The infection-induced M2 macrophages expressing Arginase-1 were significantly reduced upon treatment with the PD-L2 antibody (Figure 4f), and infection-inhibited M1 macrophages expressing iNOS were recovered, especially during the late infection period (9–12 weeks post-infection; Figure 4e), in comparison with the infected mice without treatment. This evidence concerns the gene PDCD1LG2 and infection.