Attempts to understand the SARS-CoV-2 virus have focused on a key mechanism of action: the use of a “spike protein” to interact with and gain entry to cells in the body, which enable the virus to replicate and grow. This protein has been the focus of many treatments for COVID-19; for example, some existing COVID-19 vaccines work to help the body create a similar protein and develop an effective immune system response should someone become infected with the SARS-CoV-2 virus.
However, researchers at the NYU Grossman School of Medicine and Perlmutter Cancer Center at NYU Langone Health have identified increasing evidence of a new therapeutic need: that this “spike” also interacts with different elements of the immune system. This interaction may be responsible for triggering immune system overreactions, such as a cytokine storm, a potential reason COVID-19 patients become critical or die.
According to researchers, the SARS-CoV-2 virus’s spike protein usually interacts with a protein called angiotensin-converting enzyme 2 (ACE2) in lung cells; however, this protein is largely absent in immune system cells, despite increasing evidence that the virus’s spike interacts with these cells.
In the study published in Immunity, researchers identified 6 potential new proteins in immune cells that were found to interact with the virus’s spike protein. Specifically, researchers found that myeloid cells, an important type of white blood cell, were more frequently targeted by the virus spike protein.
In response, researchers used “nanobody” technology, or small pieces of an antibody, which are potentially easier to synthesize than full antibodies. Researchers designed these nanobodies to help block interaction between the virus’s spike protein and myeloid cells.
"Our study will change how the field thinks about mechanisms behind COVID-19, demonstrating that viruses can directly reprogram immune cells with potentially deadly consequences," says co-first study author Qiao Lu, PhD.
The research team plans to take their nanobodies to pre-clinical and clinical trials to better understand their potential benefit for patients with severe COVID-19.
Source: PR Newswire