T cell regulation of Bacteroides fragilis-induced intraabdominal abscesses.
Intraabdominal abscesses (IAA) caused by Bacteroides fragilis are a major sequela to colonic spillage into the peritoneum. The development of an animal model that closely reproduces the disease observed in humans permitted careful inspection of the cellular and/or humoral contributions to the development and control of this disease. The results obtained thus far describe an immunoregulatory T cell circuit that governs both the development of and the immunity against these abscesses. T cells of CD4+8+ phenotype induce the development of IAA in response to B. fragilis. CD8+ T cells generated in response to immunization with the B. fragilis capsular polysaccharide confer protection against the development of IAA. These cells elaborate an antigen-specific factor that mediates the observed protection by these cells. Moreover, a third type of T cell, a CD8+ cell that is also present in nonimmune individuals, is required for the immune T cell or its factor to confer protection. Thus, in the specific disease process of IAA induced by the encapsulated microorganism B. fragilis, immunity proceeds by cellular and not humoral mechanisms.
Channing Laboratory, Brigham and Women's Hospital, Boston, Massachusetts 02115.
J H
JH
Crabb
R
R
Finberg
A B
AB
Onderdonk
D L
DL
Kasper
D000038:Abscess / Q000276:immunology*; D000818:Animals; D001442:Bacteroides Infections / Q000276:immunology*; D001441:Bacteroides fragilis / Q000276:immunology*; D004195:Disease Models, Animal; D010532:Peritoneal Diseases / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*