Yael Bahar (Israel)

Tel Aviv University The Shmunis School of Biomedicine and Cancer Research

Author of 1 Presentation

THE FREQUENCY OF SARS-COV-2 SPECIFIC MEMORY B CELLS IN COVID-19 RECOVERED PATIENTS REMAIN STABLE WHILE ANTIBODIES DECAY OVER TIME

Date
Fri, 19.03.2021
Session Time
10:00 - 11:00
Room
Hall A
Lecture Time
10:49 - 10:56

Abstract

Background and Aims

The breadth of the humoral immune response following SARS-CoV-2 infection was indicated to be important for recovery from COVID-19. However, the information regarding the temporal dynamics of the serological and cellular memory in COVID-19 recovered patients is scarce.

Methods

We analyzed the temporal dynamics of SARS-CoV-2 specific antibodies and B cells in 60 COVID-19 recovered patients using ELISA, in-vitro neutralization assay, flow cytometry, and Next-Generation Sequencing of the B cell receptor antibody variable genes.

Results

We found that acute phase SARS-CoV-2 patients mount a rapid, robust antibody response following infection however, the serological memory decays in COVID-19 recovered patients over the period of six months. Using an in vitro neutralization assay revealed a strong correlation between total RBD-specific (RBD+) antibodies and neutralizing antibodies suggesting that antibody levels can be used as a proxy to determine neutralizing capacity. In contrast to the observed antibody decay, the memory B cell frequency was found to be stable over time. Next-generation sequencing of viral-specific B cell receptors showed an unregular high frequency of the IgG4 isotype which is known to contribute to the manifestation of IgG4 related disease and other autoimmune diseases specifically, IgG-related lung disease.

Conclusions

The persistence of viral-specific memory B cells following recovery may contribute to a robust recall humoral response in a case of re-infection by SARS-CoV-2. Interestingly, the repertoire analysis of viral-specific B cell response suggests that the induction of IgG4 may promote COVID-19 severity and could explain the long-term outcome in some COVID-19 recovered patients.

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