CD4 super(+) effector and memory cell populations protect against Cryptosporidium parvum infection

• Published in: Microbes and infection 2013-08, Vol.15 (8-9), p.599-606
• Main Authors: McNair, Nina N, Mead, Jan R
• Format: Article
• Language: English
• Subjects: Cryptosporidium parvum
• ISSN: 1286-4579
• DOI: 10.1016/j.micinf.2013.04.009

Cryptosporidium parvum is a protozoan parasite that infects the epithelial cells of the small intestine causing diarrheal illness in humans. While T cells are known to be important in resistance and recovery from infection, little has been characterized as to the phenotypic expression of surface effector and memory markers after infection. We used an acute model of infection (C57BL/6 interleukin-12p40), which develops long-standing resistance to re-infection, to characterize expression of different effector and memory cells. Using flow cytometry, we found that heterogeneous populations were generated after infection, consisting of both CD62L super(high) central memory T cells (T sub(CM)) and CD62L super(low) effector memory T cells (T sub(EM)) that were competent to produce the Th type 1 effector cytokine, IFN- gamma . Both CD4 super(+) and CD8 super(+) T sub(CM) and T sub(EM) populations persisted in the absence of infection (up to 60 days post-infection). Additionally, transfer of either CD62L super(low)CD4 super(+) T sub(EM) or CD62L super(high)CD4 super(+) T sub(CM) into naive recipients resulted in a protective response. Taken together, these studies show that distinct subsets of effector and memory CD4 super(+) T cells develop after infection with C. parvum, and mediate protective immunity to re-challenge.