Scientists uncover SARS-CoV-2-specific T cell immunity in recovered
COVID-19 and SARS patients

Date:
July 16, 2020
Source:
Duke-NUS Medical School
Summary:
The T cells, along with antibodies, are an integral part of the
human immune response against viral infections due to their ability
to directly target and kill infected cells. A Singapore study has
uncovered the presence of virus-specific T cell immunity in people
who recovered from COVID-19 and SARS, as well as some healthy
study subjects who had never been infected by either virus.



FULL STORY ==========================================================================
The study by scientists from Duke-NUS Medical School, in close
collaboration with the National University of Singapore (NUS) Yong Loo Lin School of Medicine, Singapore General Hospital (SGH) and National Centre
for Infectious Diseases (NCID) was published in Nature. The findings
suggest infection and exposure to coronaviruses induces long-lasting
memory T cells, which could help in the management of the current pandemic
and in vaccine development against COVID-19.


==========================================================================
The team tested subjects who recovered from COVID-19 and found the
presence of SARS-CoV-2-specific T cells in all of them, which suggests
that T cells play an important role in this infection. Importantly, the
team showed that patients who recovered from SARS 17 years ago after the
2003 outbreak, still possess virus-specific memory T cells and displayed cross-immunity to SARS-CoV-2.

"Our team also tested uninfected healthy individuals and found SARS-CoV-2- specific T cells in more than 50 percent of them. This could be due to
cross- reactive immunity obtained from exposure to other coronaviruses,
such as those causing the common cold, or presently unknown animal coronaviruses. It is important to understand if this could explain why
some individuals are able to better control the infection," said Professor Antonio Bertoletti, from Duke- NUS' Emerging Infectious Diseases (EID) programme, who is the corresponding author of this study.

Associate Professor Tan Yee Joo from the Department of Microbiology
and Immunology at NUS Yong Loo Lin School of Medicine and Joint Senior Principal Investigator, Institute of Molecular and Cell Biology,
A*STAR added, "We have also initiated follow-up studies on the COVID-19 recovered patients, to determine if their immunity as shown in their T
cells persists over an extended period of time. This is very important
for vaccine development and to answer the question about reinfection."
"While there have been many studies about SARS-CoV-2, there is still a lot
we don't understand about the virus yet. What we do know is that T cells
play an important role in the immune response against viral infections
and should be assessed for their role in combating SARS-CoV-2, which has affected many people worldwide. Hopefully, our discovery will bring us a
step closer to creating an effective vaccine," said Associate Professor
Jenny Low, Senior Consultant, Department of Infectious Diseases, SGH,
and Duke-NUS' EID programme.

"NCID was heartened by the tremendous support we received from many
previous SARS patients for this study. Their contributions, 17 years
after they were originally infected, helped us understand mechanisms
for lasting immunity to SARS-like viruses, and their implications for developing better vaccines against COVID-19 and related viruses," said
Dr Mark Chen I-Cheng, Head of the NCID Research Office.

The team will be conducting a larger study of exposed, uninfected subjects
to examine whether T cells can protect against COVID-19 infection or
alter the course of infection. They will also be exploring the potential therapeutic use of SARS-CoV-2-specific T cells.


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


========================================================================== Journal Reference:
1. Nina Le Bert, Anthony T. Tan, Kamini Kunasegaran, Christine
Y. L. Tham,
Morteza Hafezi, Adeline Chia, Melissa Hui Yen Chng, Meiyin
Lin, Nicole Tan, Martin Linster, Wan Ni Chia, Mark I-Cheng
Chen, Lin-Fa Wang, Eng Eong Ooi, Shirin Kalimuddin, Paul
Anantharajal Tambyah, Jenny Guek-Hong Low, Yee-Joo Tan, Antonio
Bertoletti. SARS-CoV-2-specific T cell immunity in cases of
COVID-19 and SARS, and uninfected controls. Nature, 2020; DOI:
10.1038/s41586-020-2550-z ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/07/200716101536.htm

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