ruitment and Cytolytic Function of CD8 T Lymphocytes

Downlo help for CD8 T lymphocytes prevents tolerance and promotes the survival of effector and memory T cells. Here, we describe additional helper functions that require CD4 T cells within the tumor envint. CD8 T-cell recruitment, proliferation, and effector function within the tumor were greatly enhanced or-specific CD4 T cells. Recruitment of CD8 T cells was accelerated by IFN-γ–dependent production mokines. Production of interleukin-2 by tumor resident CD4 T cells enhanced CD8 T-cell proliferation regulated expression of granzyme B. These results highlight a novel role for tumor-specific CD4 T cells and up in promoting CD8 T-cell recruitment and cytolytic function, two previously unappreciated aspects of tumorspecific CD4 help. Cancer Res; 70(21); OF1–10. ©2010 AACR.