FIG. 2.

Surface marker expression by isolated lung CD4 T cells. (A) In the representative example, lung lymphocytes were stained for CD4 and CD62L cells. CD62L^high (R3) and CD62L^low (R4) cells were further analyzed for the expression of CD44 and CD45RB. (B) Kinetics of effector CD4 cells (CD44^high, CD45RB^mid, and CD62L^low) over the chronic phase of the infection. (C) Kinetics of memory CD4 cells (CD44^high, CD45RB^low, and CD62L^high). Data are expressed as the means ± the standard errors of the means and are from six mice per group per time point, representative of two independent experiments. Open bars, control aged-matched mice; filled bars, infected mice. Statistical significance based on a comparison of control and infected mice is indicated by an asterisk (P < 0.01).