Gut T cell-independent IgA responses to commensal bacteria require engagement of the TACI receptor on B cells

The gut mounts secretory immunoglobulin A (SIgA) responses to commensal bacteria through nonredundant T cell-dependent (TD) and T cell-independent (TI) pathways that promote the establishment of mutualistic host-microbiota interactions. SIgAs from the TD pathway target penetrant bacteria, and their...

Full description

Saved in:

Bibliographic Details
Published in:	Science immunology Vol. 5; no. 49
Main Authors:	Grasset, E K, Chorny, A, Casas-Recasens, S, Gutzeit, C, Bongers, G, Thomsen, I, Chen, L, He, Z, Matthews, D B, Oropallo, M A, Veeramreddy, P, Uzzan, M, Mortha, A, Carrillo, J, Reis, B S, Ramanujam, M, Sintes, J, Magri, G, Maglione, P J, Cunningham-Rundles, C, Bram, R J, Faith, J, Mehandru, S, Pabst, O, Cerutti, A
Format:	Journal Article
Language:	English
Published:	United States 31-07-2020
Subjects:	Animals B-Lymphocytes - immunology Bacteria - genetics Gastrointestinal Microbiome Gastrointestinal Tract - immunology Gastrointestinal Tract - microbiology Immunity, Mucosal Immunoglobulin A - genetics Immunoglobulin A - immunology Mice Mice, Inbred C57BL Mice, Knockout RNA, Ribosomal, 16S - genetics T-Lymphocytes Transmembrane Activator and CAML Interactor Protein - immunology
Online Access:	Get more information
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The gut mounts secretory immunoglobulin A (SIgA) responses to commensal bacteria through nonredundant T cell-dependent (TD) and T cell-independent (TI) pathways that promote the establishment of mutualistic host-microbiota interactions. SIgAs from the TD pathway target penetrant bacteria, and their induction requires engagement of CD40 on B cells by CD40 ligand on T follicular helper cells. In contrast, SIgAs from the TI pathway bind a larger spectrum of bacteria, but the mechanism underpinning their production remains elusive. Here, we show that the intestinal TI pathway required CD40-independent B cell-activating signals from TACI, a receptor for the innate CD40 ligand-like factors BAFF and APRIL. TACI-induced SIgA responses targeted a fraction of the gut microbiota without shaping its overall composition. Of note, TACI was dispensable for TD induction of IgA in gut-associated lymphoid organs. Thus, BAFF/APRIL signals acting on TACI orchestrate commensal bacteria-specific SIgA responses through an intestinal TI program.
ISSN:	2470-9468
DOI:	10.1126/SCIIMMUNOL.AAT7117