Neutralization of tumor necrosis factor alpha suppresses antigen-specific type 1 cytokine responses and reverses the inhibition of mycobacterial survival in cocultures of immune guinea pig T lymphocytes and infected macrophages.

Neutralization of tumor necrosis factor alpha (TNF-alpha) significantly down-regulated antigen-induced lymphoproliferation and the expression of interleukin-12 p40 and gamma interferon mRNA and enhanced the viability of intracellular attenuated and virulent mycobacteria in cocultures of immune T cells and macrophages obtained from Mycobacterium bovis BCG-vaccinated guinea pigs. This suggests the crucial role of TNF-alpha in the activation of a type 1 T-cell response against Mycobacterium tuberculosis infection.