Thyroid-infiltrating B lymphocytes in Graves' disease are related to marginal zone and memory B cell compartments.
B lymphocytes that infiltrate the thyroid (Thy-B cells) in Graves' patients appear to be implicated in the pathophysiology of this disorder. The goal of the present study was to examine the nature of these Thy-B cells. To this end, Thy-B lymphocytes were isolated from surgical thyroidal samples, and their phenotype was determined by using mouse monoclonal antibodies (mAb) directed against a wide variety of surface markers, followed by flow cytometry multicolor analysis. The results show that most Thy-B cells (approximately 60%) exhibited IgM(+) IgD(low to -) surface immunoglobulin (Ig) profile, whereas the minor cell fraction (approximately 30%) consisted of switched IgG(+) memory B lymphocytes. Thy-B cells expressed low levels of CD5, CD23, and CD62L, which distinguished them from the resting B-cell pool, the major B-cell subset in the blood. In addition, they lacked CD38, CD10, and CD71, characteristic molecules for the germinal center B lymphocytes. In addition, Thy-B lymphocytes showed peculiar patterns both of adhesion molecules (CD62L(-), CD44(intermediate)), and of activation molecules (CD69(+), CD80(+), and, in part, CD95(+)). Taken together, these results suggest that the Thy-B lymphocyte subset consists of a combination of IgM(+) B cells resembling marginal zone B lymphocytes, and isotype-switched memory B cells.
Segundo
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C
Servicio de Inmunología, Hospital Universitario Puerta del Mar, Cádiz, Spain.
Rodríguez
C
C
García-Poley
A
A
Aguilar
M
M
Gavilán
I
I
Bellas
C
C
Brieva
J A
JA
D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000502:physiology; D001402:B-Lymphocytes / Q000473:pathology / Q000502:physiology*; D015415:Biomarkers; D015815:Cell Adhesion Molecules / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006111:Graves Disease / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D007156:Immunologic Memory / Q000502:physiology*; D010641:Phenotype; D013961:Thyroid Gland / Q000473:pathology / Q000503:physiopathology*
D015703:Antigens, CD; D015415:Biomarkers; D015815:Cell Adhesion Molecules