IMMUNITY TO MELANOMA WITH IL-2-SECRETING ALLOGENEIC CELL

尽管它们表达免疫原性决定簇，但B16 黑素瘤细胞在免疫活性的C57 BL/6小鼠（H-2b）中进行性生长。 “逃逸”机制不成立。 由于细胞毒性T 淋巴细胞可以识别一系列非常广泛的小的 肽（在组织相容性I类的情况下），包括 与恶性细胞相关的新抗原，可能是 抗原性肿瘤是由免疫识别失败引起的，而不是由 缺乏肿瘤相关决定因素。 的理解 细胞“缺陷”，使肿瘤细胞生长在免疫活性 接受者可能对特异性免疫治疗有重要意义 癌症。 作为一种实验方法，我们使用转染来构建 表达黑色素瘤的分泌IL-2的同种异体小鼠成纤维细胞 相关抗原。 然后，我们测试了细胞的免疫原性， 它们在小鼠中引发抗黑色素瘤免疫应答的能力 与肿瘤同源 该结构通过以下方式制备： 将来自B16细胞（H-2b）的基因组DNA导入同种异体的LM细胞（H-2k）中 C57 BL/6小鼠。 表达黑色素瘤的转染细胞集落- 分离相关的决定簇，然后用表达 携带IL-2基因的感受态质粒。 在我们的实验中，C57 BL/6 小鼠排斥分泌IL-2的黑色素瘤抗原阳性同种异体 小鼠细胞产生了对黑素瘤的细胞免疫。 这种豁免 超过用非IL-2分泌型构建体免疫后的水平，或 B16细胞 该提案的目标是确定 B16黑色素瘤后特异性细胞类型被激活用于排斥 用IL-2分泌细胞构建体免疫C57 BL/6小鼠，和 将它们与用以下物质免疫小鼠后活化的细胞类型进行比较： 缺乏一种或多种免疫原性特性的构建体。 在 此外，我们计划确定外源性IL-2是否可以替代 IL-2的直接细胞-细胞（旁分泌）转移诱导了一种 抗黑色素瘤免疫反应。 最后，我们计划确定， 用分泌IL-2的构建体免疫荷瘤小鼠 提高了生存率。

In spite of the fact that they express immunogenic determinants, B16 melanoma cells grow progressively in immunocompetent C57BL/6 mice (H-2b). The mechanism of "escape" is not established. Since cytotoxic T lymphocytes are known to recognize an extraordinarily wide array of small peptides (in the context of histocompatibility class I), including neoantigens associated with malignant cells, it may be that the growth of antigeneic tumors results from a failure of immune recognition, not from the absence of tumor associated determinants. An understanding of the cellular "defect" that enables tumor cells to grow in immunocompetent recipients could have important implications for the specific immunotherapy of cancer. As an experimental approach, we used transfection to construct IL-2-secreting, allogeneic mouse fibroblasts that express melanoma associated antigens. We then tested the cells' immunogenic properties in terms of their ability to elicit an anti melanoma immune response in mice syngeneic with the tumor. The construct was prepared by transfecting genomic DNA from B16 cells (H-2b) into LM cells (H-2k) which are allogeneic with C57BL/6 mice. Colonies of transfected cells expressing melanoma- associated determinants were isolated, and then infected with an expression competent plasmid carrying the gene for IL-2. In our experiments, C57BL/6 mice rejecting the IL-2-secreting, melanoma antigen-positive allogeneic mouse cells developed cellular immunity to the melanoma. This immunity exceeded that following immunization with non-IL-2-secreting constructs, or with B16 cells. The objectives of the proposal are to determine the specific cell types activated for rejection of B16 melanoma following immunization of C57BL/6 mice with the IL-2-secreting cell constructs, and compare them with cell types activated following immunization of mice with constructs that lack one or more of the immunogenic properties. In addition, we plan to determine if exogenous IL-2 can substitute for the direct cell-to-cell (paracrine) transfer of IL-2 in the induction of an anti melanoma immune response. Finally, we plan to determine if immunizations of tumor-bearing mice with the IL-2-secreting constructs leads to increased survival.