CD4 and parasitic infectious disease: However, T cell-specific Ac ablation had no impact on the course of P. yoelii infection as Ac CD4cre KO (Asah1/Cd4cre/+) and Ac CD4cre WT (Asah1/Cd4+/+) mice showed similar spleen weights and parasitemia 7 and 14 days p.i. (Figure 3B).