title: Immunotherapeutic potential of recombinant ESAT-6 protein in mouse model of experimental tuberculosis.
abstract: Recent understanding of the pathogenesis of tuberculosis allows the possible application of immunotherapy for the treatment of tuberculosis. Therapies that would upregulate the host antimycobacterial immune response and/or attenuate T-cell suppressive and macrophage-deactivating cytokines may prove to be useful in the treatment of tuberculosis. ESAT6, 6-kDa early secreted antigenic target, is a potent protective antigen and is considered as major target for long-lived memory cells. In the present study the immunotherapeutic potential of ESAT-6 has been evaluated in mouse model of experimental tuberculosis. In the present study the ESAT-6 protein was cloned in Escherichia coli using pET23a(+) plasmid and purified by Ni(2+)-NTA chromatography. Further, the immunotherapeutic potential of the recombinant ESAT-6 (in terms of CFU enumeration in the target organs and histopathological analysis of lungs) was evaluated against experimental tuberculosis. The recombinant ESAT-6 with C-terminal histidine-tag and free N-terminus mimics the natural form of ESAT-6 has been successfully cloned and purified. The recombinant ESAT-6 protein adjuvanted with dimethyl dioctadecylammonium bromide (DDA) moderately reduced the bacterial load in the target organs of infected mice. Further, the formulation (ESAT-6-DDA) was able to act synergistically when given in combination with antituberculosis drugs. This recombinant ESAT-6 showed good immunotherapeutic potential against experimental tuberculosis and can be used as an adjunct to the conventional antituberculosis chemotherapy.
authors.affiliation: Department of Biochemistry, Postgraduate Institute of Medical Education & Research, Chandigarh 160012, India. Electronic address: mirshabir@gmail.com.
authors.forename: Shabir Ahmad
authors.initials: SA
authors.lastname: Mir
authors.affiliation: Department of Biochemistry, Postgraduate Institute of Medical Education & Research, Chandigarh 160012, India.
authors.forename: Indu
authors.initials: I
authors.lastname: Verma
authors.affiliation: Department of Biochemistry, Postgraduate Institute of Medical Education & Research, Chandigarh 160012, India. Electronic address: sadhnabiochem@gmail.com.
authors.forename: Sadhna
authors.initials: S
authors.lastname: Sharma
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000276:immunology; D000995:Antitubercular Agents / Q000627:therapeutic use; D058491:Bacterial Load / Q000187:drug effects; D001426:Bacterial Proteins / Q000008:administration & dosage* / Q000276:immunology; D003001:Cloning, Molecular; D003114:Colony-Forming Units Assay; D003634:DDT / Q000008:administration & dosage / Q000031:analogs & derivatives; D004195:Disease Models, Animal; D004357:Drug Synergism; D004926:Escherichia coli / Q000235:genetics*; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D008168:Lung / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011994:Recombinant Proteins / Q000008:administration & dosage* / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000276:immunology* / Q000628:therapy*
chemical_list: D000942:Antigens, Bacterial; D000995:Antitubercular Agents; D001426:Bacterial Proteins; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D011994:Recombinant Proteins; C000849:bis(p-chlorophenyl)acetic acid; D003634:DDT
keywords: Antituberculosis drugs; Chemotherapy; ESAT-6; Histopathology; Immunotherapy