Anti-CD20 antibody treatment did not alter antigen-specific serum immunoglobulin levels compared with control mice, and there were no significant differences in the numbers of lung gamma interferon-positive (IFN-γ+) CD4+, interleukin 4-positive (IL-4+) CD4+, IL-5+ CD4+, and IL-17A+ CD4+ cells between depleted and control mice after infection. This evidence concerns the gene CD4 and infection.