Passive and Acquired Immunity to Cryptosporidiosis in Bangladeshi Children
Cryptosporidiosis is a leading cause of diarrheal illness in children worldwide; however there are limited therapies and no available vaccine for this protozoal infection. With support from an NIH K23 career development award, I am studying the natural history of cryptosporidiosis in a birth cohort of children in Bangladesh as a means to understand human immune responses to the infection. We have found that 40% of children in this cohort are infected with Cryptosporidium spp. by age one, and I have discovered that anti-cryptosporidium breast milk IgA is associated with protection from Cryptosporidium spp. infection in breastfeeding infants. One aim of the study is to elucidate the mechanism by which breast milk may interfere with infection, using a novel in vitro parasite invasion assay. A second aim is to describe the phenotype and functional capacity of stimulated immune cells to evaluate whether a robust cell-mediated response to Cryptosporidium spp. can predict protection from recurrent infection. Determining the role of passive and active immunity in protection from cryptosporidiosis will inform immunization strategies aimed to prevent Cryptosporidium spp. infection in young children.