Candida albicans induces internalization of the Na + -K + -2Cl – cotransporter 1 expressed in Madin-Darby Canine Cells
Dr. Patrice Bouyer
Cell Biology Research
Candida albicans (C. albicans) is one of the most common human fungal pathogens, causing life threatening systemic infections in critically ill and immunocompromised patients. In the gut, fluid secretion participates in the body defense by flushing microorganisms and by maintaining the surface mucus hydrated. It is still unknown whether C. albicans decreases the host defense mechanism prior to invading intestinal cells. Previous work in the lab has demonstrated that the basolateral Na+ -K+ -2Cl - cotransporter 1 (NKCC1) plays a key role in the regulation of fluid secretion, and internalization of NKCC1 represents a potent pathway to blunt fluid secretion. We hypothesize that C. albicans, before invading intestinal cells, decreases fluid secretion by causing NKCC1 internalization. To test our hypothesis, we utilized Madin-Darby Canine Kidney (MDCK) cells stably expressing eGFP-NKCC1. MDCK were cultured on coverslips in 6 well plate. On the day of the experiment, MDCK were exposed to 50,000 C. albicans, for 15, 30 min,1 and 2 h hours. MDCK were also exposed to 100 nM phorbol 12-myristate 13-acetate (PMA) for 15 min as a positive control for NKCC1 internalization. Coverslips were fixed in 1% paraformaldehyde for 30 min and mounted for fluorescence microscopy. Fluorescent images were acquired using an inverted IX83 Olympus microscope equipped with a CCD camera. Exposing MDCK cells to C. albicans for 15 and 30 min did not result in NKCC1 internalization as compared to 100 nM PMA. Conversely, after 1- and 2-hours exposure to C. albicans, NKCC1 internalization was observed in some cells. Our preliminary experiments suggest that C. albicans induces NKCC1 internalization and may represent one mechanism by which C. albicans lower the intestinal defense mechanism. Gaining a better understanding of how C. albicans invades the mucosal barrier will greatly help developing new strategies for fighting candidiasis.
Zachara, Idalia; Bouyer, Patrice; and Gundelach, George, "Candida albicans induces internalization of the Na + -K + -2Cl – cotransporter 1 expressed in Madin-Darby Canine Cells" (2022). Symposium on Undergraduate Research and Creative Expression (SOURCE). 1044.