8w5m | pdb_00008w5m
Cryo-EM structure of Qb-Ab17
Structural highlights
FunctionA1_BPQBE Minor capsid protein.[1] Publication Abstract from PubMedThe germinal center (GC) sets an environment where antigen-specific B cells are compelled to continuously increase their affinity to compete for the antigen and obtain Tfh help for survival and propagation. Previous studies indicated that low-affinity B cells are disadvantaged in the presence of high-affinity ones, suggesting that competition may lead to the elimination of low-affinity B cells and their descendants. However, using a multivalent virus-mimicking antigen, our study demonstrates that low-affinity B cells not only successfully participate in GC responses alongside high-affinity B cells but also undergo accelerated affinity maturation under the more stringent competition. Furthermore, our cryo-electron-microscopy-based structural analysis reveals that both low-affinity and high-affinity B cells compete for the same antigenic epitope. Although the applicability of this idealized GC competition to true pathogen-induced responses remains uncertain, this change in perspective on the role of competition in low-affinity B cell evolution provides valuable insights for vaccine development. Competition propels, rather than limits, the success of low-affinity B cells in the germinal center response.,Li R, Bao K, Liu C, Ma X, Hua Z, Zhu P, Hou B Cell Rep. 2025 Feb 15;44(2):115334. doi: 10.1016/j.celrep.2025.115334. PMID:39955776[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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