Survival of NK cell-deficient beige mice infected with C. neoformans after administration of mAbs. (A) Beige mice were more susceptible than the parental C57BL/6J strain (P < 0.0001). (B) Average survival times and standard deviations for the IgG1, IgG3, and PBS groups were 40.40 ± 28.12, 8.00 ± 1.70, and 9.80 ± 2.25 days, respectively. The 3E5 IgG1 mAb significantly prolonged survival (P < 0.001), whereas IgG3 did not alter the course of cryptococcal infection (P > 0.05).