Science: Significant progress! Enterococcal phage can enhance the efficacy of cancer immunotherapy.

August 29, 2020 / / --- Enterococcus belongs to the genus enterococcus, which is Terrain-positive (G-plus) coli, widely distributed in the natural environment and in the digestive tract of humans and animals, and has previously been considered to be a harmless co-bacterium for humans, but recent studies have confirmed the pathogenicity of enterococcus.
since the 1980s, the occurrence and death rate of serious enterococcal infections have increased significantly.
In aerobic Glucococus, enterococcal is the second only to Staphylococcus an important hospital infection pathogenic bacteria, not only can cause urinary tract infections, skin soft tissue infections, but also cause life-threatening abdominal infections, sepsis, meningococcal and meningitis, due to the inherent resistance and access to enterococcal drugs in the treatment of enterococcal infection failure.
, it is particularly important to study the mechanism and treatment of infection caused by enterococcal pathogenesgic factors and enterococcal bacteria from the molecular level.
intestinal bacteria are involved in training T-cell immune responses, and the intestinal ecosystem affects anti-cancer immune responses.
it has been suggested that intestinal bacteri groups can induce cross-reactivity with tumor-related antigens in symbox-specific memory T cells.
in a new study, researchers from France, Sweden, China, the United States, Canada, Italy, Spain, Denmark, Hungary and the Netherlands found that a class of gut bacteria called enterococci carries phages that regulate the immune response.
phages can be integrated into the genome of enterococcus, called prophages.
they reported microbial antigens that may cross-react with antigens associated with tumor cells.
study was published in the August 21, 2020 issue of the Journal of Science under the title "Cross-reactivity between tumor MHC class I-restricted antigens and an enterococcal bacteriophage."
from Science, 2020, doi:10.1126/science.aax0701.
further, the researchers identified in Enterococcus hirae prophages (prophage) the existence of a major tissue-compatible complex Class I (MHC-I) binding table: TSLARFANI (called TMP1).
the phage TMP protein length of 1506 amino acids, this table corresponds to its amino acid bit point of 187 to 197.
mice carrying hysterectococcals containing protophages can produce TMP-specific H-2Kb restrictive CD8-T lymphocyte reactions while receiving immunotherapy for cyclophosphamide or anti-PD-1 antibodies.
to provide mice with genetically modified bacterial strains that express this TMP prolosis to improve their immunotherapy.
in patients with kidney and lung cancer, the presence of this enterococcal phage in stools and the expression of TMP cross-reactive antigens in tumors were associated with the long-term efficacy of PD-1 blocking therapy.
in melanoma patients, some human T-cells that specifically identify naturally processed melanoma antigen ideotopes appear to be able to recognize microbial peptides.
"molecular mimicry" may represent a cross-reactivity between tumor antigens and microbial antigens.
(bioon.com) Reference: Aurélie Fluckiger et al. Cross-reactivity between tumor MHC class I-restricted antigens and an enterococcal bacteriophage. Science, 2020, doi:10.1126/science.aax0701.