A groundbreaking collaborative discovery recently published in Nature involving researchers at the Research Institute of the McGill University Health Centre is shedding new light on host-microbe relationships.

While most microbiome studies have examined how commensal bacteria shape our health scientists in Irah King’s lab at The Institute have contributed to the identification of the first true commensal fungus in laboratory mice a species of yeast called Kazachstania pintolopesii (Kp). This fungus stably colonizes and dominates the mouse intestinal tract can be passed on to offspring and triggers an immune response that significantly increases resistance to intestinal helminth infections parasitic worms that affect millions of people worldwide.

Led by Iliyan Iliev PhD, at Weill Cornell Medical College in New York City the study reveals how commensal and pathogenic fungi shape intestinal immunity and opens up new opportunities to study host-fungus interactions. Most significantly it shows that Kp enhances type 2 immune responses most commonly associated with allergy and parasitic worm infection.

The experiments we performed in our lab have shown that when the intestinal barrier is disrupted Kp colonization significantly enhances resistance to intestinal helminth infection says Irah King PhD, Senior Scientist in the Translational Research in Respiratory Diseases Program at The Institute and co-author of the study. This is a very atypical response as fungi usually induce a type 3 immune response which is associated with fungal killing but is also implicated in autoimmune diseases such as multiple sclerosis and rheumatoid arthritis.

Prior to this work researchers lacked a reliable model for studying fungal commensalism because most fungi only transiently colonize the mouse gut. Our collaborative discovery provides an indispensable new model organism for understanding host-fungal interactions and their impact on the immune response to infection. This is particularly valuable because fungi are an often overlooked but crucial component of the intestinal ecosystem across all life forms adds Prof. King also Professor in the Department of Microbiology and Immunology at McGill University.

This discovery opens up a number of new research opportunities. For example understanding how Kp enhances anti-helminth immunity could inform the development of novel therapeutic strategies. Moreover characterizing Kazachstania colonization in the human microbiome may help predict and understand human immune activation in other disease contexts such as asthma.

The King Lab team is now investigating how early-life Kp colonization may influence long-term immune development and disease susceptibility. It is also seeking potential connections between Kp colonization and human health outcomes in collaboration with scientists and clinicians from the McGill Centre for Microbiome Research studies that could inform therapeutic approaches for both helminth infections and immune-mediated disorders.

Source: https://healthenews.mcgill.ca/discovery-of-a-commensal-fungus-that-shapes-anti-parasite-and-allergic-immune-responses/