Generation and Regeneration of a Novel Anti-CD8-Resistant Cytolytic T Lymphocyte Population

We recently reported that the in vivo development of a novel CD8+, but anti-CD8 mAb-resistant, CTL population is complex and distinct from that of conventional anti-CD8 mAb-sensitive CD8+ CTL. In this study, we explored the role of the thymus in the generation of anti-CD8-resistant pCTL and in their maintenance once they are generated. We also investigated the capacities of the adult periphery and thymus to support the regeneration of anti-CD8-resistant pCTL after peripheral lymphocyte and/or thymocyte depletion. These studies indicate that the thymus is necessary for the generation but not the maintenance of peripheral anti-CD8-resistant pCTL. These studies also indicate that the adult thymus can produce these pCTL and the adult periphery can support their regeneration, if a new wave of thymic maturation is experimentally induced. These results may have implications for immune reconstitution after treatment for cancer or HIV infection.