Distribution and activation of T-lymphocyte subsets in tuberculous bovine lymph-node granulomas.
The immune response against mycobacterial infections is dependant upon a complex interaction between T lymphocytes and macrophages in the context of the granuloma. For this study, we performed the analysis of 18 stage I or II, and 13 stage III or IV granulomas found in lymph nodes from 8 experimentally and 2 naturally infected cattle. T-cell subpopulations (CD3(+), CD4(+), CD8(+), WC1(+), CD25(+)) were investigated by immunohistochemistry. In the majority of stage I/II lesions, CD8(+) and CD25(+) cells were predominantly found in the lymphocytic outer region of the granuloma, suggesting a possible role for activated CD8(+) cells in the initial attempt to restrain the granuloma growth. CD4(+) T cells appeared equally distributed in the lymphocytic mantle and in the internal areas of the granulomas. WC1(+) cells appeared interspersed among the macrophages. We speculated that this could indicate a role for these 2 subsets in the maintenance and the maturation of the granuloma. In stage III/IV lesions, all of the T-cell subsets investigated appeared interspersed among the mononuclear component of the granulomas. In general terms, there was a higher density of CD8(+) cells compared with CD4(+) cells. However, there was no sense of rimming effect for any of the investigated cell populations.
Liebana
E
E
Department of Pathology, Veterinary Laboratories Agency-Weybridge, Addlestone, KT15 3NB Surrey, England, UK. E.liebana@VLA.defra.gsi.gov.UK
Marsh
S
S
Gough
J
J
Nunez
A
A
Vordermeier
H M
HM
Whelan
A
A
Spencer
Y
Y
Clifton-Hardley
R
R
Hewinson
G
G
Johnson
L
L
D000818:Animals; D002417:Cattle; D006099:Granuloma / Q000382:microbiology / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D008213:Lymphocyte Activation / Q000502:physiology*; D008297:Male; D016176:T-Lymphocyte Subsets / Q000502:physiology*; D014380:Tuberculosis, Bovine / Q000473:pathology*