a, Phenotypic analysis of GP276-specific CD8+ T cells in the spleens of immune mice that had cleared an acute LCMV Armstrong infection or mice that were chronically infected with LCMV clone 13 (day 30 after infection (p.i.)). FACS plots showing CXCR5 expression in combination with the indicated markers are gated on GP276-tetramer+ CD8+ T cells. b, Longitudinal analysis of the numbers of GP276-specific CXCR5+Tim-3− and CXCR5−Tim-3+ CD8+ T cells in the spleen at the indicated time after infection. LCMV titers in the serum are shown as the shaded yellow area. Graph shows the mean ± s.e.m. Data are the average of 8 mice from two experiments per time point (total n = 48). c, Phenotypic characterization of CXCR5+ and CXCR5− GP276-specific CD8+ T cells in the spleen of chronically infected mice (>45 days p.i.).