Cloning and expression of a cell wall associated protein gene of Mycobacterium tuberculosis

Genomic library of Mycobacterium tuberculosis (SIHV) was constructed into T7 promoter based vector pBluescript II KS (+/-) in Escherichia coil. The expression of mycobacterial antigens from recombinants was detected by immunoscreening using E-coli-preabsorbed hyperimmune rabbit anti-M tuberculosis cell wall associated proteins serum. Among 980 clones tested by immunoscreening, a clone pJJ5 was found to produce mycobacterial antigen. This clone was further characterized by immunoblotting and found to produce a 36 kDa of cell wall associated antigen Detection of antibodies response to this antigen in the serum of the majority of the individuals with tuberculosis indicates that this antigen is capable of stimulating a humoral immune response.