COVID-19: RIKEN pays attention to A24 leukocytes: 60% of Japanese have
RIKEN:
We investigated the new corona for “the type of white blood cells that 60% of Japanese have”.
Immune cells against the “seasonal coronavirus that causes the common cold”
found that it also reacts to the new coronavirus.
Found at the cell experiment level:
At the cell experiment level,
Immune cells against the seasonal coronavirus (cold),
Also against the new coronavirus (COVID 19).
This time, it was clarified that there is cross-immunity.
It may be one of the “factors that Japanese people have few severely ill people with new coronavirus”.
Pay attention to Japanese “A24” white blood cells:
The research team focused on the leukocyte type “A24” that 60% of Japanese people have.
Take out the blood cells of this type of person,
Part of the virus spike protein,
The peptide “QYI” was administered.
As a result, we found that killer T cells became active and proliferated.
New Corona Research in Japan:
There is a view that “the number of new Japanese corona patients who become severely ill or die is small.”
Research to find the cause is currently underway.
Nihon Keizai Shimbun
https://www.nikkei.com/article/DGXZQOUC103YT0Q1A211C2000000/
Has a killing effect on the new coronavirus: memory immune killer T cells
RIKEN:
A collaborative research group has succeeded in identifying memory-immune killer T cells that have a killing effect on the new coronavirus.
-Human leukocyte antigen (HLA), which is common in Japanese
Combine to type HLA-A * 24: 02,
In the S protein of SARS-CoV-2,
We have succeeded in identifying the epitope.-Antiviral effect of memory immune killer T cells
Memory immune killer T cells against seasonal coronavirus
Cross-recognize this epitope
Shows antiviral effect against SARS-CoV-2.-Effects of cross-reactive killer T cells
“Many healthy people with HLA-A * 24: 02” have this cross-reactive killer T cell.
On the other hand, it was found that there are few patients with hematopoietic tumors (cancer patients).
-Hotspots for hematopoietic tumor patients (cancer patients)
But even in patients with hematopoietic tumors
Can efficiently induce killer T cells,
We found that there are “hot spots” where the epitopes are concentrated.
It was identified for the first time in the world.
Stimulating SARS-CoV-2 infected cells with this hotspot epitope
“Memory immune killer T cells against sleeping seasonal coronavirus” respond extremely well.
main research:
It was published in the online version of the scientific journal “Communications Biology” (December 2nd).
RIKEN
https://www.riken.jp/press/2021/20211208_1/index.html
Identification of TCR repertoires in functionally competent cytotoxic T cells cross-reactive to SARS-CoV-2
Communications Biology (IF6.268), Pub Date : 2021-12-02, DOI: 10.1038/s42003-021-02885-6
SARS-CoV-2-specific CD8+ T cells are scarce but detectable in unexposed healthy donors (UHDs).
It remains unclear whether pre-existing human coronavirus (HCoV)-specific CD8+ T cells are converted to functionally competent T cells cross-reactive to SARS-CoV-2.
Here, we identified the HLA-A24-high binding, immunodominant epitopes in SARS-CoV-2 spike region
that can be recognized by seasonal coronavirus-specific CD8+ T cells from HLA-A24+ UHDs.
Cross-reactive CD8+ T cells
were clearly reduced in patients with hematological malignancy, who are usually immunosuppressed, compared to those in UHDs.Furthermore, we showed that CD8+ T cells in response to a selected dominant epitope display multifunctionality and cross-functionality across HCoVs in HLA-A24+ donors.
Cross-reactivity of T-cell receptors isolated from them exhibited selective diversity at the single-cell level.
Taken together, when stimulated well by immunodominant epitopes, selective pre-existing CD8+ T cells with high functional avidity may be cross-reactive against SARS-CoV-2.