Screening And Preliminary Evaluation Of New Anti-tubercular Agents And Construction Of Recombinant Mycobacterium Smegmatis Displaying SIV Gag On The Surface

Tuberculosis (TB) remains one of the world’s deadliest pandemic diseases. The emerence and spread of drug-resistance together with co-infection with human immunodeficiency virus (HIV), have intensified an urgent need for new anti-TB drugs discovery. The traditional model for screening anti-TB drugs is not only slow but expansive. In nearly four decades no new anti-TB drugs have emerged. Herein, we tested 5k a potential anti-tuberculosis drug showing both in vitro and in vivo efficiency by using new anti-TB drug screening models developed by our lab. The same batch of samples can be monitored continuously in this model both in vitro and in vivo without adding any substrate and the activity of a compound can be decided in 3-5 days, showing high sensitivity, besides easily replicable.The compound 5k was effective in vitro against selectable marker-free autoluminent Mycobacterium tuberculosis H37Ra (UAIRa) and exhibited promising in vitro potency with nanomolar minimum inhibitory concentration (MIC) values against the wild type laboratory Mycobacterium tuberculosis H37Rv strain and a panel of clinically isolated multidrug-resistant(MDR) Mycobacterium tuberculosis strains.The compound significantly reduces the bacterial burden in an UAIRa infected mouse model, suggesting its promising potential to be a compound for future anti-tubercular drug discovery.In the past 30 years, the search for a HIV vaccine has been elusive. This part of the study addresses the development of a safe and effective HIV vaccine since the emergence of AIDS. In recent past, the search for the vaccine has seen tactical shift to gear towards avaccine inducing multiple immune responses in vivo. It is aimed at reducing the viral load and transmission by inducing antibodies to neutralize the virus and cellular immune response to clear the viral-infected cells. Since sexual transmission is the primary transmission route, a mycobacterium vaccine vector inducing strong mucosal immunity response is hence an attractive strategy in HIV vaccine development. Previous work using HIV-1 Env antigen by recombinant Mycobacterium smegmatis demonstrated induction of effective long-term mucosal immune response when the expressed antigen was displayed on the membrane than when introduced in the cytoplasm. We postulate reduction in the viral load when the immune response is targeted on Gag rather than the Env antigen. So in this experiment, we construct vaccines for HIV by recombinant new avirulent Mycobacterium smegmatis vector expressing SIV Gag antigen using and comparing three different surface display systems.