T cells from seropositive dogs show signs of activation through decreased CCR7 and CD62L expression. T cells from twenty seropositive and twenty seronegative Argentinian dogs were stained with antibodies for CCR7, CD62L, and CTL2.58, an activation marker. A-B. Histograms of CCR7, CD62L, and CTL2.58 expression and dot plots of CCR7 and CD62L co-expression on CD8+(A) and CD4+(B) T cells. Numbers indicate percentages of either CD8+ or CD4+ cells expressing CCR7 (C, G), CD62L (D, H), CCR7 and CD62L (E, I), or the activation marker, CTL2.58 (F, J). Statistical significance was determined by one-way ANOVA using Prism v4.0c (GraphPad). ** designates p < 0.001.