The findings may help in the development of vaccines for future animal-to-human viral diseases-ScienceDaily

In a paper submitted online on January 21, 2022, Clinical research journalThe research team focused on a peptide or protein fragment called S815-827, which is a SARS-CoV-2 spike protein, the target of the two messenger RNA (mRNA) vaccines available in COVID-19. Homolog (equivalent peptide) is a virus of MERS-CoV (a virus that causes Middle East respiratory syndrome, more commonly known as MERS, which is thought to have transmitted humans from camels) and other animal coronaviruses. Found in spiked proteins. Researchers were particularly interested in studying the S815-827 homologue found in bat-hosted coronaviruses, as SARS-CoV-2 is thought to originate from bat seeds. In addition, bat-derived coronaviruses are considered a major threat to future zoonotic diseases (animal-to-human).

Previous research studies investigating various human coronaviruses that cause common cold have identified homologues of the S815-827 peptide (also known as epitopes (proteins or parts of proteins that elicit an immune response)). It has been shown to be by cells that fight infections of the immune system called CD4 + T lymphocytes.

In the first part of the study, researchers at Johns Hopkins Medicine evaluated the T cell response to 38 S815-827 epitopes that received either the Moderna or Pfizer-BioN Tech mRNA vaccine against SARS-CoV-2 twice. .. They found that peptide-specific T cells were produced by 16 (42%) study participants.

“This suggests that a significant portion of the vaccinated population may have T cells that produce an immune response to the epitope,” said a study, a professor of medicine at Johns Hopkins University School of Medicine. Senior author Joel Blankson, Doctor of Medicine, said. .. “This particular peplomer component is thought to play an important functional role in SARS-CoV-2 infection and is unlikely to change due to mutations, especially in animals. If it can be protected from, it is an attractive target for future vaccines. Corona virus that can infect humans. “

CD4 + T lymphocytes are immune system cells, also known as helper T cells. This is to support another type of immune cell, the B lymphocyte (B cell), in responding to viral surface proteins (antigens) such as SARS-CoV-. 2.2. Immature B cells activated by CD4 + T cells are plasma cells that produce antibodies that mark the body for discarding infected cells, or live antigens for a faster response to future infections. It becomes one of the memory cells that “remembers” the chemical structure. Therefore, the CD4 + T cell response serves as a measure of how well the immune system responds to the vaccine and produces humoral immunity.

The mRNA vaccine recognizes the SARS-CoV-2 spike protein and provides genetic instructions to the human immune system to initiate the production of antibodies against the virus.

Researchers recognize and respond to epitope-specific T cells, as S815-827, a highly stable component of the SARS-CoV-2 peaplomer, may be a more specific target for future vaccines. I wanted to see if it was) S815-827) What was found in vaccinated study participants behaves like the homologous peptides found in other coronavirus peplomer proteins.

“We were able to use lymphocytes from study participants to grow a series of T cells that only recognize and respond to S815-827 and its homologs,” says Blankson. “Then, we used various tests to see if these T cells recognize many bat coronavirus epitopes, which is the greatest risk of causing another disease that can be transmitted to humans. Is recognized as. “

The results excited the research team, says Blankson.

“We have found that T cells provoke an immune response against most of the bat’s coronavirus,” says Blankson. “This is our hypothesis that current mRNA vaccines may elicit a T-cell response that can mutually recognize the bat coronavirus and thus induce some protection against future zoonotic outbreaks. I support. “

In another experiment, the team showed that the S815-827 homologue of MERS-CoV and feline coronavirus also induce epitope-specific CD4 + T cell activity, Blankson says. “This finding, coupled with the main finding that epitope homologues of many bat coronaviruses stimulate the immune response, means that one day it may be possible to develop a multivalent vaccine that can protect against a wide range of animal coronaviruses. I will, “says Blankson.

This study is supported by the Johns Hopkins COVID-19 Vaccine-Related Research Fund, Bloomberg-Kimmel Cancer Chemotherapy Laboratory, President of Johns Hopkins University, COVID-19 Pneumonia Immune Virus Landscape-ARDS: IVAR Study and Three Grants I did. From the National Institutes of Health (NIH): NIH Cancer Center Support Grant P30 CA006973, Grant U54CA260492, Grant R37CA251447.

Along with Blankson, members of the Johns Hopkins Medical Research Team are lead author Bezawolde Meskel and co-authors Arbor Daichema, Caroline Garris, and Kelly Smith. Research co-author of City University of New York Hunter College is Saphira Cherfils.

Blankson, Dykema, and Smith have applied for patent protection for a subset of the technologies described in this study. Smith receives commercial research funding from Bristol Myers Squibb, AstraZeneca, and Enarabio, and travel support and honor from Illumina.

All other research authors report no conflict of interest.