Chemokines enhance immunity by guiding naive CD8 + T cells to sites of CD4 + T cell–dendritic cell interaction

摘要: CD8+ T cells have a crucial role in resistance to pathogens and can kill malignant cells; however, some critical functions of these lymphocytes depend on helper activity provided by distinct population CD4+ cells. Cooperation between lymphocyte subsets involves recognition antigens co-presented the same dendritic cell, but frequencies such antigen-bearing early an infection relevant naive are both low. This suggests that active mechanism facilitates necessary cell-cell associations. Here we demonstrate after immunization before antigen recognition, immunogen-draining lymph nodes upregulate chemokine receptor CCR5, permitting be attracted sites antigen-specific cell-CD4+ cell interaction where cognate chemokines CCL3 CCL4 (also known as MIP-1alpha MIP-1beta) produced. Interference with this actively guided recruitment markedly reduces ability promote memory T-cell generation, indicating orchestrated series differentiation events drives nonrandom interactions within nodes, optimizing immune responses involving few precursors present repertoire.