CD4 and CD8 T_Ms selectively require the expression of α4β7 or CCR7 for their formation and maintenance. (A) Tissue accumulation of MP CD4 and CD8 T_Ms (gated as CD4⁺CD25⁻CD44^hi and CD8⁺ TCRβ⁺CD44^hi, respectively) in 10-month-old CCR7KO or β7KO mice. Data are presented as mean ± SEM (n = 4). (B) Comparison of CD4 and CD8 T_M number in PLN and PP of 10-month-old wild-type (WT), CCR7KO and β7KO mice. Data are presented as mean ± SEM (n = 4). (C) Study of the influence of CCR7 or β7 deficiency on CD4 and CD8 T_M formation using BLI. Either MFG-labeled CD4 T_Es (5 × 10⁶) or CD8 T_Es (1 × 10⁶) of the indicated genotype were adoptively transferred into albino B6 recipient mice. Representative BLI images and total body luminescence (TBL) measurements of the indicated recipients (mean ± SEM, n = 4) 1 month after transfer are shown.