Local antibody feedback enforces a checkpoint on affinity maturation in the germinal center and promotes epitope spreading.

Publication/Presentation Date

3-10-2026

Abstract

Circulating antibodies from previous immune encounters impact subsequent humoral responses. Here, we investigated how local epitope-specific competition shapes ongoing germinal center (GC) responses by delivering an mRNA-LNP-encoded membrane-bound immunogen displaying three conserved HIV-1 envelope (Env) epitopes to mouse models bearing B cell receptors (BCRs) of defined affinities. High-affinity B cells exhibited shorter GC residency than lower-affinity counterparts. B cells engaged GC reactions at equivalent rates in the presence or absence of clonal lineages binding the same epitope with similar affinities; however, higher-affinity clones suppressed lower-affinity counterparts targeting the same epitope. Spatial transcriptomics revealed plasma-like cells within and adjacent to the GC, and early immunoglobulin G (IgG) was detectable in draining lymph nodes. Our findings suggest that a self-modulating local antibody feedback loop limits epitope-specific recognition-dampening selection for higher-affinity B cells and facilitating epitope spreading by redirecting the response toward alternative epitopes.

Volume

59

Issue

3

First Page

746

Last Page

767

ISSN

1097-4180

Disciplines

Medicine and Health Sciences

PubMedID

41690309

Department(s)

Medical Education

Document Type

Article

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