Figure 4. CD4⁺ T cells are required for generation and maintenance of CD8⁺ T_RM cells in the MCMV-infected brain.

A) Newborn C57BL/6 mice were injected i.p. with 200 PFU of MCMV on PND 1. Starting with PND 2 mice were depleted of CD4⁺ T cells for one month, followed by lymphocyte isolation and analysis. B) Newborn C57BL/6^JHT/JHT mice were injected i.p. with 200 PFU of MCMV on PND 1. One year after perinatal infection, C57BL/6^JHT/JHT mice were CD4⁺ T cell-depleted for one month followed by lymphocyte isolation and analysis. Representative expression of T_RM markers CD69 and CD103 by CD8⁺ T cells is shown.