CD4 and infection: While naive (CD44loCD62L+) CD4+ T cells predominated in noninfected spleens (58.0% ± 6.0% of naive, 33.6% ± 5.2% of effector, and 4.0% ± 0.4% of memory), the EM (CD44hiCD62L–) population expanded after infection, becoming predominant at 7 dpi and further increasing until 21 dpi (11.0% ± 1.1% of naive, 77.7% ± 1.1% of effector, and 8.9% ± 1.1% of memory).