Figure 5

Interleukin (IL)-7 promotes differentiation toward memory and effector T cells and cytokine-secreting T-helper cells. The number of naive CD4 T cells (CD44-CD62L⁺) was not significantly altered by IL-7. By contrast, a significant increase in central memory (CD44⁺CD62L⁺) and effector memory (CD44⁺CD62L^-) T cells was found after IL-7 administration (A). IL-7 enhances numbers (and percentages) of CD4 T cells, and of Th1 (interferon (IFN)-g)-, and Th17 (IL-17)-, and Th2 (IL-4)-cytokine-secreting CD4 T cells (B). Increased IFN-g was measured in supernatants from lymph node cells (LNs) of the IL-7-treated mice as compared with those of the PBS-treated mice. Moreover, on collagen type II (CII) restimulation of LNs, increased IL-17 and reduced IL-4 concentrations were measured, as compared with those of PBS-treated mice (C). Statistical differences with PBS group of *P < 0.05, **P < 0.01, and ***P < 0.001.