A group from Nebraska Center for Virology, University of Nebraska-Lincoln, NE 68583, USA has reported about a new lectin found from shiitake exosomes.
https://www.mdpi.com/1999-4915/16/10/1546
Exosomes from fifteen local common vegetables were isolated by ultracentrifugation. These exosomes were evaluated for their antiviral activities against SARS-CoV-2 infection using an in vitro pseudovirus platform.
Their cytotoxicity using the standard MTT method indicated that all fifteen samples did not show significant cytotoxicity in a concentration of 1 × 10^10/mL exosomes. The antiviral activities of shiitake exosomes exhibited the lowest EC50 value 5.2 × 10^8/mL.
From the proteomic analysis of the exosomes, it was found that a lectin (named Shictin) of shiitake exosomes Contributed to the Antiviral Activities and exhibited strong activity against the SARS-CoV-2 Omicron variant with an IC50 value of 87 nM. It was also found that shictin is a C-type lectin and binds to GlcNAc.