Recirculating and marginal zone B cell populations can be established and maintained independently of primary and secondary follicles.
In normal spleen, most recirculating naïve IgM+IgDhi B cells are located within primary follicles and mantle zones of secondary follicles. By contrast, the marginal zone contains a heterogeneous population of IgMhiIgDlo/- 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)-alpha-/- 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-alpha-/- 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-alpha-/- 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.
Körner
H
H
IZKF Nachwuchsgruppe 1 der Universität Erlangen-Nürnberg, Germany.
Winkler
T H
TH
Sedgwick
J D
JD
Röllinghoff
M
M
Basten
A
A
Cook
M C
MC
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000276:immunology / Q000502:physiology*; D001854:Bone Marrow Cells / Q000502:physiology; D001973:Bromodeoxyuridine / Q000008:administration & dosage / Q000378:metabolism; D019070:Cell Lineage; D002469:Cell Separation; D005434:Flow Cytometry; D007072:Immunoglobulin D / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D008233:Lymphotoxin-alpha / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D010641:Phenotype; D013154:Spleen / Q000033:anatomy & histology / Q000166:cytology* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha; D001973:Bromodeoxyuridine