Profiles of intercellular adhesion molecule-1 (ICAM-1) expression on murine peritoneal macrophages (M phi s) infected with Mycobacterium leprae during cultivation were examined with special reference to the regulatory effects of tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta). When M phi s were infected with M. leprae or stimulated with heat-killed M. leprae at day 0, their ICAM-1 expression, measured in terms of the ratio of M phi s positively stained with anti-ICAM-1 antibody (Ab), rapidly increased, peaking during days 1 to 3 and thereafter fell, returning to the normal level by day 7. The addition of TNF-alpha or anti-TGF-beta Ab inhibited the middle phase (day 7) downregulation of M phi ICAM-1 expression, although the late-phase (day 14) downregulation of ICAM-1 was not prevented by them. M. leprae-infected M phi s released small amounts of TNF-alpha and significant amounts of TGF-beta into the culture medium. This may indicate that M. leprae-infected M phi s produced the majority of TNF-alpha in a membrane-bound form. Alternatively, endogenous TNF-alpha might upregulate M phi ICAM-1 expression even at very low concentrations. In any case, these findings indicate the central roles of TNF-alpha and TGF-beta in the early phase upregulation and the middle-to-late phase downregulation, respectively, of ICAM-1 expression by M. leprae-infected M phi s.
BT - International journal of leprosy and other mycobacterial diseases : official organ of the International Leprosy Association C1 - http://www.ncbi.nlm.nih.gov/pubmed/10407627?dopt=Abstract DA - 1999 Mar IS - 1 J2 - Int. J. Lepr. Other Mycobact. Dis. LA - eng N2 -Profiles of intercellular adhesion molecule-1 (ICAM-1) expression on murine peritoneal macrophages (M phi s) infected with Mycobacterium leprae during cultivation were examined with special reference to the regulatory effects of tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta). When M phi s were infected with M. leprae or stimulated with heat-killed M. leprae at day 0, their ICAM-1 expression, measured in terms of the ratio of M phi s positively stained with anti-ICAM-1 antibody (Ab), rapidly increased, peaking during days 1 to 3 and thereafter fell, returning to the normal level by day 7. The addition of TNF-alpha or anti-TGF-beta Ab inhibited the middle phase (day 7) downregulation of M phi ICAM-1 expression, although the late-phase (day 14) downregulation of ICAM-1 was not prevented by them. M. leprae-infected M phi s released small amounts of TNF-alpha and significant amounts of TGF-beta into the culture medium. This may indicate that M. leprae-infected M phi s produced the majority of TNF-alpha in a membrane-bound form. Alternatively, endogenous TNF-alpha might upregulate M phi ICAM-1 expression even at very low concentrations. In any case, these findings indicate the central roles of TNF-alpha and TGF-beta in the early phase upregulation and the middle-to-late phase downregulation, respectively, of ICAM-1 expression by M. leprae-infected M phi s.
PY - 1999 SP - 36 EP - 45 T2 - International journal of leprosy and other mycobacterial diseases : official organ of the International Leprosy Association TI - Roles of tumor necrosis factor-alpha and transforming growth factor-beta in regulating intercellular adhesion molecule-1 expression on murine peritoneal macrophages infected with M. leprae. UR - http://ila.ilsl.br/pdfs/v67n1a06.pdf VL - 67 SN - 0148-916X ER -