IL-17A-producing resident memory gamma delta T cells orchestrate the innate immune response to secondary oral Listeria monocytogenes infection

ROMAGNOLI PA; SHERIDAN BS; PHAM QM; LEFRANCOIS L; KHANNA KM

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Lugar: Washington DC, USA; Año: 2016

0027-8424

Memory γδ T cells are important for the clearance of Listeria monocytogenes (Lm) infection in the intestinal mucosa. However, the mechanisms by which memory γδ T cells provide protectionagainst secondary oral infection are poorly understood. Here we utilized a recombinant strain of Lm that efficiently invades the intestinal epithelium to show that Vγ4+ memory γδ T cells represent a resident memory (Trm) population in the mesenteric lymph nodes (MLN). γδ Trm exhibited a remarkably static pattern of migration that radically changed following secondary oral Lminfection. The γδ Trms produced IL-17A early after rechallenge, and formed organized clusters with myeloid cells surrounding Lm replication foci only after a secondary oral infection. Antibody blocking studies showed that in addition to IL-17A, the chemokine receptor CXCR3 are both important to enable the local redistribution of γδ Trm cells and myeloid cells specifically near the sites of Lm replication within the MLN to restrict bacterial growth and spread.Our findings support a novel role for γδ Trms in orchestrating protective immune responses against intestinal pathogens.