Figure 3.

CD4⁺ T_EM cells rapidly migrate to reactive lymph nodes in a CD62P-dependent, CXCR3-independent manner. Adoptively transferred TCR transgenic OVA-specific naive T cells were primed by immunization with an s.c. injection of 10⁶ OVA-pulsed syngeneic LPS-matured DCs. 3 wk later, memory CD4⁺ T cells were enriched from spleens and lymph nodes, and 3 × 10⁶ T cells were injected i.v. into mice in which reactive lymph nodes had been induced 24 h before by injection of 10⁶ syngeneic LPS-matured DCs. Some mice received also an i.p. injection of thioglycolate 48 h before T cell transfer. (a) Relative proportion of DO11.10 CD4⁺ T_CM (CFSE⁻KJ1-26⁺CD62L⁺CD127⁺) and T_EM (CFSE⁻KJ1-26⁺CD62L⁻CD127⁺) cells in the population before transfer and in the indicated organs 12 h after transfer (percentages are shown). (b) Absolute number of DO11.10 CD4⁺ T_EM (KJ1-26⁺CD62L⁻CD127⁺) cells in reactive lymph nodes of mice 20 or 60 min after T cell transfer. (c) Expression of CD62P ligands and CXCR3 (black lines) on gated CD4⁺CD62L⁻ T_EM cells. The gray dashed lines represent background staining. (d) Percentages of T_EM-like cells from wild-type and CXCR3^−/− mice in reactive lymph nodes and spleen 24 h after i.v. injection. T cells were mixed at a ratio of 1:1, and 10⁷ cells were injected in each mouse in which a reactive lymph node was produced by s.c. injection of 3 × 10⁶ mature DCs in the footpad. (e) Absolute number of OT-II CD4⁺ T_EM (Ly5.1⁺CD62L⁻CD127⁺) cells in reactive lymph nodes of wild-type C57BL/6 or CD62P/E double-deficient mice. (f) Absolute number of DO11.10 CD4⁺ T_EM (KJ1-26⁺CD62L⁻CD127⁺) cells in reactive lymph nodes of mice 12 h after injection of blocking antibodies to CD62P or CD62E or of isotype-matched control antibodies. Data are the means ± SD of two or three independent experiments each performed with two mice per condition. p-values were obtained with the Student's t test.