Private specificities of CD8 T cell responses control patterns of heterologous immunity

Kim, Sung-Kwon; Cornberg, Markus; Wang, Xiaoting Z.; Chen, Hong D.; Selin, Liisa K.; Welsh, Raymond M.

An example of the kinetics of the host response to VV in LCMV-immune mice is given in Fig. 1 D, which shows a mouse with a preferential NP205 response. Of note is that the frequencies of total CD8 T cells and of T cells specific to each LCMV epitope were reduced at day 4 after infection. This is to be expected, as the level of protection against viral replication during heterologous immunity is insufficient to prevent the challenge virus from inducing cytokines that cause across-the-board apoptosis and lymphopenia of memory T cells (21) (22) (23) . By day 7, the percentage of NP205-specific T cells had increased from the day 4 time point, representing a marked increase in cell number from the day 0 time point, considering the substantial increase in the percent of CD8 T cells overall. These increases were similarly reflected at day 12, the chosen day for the previous assays.