McMaster Researchers Engineer Red Blood Cells as Vaccine Platform

Researchers in Ontario have successfully re-engineered red blood cells to transport viral agents that mobilize immune cells against COVID-19, findings that could lead to an improved vehicle for vaccine delivery across multiple pathogens.  

The team, comprised of physicists, chemists and immunologists at McMaster University, describe the entirely new approach to vaccination in a recent issue of PLOS ONE.   We take red blood cells and remove everything from the inside. We then attach spike proteins to their outside to mimic a corona virus,” says graduate student Isabella Passos-Gastaldo, a lead author on the paper.

The researchers found that the cells—which they called erythrocyte based virus like particles, or Erythro-VLPs—can be loaded with a large dose of viral proteins but are more likely to be well-tolerated by patients. “Current vaccine delivery methods often cause drastic immune system reactions and have short-lived responses,” says Maikel Rheinstadter, a senior supervisor on the paper and a professor in the Department of Physics & Astronomy at McMaster.

In a pilot mouse trial, seroconversion was observed via enzyme-linked immunosorbent assays (ELISA) 14 days after Erythro-VLPs were administered intravenously.

The researchers first reported this technique in 2020, when they modified red blood cells to deliver drugs throughout the body, which could then target infections or treat catastrophic diseases such as cancer or Alzheimer’s. Their most recent work shows that Erythro-VLPs are an effective way to present the S-protein to the immune system and induce seroconversion.

With a large number of viruses similar to COVID-19 circulating in bats and camels, and the emergence of variants, the possibility of additional outbreaks poses major threats to global public health, according to the authors. “The erythrocyte platform that we present in this work has therapeutic potential and can rapidly be adapted to different variants and viruses by embedding the corresponding antigenic proteins,” according to the authors.