Changes in T-lymphocyte subsets in lungs and spleens of mice with slowly progressive primary mycobacterium tuberculosis infection: involvement of unconventional T-cell subsets.
Our previous study showed that the cell-activation responses and cytokine-secretion patterns were different in lungs and spleens of mice with slowly progressive primary Mycobacterium tuberculosis infection. The aim of the present study was to characterize the T-cell subsets in lungs and spleens of mice with a similar infection. The percentages of T-cell subsets were determined by flow cytometry and the absolute numbers were calculated. Spleens of infected mice showed a threefold expansion of CD4+ cells but no change in CD8+ cells, whereas lungs had a threefold increase of both subsets. A significant expansion of CD4-CD8-alphabeta+ [double negative (DN)alphabeta+] subsets was observed in the lungs of infected mice compared with uninfected mice. This was not the case in the spleens of infected mice. In infected mice the CD4-CD8- (DN) population preferentially expressed alphabeta-T-cell receptors (TCR) in the lungs but gammadelta-TCR in the spleens. The percentages of many T-cell subsets were significantly higher in the lungs than in the spleens of both uninfected and infected mice. However, the percentages of CD4+ and CD4-CD8+TCR- subsets in the lungs were significantly lower than in the spleens of infected mice. We also observed some previously unreported T-cell subsets: double positive-TCR- (DPTCR-), DPalphabeta+ and DPgammadelta+. So far their functions are unknown.
Phyu
S
S
Centre for International Health; Broegelmann Research Laboratory, Haukeland University Hospital, Bergen, Norway.
Sornes
S
S
Mustafa
T
T
Tadesse
A
A
Jonsson
R
R
Bjune
G
G
D000818:Animals; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D008168:Lung / Q000276:immunology*; D051379:Mice; D009169:Mycobacterium tuberculosis / Q000276:immunology; D013154:Spleen / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000145:classification / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology*