Figure 1. T cell coinhibition is exploited by prostate cancer as immune evasion pathways.
T cell coinhibitory B7 family members B7x and B7-H3 are overexpressed by prostate cancer cells as revealed by immunohistochemical staining. Tissue microarrays of human prostate cancer were stained with antibodies against B7-H3 (left) or B7x (right). B7-H3 and B7x bind unidentified receptors on activated T cells to downregulate TCR-mediated signaling, which might contribute to poor clinical outcome. In addition, many prostate cancer patients have soluble B7 molecules in the blood, but the mechanism of production and the function of soluble B7 are currently unknown