Preferential Accumulation of Antigen-specific Effector CD4 T Cells at an Antigen Injection Site Involves CD62E-dependent Migration but Not Local Proliferation

The migration of antigen-specific T cells to nonlymphoid tissues is thought to be important for the elimination of foreign antigens from the body. However, recent results showing the migration of activated T cells into many nonlymphoid tissues raised the possibility that antigen-specific T cells do not migrate preferentially to nonlymphoid tissues containing antigen. We addressed this question by tracking antigen-specific CD4 T cells in the whole body after a localized subcutaneous antigen injection. Antigen-specific CD4 T cells proliferated in the skin-draining lymph nodes and the cells that underwent the most cell divisions acquired the ability to bind to CD62P. As time passed, CD62P-binding antigen-specific CD4 T cells with interferon γ production potential accumulated preferentially at the site of antigen injection but only in recipients that expressed CD62E. Surprisingly, these T cells did not proliferate in the injection site despite showing evidence of more cell divisions than the T cells in the draining lymph nodes. The results suggest that the most divided effector CD4 T cells from the lymph nodes enter the site of antigen deposition via recognition of CD62E on blood vessels and are retained there in a nonproliferative state via recognition of peptide–major histocompatibility complex II molecules.