1° M CD8 T cells are not recruited simultaneously after infection.

<p><b>A)</b> Experimental design. CFSE-labeled 1° M Thy1.1 P14 CD8 T cells (2x10⁶ cells/mouse, i.v.) were adoptively transferred into naïve B6 Thy1.2 recipient mice before LCMV infection. A non-infected group of recipient mice served as a control. The expression of <b>B)</b> CD25 and <b>C)</b> CD69 on CFSE-labeled 1° M P14 CD8 T cells isolated from the spleen of mice 24 and 48 hours after infection was determined. Numbers indicate the percentage of cells positive for the indicated molecule. Representative profiles of 3 mice per group are shown. Experiments in panels A-C are representative of 3 independent and similar experiments.