CD4 and infection: Immunization of mice with a plasmid encoding for this protein induced an IgG2a antibody response, arguing for a CD4+ TH1 response, antigen-specific lymphocyte proliferation, and IFNγ production, as well as protection against oral or intravenous lethal infection with the pathogen, which was dependent on both CD4+ and CD8+ T cells [63,64].