Survival of IFN-γ knockout mice infected with C. neoformans after the administration of mAb. (A) IFN-γ−/− mice were more susceptible than their parental C57BL/6J strain (P < 0.02). (B) Average survival times and standard deviations for the IgG1, IgG3, and PBS groups were 28.20 ± 4.24, 24.40 ± 9.11, and 25.80 ± 11.58 days, respectively. IFN-γ−/− mice were not protected by 3E5 IgG1 (P > 0.1), and IgG3 did not enhance infection (P > 0.1).