Recirculating and marginal zone B cell populations can be established and maintained independently of primary and secondary follicles
Korner, H and Winkler, TH and Sedgwick, JD and Rollinghoff, M and Basten, A and Cook, MC, Recirculating and marginal zone B cell populations can be established and maintained independently of primary and secondary follicles, Immunology and Cell Biology, 79, (1) pp. 54-61. ISSN 0818-9641 (2001) [Refereed Article]
In normal spleen, most recirculating naïve IgM +IgD hi B cells are located within primary follicles and mantle zones of secondary follicles. By contrast, the marginal zone contains a heterogeneous population of IgM hi- IgD lo/- B cells that are mostly non-recirculating. Although these are dynamic populations they are maintained at a constant size, the fundamental homeostatic mechanisms remain uncertain. One possibility is that the presence and turnover of each of the B cell populations is dependent on their location within discrete splenic compartments. To investigate this, we have characterized immature, non-recirculating, mature recirculating, marginal zone and B-1 cell populations in TNF -/- and TNF/lymphotoxin(LT)-α -/- mice that have disorganized splenic architecture. Labelling with 5-bromo-2′-deoxyuridine revealed that turnover of B cells in TNF -/- mice is normal, but is diminished in TNF/LT-α -/- mice. The recirculating B cell populations in both mutant strains are normal in proportion and phenotype. Marginal zone B cells are not seen in TNF/LT-α -/- mice, but this population appears normal in TNF -/- mice, even though they lack germinal centres. These findings indicate that peripheral B cell subsets can be established and maintained independently of normal follicular architecture.