Macrophage MR1 antigen presentation promotes MAIT cell immunity and lung microbiota modulation

Abstract

INTRODUCTION: The immune system consists of cells that detect microorganisms with varying degrees of selectivity. Many cell types react against components found in most viruses or bacteria, whereas only a few among a huge number of T and B lymphocytes react against a specific fragment of an individual pathogen. Mucosal associated invariant T cells (MAIT cells) sit between these extremes. They are abundant but highly specific for vitamin B–derived antigens (VitBAg), small molecules produced only by bacteria and fungi. VitBAg detection enables MAIT cells to “sense” and interact with the healthy microbiome and to respond against pathogens. However, MAIT cells can only detect VitBAg that have be..