| Abstract: | Peripheral blood mononuclear cells (PBMC) were obtained from tuberculosis (TB) patients and Mycobacterium bovis bacillus Calmette-Guerin vaccinated healthy subjects. PBMC were tested for secretion of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-5 (IL-5) and IL-10 in response to complex (whole cells, culture filtrate and cell walls), single secreted (Ag85B, ESAT6, MPT64, PstS and MPT70) and single cytosolic (DnaK, GroES and GroEL) antigens of Mycobacterium tuberculosis. In the absence of antigens, detectable concentrations of TNF-alpha, IFN-gamma and IL-10 were secreted by PBMC of both donor groups, but the concentrations of only IL-10 were significantly higher (P=0.015) in TB patients than in healthy subjects. In the presence of complex antigens, PBMC secreted IFN-gamma and TNF-alpha in response to all three preparations, whereas IL-10 was secreted in response to whole cells and cell walls only. In the presence of single antigens, IFN-gamma was secreted in response to Ag85B, ESAT6 and MPT64 in TB patients and ESAT6 in healthy donors. Except for GroEL and DnaK, single antigens did not induce TNF-alpha and IL-10 secretion from PBMC in either donor group. The secretion of IFN-gamma, but not IL-10, in the presence of Ag85B, ESAT6 and MPT64 supports their potential as subunit vaccine candidates against TB. |
