Cell: Reveals that cytokine storms prevent patients with neocyto pneumonia from developing long-lasting immune responses.

!-- webeditor: page title-- August 24, 2020 // the release of a large number of cytokines in --- can lead to some of the most severe symptoms of COVID-19.
When a large number of immune cells release cytokines, this increases inflammation and forms a feedback loop that activates more immune cells, a phenomenon sometimes referred to as cytokine storms.
In a new study, researchers from research institutions such as the Bregan Women's Hospital and the Lagan Institute in the United States point out that some cytokines may also prevent infected people from developing long-term immunity at high levels because infected people are rarely observed to produce the type of B cells needed to produce a lasting immune response.
results were published online August 19, 2020 in the journal Cell under the title "Ross of Bcl-6-expressing T follicular helper cells and germinal centers in COVID-19".
images from CC0 Public Domain.
"We've seen a lot of studies that have shown that immunity to COVID-19 is unsustainable because antibodies decline over time," said Professor Shiv Pillai of the Lagan Institute, co-author of the paper.
study provides a mechanism to explain this lower-quality immune response.
" authors focused on the germinal center --- located in the area of the lymph nodes and spleen, where B cells, the immune cells that produce antibodies, differentiate.
and antibody gene changes are necessary to build immunity against infectious pathogens.
is a structure formed in the lymph nodes and spleen during infection or vaccination.
these structures, B cells, the immune cells that produce antibodies, mature into long-lived "memory" cells.
this process, coupled with controlled mutations in antibody genes, allows the immune system to screen B cells and make them biogenic, which allows them to produce the best antibodies against specific pathogens.
this creates a lifetime "memory" of the pathogen, which can be identified and attacked quickly and effectively when the body is infected again.
if there is no hair center, there are not enough B cells to produce a high-quality antibody response to produce long-term immunity.
in order to form a birth center, B cells rely on the important support of another special type of immune cell called auxiliary T cells.
the authors found that in patients with COVID-19, this particular type of auxiliary T cells were not produced, so B cells were not properly assisted.
they did not find birth centers in patients with acute critical COVID-19. "When we looked at the lymph nodes and spleen of patients who died of COVID-19 --- including some who died shortly after getting sick--- we saw that these birth center structures had not yet formed," said co-author of the
paper, Professor Robert Padera of Bregan Women's Hospital.
we decided to determine why this was the case.
the disease is so new, there are no animal models used to study COVID-19 infections when the authors begin their research," the authors said.
They took inspiration from previous mouse model studies involving other infections, in which infections induced cytokine storms in these mouse models ---a model of malaria mice and a model of a lost bacterial infection in the birth center---
one of the most abundant cytokines released in patients with severe COVID-19 is TNF.
in infected mice, TNF appears to have prevented the formation of birth centers.
in previous cytokine storm models, the birth center was able to form when mice were injected with antibodies that blocked TNF or rejected the TNF gene.
when the authors looked at the lymph nodes of patients who died of COVID-19, they found high levels of TNF in these organs.
led them to conclude that TNF may also be preventing the formation of birth centers in PATIENT-19 patients.
studies have shown that this lack of birth centers occurs in SARS infections," said Pillai, director of the Study Group.
we even think this is happening in some Ebola virus patients, so it's not surprising to us.
also looked at the blood and lymphatic tissue of active infections at different stages of COVID-19.
they found that although the birth center did not form, the B cells were activated and appeared in the blood, which would allow the patients to produce some meso-antibodies.
, "There is an immune response, but it doesn't come from the birth center," Padera said.
," Pillai adds, "if there is no birth center, there is no long-term memory of the original."
" he noted, studies of other coronavirus that cause colds have shown that someone can be infected with the same coronavirus three or four times in the same year.
the authors say that despite these findings, they still believe a successful COVID-19 vaccine could be developed because it should not lead to high levels of cytokine release.
(bioon.com) Reference: 1.Naoki Kaneko et al. Ross of Bcl-6-expressing T follicular helper cells and germinal centers in COVID-19. Cell, 2020, doi:10.1016/j.cell.2020.08.025.COVID-19 cytokine storms may prevent a reed immune response patients who experience cytokine storms make may few memory B cells title !--.