An Investigation of the Memory Response of the Local Immune System to Shigella Antigens.
Abstract
When the mucosal system is appropriately stimulated, the secretory immunoglobulin A response which results can protect the intestine from damage by microorganisms or their toxic products. Our laboratory has found that oral immunization with virulent or avirulent Shigella flexneri can elicit a significant memory mucosal IgA response. In the present studies, we determine the mechanism of initiation of that immune response. We have found that both invasive and noninvasive S. flexneri are taken up by these specialized surface epithelial cells, M cells, and are packaged into vesicles. This explains why both virulent and avirulent S. flexneri are able to stimulate the mucosal immune response. However, we have also found that the virulent M4243 strain is able to replicate within the follicle-associated epithelium and produces ulceration initially in these sites. Therefore, the M cells serve as a double-edged sword. They ingest antigen including live microorganisms from the gut lumen to process this antigen for a secretory IgA response. However, when pathogenic strains which can break out of the vesicles and replicate are ingested, a focal ulceration results with damage to the intestine. To determine the stimulation of specific lymphocytes within the gut-associated lymphoid tissues following uptake of the antigen, we have begun development of an in vitro model system to follow the course of stimulation for S. flexneri antigens.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1987
- Accession Number
- ADA192223
Entities
People
- David F. Keren
Organizations
- University of Michigan