a method of treating cancer comprising administering of an CTLA-4 antagonist, wherein the method comprises: (a) measuring in the mammal the level of at least one biomarker; (b) exposing a biological sample from the mammal to the CTLA-4 antagonist; (c) following the exposing in step (b), measuring in said biological sample the level of the at least one biomarker, wherein a difference in the level of the at least one biomarker measured in step (c) compared to the level of the at least one biomarker measured in step (a) indicates that the mammal will respond therapeutically to the said method of treating cancer. 
         [0025]    In another aspect, the invention provides a method for identifying a mammal that will respond therapeutically to a method of treating cancer comprising administering an CTLA-4 antagonist, wherein the method comprises: (a) exposing a biological sample from the mammal to the CTLA-4 antagonist; (b) following the exposing of step (a), measuring in said biological sample the level of at least one biomarker, wherein a difference in the level of the at least one biomarker measured in step (b), compared to the level of the at least one biomarker in a mammal that has not been exposed to said CTLA-4 antagonist, indicates that the mammal will respond therapeutically to said method of treating cancer. 
         [0026]    In yet another aspect, the invention provides a method for testing or predicting whether a mammal will respond therapeutically to a method of treating cancer comprising administering an CTLA-4 antagonist, wherein the method comprises: (a) measuring in the mammal the level of at least one biomarker; (b) exposing the mammal to the CTLA-4 antagonist; (c) following the exposing of step (b), measuring in the mammal the level of the at least one biomarker, wherein a difference in the level of the at least one biomarker measured in step (c) compared to the level of the at least one biomarker measured in step (a) indicates that the mammal will respond therapeutically to said method of treating cancer. 
         [0027]    In another aspect, the invention provides a method for determining whether a compound inhibits CTLA-4 activity in a mammal, comprising: (a) exposing the mammal to the compound; and (b) following the exposing of step (a), measuring in the mammal the level of at least one biomarker, wherein a difference in the level of said biomarker measured in step (b), compared to the level of the biomarker in a mammal that has not been exposed to said compound, indicates that the compound inhibits CTLA-4 activity in the mammal. 
         [0028]    In yet another aspect, the invention provides a method for determining whether a mammal has been exposed to a compound that inhibits CTLA-4 activity, comprising (a) exposing the mammal to the compound; and (b) following the exposing of step (a), measuring in the mammal the level of at least one biomarker, wherein a difference in the level of said biomarker measured in step (b), compared to the level of the biomarker in a mammal that has not been exposed to said compound, indicates that the mammal has been exposed to a compound that inhibits CTLA-4 activity. 
         [0029]    In another aspect, the invention provides a method for determining whether a mammal is responding to a compound that inhibits CTLA-4 activity, comprising (a) exposing the mammal to the compound; and (b) following the exposing of step (a), measuring in the mammal the level of at least one biomarker, wherein a difference in the level of the at least one biomarker measured in step (b), compared to the level of the at least one biomarker in a mammal that has not been exposed to said compound, indicates that the mammal is responding to the compound that inhibits CTLA-4 activity. 
         [0030]    As used herein, “responding” encompasses responding by way of a biological and cellular response, as well as a clinical response (such as improved symptoms, a therapeutic effect, or an adverse event), in a mammal. 
         [0031]    The invention also provides an isolated biomarker. The biomarkers of the invention comprise sequences selected from the nucleotide and amino acid sequences, as well as fragments and variants thereof. 
         [0032]    The invention also provides a biomarker set comprising two or more biomarkers. 
         [0033]    The invention also provides kits for determining or predicting whether a patient would be susceptible to a treatment that comprises one or more CTLA-4 antagonists. The patient may have a cancer or tumor. 
         [0034]    In one aspect, the kit comprises a suitable container that comprises one or more specialized microarrays of the invention, one or more CTLA-4 antagonists for use in testing cells from patient tissue specimens or patient samples, and instructions for use. The kit may further comprise reagents or materials for monitoring the expression of a biomarker set at the level of mRNA or protein. 
         [0035]    In another aspect, the invention provides a kit comprising two or more biomarkers. 
         [0036]    In yet another aspect, the invention provides a kit comprising at least one of an antibody and a nucleic acid for detecting the presence of at least one of the biomarkers. In one aspect, the kit further comprises instructions for determining whether or not a mammal will respond therapeutically to a method of treating cancer comprising administering a compound that inhibits CTLA-4 activity. In another aspect, the instructions comprise the steps of (a) measuring in the mammal the level of at least one biomarker, (b) exposing the mammal to the compound, (c) following the exposing of step (b), measuring in the mammal the level of the at least one biomarker, wherein a difference in the level of the at least one biomarker measured in step (c) compared to the level of the at least one biomarker measured in step (a) indicates that the mammal will respond therapeutically to said method of treating cancer. 
         [0037]    The invention also provides screening assays for determining if a patient will be susceptible to treatment with one or more CTLA-4 antagonists. 
         [0038]    The invention also provides a method of monitoring the treatment of a patient having a disease, wherein said disease is treated by a method comprising administering one or more CTLA-4 antagonists. 
         [0039]    The invention also provides individualized genetic profiles which are necessary to treat diseases and disorders based on patient response at a molecular level. 
         [0040]    The invention also provides specialized microarrays, e.g., oligonucleotide microarrays or cDNA microarrays, comprising one or more biomarkers having expression profiles that correlate with sensitivity to one or more CTLA-4 antagonists. 
         [0041]    The invention also provides antibodies, including polyclonal or monoclonal, directed against one or more biomarkers of the invention. 
         [0042]    The invention will be better understood upon a reading of the detailed description of the invention when considered in connection with any accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0043]      FIG. 1  illustrates the results obtained of the anti-tumor activity of UC10 in the Sa1N tumor model. 
           [0044]      FIG. 2  illustrates the results obtained from immunohistochemistry staining. 
           [0045]      FIG. 3  ( FIGS. 3A and 3B ) illustrates the results obtained from expansion of T cells with an effector/memory phenotype following UC treatment. 
           [0046]      FIG. 4  illustrates the results obtained from qPCR analysis of tumor RNA 
           [0047]      FIG. 5  illustrates the results obtained from qPCR analysis of peripheral blood RNA. 
           [0048]      FIG. 6  illustrates the results obtained from induction of T cell receptor, immunoglobulin, and class II MHC genes. 
           [0049]      FIG. 7  illustrates the results obtained showing a lack of anti-tumor activity of UC10 in the EMT6 tumor model. 
           [0050]      FIG. 8  illustrates the results obtained from qPCR analysis of tumor RNA. 
           [0051]      FIG. 9  illustrates the results obtained from qPCR analysis of peripheral blood RNA. 
           [0052]      FIG. 10  illustrates the results obtained from measuring the time course of Ym1 and arginase 1 gene expression in the blood. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0053]    As used herein, the terms “cytotoxic T lymphocyte-associated antigen-4,” “CTLA-4,” “CTLA4,” “CTLA-4 antigen” and “CD152” (see, e.g., Murata, Am. J. Pathol. 1999; 155:453-460) are used interchangeably, and include variants, isoforms, species homologs of human CTLA-4, and analogs having at least one common epitope with CTLA-4 (see, e.g., Balzano (1992) Int. J. Cancer Suppl. 7:28-32). CTLA-4&#39;s complete sequence is found in GenBank Accession No. L15006. 
         [0054]    The human monoclonal antibody MDX-010 (Medarex, Inc.) in clinical development corresponds to monoclonal antibody 10D1, which is disclosed in U.S. Patent Publication No. 20050201994 and PCT Publication No. WO 01/14424. MDX-010 has been administered as single or multiple doses, alone or in combination with a vaccine, chemotherapy, or interleukin-2 to greater than 500 patients diagnosed with metastatic melanoma, prostate cancer, lymphoma, renal cell cancer, breast cancer, ovarian cancer, and HIV. 
         [0055]    Other anti-CTLA-4 antibodies that can be used in a method of the present invention include, for example, those disclosed in: WO 98/42752; WO 00/37504; U.S. Pat. No. 6,207,156; Hurwitz et al., PNAS 1998; 95(17):10067-10071; Camacho et al., J Clin Oncology 2004:22(145):abstract no. 2505 (antibody CP-675206); and Mokyr, et al., Cancer Research 1998; 58:5301-5304. 
         [0056]    In this study, the effect of anti-CTLA-4 treatment on various biomarkers was characterized in mouse tumor models with the goal to obtain candidate biomarkers useful in monitoring the biological effects of this treatment in the clinical setting. Two mouse tumor models, Sa1N (fibrosarcoma, ALT mouse strain) and EMT-6 (mammary carcinoma, Balb/c mouse strain), were used in these studies. The anti-CTLA-4 treatment was highly efficacious against Sa1N tumors, producing complete regressions in most of the treated mice. However, it showed no inhibitory effect on the growth of EMT-6 tumors. Tumor and blood samples from SA1N and EMT-6-bearing mice treated with anti-CTLA-4 antibody or control vehicle were collected at various timepoints. Several selected markers were analyzed by immunohistochemistry (IHC) (tumor only) or RT-PCR (tumor and blood). A significant increase of CD4+ and CD8+ T cells were detected in SA1N tumors (sensitive model) upon treatment but not in EMT-6 tumors (resistant model). Gene expression analysis corroborated the IHC result by showing the induction of various immune response related genes including Cd3d, Cd4, Cd8b1, interferon-γ, perforin 1, and granzyme B in Sa1N tumor, but not in EMT6. These gene expression changes in the tumor tissue reflected the anti-tumor immune reaction induced by this treatment. In the peripheral blood, anti-CTLA-4 treatment in Sa1N-bearing mice also induced IFN-γ, perforin 1, and granzyme B genes, indicating the systemic elevation of Th1 and cytotoxic immune responses. However the same treatment failed to raise the levels of these genes in the EMT6 model blood, and instead it induced the genes related to the alternative activation of macrophages, such as Chi313 (Ym1) and Retnla (Fizz1). Such changes of the gene expression patterns in the peripheral blood reflect different types of immune response induced by this treatment, and may provide useful biomarkers to monitor the action of anti-CTLA4 treatment in the clinical setting. 
         [0057]    The invention provides biomarkers that correlate with CTLA-4 antagonist sensitivity or resistance. These biomarkers can be employed for predicting response to one or more CTLA-4 antagonists. The biomarkers of the invention include polynucleotide and polypeptide sequences. 
         [0058]    The biomarkers have expression levels in cells that may be dependent on the activity of the CTLA-4 signal transduction pathway, and that are also highly correlated with CTLA-4 antagonist sensitivity exhibited by the cells. Biomarkers serve as useful molecular tools for predicting the likelihood of a response to CTLA-4 antagonists, preferably biological molecules, small molecules, and the like that affect CTLA-4 kinase activity via direct or indirect inhibition or antagonism of CTLA-4 kinase function or activity. 
       Biomarkers and Biomarker Sets 
       [0059]    The invention includes individual biomarkers and biomarker sets having both diagnostic and prognostic value in disease areas in which signaling through CTLA-4 or the CTLA-4 pathway is of importance, e.g., in cancers or tumors, in immunological disorders, conditions or dysfunctions, or in disease states in which cell signaling and/or cellular proliferation controls are abnormal or aberrant. The biomarker sets comprise a plurality of biomarkers that highly correlate with sensitivity to one or more CTLA-4 antagonists. 
         [0060]    The biomarkers and biomarker sets of the invention enable one to predict or reasonably foretell the likely effect of one or more CTLA-4 antagonists in different biological systems or for cellular responses. The biomarkers and biomarker sets can be used in in vitro assays of CTLA-4 antagonist response by test cells to predict in vivo outcome. In accordance with the invention, the various biomarkers and biomarker sets described herein, or the combination of these biomarker sets with other biomarkers or markers, can be used, for example, to predict how patients with cancer might respond to therapeutic intervention with one or more CTLA-4 antagonists. 
         [0061]    A biomarker and biomarker set of cellular gene expression patterns correlating with sensitivity of cells following exposure of the cells to one or more CTLA-4 antagonists provides a useful tool for screening one or more tumor samples before treatment with the CTLA-4 antagonist. The screening allows a prediction of cells of a tumor sample exposed to one or more CTLA-4 antagonists, based on the expression results of the biomarker and biomarker set, as to whether or not the tumor, and hence a patient harboring the tumor, will or will not respond to treatment with the CTLA-4 antagonist. 
         [0062]    The biomarker or biomarker set can also be used as described herein for monitoring the progress of disease treatment or therapy in those patients undergoing treatment for a disease involving an CTLA-4 antagonist. 
         [0063]    The biomarkers also serve as targets for the development of therapies for disease treatment. Such targets may be particularly applicable to treatment of colorectal cancer. Indeed, because these biomarkers are differentially expressed in sensitive cells, their expression patterns are correlated with relative intrinsic sensitivity of cells to treatment with CTLA-4 antagonists. 
         [0064]    The level of biomarker protein and/or mRNA can be determined using methods well known to those skilled in the art. For example, quantification of protein can be carried out using methods such as ELISA, 2-dimensional SDS PAGE, Western blot, immunopreciptation, immunohistochemistry, fluorescence activated cell sorting (FACS), or flow cytometry. Quantification of mRNA can be carried out using methods such as PCR, array hybridization, Northern blot, in-situ hybridization, dot-blot, Taqman, or RNAse protection assay. 
       Microarrays 
       [0065]    The invention also includes specialized microarrays, e.g., oligonucleotide microarrays or cDNA microarrays, comprising one or more biomarkers, showing expression profiles that correlate with sensitivity to one or more CTLA-4 antagonists. Such microarrays can be employed in in vitro assays for assessing the expression level of the biomarkers in the test cells from tumor biopsies, and determining whether these test cells are likely to be sensitive to CTLA-4 antagonists. For example, a specialized microarray can be prepared using all the biomarkers, or subsets thereof, as described herein. Cells from a tissue or organ biopsy can be isolated and exposed to one or more of the CTLA-4 antagonists. In one aspect, following application of nucleic acids isolated from both untreated and treated cells to one or more of the specialized microarrays, the pattern of gene expression of the tested cells can be determined and compared with that of the biomarker pattern from the control panel of cells used to create the biomarker set on the microarray. Based upon the gene expression pattern results from the cells that underwent testing, it can be determined if the cells show a sensitive profile of gene expression. Whether or not the tested cells from a tissue or organ biopsy will respond to one or more of the CTLA-4 antagonists and the course of treatment or therapy can then be determined or evaluated based on the information gleaned from the results of the specialized microarray analysis. 
       Antibodies 
       [0066]    The invention also includes antibodies, including polyclonal or monoclonal, directed against one or more of the polypeptide biomarkers. Such antibodies can be used in a variety of ways, for example, to purify, detect, and target the biomarkers of the invention, including both in vitro and in vivo diagnostic, detection, screening, and/or therapeutic methods. 
       Kits 
       [0067]    The invention also includes kits for determining or predicting whether a patient would be susceptible to a treatment that comprises one or more CTLA-4 antagonists. The patient may have a cancer or tumor such as, for example, colorectal cancer. Such kits would be useful in a clinical setting for use in testing a patient&#39;s biopsied tumor or other cancer samples, for example, to determine or predict if the patient&#39;s tumor or cancer will be sensitive to a given treatment or therapy with an CTLA-4 antagonist. The kit comprises a suitable container that comprises: one or more microarrays, e.g., oligonucleotide microarrays or cDNA microarrays, that comprise those biomarkers that correlate with sensitivity to CTLA-4 antagonists, particularly CTLA-4 inhibitors; one or more CTLA-4 antagonists for use in testing cells from patient tissue specimens or patient samples; and instructions for use. In addition, kits contemplated by the invention can further include, for example, reagents or materials for monitoring the expression of biomarkers of the invention at the level of mRNA or protein, using other techniques and systems practiced in the art such as, for example, RT-PCR assays, which employ primers designed on the basis of one or more of the biomarkers described herein, immunoassays, such as enzyme linked immunosorbent assays (ELISAs), immunoblotting, e.g., Western blots, or in situ hybridization, and the like. 
       Application of Biomarkers and Biomarker Sets 
       [0068]    The biomarkers and biomarker sets may be used in different applications. 
         [0069]    Biomarker sets can be built from any combination of biomarkers to make predictions about the effect of an CTLA-4 antagonist in different biological systems. The various biomarkers and biomarkers sets described herein can be used, for example, as diagnostic or prognostic indicators in disease management, to predict how patients with cancer might respond to therapeutic intervention with compounds that modulate the CTLA-4, and to predict how patients might respond to therapeutic intervention that modulates signaling through the entire CTLA-4 regulatory pathway. 
         [0070]    The biomarkers have both diagnostic and prognostic value in diseases areas in which signaling through CTLA-4 or the CTLA-4 pathway is of importance, e.g., in immunology, or in cancers or tumors in which cell signaling and/or proliferation controls have gone awry. 
         [0071]    In one aspect, cells from a patient tissue sample, e.g., a tumor or cancer biopsy, can be assayed to determine the expression pattern of one or more biomarkers prior to treatment with one or more CTLA-4 antagonists. In one aspect, the tumor or cancer is colorectal. Success or failure of a treatment can be determined based on the biomarker expression pattern of the cells from the test tissue (test cells), e.g., tumor or cancer biopsy, as being relatively similar or different from the expression pattern of a control set of the one or more biomarkers. Thus, if the test cells show a biomarker expression profile which corresponds to that of the biomarkers in the control panel of cells which are sensitive to the CTLA-4 antagonist, it is highly likely or predicted that the individual&#39;s cancer or tumor will respond favorably to treatment with the CTLA-4 antagonist. 
         [0072]    The invention also provides a method of monitoring the treatment of a patient having a disease treatable by one or more CTLA-4 antagonists. The isolated test cells from the patient&#39;s tissue sample, e.g., a tumor biopsy or tumor sample, can be assayed to determine the expression pattern of one or more biomarkers before and after exposure to an CTLA-4 antagonist wherein, preferably, the CTLA-4 antagonist is an CTLA-4 inhibitor. The resulting biomarker expression profile of the test cells before and after treatment is compared with that of one or more biomarkers as described and shown herein to be highly expressed in the control panel of cells that are sensitive to an CTLA-4 antagonist. Thus, if a patient&#39;s response is sensitive to treatment by an CTLA-4 antagonist, based on correlation of the expression profile of the one or biomarkers, the patient&#39;s treatment prognosis can be qualified as favorable and treatment can continue. Also, if, after treatment with an CTLA-4 antagonist, the test cells don&#39;t show a change in the biomarker expression profile corresponding to the control panel of cells that are sensitive to the CTLA-4 antagonist, it can serve as an indicator that the current treatment should be modified, changed, or even discontinued. This monitoring process can indicate success or failure of a patient&#39;s treatment with an CTLA-4 antagonist and such monitoring processes can be repeated as necessary or desired. 
       EXAMPLES 
       [0073]    In Examples 1 and 2, the effect of an anti-CTLA4 antibody (UC10) was investigated on the biomarker patterns in a sensitive mouse tumor model (Sa1N fibrosarcoma) and a resistant model (EMT6 mammary carcinoma). UC10 is known in the art and is described, for example, in T. Walunas et al., Immunity., August; 1(5):405-13 (1994). 
       RNA Isolation: 
       [0074]    In the Sa1N model, UC10 induced the infiltration of T cells into the tumor. The gene expression analysis supported this by detecting the induction of various immune response genes including interferon gamma, granzyme B and perforin 1. Gene expression data also indicated the activation of humoral immunity and antigen presentation in the tumor. The activation of interferon gamma, granzyme B and perforin 1 genes was also observed in the peripheral blood. These result indicated the checkpoint blockade by the anti-CTLA4 antibody induced a wide range of immune responses, including those that are crucial to the anti-tumor response. 
         [0075]    On the other hand, the effect of UC10 on the EMT6 (resistant model) was entirely different. There, we observed no increase of tumor infiltrating lymphocytes, and no induction of interferon gamma, granzyme B and perforin 1 in the tumor. Thus, a biomarker signal of anti-tumor immunity was not detected in this model. Thus, it appears UC10 failed to modulate any immune response to EMT6 tumors. 
         [0076]    However, in the peripheral blood of mice bearing EMT6 tumors, UC10 induced the genes that were the hallmark of alternatively activated macrophages (M2), such as Ym1, Fizz1, and arginase 1. 
         [0077]    Currently, it is not known what is the exact type of cell that expresses these genes in the peripheral blood. However, the close resemblance of the induced gene expression pattern with that of alternatively activated macrophages suggests that this type of macrophages or a related type of cells may be highly induced by the UC10 treatment in this model. Alternatively, activated macrophages can be induced by Th2 cytokines and are known to dampen the anti-tumor immune response at least in some cases. Balb/c mice (host of EMT6 tumor) are genetically predisposed to the Th2 response, and the induction of alternatively activated macrophage type genes by CTLA4 blockade with UC10 may be due to this genetic predisposition of the host mice. This may be one of the reasons why this anti-CTLA4 antibody was unable to mount an effective anti-tumor immunity in this model. 
         [0078]    In Examples 1 and 2, tumor samples were collected in RNAlater reagent (Ambion, Inc., Austin, Tex.) following the manufacturer&#39;s manual. Tumor RNA was extracted using Qiagen RNAeasy mini kit. The quality of isolated RNA was confirmed using Agilent 2100 nucleic acid analyzer detecting the peaks for 18S and 28S rRNA. 
       Affymetrix GeneChip Process for Examples 1 and 2: 
       [0079]    Mouse GeneChip 430A, v2.0 was used and globin reduction pretreatment was required. Experimental process (cDNA synthesis, in vitro transcription/IVT, and GeneChip hybridization) followed the standard Affymetrix manual. Transcriptional profiling was performed on the RNA obtained from the tumor samples. The Affymetrix GeneChip system (Affymetrix, Santa Clara, Calif.) was used for hybridization and scanning of the mouse 430A arrays. Data were preprocessed using the MAS 5.0 software. Generation of cRNA followed a standard T7 amplification protocol. Total RNA was reverse-transcribed with SuperScript II (Gibco, Carlsbad, Calif.) in the presence of T7-(dT) 24  primer to generate first strand cDNA. A second-strand cDNA synthesis was performed in the presence of DNA Polymerase I, DNA ligase, and RNase H (Gibco). The resulting double-stranded cDNA was blunt-ended using T4 DNA polymerase. This double-stranded cDNA was then transcribed into cRNA in the presence of biotin-ribonucleotides using the BioArray High Yield RNA transcript labeling kit (Enzo Life Sciences, Farmingdale, N.Y.). The amplified, biotin-labeled cRNA was purified using Qiagen RNeasy columns (Qiagen Sciences), quantified and fragmented at 94° C. for 35 minutes in the presence of fragmentation buffer (1×). Fragmented cRNA was hybridized to the Affymetrix 430A arrays overnight at 42° C. The arrays were then placed in the fluidics stations for staining and washing as recommended by Affymetrix protocols. The chips were scanned and raw intensity values were generated for each probe on the arrays. The trimmed mean intensity for each array was scaled to 1,500 to account for minor differences in global chip intensity so that the overall expression level for each sample was comparable. 
       Data Analysis for Examples 1 and 2: 
       [0080]    The GeneChip data was uploaded to PartekPro Pattern Recognition software (Partek, St. Louis, Mo.) for data analysis after using the RMA (Robust Multi-array Analysis) normalization procedure (Irizarry et al., Biostatistics, April; 4(2):249-64 (2003)) with a log 2 transformation. 
       Example 1 
     Identification of Biomarkers Using Sa1N Mouse Tumor Model 
       [0081]    The effect of the anti-CTLA4 monoclonal antibody UC10 was studied on various biomarkers in the Sa1N fibrosarcoma model. (D. Leach et al., J. Immunol., January 15; 154(2):738-43 (1995)) 
         [0082]    Tumor and peripheral blood samples were collected for RNA analysis. Both the tumor and the blood RNA samples were analyzed by quantitative real-time PCR (qPCR). This was followed up by RNA expression profile analysis of the tumor samples using Affymetrix GeneChip. 
       Animal Sample Collection: 
       [0083]    SA1N tumor cells were injected in the subcutaneous space of A/J mice. Treatments were initiated on day 6 post implantation when the subcutaneous tumor reached a median size of approximately 145-160 mm 3 . 0.3125, 1.25, 5, or 20 mg/kg of anti-CTLA4 monoclonal antibody UC10 or 0.2 mL of PBS (phosphate buffered saline) was injected intraperitoneally every three days for three doses (q3dx3). At days 4 (one day post second injection), 7 (one day post third injection), and 11 (seven days post third injection), four mice from each treatment arm were sacrificed. 
         [0084]    As shown in  FIG. 1 , UC10 treatments resulted in complete regressions of SA1N tumors in &gt;50% of mice at doses&gt;0.3 mg/kg. 
       SA1N Immunohistochemistry Staining: 
       [0085]    Tumors were collected and frozen 1 day following the third dose of anti-CTLA-4 mAb (5 mg/kg, day 7). Tumor sections were stained with anti-mouse CD4 and anti-mouse CD8 monoclonal antibodies (BD Pharmingen). Higher infiltration of CD4 and CD8 T cells were observed in tumors from animals treated with anti-CTLA-4 mAb vs. control mice ( FIG. 2 ) 
         [0000]    Expansion of T Cells with an Effector/Memory Phenotype Following Anti-CTLA-4 Treatment: 
         [0086]    UC10 did not affect frequencies of CD4 or CD8 T cells in blood at the times tested. However, an expansion of CD44high was observed preferentially in the CD8 T cell subset, suggesting an induction of an effector/memory T cell response. ( FIG. 3A  and  FIG. 3B ) 
         [0000]    qPCR Analysis: 
         [0087]    Tumor RNA samples were analyzed by quantitative PCR (qPCR) using Taqman assay on demand reagents (Applied Biosystems) and results are illustrated in  FIG. 4 . Interferon-gamma and cytotoxic T-cell effector genes (granzyme B and perforin 1) as well as T cell marker genes (Cd3d, Cd4, Cd8b1; not shown) were induced by UC10 in the tumor. The gene for indoleamine-pyrrole 2,3 dioxygenase (IDO) was also induced. IDO is an interferon-gamma inducible gene and can potentially be immunosuppressive. 
         [0088]    Quantitative PCR (qPCR) analysis of peripheral blood RNA was also performed and the results are illustrated in  FIG. 5 . Interferon gamma, Cd8b1, granzyme B and perforin 1 genes were all induced in the peripheral blood by UC10. The expression of interferon gamma, granzyme B and Cd8b1 was highest at day 7 (one day after the 3rd injection), and it also was higher at the fully efficacious dose (5 mg/kg) than at the sub-optimal dose (0.5 mg/kg). 
       Tumor RNA Expression Analysis: 
       [0089]    The tumor cells were collected and tumor RNA extracted as described above. The Affymetrix GeneChip process and data analysis as described above. 
       RNA Expression Profiling: 
       [0090]    To further identify genes induced by UC10 in the tumor, the same RNA samples were analyzed by RNA expression profiling using Affymetrix mouse A430 — 2 GeneChip. 
         [0091]    The RNA expression data was exported from Xpress using the RMA method with log 2  transformation. The entire data was loaded onto Partek software and the subsequent analysis was performed using this software. Initially, the genes were filtered to select for those with a reliable signal and inter sample variations, applying the following two criteria: (i) CV&gt;10% (to remove the genes that did not have significant variation among different samples); and (ii) the maximal signal &gt;5 (to select genes with a reliable expression level at least in one of the samples). 
         [0092]    The genes induced by UC10 were identified using a t-test comparing the expression levels in all the UC10 treated samples (all time points combined) and the control samples (all the time points combined) and are provided in Table 1A. 
         [0000]                                                        TABLE 1A                   Top 30 genes induced by UC10 (ranked by p-values)                        Fold       Probe Set ID   Gene Symbol   p-value   change                    1419762_at   Ubd   7.56E−07   6.18       1422527_at   H2-DMa   2.53E−06   5.67       1424923_at   Serpina3g   4.07E−06   6.26       1418641_at   Lcp2   4.20E−06   3.05       1418638_at   —   7.49E−06   2.62       1449556_at   H2-T23 /// C920025E04Rik   1.20E−05   2.77       1419004_s_at   Bcl2a1a /// Bcl2a1b /// Bcl2a1d   1.46E−05   2.89       1450678_at   —   1.49E−05   3.01       1449580_s_at   H2-DMb1 /// H2-DMb2   1.96E−05   4.90       1420915_at   Stat1   2.64E−05   2.76       1460218_at   Cd52   2.89E−05   4.96       1417025_at   H2-Eb1   3.69E−05   7.30       1425477_x_at   H2-Ab1 /// Rmcs1   3.77E−05   5.26       1451721_a_at   H2-Ab1   4.43E−05   5.49       1419060_at   Gzmb   4.62E−05   4.50       1452117_a_at   Fyb   4.84E−05   3.34       1433741_at   Cd38   5.22E−05   3.34       1450648_s_at   H2-Ab1 /// Rmcs1   5.43E−05   5.73       1448786_at   1100001H23Rik   5.65E−05   3.10       1435176_a_at   Idb2   6.76E−05   2.69       1422124_a_at   Ptprc   6.82E−05   4.90       1450753_at   Nkg7   6.88E−05   3.75       1425519_a_at   Ii   8.26E−05   5.42       1454268_a_at   Cyba   8.64E−05   2.52       1416016_at   —   8.67E−05   2.18       1431008_at   0610037M15Rik   8.68E−05   3.08       1451318_a_at   Lyn   8.78E−05   2.30       1416296_at   —   9.83E−05   3.35       1422903_at   Ly86   0.0001101   3.32       1423467_at   Ms4a4b   0.0001104   12.83                    
The top 15 genes (probes) of Table 1A included various class II MHC genes as well as other genes important in immune response. Various other genes involved in T cell and B cell activation were also induced. Table 1 provides the biomarkers of Table 1A.
 
         [0000]                                                                                                                                                                                                                                                                                    TABLE 1                   Biomarkers of Table 1A                                    Protein                           DNA       SEQ           NCBI Gene   Gene   Probe   SEQ   DNA   ID   Protein       Entry   (LocusLink) Title   Symbol   Set ID   ID NO:   Accession   NO:   Accession                    1   Ubiquitin D   Ubd   1419762_at    1   NM_023137.2    2   NP_075626.1       2   Histocompatibility   H2-   1422527_at    3   AK146950.1    4   BAE27559.1           2, class II, locus   DMa           DMa {POOR HIT   (66%)           66%}       3   Serine (Or cysteine)   Serpina   1424923_at    5   NM_009251.1    6   NP_033277.1           peptidase inhibitor,   3g           clade A, member           3G       4   Lymphocyte   Lcp2   1418641_at    7   NM_010696.3    8   NP_034826.2           cytosolic protein 2       5   Histocompatibility   H2-   1418638_at   9; 11   AK170866.1;   10; 12   BAE42080.1;           2, class II, locus   DMb1           BC002237.1       AAH02237.1           Mb1   (??)           {UNVALIDATED}       6   similar to H-2 class   N/A;   1449556_at   13; 15;   NM_010398.1;   14; 16;   NP_034528.1;           I histocompatibility   N/A;       17; 19;   XM_904658.2;   18; 20   XP_909751.1;           antigen, D-37 alpha   N/A;       21   XM_975970.1;       XP_981064.1;           chain precursor;   H2-T23           XM_992574.1;       XP_997668.1           similar to H-2 class               XR_003960.1           I histocompatibility           antigen, D-37 alpha           chain precursor;           similar to H-2 class           I histocompatibility           antigen, D-37 alpha           chain precursor;           histocompatibility           2, T region locus 23       7   B-cell   Bcl2a1a;   1419004_s_at   22; 24;   NM_007534.1;   23; 25;   NP_031560.1;           leukemia/lymphoma   Bcl2a1b;       26   NM_007536.2;   27   NP_031562.1;           2 related protein   Bcl2a1d           NM_009742.3       NP_033872.1           A1a; B-cell           leukemia/lymphoma           2 related protein           A1b; B-cell           leukemia/lymphoma           2 related protein           A1d       8   Integrin beta 2   Itgb2   1450678_at   28   NM_008404.2   29   NP_032430.2       9   Histocompatibility   H2-   1449580_s_at   30; 32   NM_010387.2;   31; 33   NP_034517.2;           2, class II, locus   DMb1;           NM_010388.2       NP_034518.1           Mb1;   H2-           histocompatibility   DMb2           2, class II, locus           Mb2       10   Signal transducer   Stat1   1420915_at   34   NM_009283.3   35   NP_033309.3           and activator of           transcription 1       11   CD52 antigen   Cd52   1460218_at   36   NM_013706.1   37   NP_038734.1       12   N/A;   N/A;   1417025_at   38; 39   AK005018.1;   40   BAE33527.1           histocompatibility   H2-Eb1           AK155968.1           2, class II antigen E   (74%)           beta {POOR HIT           74%}       13   Histocompatibility   H2-Ab1   1425477_x_at   41; 43   M15848.1;   42; 44   AAA39547.1;           2, class II antigen   (72%)           NM_207105.1       NP_99698.1           A, beta 1 {POOR           HIT 72%}       14   N/A;   N/A;   1451721_a_at   41; 45;   M15848.1;   42; 46;   AAA39547.1;           Histocompatibility   H2-Ab1       47; 49;   BC008168.1;   48; 51;   AAH08168.1;           2, class II antigen           50; 52   BC057998.1;   53   AAH57998.1;           A, beta 1               ENSMUST00000040828.4;       AAA39633.1;                           M13537.1;       AAA39635.1                           M13539.1            15   !! [Gzmb]       1419060_at   54   ENSMUST00000015581.3               Granzyme B            16   FYN binding   Fyb   1452117_a_at   55   NM_011815.1   56   NP_035945.1           protein       17   CD38 antigen   Cd38   1433741_at   57   NM_007646.2   58   NP_031672.2       18   Histocompatibility   H2-Ab1   1450648_s_at   43   NM_207105.1   44   NP_996988.1           2, class II antigen           A, beta 1       19   RIKEN cDNA   1100001H23Rik   1448786_at   59; 61;   NM_025806.1;   60; 62;   NP_080082.1;           1100001H23 gene           63   XM_974622.1;   64   XP_979716.1;                           XM_974657.1       XP_979751.1       20   N/A; Inhibitor of   N/A;   1435176_a_at   65; 66;   BF019883.1;   68   NP_034626.1           DNA binding 2   Id2       67   ENSMUST00000020974.3;                           NM_010496.2       21   Protein tyrosine   Ptprc   1422124_a_at   69   NM_011210.2   70   NP_035340.2           phosphatase,           receptor type, C       22   Natural killer cell   Nkg7   1450753_at   71   NM_024253.4   72   NP_077215.2           group 7 sequence       23   CD74 antigen   Cd74   1425519_a_at   73   NM_010545.3   74   NP_034675.1           (invariant           polypeptide of           major           histocompatibility           complex, class II           antigen-associated)       24   Cytochrome b-245,   Cyba   1454268_a_at   75   NM_007806.1   76   NP_031832.1           alpha polypeptide            25   N/A; transporter 1,   N/A;   1416016_at   77; 78;   AK166046.1; AW048052.1;           ATP-binding   Tap1       79   ENSMUST00000041633.5           cassette, sub-family   (74%)           B (MDR/TAP)           {POOR HIT 74%}            26   RIKEN cDNA   0610037M15Rik   1431008_at   80   XM_903697.2   81   XP_908790.2           0610037M15 gene       27   similar to   N/A;   1451318_a_at   82; 84;   NM_010747.1;   83; 85;   NP_034877.1;           Yamaguchi sarcoma   Lyn       86   XM_973394.1;   87   XP_978488.1;           viral (v-yes-1)               XM_991890.1       XP_996984.1           oncogene homolog;           Yamaguchi sarcoma           viral (V-yes-1)           oncogene homolog       28   N/A; interleukin 2   N/A;   1416296_at   88; 89   ENSMUST00000033664.5;   90   AAA39286.1           receptor, gamma   Il2rg           L20048.1           chain            29   !! [Ly86]       1422903_at   91   ENSMUST00000021860.3               Lymphocyte           antigen 86            30   membrane-spanning   Ms4a4b   1423467_at   92   NM_021718.2   93   NP_068364.1           4-domains,           subfamily A,           member 4B                    
Table 2 provides the top genes of Table 1A inducted by UC10 ranked by fold changes.
 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Top genes induced by UC10 (ranked by fold changes) 
               
             
          
           
               
                 Probe Set ID 
                 Gene Symbol 
                 p-value 
                 Fold change 
               
               
                   
               
             
          
           
               
                 1425324_x_at 
                 Igh-4 
                 0.0024827 
                 42.01 
               
               
                 1425247_a_at 
                 Igh-4 
                 0.0026075 
                 33.24 
               
               
                 1427455_x_at 
                 Igk-V8 
                 0.0012493 
                 31.51 
               
               
                 1424305_at 
                 Igj 
                 0.0037365 
                 29.12 
               
               
                 1427756_x_at 
                 Igh-4 
                 0.0037902 
                 26.47 
               
               
                 1452463_x_at 
                 Igk-V8 
                 0.0022802 
                 23.03 
               
               
                 1452417_x_at 
                 2010205A11Rik 
                 0.0018467 
                 20.49 
               
               
                 1427660_x_at 
                 Igk-V8 
                 0.0015737 
                 20.02 
               
               
                 1451632_a_at 
                 Igh-6 
                 0.0067362 
                 20.02 
               
               
                 1427351_s_at 
                 Igh-6 
                 0.00119 
                 19.43 
               
               
                 1430523_s_at 
                 Igl-V1 
                 0.0058301 
                 16.77 
               
               
                 1424931_s_at 
                 Igl-V1 
                 0.0060744 
                 16.38 
               
               
                 1427329_a_at 
                 Igh-6 
                 0.0039934 
                 15.09 
               
               
                 1427870_x_at 
                 Igh-4 
                 0.0041593 
                 14.59 
               
               
                 1423467_at 
                 Ms4a4b 
                 0.0001104 
                 12.83 
               
               
                 1424825_a_at 
                 Glycam1 
                 0.0074547 
                 11.35 
               
               
                 1425738_at 
                 LOC243469 
                 0.0070091 
                 10.97 
               
               
                 1419426_s_at 
                 Ccl21b /// Ccl21a /// Ccl21c 
                 0.0077637 
                 9.96 
               
               
                 1425871_a_at 
                 LOC384413 /// LOC434038 
                 0.0147353 
                 9.93 
               
               
                 1417851_at 
                 Cxcl13 
                 0.0004093 
                 9.67 
               
               
                 1426772_x_at 
                 Tcrb-V13 
                 0.0010696 
                 9.47 
               
               
                 1426113_x_at 
                 Tcra 
                 0.0005445 
                 9.26 
               
               
                 1425226_x_at 
                 Tcrb-V13 
                 0.0011634 
                 8.66 
               
               
                 1448377_at 
                 Slpi 
                 0.003984 
                 8.46 
               
               
                 1452205_x_at 
                 Tcrb-V13 
                 0.0020205 
                 8.18 
               
               
                 1426174_s_at 
                 Ighg 
                 0.0095374 
                 8.05 
               
               
                 1417640_at 
                 Cd79b 
                 0.00978 
                 8.00 
               
               
                 1452557_a_at 
                 — 
                 0.0058116 
                 7.93 
               
               
                 1425854_x_at 
                 Tcrb-V13 
                 0.002944 
                 7.58 
               
               
                 1422828_at 
                 Cd3d 
                 0.0018528 
                 7.52 
               
               
                   
               
             
          
         
       
     
         [0093]      FIG. 6  illustrates the expression levels of T cell receptor beta, immunoglobulin, and class II MHC genes in the tumor RNA expression profile analysis. These genes were induced by UC10 treatment, suggesting the infiltration of T, B, and possibly antigen presenting cells as well in the tumor. 
         [0094]    Ubd (FAT10/diubiquitin) gene was induced strongly by UC10 treatment. This gene may be a marker for the activation of anti-tumor immunity. Ubd gene is known to be induced by IFN-gamma and TNF-alpha, but its role in anti-immune response has not been described in the literature. (A. Canaan et al., Mol. Cell. Biol., July; 26(13):5180-9 (2006); E. Bates et al., Eur. J. Immunol., October; 27(10):2471-7 (1997)) 
       Example 2 
     Identification of Biomarkers Using EMT-6 Mouse Tumor Model 
       [0095]    The effect of UC10 vs. control (hamster IgG) was studied. Initially, tumor and blood total RNA were analyzed by qPCR. This was followed by RNA expression profile analysis using Affymetrix GeneChip. 
       Animal Sample Collection: 
       [0096]    EMT6 mouse mammary tumor was maintained in vitro. (Rockwell and Kallman, Radiat Res., February; 53(2):281-94 (1973)) EMT6 tumor cells were injected in the subcutaneous space of the right flank of Balb/c mice. Treatments were initiated when the subcutaneous tumor reached a median size between 100-200 mm 3 . 4.5 mg/kg of UC10 or Hamster IgG was injected intravenously once per week for three weeks (q7dx3 IV). At 24h after the third treatment of UC10, four mice were sacrificed. At seven days after the third treatment of hamster IgG, four mice were sacrificed. 
         [0097]    Separately, anti-tumor activity of UC10 was studied in EMT6 tumor cells. The results are provided in  FIG. 7 , wherein UC10 treatments resulted in no activity at doses as high as 39 mg/kg. 
         [0000]    RNA Expression Analysis by Quantitative PCR (qPCR): 
         [0098]    Tumor and blood samples were collected from these mice. Tumors were collected in RNAlater, while blood samples were collected in PAXgene tubes. Total RNA was extracted from the blood using PAXgene RNA extraction kit. Tumor RNA was extracted using Qiagene RNAeasy mini kit. The quality of isolated RNA was confirmed using Agilent 2100 nucleic acid analyzer detecting the peaks for 18S and 28S rRNA. cDNA was synthesized with a reverse transcription kit (Applied Biosystems) using random hexamers as primers. 
         [0099]    qPCR was performed using the Taqman method using Applied Biosystems (AB)&#39;s ‘Assay on Demand (AoD)’ premade assays. Some of the analysis was done using individual Taqman reagents in 96-well formats. Other assays were performed using Taqman Low Density Array (TLDA) microfluidic card system. All of these assays were run on the 7900HT sequence detection machine (AB). 
       Tumor Result: 
       [0100]    Tumor qPCR analysis was done for all the samples including the UC10 treated arm.  FIG. 8  illustrates the EMT6 tumor RNA qPCR results. As shown in  FIG. 8 , EMT6 model does not respond to the UC10 treatment. In this model, UC10 did not induce the induction of interferon gamma, granzyme B, or perforin 1 genes suggesting there was no activation of the immune response in the tumor. 
       Blood Result: 
       [0101]    The same set of genes were analyzed in the blood. As illustrated in  FIG. 9 , UC10 did not induce granzyme B or perforin 1 gene expression in the blood of EMT6 model. This contrasted with the Sa1N model, again reflecting the lack of anti-tumor response in this model. 
       Tumor RNA Expression Analysis: 
       [0102]    The tumor cells were collected and tumor RNA extracted as described above. The Affymetrix GeneChip process and data analysis as described above. The blood analysis protocol was identical to the tumor analysis, except for the globin reduction pretreatment that was required since a pilot experiment indicated that mouse blood RNA generated a poor quality RNA expression data without the globin reduction process. Globin reduction was performed using the Ambion protocol following the manufacturer&#39;s manual. 
         [0103]    UC10 effect was analyzed for one time point (1 day after the third treatment), as this was the only time the samples were collected. The analysis was done as a one-way ANOVA (essentially a t-test) using Partek software. None of the genes appeared to be changed significantly by UC10. Also, the genes with the lowest p-value for treatment effect appeared from random from various pathways. This reflects the efficacy results. 
       Blood RNA Expression Analysis: 
       [0104]    To further identify genes induced by UC10 in the blood, the same RNA samples were analyzed by RNA expression profiling using Affymetrix mouse A430 — 2 GeneChip. 
         [0105]    The RNA expression data was exported from Xpress using the RMA method with log 2  transformation. The entire data was loaded onto Partek software and the subsequent analysis was performed using this software. Initially, the genes were filtered to select for those with a reliable signal and inter sample variations, applying the following two criteria: (i) CV&gt;10% (to remove the genes that did not have significant variation among different samples); and (ii) the maximal signal &gt;6.6 (to select genes with a reliable expression level at least in one of the samples), which corresponds to the signal of 100 without log 2 transformation. 
         [0106]    The top 29 genes (probes) based on the p-value are provided in Table 3A. 
         [0000]                                                                TABLE 3A                   Top 29 genes induced by UC10 (ranked by p-values)                        Fold   p-       Probe Set ID   Gene Symbol   Gene Title   change   value (treatment)                    1425295_at   Ear11   eosinophil-associated,   30.75   0.00030               ribonuclease A family,               member 11       1419764_at   Chi3l3   chitinase 3-like 3   46.74   0.00046       1455530_at   —   —   0.37   0.00059       1422122_at   Fcer2a   Fc receptor, IgE, low affinity   0.34   0.00098               II, alpha polypeptide       1416746_at   H2afx   H2A histone family,   2.51   0.00156               member X       1425451_s_at   Chi3l3 ///   chitinase 3-like 3 ///   20.60   0.00176           Chi3l4   chitinase 3-like 4       1419549_at   Arg1   arginase 1, liver   24.05   0.00205       1449015_at   Retnla   resistin like alpha   7.98   0.00239       1420249_s_at   Ccl6   chemokine (C-C motif)   2.94   0.00285               ligand 6       1450430_at   Mrc1   mannose receptor, C type 1   6.34   0.00558       1455106_a_at   Ckb   creatine kinase, brain   3.63   0.00567       1419515_at   Fgd2   FYVE, RhoGEF and PH   3.00   0.00582               domain containing 2       1417936_at   Ccl9   chemokine (C-C motif)   3.15   0.00628               ligand 9       1448898_at   Ccl9   chemokine (C-C motif)   3.04   0.00783               ligand 9       1418509_at   Cbr2   carbonyl reductase 2   5.46   0.00817       1417346_at   Pycard   PYD and CARD domain   2.01   0.00897               containing       1425469_a_at   —   —   2.07   0.00900       1438009_at   Hist1h2ad   Histone 1, H2ae, mRNA   3.20   0.00945               (cDNA clone MGC: 90847               IMAGE: 5713252) /// CDNA               clone MGC: 103288               IMAGE: 5150365       1423756_s_at   Igfbp4   insulin-like growth factor   0.45   0.01371               binding protein 4       1455332_x_at   Fcgr2b   Fc receptor, IgG, low   2.80   0.01505               affinity IIb       1451941_a_at   Fcgr2b   Fc receptor, IgG, low   3.88   0.01528               affinity IIb       1434437_x_at   Rrm2   ribonucleotide reductase M2   3.78   0.01718       1435476_a_at   Fcgr2b   Fc receptor, IgG, low   2.41   0.01721               affinity IIb       1448883_at   Lgmn   legumain   2.15   0.01815       1435477_s_at   Fcgr2b   Fc receptor, IgG, low   3.23   0.02094               affinity IIb       1460287_at   Timp2   tissue inhibitor of   3.14   0.02462               metalloproteinase 2       1416108_a_at   Tmed3   transmembrane emp24   1.87   0.02477               domain containing 3       1416713_at   2700055K07Rik   RIKEN cDNA 2700055K07   2.32   0.02703               gene       1430523_s_at   Igl-V1   immunoglobulin lambda   1.99   0.02782               chain, variable 1                    
Table 3 provides the biomarkers of Table 3A.
 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Biomarkers of Table 3A 
               
             
          
           
               
                   
                   
                   
                   
                 DNA 
                   
                   
                   
               
               
                   
                 NCBI Gene 
                   
                   
                 SEQ 
                   
                 Protein 
               
               
                   
                 (LocusLink) 
                 Gene 
                 Probe Set 
                 ID 
                 DNA 
                 SEQ ID 
                 Protein 
               
               
                 Entry 
                 Title 
                 Symbol 
                 ID 
                 NO: 
                 Accession 
                 NO: 
                 Accession 
               
               
                   
               
             
          
           
               
                 1 
                 Eosinophil- 
                 Ear11 
                 1425295_at 
                  94 
                 NM_053113.2 
                  95 
                 NP_444343.2 
               
               
                   
                 associated, 
               
               
                   
                 ribonuclease 
               
               
                   
                 A family, 
               
               
                   
                 member 11 
               
               
                 2 
                 chitinase 3- 
                 Chi313 
                 1419764_at 
                  96 
                 XM_992616.1 
                  97 
                 XP_997710.1 
               
               
                   
                 like 3 
               
             
          
           
               
                 3 
                 !! uv90d11.x1 Soares 
                 1455530_at 
                  98 
                 BE686052.1 
                   
               
               
                   
                 mouse 3NbMS  Mus   
               
               
                   
                   musculus  cDNA clone 
               
               
                   
                 IMAGE: 3414453 3′, 
               
               
                   
                 mRNA sequence 
               
             
          
           
               
                 4 
                 Fc receptor, 
                 Fcer2a 
                 1422122_at 
                  99 
                 NM_013517.1 
                 100 
                 NP_038545.1 
               
               
                   
                 IgE, low 
               
               
                   
                 affinity II, 
               
               
                   
                 alpha 
               
               
                   
                 polypeptide 
               
               
                 5 
                 H2A 
                 H2afx 
                 1416746_at 
                 101 
                 NM_010436.2 
                 102 
                 NP_034566.1 
               
               
                   
                 histone 
               
               
                   
                 family, 
               
               
                   
                 member X 
               
               
                 6 
                 chitinase 3- 
                 Chi313; 
                 1425451_s_at 
                 96; 
                 XM_992616.1; 
                 97; 104; 
                 XP_997710.1; 
               
               
                   
                 like 3; 
                 Chi314 
                   
                 103; 
                 NM_009892.1; 
                 106 
                 NP_034022.1; 
               
               
                   
                 chitinase 3- 
                   
                   
                 105 
                 NM_145126.1 
                   
                 NP_660108.1 
               
               
                   
                 like 4 
               
               
                 7 
                 N/A; 
                 N/A; 
                 1419549_at 
                 107; 
                 BC050005.1; 
                 108; 111 
                 AAH50005.2; 
               
               
                   
                 arginase 1, 
                 Arg1 
                   
                 109; 
                 ENSMUST00000020161.5; 
                   
                 AAA98611.1 
               
               
                   
                 liver 
                 (65%) 
                   
                 110 
                 U51805.1 
               
               
                   
                 {POOR 
               
               
                   
                 HIT 65%} 
               
               
                 8 
                 resistin like 
                 Retnla 
                 1449015_at 
                 112 
                 NM_020509.3 
                 113 
                 NP_065255.2 
               
               
                   
                 alpha 
               
               
                 9 
                 chemokine 
                 Cc16 
                 1420249_s_at 
                 114 
                 NM_009139.3 
                 115 
                 NP_033165.1 
               
               
                   
                 (C-C motif) 
               
               
                   
                 ligand 6 
               
               
                 10 
                 Mannose 
                 Mrc1 
                 1450430_at 
                 116 
                 NM_008625.1 
                 117 
                 NP_032651.1 
               
               
                   
                 receptor, C 
               
               
                   
                 type 1 
               
               
                 11 
                 N/A; 
                 N/A; 
                 1455106_a_at 
                 118; 
                 AK165779.1; 
                 122 
                 NP_067248.1 
               
               
                   
                 Creatine 
                 Ckb 
                   
                 119; 
                 BG967663.1; 
               
               
                   
                 kinase, 
                   
                   
                 120; 
                 ENSMUST00000001304.5; 
               
               
                   
                 brain 
                   
                   
                 121 
                 NM_021273.3 
               
             
          
           
               
                 12 
                 !! [Fgd2] 
                   
                 1419515_at 
                 123 
                 ENSMUST00000024810.4 
                   
               
               
                   
                 FYVE, 
               
               
                   
                 RhoGEF 
               
               
                   
                 and PH 
               
               
                   
                 domain 
               
               
                   
                 containing 2 
               
             
          
           
               
                 13 
                 Chemokine 
                 Ccl9 
                 1417936_at 
                 124; 
                 AF128196.1; 
                 125; 127 
                 AAF22537.1; 
               
               
                   
                 (C-C motif) 
                   
                   
                 126 
                 NM_011338.2 
                   
                 NP_035468.1 
               
               
                   
                 ligand 9 
               
               
                 14 
                 Chemokine 
                 Ccl9 
                 1448898_at 
                 126 
                 NM_011338.2 
                 127 
                 NP_035468.1 
               
               
                   
                 (C-C motif) 
               
               
                   
                 ligand 9 
               
               
                 15 
                 Carbonyl 
                 Cbr2 
                 1418509_at 
                 128 
                 NM_007621.1 
                 129 
                 NP_031647.1 
               
               
                   
                 reductase 2 
               
               
                 16 
                 PYD and 
                 Pycard 
                 1417346_at 
                 130 
                 NM_023258.3 
                 131 
                 NP_075747.2 
               
               
                   
                 CARD 
               
               
                   
                 domain 
               
               
                   
                 containing 
               
             
          
           
               
                 17 
                 !! hypothetical protein 
                 1425469_a_at 
                 132; 
                 AK085738.1; 
                 134 
                 AAH03855.1 
               
               
                   
                 LOC624610|| 
                   
                 133 
                 BC003855.1 
               
               
                   
                 hypothetical protein 
               
               
                   
                 LOC675730 || similar 
               
               
                   
                 to IG KAPPA CHAIN 
               
               
                   
                 V-V REGION L6 
               
               
                   
                 PRECURSOR 
               
             
          
           
               
                 18 
                 Similar to 
                 MGC73635 
                 1438009_at 
                 135; 
                 XM_978296.1; 
                 136; 138 
                 XP_983390.1; 
               
               
                   
                 histone 2a 
                 (*) 
                   
                 137 
                 XM_978341.1 
                   
                 XP_983435.1 
               
               
                 19 
                 Insulin-like 
                 Igfbp4 
                 1423756_s_at 
                 139 
                 NM_010517.3 
                 140 
                 NP_034647.1 
               
               
                   
                 growth 
               
               
                   
                 factor 
               
               
                   
                 binding 
               
               
                   
                 protein 4 
               
               
                 20 
                 N/A; Fc 
                 N/A; 
                 1455332_x_at 
                 141; 
                 BM224327.2; 
                 143 
                 NP_034317.1 
               
               
                   
                 receptor, 
                 Fcgr2b 
                   
                 142 
                 NM_010187.2 
               
               
                   
                 IgG, low 
               
               
                   
                 affinity IIb 
               
               
                 21 
                 Fc receptor, 
                 Fcgr2b 
                 1451941_a_at 
                 142 
                 NM_010187.2 
                 143 
                 NP_034317.1 
               
               
                   
                 IgG, low 
               
               
                   
                 affinity IIb 
               
               
                 22 
                 ribonucleotide 
                 Rrm2 
                 1434437_x_at 
                 144 
                 NM_009104.1 
                 145 
                 NP_033130.1 
               
               
                   
                 reductase 
               
               
                   
                 M2 
               
               
                 23 
                 Fc receptor, 
                 Fcgr2b 
                 1435476_a_at 
                 142 
                 NM_010187.2 
                 143 
                 NP_034317.1 
               
               
                   
                 IgG, low 
               
               
                   
                 affinity IIb 
               
             
          
           
               
                 24 
                 !! [Lgmn] 
                   
                 1448883_at 
                 146 
                 ENSMUST00000021607.5 
                   
               
               
                   
                 Legumain 
               
             
          
           
               
                 25 
                 Fc receptor, 
                 Fcgr2b 
                 1435477_s_at 
                 142 
                 NM_010187.2 
                 143 
                 NP_034317.1 
               
               
                   
                 IgG, low 
               
               
                   
                 affinity IIb 
               
               
                 26 
                 Tissue 
                 Timp2 
                 1460287_at 
                 147 
                 NM_011594.3 
                 148 
                 NP_035724.2 
               
               
                   
                 inhibitor of 
               
               
                   
                 metalloproteinase 2 
               
               
                 27 
                 Transmembrane 
                 Tmed3 
                 1416108_a_at 
                 149 
                 NM_025360.1 
                 150 
                 NP_079636.1 
               
               
                   
                 emp24 
               
               
                   
                 domain 
               
               
                   
                 containing 3 
               
               
                 28 
                 RIKEN 
                 2700055K07Rik 
                 1416713_at 
                 151 
                 NM_026481.2 
                 152 
                 NP_080757.1 
               
               
                   
                 cDNA 
               
               
                   
                 2700055K07 
               
               
                   
                 gene 
               
               
                 29 
                 immunoglobulin 
                 Igl-V1 
                 1430523_s_at 
                 153; 
                 AK008094.1; 
                 154; 156 
                 BAB25455.1; 
               
               
                   
                 lambda 
                   
                   
                 155; 
                 AK008145.1; 
                   
                 BAB25493.1 
               
               
                   
                 chain, 
                   
                   
                 157 
                 AY170495.1 
               
               
                   
                 variable 1 
               
               
                   
               
             
          
         
       
     
         [0107]    The highest induction was seen with genes associated with Th2 response or alternative activation of macrophage. Both of these pathways can be anti-inflammatory, and may suppress anti-tumor immunity. It should be also noted that none of these patterns was observed in the tumor gene expression from the same mice. 
         [0108]    Earl1 is one of the mouse versions of eosinophil cationic protein (ECP), which is one of the mediators of the Th2 response. 
         [0109]    Tables 3A and 3 include genes associated with alternative activation of macrophages (Ym1, arginase 1 and Fizz 1). Arginasel, Chi313 (Ym1), Retnla (resistin-like alpha/Fizz1) have all been reported to be markers of alternatively activated macrophages in mice. (Nair et al., Immunol Lett., January 22; 85(2):173-80 (2003)) Mrc1 may also be involved in the type-2 activation of monocyte derived DCs, which can be anti-inflammatory. (Chieppa et al., J. Immunol., November 1; 171(9):4552-60 (2003)) 
         [0110]    Activation of creatine kinase has been observed during monocyte to macrophage development. (Loike et al., J Exp Med., March 1; 159(3):746-57 (1984)) 
         [0111]    The same blood RNA samples analyzed in  FIG. 9  were analyzed for the expression of Ym1 and ariginase 1 and the results are provided in  FIG. 10 . The induction of these genes by UC10 was reproduced, and the expression level was extremely high at day 7. This high expression of Ym1 and arginase 1 mostly disappeared by day 13. 
       Example 3 
     Production of Antibodies Against the Biomarkers 
       [0112]    Antibodies against the biomarkers can be prepared by a variety of methods. For example, cells expressing a biomarker polypeptide can be administered to an animal to induce the production of sera containing polyclonal antibodies directed to the expressed polypeptides. In one aspect, the biomarker protein is prepared and isolated or otherwise purified to render it substantially free of natural contaminants, using techniques commonly practiced in the art. Such a preparation is then introduced into an animal in order to produce polyclonal antisera of greater specific activity for the expressed and isolated polypeptide. 
         [0113]    In one aspect, the antibodies of the invention are monoclonal antibodies (or protein binding fragments thereof). Cells expressing the biomarker polypeptide can be cultured in any suitable tissue culture medium, however, it is preferable to culture cells in Earle&#39;s modified Eagle&#39;s medium supplemented to contain 10% fetal bovine serum (inactivated at about 56° C.), and supplemented to contain about 10 g/l nonessential amino acids, about 1.00 U/ml penicillin, and about 100 μg/ml streptomycin. 
         [0114]    The splenocytes of immunized (and boosted) mice can be extracted and fused with a suitable myeloma cell line. Any suitable myeloma cell line can be employed in accordance with the invention, however, it is preferable to employ the parent myeloma cell line (SP2/0), available from the ATCC (Manassas, Va.). After fusion, the resulting hybridoma cells are selectively maintained in HAT medium, and then cloned by limiting dilution as described by Wands et al. (1981 , Gastroenterology,  80:225-232). The hybridoma cells obtained through such a selection are then assayed to identify those cell clones that secrete antibodies capable of binding to the polypeptide immunogen, or a portion thereof. 
         [0115]    Alternatively, additional antibodies capable of binding to the biomarker polypeptide can be produced in a two-step procedure using anti-idiotypic antibodies. Such a method makes use of the fact that antibodies are themselves antigens and, therefore, it is possible to obtain an antibody that binds to a second antibody. In accordance with this method, protein specific antibodies can be used to immunize an animal, preferably a mouse. The splenocytes of such an immunized animal are then used to produce hybridoma cells, and the hybridoma cells are screened to identify clones that produce an antibody whose ability to bind to the protein-specific antibody can be blocked by the polypeptide. Such antibodies comprise anti-idiotypic antibodies to the protein-specific antibody and can be used to immunize an animal to induce the formation of further protein-specific antibodies. 
       Example 4 
     Immunofluorescence Assays 
       [0116]    The following immunofluorescence protocol may be used, for example, to verify CTLA-4 biomarker protein expression on cells or, for example, to check for the presence of one or more antibodies that bind CTLA-4 biomarkers expressed on the surface of cells. Briefly, Lab-Tek II chamber slides are coated overnight at 4° C. with 10 micrograms/milliliter (μg/ml) of bovine collagen Type II in DPBS containing calcium and magnesium (DPBS++). The slides are then washed twice with cold DPBS++ and seeded with 8000 CHO—CCR5 or CHO pC4 transfected cells in a total volume of 125 μl and incubated at 37° C. in the presence of 95% oxygen/5% carbon dioxide. 
         [0117]    The culture medium is gently removed by aspiration and the adherent cells are washed twice with DPBS++ at ambient temperature. The slides are blocked with DPBS++ containing 0.2% BSA (blocker) at 0-4° C. for one hour. The blocking solution is gently removed by aspiration, and 125 μl of antibody containing solution (an antibody containing solution may be, for example, a hybridoma culture supernatant which is usually used undiluted, or serum/plasma which is usually diluted, e.g., a dilution of about 1/100 dilution). The slides are incubated for 1 hour at 0-4° C. Antibody solutions are then gently removed by aspiration and the cells are washed five times with 400 μl of ice cold blocking solution. Next, 125 μl of 1 μg/ml rhodamine labeled secondary antibody (e.g., anti-human IgG) in blocker solution is added to the cells. Again, cells are incubated for 1 hour at 0-4° C. 
         [0118]    The secondary antibody solution is then gently removed by aspiration and the cells are washed three times with 400 μl of ice cold blocking solution, and five times with cold DPBS++. The cells are then fixed with 125 μl of 3.7% formaldehyde in DPBS++ for 15 minutes at ambient temperature. Thereafter, the cells are washed five times with 400 μl of DPBS++ at ambient temperature. Finally, the cells are mounted in 50% aqueous glycerol and viewed in a fluorescence microscope using rhodamine filters.