Human tonsil-derived fibroblasts normally support B cell activation and expansion, but once pushed into a senescent state they block B cell proliferation while leaving early activation intact. The arrested B cells fail to complete the metabolic switch to glycolysis and synthesise almost no new protein, with direct cell–cell contact proving more inhibitory than secreted factors alone. The work identifies the lymphoid stromal niche, rather than B cells themselves, as a limiting factor in age-related decline of antibody responses.
Key Points
- Senescent fibroblasts halt B cell proliferation despite normal early activation markers
- Cell–cell contact inhibits more strongly than conditioned media alone
- Arrested B cells fail glycolytic switch and protein synthesis
Longevity Analysis
Immune decline with age is often attributed to the lymphocytes themselves, yet here the defect originates in the supporting tissue architecture that B cells depend on for expansion. Senescent stromal cells impose a contact-dependent brake, including upregulation of inhibitory ligands such as PDCD1LG2, that prevents the energy and protein synthesis required for clonal expansion. Clearing or modulating senescent cells within lymphoid tissue becomes a plausible route to restoring vaccine responsiveness in older adults, and reframes the metabolic readiness of immune cells as a downstream consequence of the environment they occupy.
Original published by Wiley Aging Cell, by Kassandra Vezyrgianni, Elizabeth MacLeod, Abigail Nutley, Yuchen Zhu, Alice E. Denton .