Identification of transitional type II B cells in the salivary glands of patients with Sjögren's syndrome.
OBJECTIVE
To identify B cell subpopulations participating in the lymphocyte infiltrate of salivary glands from patients with primary Sjögren's syndrome. A special emphasis was placed on those B lymphocytes included in the ectopic germinal centers (GCs).


METHODS
The presence of B cells in salivary glands and their polyclonality were ascertained by phenotyping and reverse transcription-polymerase chain reaction in salivary gland samples from 18 patients. Their phenotype was thoroughly analyzed using a number of double-staining combinations. The results obtained in tissue sections were confirmed by fluorescence-activated cell sorting analysis of B cells eluted from salivary glands, and these findings were compared with those in tonsils.


RESULTS
Memory-type B cells were defined as CD20+, CD27+ and were seen in all specimens, whereas GCs were found in only 7 specimens. Furthermore, B cells found in these GCs lacked certain characteristics of centroblasts and centrocytes. Instead, they fulfilled the criteria for transitional type II (TII) B cells and resembled marginal-zone B cells. BAFF (the assistance of which is required for proper transformation of transitional TI B cells into transitional TII B cells) accumulated adjacent to transitional and marginal-zone-like B lymphocytes. Further evidence for the involvement of BAFF came from the expression of its receptors on infiltrating B cells.


CONCLUSIONS
These transitional TII and marginal-zone-like B cells are probably instrumental in the local production of autoantibodies and possibly influential in the ensuing destruction of epithelial cells.
Daridon
Capucine
C
Laboratory of Immunology, Brest University Medical School Hospital, BP824, F-29609 Brest, France.
Pers
Jacques-Olivier
JO
Devauchelle
Valérie
V
Martins-Carvalho
Christine
C
Hutin
Pascal
P
Pennec
Yvon-Louis
YL
Saraux
Alain
A
Youinou
Pierre
P
D000328:Adult; D000368:Aged; D018951:Antigens, CD20 / Q000276:immunology; D001323:Autoantibodies; D053264:B-Cell Activating Factor; D053265:B-Cell Activation Factor Receptor; D016175:B-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D005260:Female; D018858:Germinal Center / Q000276:immunology / Q000473:pathology; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D008875:Middle Aged; D014066:Palatine Tonsil / Q000473:pathology; D010641:Phenotype; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D012469:Salivary Glands / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D012859:Sjogren's Syndrome / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D018951:Antigens, CD20; D001323:Autoantibodies; D053264:B-Cell Activating Factor; D053265:B-Cell Activation Factor Receptor; D008565:Membrane Proteins; D018124:Receptors, Tumor Necrosis Factor; C435926:TNFRSF13C protein, human; C505719:TNFSF13B protein, human; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D014409:Tumor Necrosis Factor-alpha