Role of gamma delta T cells in immunopathology of pulmonary Mycobacterium avium infection in mice.
Several studies have shown that gamma delta T cells influence granuloma development after infection with intracellular pathogens. The role of gamma delta T cells in controlling the influx of inflammatory cells into the lung after Mycobacterium avium infection was therefore examined with gene-disrupted mice (K/O). The mice were infected with either M. avium 724, a progressively replicating highly virulent strain of M. avium, or with M. avium 2-151 SmT, a virulent strain that induces a chronic infection. gamma delta-K/O mice infected with M. avium 2-151 SmT showed early enhanced bacterial growth within the lung compared to the wild-type mice, although granuloma formation was similar in both strains. gamma delta-K/O mice infected with M. avium 724 showed identical bacterial growth within the lung compared to the wild-type mice, but they developed more-compact lymphocytic granulomas and did not show the extensive neutrophil influx and widespread tissue necrosis seen in wild-type mice. These data support the hypothesis that isolates of M. avium that induce protective T-cell-specific immunity are largely unaffected by the absence of gammadelta T cells. Whereas with bacterial strains that induce poor protective immunity, the absence of gamma delta T cells led to significant reductions in both the influx of neutrophils and tissue damage within the lungs of infected mice.
Mycobacterial Research Laboratories, Department of Microbiology, Colorado State University, Fort Collins, Colorado 80523, USA. saunders@cvmbs.colostate.edu
B M
BM
Saunders
A A
AA
Frank
A M
AM
Cooper
I M
IM
Orme
D000818:Animals; D002465:Cell Movement / Q000235:genetics / Q000276:immunology; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009162:Mycobacterium avium / Q000254:growth & development / Q000276:immunology* / Q000472:pathogenicity; D009504:Neutrophils / Q000276:immunology / Q000473:pathology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014376:Tuberculosis / Q000235:genetics / Q000276:immunology* / Q000473:pathology*
D016692:Receptors, Antigen, T-Cell, gamma-delta