Effects of Cryptosporidium protozoa on intestinal stem cells (2013)

Undergraduate: Amit Amin

Faculty Advisor: Scott Magness
Department: Biology

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Cryptosporidium protozoa are prone to infect the intestinal epithelium causing diarrhea which can be lethal for individuals with weakened immune systems. TheCryptosporidium parasites infect and reproduce in epithelial cells (enterocytes) that reside on villi of the small intestine. Residing in the crypts of the intestine areintestinal epithelial stem cells (IESCs) which are essential for intestinal regeneration. Proliferation of epithelial cells depends on the Wnt signaling pathway and is critical for recovery from Cryptosporidium infection. Cryptosporidiumare known to secrete IFN-a/ β which are thought to inhibit the Wnt signaling pathway by preventing necessary transcriptional activation. To test the hypothesis, varying concentrations of IFN-a/ β was added to crypts in culturefrom mice with a wild-type or a knock-out IFN-a/ βreceptor. Significantly less proliferation was expected to be seen in crypts from the wild-type IFN-a/ β receptor mice. The study not only confirmed the initial hypothesis but it also displayed that as the concentration of IFN-a/ βincreased, cell death increased. By understanding the mechanism behind the Cryptosporidium infection, more specific treatments can be produced.