CD19 and infection: Figure 1.B. shows disparate behaviors among peritoneal lymphocytes. Both T cells (CD3+) and NK cells (pan NK+) number rapidly increased by day 3 pi, peaking at day 5–7 pi (Figure 1.B.). On the contrary, B cells (CD19+) behavior was very different. CD19+ cells number significantly decreased by day 5 pi, and then recovered reaching a 2-fold increase by day 7–9 pi (Figure 1.B.). Overall, these results show that infection by E. granulosus induces significant and early changes mainly in the peritoneal lymphoid compartment of infected mice.