More than one antibody of individual B cells revealed by single-cell immune profiling

Abstract

Antibodies have a common structure consisting of two identical heavy (H) and two identical light (L) chains. It is widely accepted that a single mature B cell produces a single antibody through restricted synthesis of only one VHDJH (encoding the H-chain variable region) and one VLJL (encoding the L-chain variable region) via recombination. Naive B cells undergo class-switch recombination (CSR) from initially producing membrane-bound IgM and IgD to expressing more effective membrane-bound IgG, IgA, or IgE when encountering antigens. To ensure the “one cell — one antibody” paradigm, only the constant region of the H chain is replaced during CSR, while the rearranged VHDJH pattern and the L chain are kept unchanged. To define those long-standing classical concepts at the single-cell transcriptome level, we applied the Chromium Single-Cell Immune Profiling Solution and Sanger sequencing to evaluate the Ig transcriptome repertoires of single B cells. Consistent with the “one cell — one antibody” rule, most of the B cells showed one V(D)J recombination pattern. Intriguingly, however, two or more VHDJH or VLJL recombination patterns of IgH chain or IgL chain were also observed in hundreds to thousands of single B cells. Moreover, each Ig class showed unique VHDJH recombination pattern in a single B-cell expressing multiple Ig classes. Together, our findings reveal an unprecedented presence of multi-Ig specificity in some single B cells, implying regulation of Ig gene rearrangement and class switching that differs from the classical mechanisms of both the “one cell — one antibody” rule and CSR.

Single-cell RNA sequencing confirms IgG transcription and limited diversity of VHDJH rearrangements in proximal tubular epithelial cells

“…Second, PTEC-derived IgG had conservative V(D)J rearrangements, showing that VH1-24/DH2-15/JH4 was predominant in more than 10% of PTECs, 10 pairs of single PTECs from different individuals and 5 pairs of single PTECs from the same individual shared the same V H DJ H rearrangements. All these are considered impossible in such a small number of B cells, and primer bias was excluded as the diversity of V(D)J rearrangements was proven in PBMCs (Table S6) or single B cells 24 . The phenomenon of conserved IgG characteristics has also been described in other non-B cells, such as human epithelial cancer cells 25 or endothelial cells 26 .…”

“…The concentration of the single-cell suspension was counted and adjusted to 1000 cells/μl for sorting 7000 cells. All remaining procedures, including library construction, were performed according to the manufacturer's standard protocol described in Shi's work 24 . We used the Cell Ranger software pipeline (version 3.0.0) to demultiplex cellular barcodes and map reads to the genome.…”

“…To compare the characteristics of the immune repertoire between PTECs and B cells at the single-cell level, we obtained V H DJ H sequence information of B cell-derived IgG in a previous article by Shi 24 . We screened 3187 IgG + B cells and obtained 3300 V H DJ H sequences (including 130 unproductive sequences).…”

Correlations Between Apparent Diffusion Coefficient Values of WB-DWI and Clinical Parameters in Multiple Myeloma

“…However, this result is limited to single-locus gene changes. Studies have shown that IGH rearrangement can affect related genes and trigger the autocrine mechanism of tumors [32] , leading to disease progression [33] . This may be the cause of the increased tumor load that leads to a decrease in the ADC value.…”

Evidence of Antibody Repertoire Functional Convergence through Public Baseline and Shared Response Structures

“…On antigenic exposure, 'baseline' (resting-state) antibodies with sufficiently complementary binding sites to an antigen surface epitope are positively selected. The corresponding parent B cells subsequently migrate to the marginal zone of the lymph nodes, where intentional mutations are introduced to their sequence and only the highest-affinity binders survive in the competition for cognate T-helper cells (2). Therefore, sequencing antibody repertoires before and during an immune response (e.g.…”