Abstract
Neutralization of tumor necrosis factor alpha (TNF-α) 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-α in the activation of a type 1 T-cell response against Mycobacterium tuberculosis infection.