Consistent with this hypothesis, mice that received a higher inoculum of PbA had increased concentrations of BALF IgM at day 6 post-infection (Figure 6A; Kruskal-Wallis test with Dunn's multiple comparison test, 1×106 vs. 1×105 PE: p<0.05) corresponding with elevated circulating parasitemias (Figure 6B; Kruskal-Wallis test with Dunn's multiple comparison test, 1×106 vs. 1×105 PE: p<0.05). The gene discussed is CD40LG; the disease is parasitic infectious disease.