Cryptosporidium species are protozoan parasites that cause severe diarrhea in immunocom
promised individuals and children, especially in developing countries. This study investigated 
the roles of IFN-γ and IL-4 in controlling Cryptosporidium infections in neonatal mice. Mice 
were grouped into four groups: normal control, infected control, infected/anti-IFN-γ mAb 
treated, and infected/anti-IL-4 mAb treated groups. Fecal assessments for C. parvum oocysts, 
cytokines detection, histopathological evaluations, and gene expression investigations for IL
4 and IFN-γ were conducted.  
The results showed a 22% mortality rate was among the infected anti-IFN-γ mAb-treated 
mice (11%) and anti-IL-4 mAb-treated ones (6%). Infected mice showed significantly higher 
IFN-γ levels than controls. The anti-IFN-γ & anti-IL-4 treated ones raised serum cytokines 
with blocked biological activity by compensatory responses. The increase in IFN-γ secretion 
in infected mice attempted to overcome infection correlated with oocyst counts, histopathol- 
ogical, and gene expression changes. But, a negative correlation was between oocyst shedd- 
ing and IFN-γ levels in serum as well as intestinal expression implying the IFN-γ role in infe- 
ction control. Consequently, neutralization with anti-IL-4 mAb increased oocyst shedding 
early in cryptosporidiosis, clarifying the IL 4 role in early infection control.