Singh, B. (7405638271)B. (7405638271)SinghSingh, G. (55470623300)G. (55470623300)SinghTrajkovic, V. (7004516866)V. (7004516866)TrajkovicSharma, P. (7403232336)P. (7403232336)Sharma2025-07-022025-07-022003https://doi.org/10.1046/j.1365-2249.2003.02258.xhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-0141539435&doi=10.1046%2fj.1365-2249.2003.02258.x&partnerID=40&md5=db48a7cb4476539608f58b4eb5bc2efchttps://remedy.med.bg.ac.rs/handle/123456789/14395To explore the role of the 10-kDa Mycobacterium tuberculosis-specific secreted antigen (MTSA-10 or CFP-10) in modulation of macrophage function, J774 macrophages were transfected stably with DNA encoding MTSA-10. Compared to normal or mock-transfected controls, MTSA-10-expressing macrophages had markedly lower levels of co-stimulatory molecule B7·1 on their surface, while the expression of B7·2 and ICAM-1 was not affected. MTSA-transfected cells also produced significantly less microbicidal free radical nitric oxide (NO) upon stimulation with interferon (IFN)-γ, lipopolysaccharide or M. tuberculosis cell lysate. Western blot analysis revealed the absence of tyrosine-phosphorylated protein slightly larger than 112 kDa in MTSA-transfected macrophages. Moreover, the treatment of control J774 cells with protein tyrosine kinase inhibitor genistein completely mimicked the effects of transfection with MTSA-10, selectively down-regulating NO and B7·1, but not B7·2 or ICAM-1 expression. The observed MTSA-10-mediated block of B7·1 expression and NO release might contribute to the suppression of antimycobacterial response in tuberculosis.B7·1CFP-10 IFN-γM. tuberculosis MTSA-10MacrophagesNitric oxide