Immune memory less durable after severe COVID-19, study suggests
Researchers compared results in less-severe and severe COVID-19 cases one
and five months after symptom onset

Date:
December 23, 2021
Source:
University of Texas Health Science Center at San Antonio
Summary:
Patients recovering from severe COVID-19 may have a more
dysfunctional B cell response than patients who had less-severe
COVID-19, a new study suggests.



FULL STORY ========================================================================== Infection-fighting B cells retain better memory of the coronavirus spike protein in University Hospital patients who recover from less-severe
cases of COVID-19 than in those recovering from severe COVID-19, a new
study suggests.

Findings by scientists from The University of Texas Health Science Center
at San Antonio were published Wednesday (Dec. 22) in the journal PLOS ONE.


========================================================================== Evelien Bunnik, PhD, corresponding author of the paper, said the results
hint of subtle differences in the quality of immune response based on
COVID-19 severity. Dr. Bunnik is an assistant professor of microbiology, immunology and molecular genetics at the health science center, also
referred to as UT Health San Antonio.

The study focused on memory B cells that react against the SARS-CoV-2
spike protein. Blood samples were analyzed one month after symptom onset
and five months post-onset. After one month, a significant proportion
of spike-specific B cells were active.

However, samples from eight individuals who recovered from less-severe
disease showed increased expression of markers associated with durable B
cell memory as compared to individuals who recovered from severe disease,
the authors wrote.

The markers include T-bet and FcRL5.

T-bet-positive, spike-specific B cells nearly disappeared from the blood samples five months post-symptom onset, the authors noted. Overall, a more dysfunctional B cell response is seen in severe disease cases, they wrote.

Non-severe cases were defined as not requiring supplemental oxygen
or invasive ventilation, while severe cases needed invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO). "The definition
of severe disease was made based on the need for mechanical ventilation
or ECMO, because this distinguishes the most critical patients, who
are the most likely to develop impaired immune responses," said study
senior author Thomas Patterson, MD, professor and chief of infectious
diseases at UT Health San Antonio who leads COVID-19 care at clinical
partner University Health.

Study participants were enrolled in the Adaptive COVID-19 Treatment Trial (ACTT)-1 or ACTT-2 clinical trials. Samples were from University Health patients co-enrolled in the UT Health San Antonio COVID-19 Repository.

"The increased percentage of B cells associated with long-lived immunity
in non-severe COVID-19 patients may have consequences for long-term
immunity against SARS-CoV-2 re-infection or severity of the resulting
disease," the authors wrote.

Acknowledgments This work was supported by a COVID-19 pilot award from
the UT Health San Antonio Joe R. and Teresa Lozano Long School of Medicine (10009547 to Dr.

Evelien Bunnik). Raphael A. Reyes was supported by Translational Science Training award TL1 TR002647. Data were generated in the Flow Cytometry
Shared Resource Facility, which is supported by UT Health San Antonio,
NIH-NCI P30 CA054174-20 (Mays Cancer Center, home to UT Health San
Antonio MD Anderson) and UL1 TR001120 (Clinical Translational Science
Award grant). The funders had no role in study design, data collection
and analysis, decision to publish, or preparation of the manuscript.

========================================================================== Story Source: Materials provided by University_of_Texas_Health_Science_Center_at_San_Antonio.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Raphael A. Reyes, Kathleen Clarke, S. Jake Gonzales, Angelene M.

Cantwell, Rolando Garza, Gabriel Catano, Robin E. Tragus, Thomas F.

Patterson, Sebastiaan Bol, Evelien M. Bunnik. SARS-CoV-2
spike-specific memory B cells express higher levels of T-bet and
FcRL5 after non-severe COVID-19 as compared to severe disease. PLOS
ONE, 2021; 16 (12): e0261656 DOI: 10.1371/journal.pone.0261656 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/12/211223161016.htm

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