期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2001
卷号：98
期号：25
页码：14571-14576
DOI：10.1073/pnas.251547298
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Recognition of altered self-antigens in tumor cells by lymphocytes forms the basis for antitumor immune responses. The effector cells in most experimental tumor systems are CD8+ T cells that recognize MHC class I binding peptides derived from molecules with altered expression in tumor cells. Although the need for CD4+ helper T cells in regulating CD8+ T cells has been documented, their target epitopes and functional impact in antitumor responses remain unclear. We examined whether broadly expressed wild-type molecules in murine tumor cells eliciting humoral immunity contributed to the generation of CD8+ T cells and protective antitumor immune responses to unrelated tumor-specific antigens [mutated ERK2 (mERK2) and c-erbB2/HER/neu (HER2)]. The immunogenic wild-type molecules, presumably dependent on recognition by CD4+ helper T cells, were defined by serological analysis of recombinant cDNA expression libraries (SEREX) using tumor-derived {lambda} phage libraries screened with IgG antibodies of hosts bearing transplanted 3-methylchoranthrene-induced tumors. Coimmunization of mice with plasmids encoding SEREX-defined murine wild-type molecules and mERK2 or HER2 led to a profound increase in CD8+ T cells specific for mERK2 or HER2 peptides. This heightened response depended on CD4+ T cells and copresentation of SEREX-defined molecules and CD8+ T cell epitopes. In tumor protection assays, immunization with SEREX-defined wild-type molecules and mERK2 resulted in an inhibition of pulmonary metastasis, which was not achieved by immunization with mERK2 alone.
