Characterization of B-cell receptor clonality and immunoglobulin gene
usage at multiple time points during active SARS-CoV-2 infection
Abstract
Purpose Although monoclonal antibodies specific to the severe
acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are known,
information about the B-cell receptor (BCR) repertoire and its change in
patients during COVID-19 disease progression is underreported.
Methods We used immunoglobulin heavy chain (IGH) variable
region (IGHV) spectratyping and next-generation sequencing of peripheral
blood B-cell genomic DNA collected at multiple time points during
disease evolution to study B-cell response to SARS-CoV-2 infection in 14
individuals with acute COVID-19. Results We found a broad
distribution of responding B-cell clones. The IGH gene usage was not
significantly skewed but frequencies of individual IGH genes changed
repeatedly. We found predominant usage of unmutated and low
mutation-loaded IGHV rearrangements characterizing naïve and
extrafollicular B-cells among the majority of expanded peripheral B-cell
clonal lineages at most tested time points in most patients. IGH
rearrangement usage showed no apparent relation to anti-SARS-CoV-2
antibody titers. Some patients demonstrated mono/oligoclonal populations
carrying highly mutated IGHV rearrangements indicating antigen
experience at some of the time points tested, including even before
anti-SARS-CoV-2 antibodies were detected. Conclusion We present
evidence demonstrating that the B-cell response to SARS-CoV-2 is
individual and includes different lineages of B-cells at various time
points during COVID-19 progression.