The 65 kDa protein of Mycobacterium habana and its putative role in immunity against experimental tuberculosis

Abstract

Summary Mycobacteria including Mycobacterium tuberculosis and Mycobacterium leprae possess multiple antigens some of which inhibit other anti-mycobacterial immune responses. Whole cell vaccines are not free from these suppressive molecules and may adversely affect the immunogenic response(s). Purified protein components having only immunogenic properties should prove to be superior vaccine(s). Mycobacterium habana, a candidate vaccine for mycobacterial infections has been dissected for analysing its antigenic myriad. A 65 kDa protein of this mycobacterium has been isolated and characterized for its protective and celJ mediated immune responses. The protein was isolated in pure form using an isotachophoresis (SDS-PAGE filtration) technique and identified with low molecular weight markers along with mAb using the immunoblot technique. Mab IIH9 has identified a 65 kDa protein in M. habana. This protein has been found to be immunoprotective in mice against M. tuberculosis H37RV infection. It generates high levels of DTH responses in mice against M. tuberculosis and M. leprae antigens and inhibits migration of sensitized cells under the antigenic influence of homologous and heterologous origin. Possibilities of developing this protein as a subunit vaccine are discussed in this report.

Analysis of lipids reveals differences between ‘Mycobacterium habana’ and Mycobacterium simiae

“…habana' TMC 5135 and several M. simiae strains differ in glycopeptidolipid (GPL) composition. This fact, together with a renewed interest in the study of 'true ' strains of ' M. habana ' as a candidate vaccine against tuberculosis and leprosy (Singh et al, 1989(Singh et al, , 1995(Singh et al, ,1997, led us to carry out a comparative analysis of some representative lipids of both bacteria, work so far not undertaken. Moreover, since the synonymy was established, no other phenotypic features have been defined in 'M.…”

Evaluation of integral membrane antigens ofMycobacterium habanafor serodiagnosis of extrapulmonary tuberculosis: association between levels of antibodies andMycobacterium tuberculosisantigens

“…In the present study antimycobacterial antibodies were detected in extrapulmonary tuberculosis patients by ELISA using non‐tubercular antigens. The antigens used were of M. habana TMC 5135, which in earlier experiments have shown antigenic closeness with M. tuberculosis [12–17]. Antigens were recovered from the detergent phase by treating the membrane fraction with Triton X‐114.…”

“…The rationale behind using the antigens of M. habana in the diagnosis of tuberculosis was its antigenic closeness with M. tuberculosis as evident from the following observations: (a) similarity in the protein profiles of the two strains [13] and (b) reactivity of M. habana antigens with TB patients’ sera [14] and TB 23, a monoclonal antibody against the 19 kDa antigen of M. tuberculosis which possesses limited cross‐reactivity [12]. Most importantly, appreciable protection was provided by the whole cell [12,15] or fractionated cellular [16] and secretary [17] antigens of M. habana against the virulent challenge of M. tuberculosis in experimental animals.…”

Evaluation of integral membrane antigens of Mycobacterium habana for serodiagnosis of extrapulmonary tuberculosis: association between levels of antibodies and Mycobacterium tuberculosis antigens

“…The rationale behind using the antigens of M. habana in the diagnosis of tuberculosis was its antigenic closeness with M. tuberculosis as evident from the following observations: (a) similarity in the protein pro¢les of the two strains [13] and (b) reactivity of M. habana antigens with TB patients' sera [14] and TB 23, a monoclonal antibody against the 19 kDa antigen of M. tuberculosis which possesses limited cross-reactivity [12]. Most importantly, appreciable protection was provided by the whole cell [12,15] or fractionated cellular [16] and secretary [17] antigens of M. habana against the virulent challenge of M. tuberculosis in experimental animals.…”