Expression of CCR7 and CD45RA by cord blood T cells. Cord blood mononuclear cells from healthy and congenitally Trypanosoma cruzi-infected newborns were stained with (a) anti-CD8, anti-CD45RA, anti-CCR7 or with (b) anti-CD8, anti-CD45RA, anti-CCR7 and either anti-NKG2A or a pool of anti-killer-cell immunoglobulin-like receptors (KIR) monoclonal antibodies (CD158a, CD158b, CD158e and CD158k). Scatter plots represent the proportion of CCR7+/− CD45RA+/− cells among (a) CD8+ T cells from uninfected or T. cruzi-infected newborns or (b) KIR+ CD8+ and NKG2A+ CD8+ T cells from T. cruzi-infected newborns. Horizontal bars show the medians (n = 3–7). A statistically significant difference was observed in the proportion of naive CCR7+ CD45RA+ CD8+ T cells between total CD8+ T cells of uninfected and T. cruzi-infected newborns (*P < 0·01). P-values were calculated using Wilcoxon matched pair test.