BENGALURU: Researchers from the IISc have designed a new method to deliver a vaccine candidate for tuberculosis (TB). It involves using spherical vesicles secreted by bacteria coated on gold nanoparticles, which can then be delivered to immune cells. This can potentially trigger an immune response and offer protection against the disease. The only effective vaccine currently in use is the BCG vaccine, which contains a weakened form of the disease-causing bacterium. When injected into the bloodstream, it triggers the production of antibodies that can help fight the disease. While the BCG vaccine works well in children, it is not as effective at protecting adolescents and adults.
This prompted Rachit Agarwal, assistant professor at the Centre for BioSystems Science and Engineering, IISc, and his group to develop a potential subunit vaccine candidate that contains only parts of the infectious bacterium to stimulate an immune response. “They’re safer compared to live bacterium, and since they are membrane-derived, they contain all kinds of antigens,” Agarwal explained.
Subunit vaccines typically only contain a limited number of antigens – bacterial proteins that can elicit an immune response in the host. By contrast, Outer Membrane Vesicles contain a variety of antigens and can induce a better immune response,” researchers said. The study also explained that immune cells cultured in the lab were treated with OMVs derived from Mycobacterium smegmatis, a related bacterial species that does not cause disease in humans.