Original Research ARTICLE
Influenza activated ILC1s contribute to anti-viral immunity partially influenced by differential GITR expression
- 1Vaccinology and Microbiology, Helmholtz Centre for Infection Research (HZ), Germany
- 2Center for Infectious Medicine, Department of Medicine, Karolinska Institute, Sweden
Innate lymphoid cells (ILCs) represent diversified subsets of effector cells as well as immune regulators of mucosal immunity and are classified into group1 ILCs, group 2 ILCs and group 3 ILCs. Group 1 ILCs encompass NK cells and non-NK ILCs (ILC1s) and mediate their functionality via the rapid production of IFN-γ and TNF-α. The current knowledge of ILC1s mainly associates them to inflammatory processes. Much less is known about their regulation during infection and their capacity to interact with cells of the adaptive immune system. The present study dissected the role of ILC1s during early influenza A virus (IAV) infection, thereby revealing their impact on the antiviral response. Exploiting in vitro and in vivo H1N1 infection systems, a cross-talk of ILC1s with cells of the innate and the adaptive immunity was demonstrated, which contributes to anti-influenza immunity. A novel association of ILC1 functionality and the expression of the glucocorticoid-induced TNFR-related protein (GITR) was observed, which hints towards a so far undescribed role of GITR in regulating ILC1 responsiveness. Overexpression of GITR inhibits IFN-γ production by ILC1s, whereas partial reduction of GITR expression can reverse this effect, thereby regulating ILC1 functionality. These new insights into ILC1 biology define potential intervention targets to modulate the functional properties of ILC1s, thus contributing towards the development of new immune interventions against influenza.
Keywords: influenza, ILC1, regulation, GITR, Cross-talk
Received: 21 Apr 2017;
Accepted: 26 Feb 2018.
Edited by:Carsten Watzl, Leibniz Research Centre for Working Environment and Human Factors (LG), Germany
Reviewed by:Ali Ellebedy, Washington University in St. Louis, United States
Chiara Romagnani, Deutsches Rheuma-Forschungszentrum (DRFZ), Germany
Copyright: © 2018 Vashist, Trittel, Ebensen, Chambers, Guzman and Riese. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Peggy Riese, Helmholtz Centre for Infection Research (HZ), Vaccinology and Microbiology, Braunschweig, Germany, Peggy.Riese@helmholtz-hzi.de