T cell infiltration of the prostate induced by androgen withdrawal in patients with prostate cancer

Manipulations capable of breaking host tolerance to induce tissue-specific T cell-mediated inflammation are of central importance to tumor immunothera py and our understanding of autoimmunity. We demonstrate that androgen abla tive therapy induces profuse T cell infiltration of benign glands and tumor s in human prostates. T cell infiltration is readily apparent after 7-28 da ys of therapy and is comprised predominantly of a response by CD4+ T cells and comparatively fewer CD8+ T cells. Also, T cells within the treated pros tate exhibit restricted TCR V beta gene usage, consistent with a local olig oclonal response. Recruitment/activation of antigen-presenting cells in tre ated prostate tissues may contribute to local T cell activation. The induct ion of T cell infiltration in prostate tissues treated with androgen ablati on may have implications for the immunotherapeutic treatment of prostate ca ncer as well as other hormone-sensitive malignancies, including breast carc inoma.