Immunological evaluation of tuberculosis (TB) derived-antigen for an effective vaccine development

Abstract

Objective: Tuberculosis (TB) remains a major global health problem and subunit vaccines for the control of the disease. New studies of experimental vaccines in the animal model of TB support interferon-y as a relevant marker for the induction of a protective immune response. In contrast, searching for immunodominant Ags capable of inducing strong interferon-y responses in TB infected individuals may not identify all relevant candidate antigens for inclusion in a novel TB subunit vaccine. Material and methods: The main protective 32 kDa Ag in BCG culture fluids was separated by 491-prep cell and was tested after separation by gel filtration and SDS-PAGE. Ag-32kDa was selected and evaluated with human CD/ and CD8+ cells to produce IFN-y by testing intracellular cytokine in different T-cell subpopulation

using t1ow cytometery. Also, testing extracellular cytokines levels by ELISA and the ability of Ag to proliferate the immune cells. Ag-32kDa was evaluated in vitro proliferative response, cytokine levels and histopathological changes in mice and guinea pigs. Results: The levels of extracellular and intracellular IFN-y were highly significant in TB infected patients when stimulated by 32 kDa Ag and cell proliferation was significally higher than healthy controls. Mice immunized with CF, BCG or 32 kDa Ag exhibited a pronounced cellular reactivity to all components of