Zhai Y, Yang J C, Spiess P, Nishimura M I, Overwijk W W, Roberts B, Restifo N P, Rosenberg S A
Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Immunother. 1997 Jan;20(1):15-25. doi: 10.1097/00002371-199701000-00002.
The recent identification of genes encoding melanoma-associated antigens has opened new possibilities for the development of cancer vaccines designed to cause the rejection of established tumors. To develop a syngeneic animal model for evaluating antigen-specific vaccines in cancer therapy, the murine homologues of the human melanoma antigens MART1 and gp100, which were specifically recognized by tumor-infiltrating lymphocytes from patients with melanoma, were cloned and sequenced from a murine B16 melanoma cDNA library. The open reading frames of murine MART1 and gp100 encode proteins of 113- and 626-amino acids with 68.8 and 77% identity to the respective human proteins. Comparison of the DNA sequences of the murine MART1 genes, derived from normal melanocytes, the immortalized nontumorgenic melanocyte line Melan-a and the B16 melanoma, showed all to be identical. Northern and Western blot analyses confirmed that both genes encoded products that were melanocyte lineage proteins. Mice immunized with murine MART1 or gp100 using recombinant vaccinia virus failed to produce any detectable T-cell responses or protective immunity against B16 melanoma. In contrast, immunization of mice with human gp100 using recombinant adenoviruses elicited T cells specific for hgp100, but these T cells also cross reacted with B16 tumor in vitro and induced significant but weak protection against B16 challenge. Immunization with human and mouse gp100 together [adenovirus type 2 (Ad2)-hgp100 plus recombinant vaccinia virus (rVV)-mgp100], or immunization with human gp100 (Ad2-hgp100) and boosting with heterologous vector (rVV-hgp100 or rVV-mgp100) or homologous vector (Ad2-hgp100), did not significantly enhance the protective response against B16 melanoma. These results may suggest that immunization with heterologous tumor antigen, rather than self, may be more effective as an immunotherapeutic reagent in designing antigen-specific cancer vaccines.
最近对编码黑色素瘤相关抗原的基因的鉴定为开发旨在促使已形成肿瘤被排斥的癌症疫苗开辟了新的可能性。为了开发一种用于评估癌症治疗中抗原特异性疫苗的同基因动物模型，从鼠B16黑色素瘤cDNA文库中克隆并测序了人黑色素瘤抗原MART1和gp100的鼠同源物，这些抗原被黑色素瘤患者的肿瘤浸润淋巴细胞特异性识别。鼠MART1和gp100的开放阅读框分别编码113个和626个氨基酸的蛋白质，与各自的人蛋白质具有68.8%和77%的同一性。对来自正常黑素细胞、永生化非致瘤性黑素细胞系Melan-a和B16黑色素瘤的鼠MART1基因的DNA序列进行比较，结果显示它们完全相同。Northern印迹和Western印迹分析证实这两个基因编码的产物都是黑素细胞谱系蛋白。用重组痘苗病毒免疫鼠MART1或gp100的小鼠未能产生任何可检测到的T细胞反应或对B16黑色素瘤的保护性免疫。相比之下，用重组腺病毒免疫小鼠人gp100可引发对hgp100特异的T细胞，但这些T细胞在体外也与B16肿瘤发生交叉反应，并诱导了对B16攻击的显著但较弱的保护作用。一起用人和鼠gp100免疫（腺病毒2型（Ad2）-hgp100加重组痘苗病毒（rVV）-mgp100），或用人gp100免疫（Ad2-hgp100）并用异源载体（rVV-hgp100或rVV-mgp100）或同源载体（Ad2-hgp100）加强免疫，均未显著增强对B16黑色素瘤的保护性反应。这些结果可能表明，用异源肿瘤抗原而非自身抗原进行免疫，在设计抗原特异性癌症疫苗时作为免疫治疗试剂可能更有效。
