Effect of blocking TNF-α on intracellular BCG (Bacillus Calmette Guerin) growth in human monocyte-derived macrophages

Abstract Four agents, thalidomide, oxpentifylline, dexamethasone and a polyclonal anti-TNF-α antibody, were all shown by specific Elisa to block endogenous TNF-α production by Bacillus Calmette Guerin (BCG)-infected human monocyte-derived macrophages in in vitro culture. There was however no significant enhancement of intracellular BCG growth, over a 7-day incubation, in human monocyte-derived macrophages in the presence of any of the TNF-α-blocking agents, as determined by both radiometric and CFU counting methods of assessing bacterial viability and growth. The result suggests that the action of TNF-α alone is unlikely to be an important effector mechanism in antimycobacterial immunity within human cells.