Mucosal Associated Invariant T cells (MAIT) in the human gastric mucosa and blood: Role in <i>Helicobacter pylori </i>infection

Booth, Jayaum S

Friday, July 17, 2015

Grand Hall and Gallery, Ground Floor & 1st Floor (Maritim Hotel)

Jayaum S Booth , Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD

Rosangela Salerno-Goncalves , Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD

Thomas G. Blanchard , Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD

Seema Patil , Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD

Howard A. Kader , Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD

Anca M. Safta , Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD

Lindsay M. Morningstar , Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD

Steven J. Czinn , Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD

Bruce D. Greenwald , Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD

Marcelo Sztein , Department of Medicine, University of Maryland School of Medicine, Baltimore, MD

Mucosal-associated invariant T (MAIT) cells represent a class of antimicrobial innate-like T cells that have been characterized in human blood, liver, lungs and intestine. Here, we investigated, for the first time, the presence of MAIT cells in the stomach of children, adults and the elderly undergoing routine endoscopy and assessed their reactivity to Helicobacter pylori (H. pylori-Hp), a major gastric pathogen. We observed that MAIT cells are present in the lamina propria compartment of the stomach and display a similar memory phenotype to blood MAIT cells. We then demonstrated that gastric and blood MAIT cells are able to recognize and respond to H. pylori-infected macrophage stimulation by producing cytokines (IFNg, TNFa, and IL-17A) and exhibiting cytotoxic activity. Interestingly, we observed that blood MAIT cells frequency in Hp^+ve individuals was significantly lower than in Hp^-ve individuals. However, gastric MAIT cells frequency was not significantly different between Hp^+ve and Hp^-ve individuals, demonstrating a dichotomy between blood and gastric tissues. These results contribute important new information to the understanding of MAIT cell function on peripheral and mucosal tissues and demonstrate that MAIT cells might be important in the host response to H. pylori.

ICMI 2015

F.51 Mucosal Associated Invariant T cells (MAIT) in the human gastric mucosa and blood: Role in Helicobacter pylori infection