Science subjournal: strategically deployed mucosal tissue resident T-cell army can fight against virus infection and cancer

December 28, 2019 / Biovalley BIOON / - -- the immune system has a strong immune response to infection, vaccines and cancer, but until now, scientists have fully begun to explain how the non circulating T cell population residing in the human "mucosal barrier tissue" can prevent the threat Although the academic attention to the non circulating T cells in mucosal tissue seems to be a mysterious research field, it is the lifeblood of Dr Martin Plic's Laboratory of Fred Hutchinson Cancer Research Center in the United States There, Plic and his team are particularly interested in the function of T cells in an inflammatory environment Infectious diseases are notorious causes of inflammation Equally important in the study of the pulic laboratory is the inflammatory environment, which is synonymous with a variety of cancers It turns out that there are a lot of T cells in the human body, which stick to their posts in the mucosa, and they will not deviate from these local compartments These mucosal tissues can be found in vulnerable entrances (mouth, anus and vagina) and other important areas where disease exposure and inflammation may occur In a new study, the team focused on a receptor called CCR5 +, and confirmed that even if this T cell component is inhibited, the T cells in the mucosal compartment still perform their full function to resist infection and prevent cancer Relevant research results were recently published in the Journal of Science Translational Medicine, and the title of the paper is "the human tissue resident CCR5 + T cell department maintains protective and functional properties during information" Scanning electron micrograph of human T cells from the immune system of healthy donors The picture is from NIAID The team explained that there are many kinds of T cells in the mucosa In addition, during the treatment with CCR5 + inhibitors, a group of anti-inflammatory drugs, these T cells remained in place to maintain immunity in the body's mucosal barrier Plic's team's experiment helped solve the paradox of how CCR5 + inhibitors can interfere with disease and inhibit inflammation without affecting mucosal barrier immunity This new study opens a new window to understand not only what happens when inflammation is inhibited, but also how T cells can stably resist infection or cancer on the "site" of mucosal barrier tissue "Our data show that the human CCR5 + tissue resident memory T cell compartment can maintain mucosal barrier immunity in function and space," the team wrote The mucosal barrier is the first line of defense - the physical barrier in the immune system that provides immune protection Mucosal barriers have been identified as some of the most effective and elegant forms of nature's bioengineering For example, Dr Kenneth E.L McColl of the University of Glasgow, UK, who was not involved in the new study, wrote in 2012 that the gastric mucosal barrier "is an example of excellent natural engineering" because it has to withstand the most adverse chemical environment of highly acidic and proteolytic gastric juice, which can rapidly kill the ingested microorganisms and decompose the ingested food " McColl presented his views on mucosal barrier tissue in BMJ journal Resident T cells have also been found in the cervix and vagina, which are potential entrances to viral pathogens, especially HIV and herpes simplex virus The T cells that reside in the mucosal barrier tissue are important because they are noncircular and provide local defense against the virus, said pollic and colleagues The full name of CCR5 + is chemokine receptor 5, which can activate the cell receptor on the surface of T cells and coordinate the migration of immune cells to the inflammatory site in vivo Studies have shown that drugs that inhibit CCR5 +, such as maraviroc, an HIV treatment drug, can be reused to treat a variety of other medical diseases In fact, clinical trials have been carried out to study the potential of malavero and similar drugs to fight multiple medical diseases "Clinical trials using CCR5 antagonists include studies to prevent graft-versus-host disease and cancer metastasis, but their clinical application may extend to other inflammatory mediating diseases," Pryc and colleagues wrote in the new study The results of phase 1 and phase 2 clinical trials for graft-versus-host disease seem promising, indicating that CCR5 + antagonist therapy is an effective treatment to prevent the migration of immune cells to inflammatory sites " The researchers found that although CCR5 + inhibitors block a receptor that is important for immune cell migration, it is surprising that these drugs have little or no negative effect on the immune function of patients in the mucosal barrier, such as oral mucosa or other parts of the body To determine why, the team studied the T-cell population in the blood and oral mucosa of healthy subjects They observed that 65% of T cells expressed CCR5 + and accumulated in or near the inner wall of mucosal barrier tissue This new study shows that even in inflamed mucosal tissue, this T cell population remains stable and highly diverse, consisting of several types of helper and regulatory T cells The team also looked at live rectal tissue samples from 10 healthy subjects treated with malavero and observed that the treatment did not disrupt the tissue resident T cell population expressing CCR5 in the mucosal tissue The significance of these results, they add, is that patients who lack tissue resident T cells may be more vulnerable to mucosal barrier immunity damage during treatment with CCR5 inhibitors They concluded that "the presence of human tissue in the CCR5 T cell compartment remains protective and functional during inflammation." (BIOON Com) reference: 1 Amanda S Woodward Davis et al The human tissue resident CCR5 + T cell Department maintenances protective and functional properties during information Science Translational Medicine, 2019, doi:10.1126/scitranslmed.aaw8718 2.New Insights: Armies of strategically stationed T cells fight viral infections, cancer https://medicalxpress.com/news/2019-12-insights-armies-strategically-stationed-cells.html