Discrete populations of isotype-switched memory B lymphocytes are maintained in murine spleen and bone marrow
René Riedel, Richard Addo, Marta Ferreira‐Gomes, Gitta Anne Heinz, Frederik Heinrich, Jannis Kummer, Victor Greiff, Daniel Schulz, Cora Klaeden, Rebecca Cornelis, Ulrike Menzel, Stefan Kröger, Ulrik Stervbo, Ralf Köhler, Claudia Haftmann, Silvia Kühnel, Katrin Lehmann, Patrick Maschmeyer, Mairi McGrath, Sandra Naundorf, Stefanie Hahne, Özen Sercan, Francesco Siracusa, Jonathan Stefanowski, Melanie Weber, Kerstin Westendorf, Jakob Zimmermann, Anja E. Hauser, Sai T. Reddy, Pawel Durek, Hyun‐Dong Chang, Mir‐Farzin Mashreghi, Andreas Radbruch
Abstract
Abstract At present, it is not clear how memory B lymphocytes are maintained over time, and whether only as circulating cells or also residing in particular tissues. Here we describe distinct populations of isotype-switched memory B lymphocytes (Bsm) of murine spleen and bone marrow, identified according to individual transcriptional signature and B cell receptor repertoire. A population of marginal zone-like cells is located exclusively in the spleen, while a population of quiescent Bsm is found only in the bone marrow. Three further resident populations, present in spleen and bone marrow, represent transitional and follicular B cells and B1 cells, respectively. A population representing 10-20% of spleen and bone marrow memory B cells is the only one qualifying as circulating. In the bone marrow, all cells individually dock onto VCAM1 + stromal cells and, reminiscent of resident memory T and plasma cells, are void of activation, proliferation and mobility.