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.
Saunders
B M
BM
Mycobacterial Research Laboratories, Department of Microbiology, Colorado State University, Fort Collins, Colorado 80523, USA. saunders@cvmbs.colostate.edu
Frank
A A
AA
Cooper
A M
AM
Orme
I M
IM
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