Unconventional T cells in severe COVID-19 patients could predict disease outcome

Date:
September 4, 2020
Source:
Rockefeller University Press
Summary:
Researchers in France have discovered that patients suffering from
severe COVID-19 show changes in a class of immune cells known as
unconventional T cells. The study suggests that monitoring the
activity of these cells in the blood of patients could predict
the severity and course of the disease.



FULL STORY ========================================================================== Researchers in France have discovered that patients suffering from severe COVID-19 show changes in a class of immune cells known as unconventional T cells. The study, published today in the Journal of Experimental Medicine (JEM), suggests that monitoring the activity of these cells in the blood
of patients could predict the severity and course of the disease.


========================================================================== While most people infected with the SARS-CoV-2 virus experience relatively
mild symptoms, some patients mount an aberrant inflammatory response
that can damage the lungs and cause acute respiratory distress syndrome
(ARDS), potentially resulting in the patient's death. However, the immune
cells and inflammatory molecules responsible for ARDS associated with
COVID-19 remain unclear.

Unconventional T cells are a diverse class of immune cells that help
control the response to viral infection and are commonly found in
the lungs and other mucosal tissues in the body. "Despite this, the
role of unconventional T cells in the pathophysiological process of SARS-CoV-2-driven ARDS has not yet been explored," says Christophe Paget,
a researcher at the INSERM Research Center for Respiratory Diseases,
University of Tours.

Paget and colleagues, including co-lead author Youenn Jouan, an
intensivist at the academic hospital of Tours, examined 30 patients
admitted to intensive care with severe COVID-19 and compared the immune
cells in their blood and lungs to those found in healthy volunteers or
patients admitted to the ICU for reasons other than COVID-19.

The researchers found that two types of unconventional T cells -- known
as mucosal-associated invariant T (MAIT) and invariant natural killer T
(iNKT) cells -- were dramatically reduced in the blood of patients with
severe COVID- 19. However, the number of MAIT cells increased in the
patients' airways, suggesting that these cells might move from the blood
to the lungs to control the response to SARS-CoV-2 infection.

The MAIT and iNKT cells of COVID-19 patients appeared to be highly
activated and produced distinct sets of inflammatory molecules. The
researchers found that patients whose circulating MAIT and iNKT cells were particularly active at the time of their admittance to the ICU were less susceptible to hypoxemia (low blood oxygen levels) and were discharged
sooner than patients whose MAIT and iNKT cells were less active.

"This suggests that MAIT and iNKT cells might play a beneficial role
during severe COVID-19, although their precise functions and associated mechanisms require further investigation," says Jouan.

"Altogether, our findings should encourage further studies on MAIT
and iNKT cells in SARS-CoV-2-induced ARDS to assess their potential as biomarkers and/or targets for immune intervention strategies," adds Paget.


========================================================================== Story Source: Materials provided by Rockefeller_University_Press. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Youenn Jouan, Antoine Guillon, Loi"c Gonzalez, Yonatan Perez, Chloe'
Boisseau, Stephan Ehrmann, Marion Ferreira, Thomas Daix, Robin
Jeannet, Bruno Franc,ois, Pierre-Franc,ois Dequin, Mustapha
Si-Tahar, Thomas Baranek, Christophe Paget. Phenotypical and
functional alteration of unconventional T cells in severe COVID-19
patients. Journal of Experimental Medicine, 2020; 217 (12) DOI:
10.1084/jem.20200872 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200904121322.htm

--- up 1 week, 4 days, 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)