Related Experiment Video
Updated: Jul 20, 2026

An Intestinal Gut Organ Culture System for Analyzing Host-Microbiota Interactions
Published on: June 30, 2021
A primitive T cell-independent mechanism of intestinal mucosal IgA responses to commensal bacteria
A J Macpherson1, D Gatto, E Sainsbury
1Institute of Experimental Immunology, Universitätsspital, Schmelzbergstrasse 12, CH8091, Zürich, Switzerland. amacpher@pathol.unizh.ch
Abstract:
The immunoglobulin A (IgA) is produced to defend mucosal surfaces from environmental organisms, but host defenses against the very heavy load of intestinal commensal microorganisms are poorly understood. The IgA against intestinal commensal bacterial antigens was analyzed; it was not simply "natural antibody" but was specifically induced and responded to antigenic changes within an established gut flora. In contrast to IgA responses against exotoxins, a significant proportion of this specific anti-commensal IgA induction was through a pathway that was independent of T cell help and of follicular lymphoid tissue organization, which may reflect an evolutionarily primitive form of specific immune defense.
Related Concept Videos
Cell-mediated Immune Responses
Defense Mechanism Against Infection
In addition, many body organ systems have unique defenses against infection. The skin is an intact, multilayered surface preventing invasion by microorganisms unless impaired. Mucous membranes lining the mouth, nose, and eyelids are barriers...
Antigens Involved in Adaptive Immunity
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Defense Against Bacterial Pathogens
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Microbiota of the Stomach and Small Intestine
Functions of the Gut Microbiota

