The role of CD4 T cells in tumor immunity is not yet understood, as CD4 T cells recognize MHC class II epitopes expressed on antigen-presenting cells but not on tumor cells. Still, they send critical signals to dendritic cells, which then upregulate the expression of MHC class I molecules, costimulatory molecules, and secretion of IL-12 and IL-15, thereby driving CD8 T cells response for lysis of tumor cells.
The overall goal of our study is to determine the importance of CD4 T cells in adaptive immune responses and immunotherapy against HCC.
Mice were inoculated with HCC cells with different MHC class II expressions, containing defined CD8 and CD4 T cell neoepitopes, and the specific T cell immune responses were analyzed. Early evaluations indicate increased CD8 T cell immune response in MHC-II positive tumors and tumors with CD4 T cell neoepitopes.
In a subcutaneous cancer model we will use therapeutic T cell vaccinations in order analyze the anti-tumoral T cell responses by flow cytometry and to evaluate the relevance of CD4 epitope and MHCII expression in cancer cells.
Our study will bring us closer to understanding the importance of CD4 T cell help in HCC.
