Microbiota prime leukocyte response for intestinal innate immunity

Abstract

The number of microbiota in the intestinal lumen is overwhelmingly larger than the total number of an individual‘s cells. This alludes to a significant contribution of the microbiota to the life of an individual, particularly priming the immune system. The diverse microbiota antigens are encountered by leukocytes that drive non-specific innate immunity. While these leukocytes are insensitive to harmless agents in terms of inciting inflammatory response, they respond to noxious agents by immediately destroying and eliminating them from the body. This is done through phagocytosis, granulocytosis, degranulation to release enzymes and inflammatory mediators, antigen presentation, and activation of adaptive immune system. These functions are influenced by microbiota whose disruption impairs the optimal functioning of leukocytes and predisposes the intestine to diseases like allergy, inflammatory bowel diseases, and irritable bowel syndrome. Maneuvers that restore disrupted microbiota benefit patients with these diseases. Gaining insight into the microbiota-leukocyte crosstalk and its subsequent role in maintaining intestinal immunity is pivotal to designing medicaments against microbiotal dysbiosis-mediated illnesses.

Key words: Microbiota, natural killer cells, innate lymphoid cells, mast cells, eosinophils, intestinal innate immunity