Human IgMhiCD300a+ B cells are circulating marginal zone memory B cells that respond to pneumococcal polysaccharides and their frequency is decreased in people living with HIV
Ikusi/ Ireki
Data
2023-09-06Egilea
Zenarruzabeitia Belaustegui, Olatz
Vitallé Andrade, Joana
Merino Pérez, Aitana
Terrén Martínez, Iñigo
Orrantia Robles, Ane
Pacho de Lucas, Arantza
Iribarren Loyarte, José Antonio
García Fraile, Lucio
Balsalobre, Luz
Amo Herrero, Laura
De Andrés, Belén
Borrego Rabasco, Francisco
International Journal of Molecular Sciences 24(18) : (2023) // Article ID 13754
Laburpena
CD300a is differentially expressed among B cell subsets, although its expression on IgM+ B cells is not well known. We have identified a B cell subset expressing CD300a and high levels of IgM (IgMhiCD300a+). Results showed that IgMhiCD300a+ B cells were CD10-CD27+CD25+IgDloCD21hiCD23-CD38loCD1chi, suggesting that they are circulating marginal zone IgM memory B cells. Regarding the immunoglobulin repertoire, IgMhiCD300a+ B cells exhibited a higher mutation rate and usage of the IgH-VDJ genes than the IgM+CD300a- counterpart. Moreover, the shorter CDR3 AA length from IgMhiCD300a+ B cells together with the predicted antigen experience repertoire, indicates that this B cell subset has a memory phenotype. IgM memory B cells are important in T cell-independent responses. Accordingly, we demonstrate that this particular subset secretes higher amounts of IgM after stimulation with pneumococcal polysaccharides or a TLR9 agonist than IgM+CD300a- cells. Finally, the frequency of IgMhiCD300a+ B cells was lower in people living with HIV-1 (PLWH) and it was inversely correlated to the years with HIV infection. Altogether, these data help to identify a memory B cell subset that contributes to T cell-independent responses to pneumococcal infections and may explain the increase in severe pneumococcal infections and the impaired responses to pneumococcal vaccination in PLWH.
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Bestelakorik adierazi ezean, itemaren baimena horrela deskribatzen da:© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).