title: 1,25-dihydroxyvitamin D3 and development of tuberculosis in cattle.
abstract: This report describes the presence and activity of 1,25-dihydroxyvitamin D3 (1,25-D3) in experimental bovine tuberculosis. Animals that went on to develop tuberculous lesions exhibited a rapid transient increase in serum 1,25-D3 within the first 2 weeks following infection with Mycobacterium bovis. 1,25-D3-positive mononuclear cells were later identified in all tuberculous granulomas by immunohistochemical staining of postmortem lymph node tissue. These results suggest a role for 1,25-D3 both at the onset of infection and in the development of the granuloma in these infected animals. Using a monoclonal antibody to the vitamin D receptor (VDR) as a VDR agonist, we confirmed that activation of the vitamin D pathway profoundly depresses antigen-specific, but not mitogenic, bovine peripheral blood T-cell responses (proliferation and gamma interferon production). Investigation of the mechanism of this suppression showed that the VDR antibody modified the expression of CD80 by accessory cells, such that a significant positive correlation between T-cell proliferation and accessory cell CD80 emerged.
authors: TB Research Group, Veterinary Laboratories Agency, Addlestone, Surrey KT15 3NB, United Kingdom.
authors: S G
authors: SG
authors: Rhodes
authors: L A
authors: LA
authors: Terry
authors: J
authors: J
authors: Hope
authors: R G
authors: RG
authors: Hewinson
authors: H M
authors: HM
authors: Vordermeier
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000032:analysis; D002117:Calcitriol / Q000032:analysis* / Q000502:physiology*; D002417:Cattle; D006099:Granuloma / Q000209:etiology; D007963:Leukocytes, Mononuclear / Q000737:chemistry; D008198:Lymph Nodes / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology; D009163:Mycobacterium bovis; D013601:T-Lymphocytes / Q000276:immunology; D014380:Tuberculosis, Bovine / Q000378:metabolism*
chemical_list: D018122:B7-1 Antigen; D002117:Calcitriol