Margherita Cantorna PhD

Other areas of research:

The immunoregulatory properties of edible mushrooms.

Peroxisome proliferator activated receptor-gamma and asthma.

Research:

Vitamin D Regulation of the Immune System

The classic functions of vitamin D are in the regulation of bone remodeling and calcium homeostasis. The identification of vitamin D receptors in cells of the immune system sparked the early interest in vitamin D as an immune system regulator. Anecdotal data suggests a link between vitamin D status and the human autoimmune disease multiple sclerosis (MS). Experimentally, vitamin D deficiency exacerbates experimental autoimmune encephalomyelitis (EAE) an animal model of MS. Conversely, vitamin D supplementation prevents and ameliorates symptoms of EAE. The overall goal of the laboratory is to identify and characterize the cellular and molecular targets of vitamin D in the immune system and to therefore understand why vitamin D treatments are effective in EAE. In addition we are interested in identifying other diseases/conditions which might be affected by vitamin D status.

Vitamin D and Th cell function

Helper T (Th) lymphocytes orchestrate the immune mediated attack against self- tissues in EAE. Deletion of Th cells eliminates EAE. Treatments that suppress inflammatory type-1 Th (Th1) cells suppress EAE symptoms as well. Our evidence suggests that vitamin D is inhibiting the development of Th1 cells both directly and indirectly by inducing other cells which suppress Th1 cell development. Based on this information we are testing the hypothesis that one of the mechanisms by which vitamin D suppresses EAE is by regulating the development and function of Th cells.

Vitamin D and multiple sclerosis

Although it is known that human lymphocytes have vitamin D receptors what isn't known is whether vitamin D supplementation of humans will alter immune function. Our collaborator Dr. Cosman has identified a pool of MS patients with low bone density and vitamin D deficiency. She is vitamin D supplementing her patients to try to improve vitamin D status and bone density. Experiments in our laboratory will determine if the T cell function of these patients changes after vitamin D supplementation.

Vitamin D status and inflammatory bowel disease

Inflammatory bowel diseases (IBDs) are immune mediated diseases of unknown etiology affecting the gastrointestinal tract. There are several factors, which suggest that vitamin D status and IBD are linked. The first is the geographical distribution of IBD. IBD is most prevalent in northern climates such as North America and Northern Europe . A major source of vitamin D is from its manufacture via a photolysis reaction in the skin and vitamin D synthesis from sunlight exposure is significantly less in northern climates. The second factor, which links vitamin D and IBD, is diet. Weight loss and vitamin D deficiency occurs in 65-75% of patients diagnosed with IBD. Whether vitamin D deficiency is a cause or an effect of IBD development is not known. We hypothesize and are presently in the process of determining whether vitamin D deficiency will exacerbate experimental IBD and whether supplementation with vitamin D will ameliorate symptoms of IBD.