Cellular Immunity Targeting Epithelial Ovarian Cancer

在美国，卵巢癌是妇科恶性肿瘤导致死亡的主要原因，每年约有1.4万人死于卵巢癌。尽管治疗方法有所改进，晚期卵巢癌的5年生存率仍约为20-30%。卵巢癌差异表达某些蛋白质通常存在于其他组织只有在胚胎发育期间。这些肿瘤胎儿蛋白包括WT1蛋白、糖基化粘蛋白Ca125 （MUC16）和HER2/neu。最近，我们和其他人已经鉴定出来自WT1和MUC16的潜在免疫原性肽，它们结合HLA常见等位基因HLA A0201。我们对免疫原性WT1肽和候选MUC16肽的初步研究表明，这些肽可用于致敏来自正常人和卵巢癌患者的T细胞，并可在体外扩增。被WT1和MUC16致敏的T细胞在肽的作用下产生IFNy等细胞因子，并在体外特异性地裂解原代HLA A2+ WT1+或MUC16+白血病和特定的癌症，包括卵巢癌细胞。在SCID小鼠，人类肿瘤异种移植模型中，我们发现过继性转移WT1特异性HLA A2+ T细胞，并特异性诱导某些HLA A2+ WT1+白血病和包括卵巢癌在内的特定癌症的消退。在这项研究中，我们建议首先鉴定和表征WT-1和MUC16对HLA A2具有中等至高亲和力的肽，然后是其他HLA等位基因。然后，我们将使用装载WT1、MUC16或HER2/neu肽或转导表达这些蛋白的EBV BLCL，因为它们具有致敏和刺激肽特异性T细胞扩增的能力，这些T细胞能够在体外裂解原发性卵巢癌细胞和已建立的细胞系。我们还将探索一种新的五肽方法来鉴定WT1和MUC16中的新抗原。然后，我们将确定这些肿瘤的特征，这些特征可以增强或抑制这些T细胞在体外的杀肿瘤活性。我们还将比较评估从患者和正常人身上产生的T细胞群

Ovarian carcinoma is the leading cause of death from gynecologic malignancies in the United States, responsible for an estimated 14,000 deaths per year. Despite improvements in therapy, 5-year survival for advanced ovarian cancer remains approximately 20-30%. Ovarian cancers differentially express certain proteins normally present on other tissues only during embryonal development. Among these onco fetal proteins are the WT1 protein, the glycosylated mucin Ca125 (MUC16) and HER2/neu. Recently, we and others have identified potentially immunogenic peptides derived from WT1 and MUC16 which bind the common HLA allele, HLA A0201. Our initial studies with immunogenic WT1 peptides and with candidate MUC16 peptides suggest that these peptides can be used to sensitize T cells from normal individuals and from ovarian cancer patients, which can be expanded in vitro. The T cells sensitized with WT1 and MUC16 generate IFNy and other cytokines in response to peptide and specifically lyse primary HLA A2+ WT1+ or MUC16+ leukemias and selected carcinomas, including ovarian cancer cells in vitro. In a SCID mouse, human tumor xenograft model, we have found that adoptively transferred WT1 specific HLA A2+ T cells home to and specifically induce regressions of certain HLA A2+ WT1+ leukemia and selected carcinomas including ovarian cancer. In this grant, we propose first, to identify and characterize peptides of WT-1 and MUC16 which have moderate to high affinity for HLA A2, and thereafter, other HLA alleles. We will then use EBV BLCL either loaded with WT1, MUC16 or HER2/neu peptides or transduced to express these proteins, for their capacity to sensitize and stimulate the expansion of peptide-specific T cells capable of lysing primary ovarian cancer cells and established cell lines in vitro. We will also explore a novel pentadecapeptide approach to identify novel antigens in WT1 and MUC16. We will then identify features of these tumors which can potentiate or inhibit the tumoricidal activity of these T cells in vitro. We will also comparatively evaluate T cell populations generated from patients and from normal individuals against these peptides to determine whether disparities in phenotypic or functional features of those T cells affect tumor cell interactions in vitro. Third, we will test these peptide-specific cells for their capacity to home to, using a novel in vivo imaging approach, and induce regressions of human ovarian carcinoma xenografts in a SCID mouse model. Lastly, we propose to conduct a phase I/II trial of WT1 or MUC16 peptide-specific T cells in the treatment of women with advanced ovarian carcinoma. These studies may provide important new information regarding the potential of T cells generated ex vivo against these immunogenic peptides for adoptive cell therapy of ovarian cancer.