CCR7 expression alters memory CD8 T-cell homeostasis by regulating occupancy in IL-7–and IL-15–dependent niches

YW Jung, HG Kim, CJ Perry… - Proceedings of the …, 2016 - National Acad Sciences
YW Jung, HG Kim, CJ Perry, SM Kaech
Proceedings of the National Academy of Sciences, 2016National Acad Sciences
CC receptor 7 (CCR7) is important to allow T cells and dendritic cells to migrate toward
CCL19-and CCL21-producing cells in the T-cell zone of the spleen and lymph nodes. The
role of this chemokine receptor in regulating the homeostasis of effector and memory T cells
during acute viral infection is poorly defined, however. In this study, we show that CCR7
expression alters memory CD8 T-cell homeostasis following lymphocytic choriomeningitis
virus infection. Greater numbers of CCR7-deficient memory T cells were formed and …
C-C receptor 7 (CCR7) is important to allow T cells and dendritic cells to migrate toward CCL19- and CCL21-producing cells in the T-cell zone of the spleen and lymph nodes. The role of this chemokine receptor in regulating the homeostasis of effector and memory T cells during acute viral infection is poorly defined, however. In this study, we show that CCR7 expression alters memory CD8 T-cell homeostasis following lymphocytic choriomeningitis virus infection. Greater numbers of CCR7-deficient memory T cells were formed and maintained compared with CCR7-sufficient memory T cells, especially in the lung and bone marrow. The CCR7-deficient memory T cells also displayed enhanced rates of homeostatic turnover, which may stem from increased exposure to IL-15 as a consequence of reduced exposure to IL-7, because removal of IL-15, but not of IL-7, normalized the numbers of CCR7-sufficient and CCR7-deficient memory CD8 T cells. This result suggests that IL-15 is the predominant cytokine supporting augmentation of the CCR7−/− memory CD8 T-cell pool. Taken together, these data suggest that CCR7 biases memory CD8 T cells toward IL-7–dependent niches over IL-15–dependent niches, which provides insight into the homeostatic regulation of different memory T-cell subsets.
National Acad Sciences