CD4(+) T cells comprise a significant portion of tumor-infiltrating lymphocytes. Different subsets of CD4(+) T cells exist and they exert different effector functions in tumor immunity depending on the cytokines produced going from antitumor to pro-tumor. Methods that use small aliquots of cells to identify ex vivo the frequency and functional orientation of tumor-specific CD4(+) T cells in the blood and visualization of the presence of different CD4(+) T cell subsets and their localization at the tumor site are valuable tools to determine their clinical impact in neoplastic diseases.
Keywords: Antigen-specific CD4+ T cell frequency; Antitumor cytokine; CD4+ T cells; GATA-3; Pro-tumor cytokine; T-bet; Th subsets; Tumor antigens.