Page 11 - Covid Newsletter 11_10

Schematics describing experimental protocols for SARS-CoV-2 spike-pseudovirus transduction assay
therapeutic strategies. Here, researchers from InStem demonstrate that the receptor binding domain (RBD) of SARS-CoV-2 spike protein is internalised via the pH-dependent CLIC/ GEEC (CG) endocytic pathway in human gastric-adenocarcinoma (AGS) cells expressing undetectable levels of ACE2. Ectopic expression of ACE2 (AGS-ACE2) results in RBD traffic via both CG and clathrin-mediated endocytosis. Endosomal acidification inhibitors like BafilomycinA1 and NH4Cl, which inhibit the CG pathway, reduce the uptake of RBD and impede Spike-pseudoviral infection in both AGS and AGS-ACE2 cells. The inhibition by BafilomycinA1 was found to be distinct from Chloroquine, which neither affects RBD uptake nor alters endosomal pH yet attenuates Spike-pseudovirus entry. By screening a subset of FDA- approved inhibitors for functionality similar to BafilomycinA1, they identified Niclosamide as a SARS-CoV-2 entry inhibitor. Further validation using a clinical isolate of SARS-CoV-2 in AGS- ACE2 and Vero cells confirmed its antiviral effect. Researchers propose that Niclosamide, and other drugs which neutralise endosomal pH as well as inhibit the endocytic uptake, could provide broader applicability in subverting infection of viruses entering host cells via a pH- dependent endocytic pathway.
Website link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8297935/pdf/ppat.1009706.pdf
IIT Bombay studies severity of COVID-19 infection
Researchers from the Indian Institute for Technology Bombay (IIT Bombay) and Kasturba Hospital for Infectious Diseases, Mumbai, led by Prof Sanjeeva Srivastava of IIT Bombay, have found that levels of specific proteins in the nasopharyngeal samples of a person can differentiate
VOL. IV ISSUE 12
VIGYAN PRASAR 7
COVID-19 SCIENCE & TECHNOLOGY EFFORTS IN INDIA