Cryptosporidium parvum oocytic antigen induces dendritic cell maturation that suppresses Th2 cytokines when co-cultured with CD4+ cells

Abstract

Cryptosporidium parvum is an opportunistic intracellular parasite that causes disease in animal populations such as calves and goats. It is also a significant zoonotic disease globally, causing mild to severe human diarrhea. In immunocompromised animals, calves and lambs, and immunocompromised humans such as AIDS patients, an infection can be life-threatening as no effective treatments are currently available to control infection. The effects of Cryptosporidium parvum antigen (CPA) on dendritic cells (DCs) were investigated. This study examined cytokine secretion and cell surface marker expression on DCs exposed to CPA. Cytokine production in CD4+ cells co-cultured with CPA primed DCs in the presence of anti-CD3 was also measured. CPA induced a significant increase in the production of interleukin (IL)-12p40, IL-10, IL-6, and TNF-α by DCs and enhanced the expression of the cell surface markers TLR4, CD80, CD86, and MHC11. CPA primed DC co-cultured in the presence of anti-CD3 with CD4+ T-cells inhibited the secretion of Th2-associated cytokines, notably IL-5 and IL-13, with no effects on the secretions of interferon (IFN)-γ, IL-2, IL-17, and IL-10. These findings support studies in the literature that CPA can induce the full maturation of DCs that subsequently initiate Th1 immune responses critical to the resolution of C. parvum infection.