Hyderabad: In a new development, the Centre for Cellular and Molecular Biology (CCMB) has developed stable cultures of the novel coronavirus taking samples from COVID-19 patients. The researchers at CCMB are of the opinion that this virus culturing will help towards further drug testing and vaccine development against COVID-19.
Virus culture refers to a laboratory technique in which samples of a virus are placed on different cell lines, to test whether the virus is able to infect them. In the context of the COVID-19 pandemic, the researchers mentioned the challenges involved in developing this particular virus culture. The respiratory disease in the infected patients, is caused by the infected epithelial cells, that bind with the ACE-2 receptors. (ACE-2 receptor is the host cell receptor responsible for mediating infection by SARS-CoV-2, the novel coronavirus responsible for COVID-19). However, these epithelial cells cannot be grown in a lab.
“Currently, primary epithelial cells generated from human origins do not grow for many generations in labs, which is key to culturing viruses continuously. At the same time, the labs that are growing the virus need an ‘immortal’ cell line”, says Dr Krishnan H Harshan, Principal Scientist, CCMB. They use Vero cells (kidney epithelial cell lines from green African monkey), which express ACE-2 proteins and carry a cell division that allows them to proliferate indefinitely.
Cultivating the novel coronavirus through virus culture and inactivating them will help in the development of an inactivated virus vaccine. “Once we inject the inactivated virus, the human immune system triggers the production of germ-specific antibodies. One can inactivate the virus by heat or chemical means. The inactivated virus can trigger antibody response, but does not infect and make us sick as they cannot reproduce.,” the researcher said.
“Using the Vero cell lines to grow the coronavirus, CCMB is now in a position to isolate and maintain viral strains from different regions. We are working towards producing viruses in huge quantities that can be inactivated, and used in vaccine development and antibody production for therapeutic purposes”, says CCMB Director, Dr Rakesh Mishra. CCMB has also started testing potential drugs with other partners such as the Defence Research Development Organisation (DRDO) using this viral culture.