Study Finds Vaccines May Offer Increased Protection Against New Variants Of Covid

California [US], Dec. 15 (ANI): Researchers have discovered rare natural T cells capable of targeting a protein found in SARS-CoV-2 and a range of other coronaviruses.

The study was published in the “Cell Reports Journal”.

The results suggest that a component of this protein, called viral polymerase, could potentially be added to COVID-19 vaccines to create a longer lasting immune response and increase protection against new variants of the virus.

Most COVID-19 vaccines use some of the spike protein found on the surface of the virus to trick the immune system into making antibodies. However, newer variants, such as delta and omicron, carry mutations on the spike protein, which may make them less recognizable to immune cells and immunization-stimulated antibodies. The researchers said a new generation of vaccines will likely be needed to create a more robust and broad immune response capable of fending off current variants and those that may arise in the future.

One way to do this was to add a fragment of a different viral protein to the vaccines – a protein less prone to mutations than the spike protein and which will activate T cells in the immune system. T cells are equipped with molecular receptors on their surface that recognize fragments of foreign proteins called antigens. When a T cell encounters an antigen recognized by its receptor, it self-replicates and produces additional immune cells, some of which immediately target and kill infected cells and others that remain in the body for decades to fight this disease. same infection if she ever came back.

The researchers focused on the viral protein polymerase, which is found not only in SARS-CoV-2 but in other coronaviruses, including those that cause SARS, MERS and the common cold. Viral polymerases serve as engines that coronaviruses use to copy themselves, allowing infection to spread. Unlike the spike protein, viral polymerases are unlikely to change or mutate, even as viruses evolve.

To determine whether or not the human immune system has T cell receptors capable of recognizing viral polymerase, the researchers exposed blood samples from healthy human donors (collected before the COVID-19 pandemic) to the virus antigen. viral polymerase. They found that certain T cell receptors actually recognized the polymerase. They then used a method they developed called CLInt-Seq to genetically sequence these receptors. Next, the researchers designed T cells to transport these polymerase-targeting receptors, which allowed them to study the receptors’ ability to recognize and kill SARS-CoV-2 and other coronaviruses.

More than 5 million people have died from COVID-19 worldwide. Current vaccines offer significant protection against serious disease, but as new, potentially more contagious variants emerge, researchers have recognized that vaccines may need to be updated – and new findings from UCLA point to a strategy that can help increase long-term protection and immunity. Researchers are currently conducting further studies to evaluate viral polymerase as a potential new vaccine component.

Pavlo Nesterenko, a UCLA graduate student, is the study’s first author; the corresponding author is Dr. Owen Witte, Presidential Chair in Developmental Immunology in the Department of Microbiology, Immunology and Molecular Genetics at UCLA and Founding Director Emeritus of the Broad Stem Cell Research Center.

The research was supported by the Parker Institute for Cancer Immunotherapy, a Ruth L. Kirschstein Institutional National Research Service Award from the National Institutes of Health, and the UCLA WM Keck Foundation COVID-19 Research Award Program. (ANI)