Immunological and functional characterization of proteins of the Mycobacterium tuberculosis antigen 85 complex using...

As tuberculosis re-emerges as an important health problem worldwide, new drugs, better diagnostic tests and vaccines are being sought. In order to identify potentially useful peptides for the development of a synthetic vaccine against tuberculosis, immunological and functional studies were performed using proteins of the antigen 85 complex. Western blot (immuno-blot) analysis and a lymphoproliferation study was used to investigate the B- and T-cell immune response of tuberculosis patients, healthy household contacts and normal controls to proteins of the Mycobacterium tuberculosis antigen 85 complex. Peptides derived from the 85A amino acid sequence were synthesized and used in fibronectin-binding and in ELISA assays. A peptide with the sequence CQPACRKAGCQTYKWEC bound to radiolabelled fibronectin in a time-dependent manner and was recognized by human sera in ELISA. This peptide was identified as a potential component of a synthetic vaccine against tuberculosis.