PRF1 and infection: Infected Prf1-/- mice mounted higher-titer IgM (Fig 3A), IgG (Fig 3B), IgG1 (Fig 3C) and IgG2a (Fig 3D) antibody responses against T. brucei AnTat 1.1 components present in 0.5% NP40 lysate than infected intact mice during the first 30 days after infection, as shown by ELISA.