Did you know that your body is not only composed of ‘you?’ It’s true!
Our bodies act as a ‘host’ to many different types of microbes, including bacteria, viruses and even fungi. Sometimes our bodies are at war with microbe invaders – like when we get food poisoning from eating a microbe that was an unwanted ‘passenger’ on the food. Most of the time though, these microbes are part of our micriobiome and live peacefully within us. The microbes generally help our bodies thrive by processing nutrients from food or helping our immune systems discern which microbes are helpful or harmful.
Kyla Ost, PhD, is a researcher at the University of Colorado Anschutz Medical Campus who looks at how one particular fungus, Candida albicans, can shift from a harmless round shape into an elongated sword-like, pathogenic form that can cause serious inflammation and disease in the intestines. Scientists have found out that between 40% to 80% of all people live with C. albicans in their intestines, and most of the time C. albicans stays in its round shape because our immune systems effectively eliminate the more destructive form. However, sometimes C. albicans shifts into the pathogenic form and grows out of control, wreaking havoc as it invades the intestinal walls, causing illnesses including thrush, vaginal yeast infections and chronic inflammatory bowel disease (IBD).
Immune system keeps this fungus in check
Ost’s research focuses on how the immune system keeps this fungus from causing harm in our bodies, particularly our gastrointestinal system. A specific type of immune cell, the B cell, is a key player in limiting growth of the sword-shaped C. albicans. B cells are a type of immune cell that produce antibodies, or Y-shaped molecules, that act like arrows that bind to their target and alert other immune cells that the tagged enemy needs to be eliminated. Experiments in Ost’s lab have shown that mice without B cells have a lot more sword-shaped C. albicans in their intestine than those retaining their B cells. This difference tells us that B cells are very important and help keep the levels of disease-causing C. albicans in check.
In another experiment, Ost’s research team used a vaccine that causes B cells to make antibodies specifically against the sword-shaped form of C. albicans and found the treatment protected mice from severe inflammation associated with IBD. This exciting result suggests that vaccination could be used to increase the amount of protective antibodies and prevent the harmful form of C. albicans from causing IBD.
Scientists in Ost’s lab are exploring even more questions related to C. albicans and the immune response. Examples of questions being investigated are:
- How do B cells and antibodies keep sword-shaped albicans in check?
- How does the albicans vaccine protect mice from disease-causing inflammation?
- How do C. albicans and other microbes living in our bodies stimulate antibody responses in the first place?
Guest contributor: Kyla Ost, PhD, is an assistant professor in the Department of Immunology/Microbiology at the University of Colorado School of Medicine.
