Thymic B cells from myasthenia gravis patients are activated B cells. Phenotypic and functional analysis.
Thymic cell populations from 12 patients displaying myasthenia gravis were submitted to a phenotypic and functional study. Immunofluorescence analysis of thymic sections revealed the presence in germinal centers of B lymphocytes expressing the B cell markers--CD19, CD21, IgD, or IgM. After T cell and macrophage depletion of thymic single cell suspensions, B cell-enriched populations were isolated. Enriched B cells expressed at variable levels activation markers such as CD71, 4F2, CD23, and B8.7, indicating that a marked proportion of them are activated. Moreover, addition of B cell growth factor 12kDa and to a lesser extent of rIL-2 induced a spontaneous proliferation of these B cell populations. These functional and phenotypic signs of activation may reveal the first steps of an autoimmune response against acetylcholine receptor as enriched B cell populations have the capacity to spontaneously secrete anti-acetylcholine receptor antibody.
Leprince
C
C
INSERM U.131, Clamart, France.
Cohen-Kaminsky
S
S
Berrih-Aknin
S
S
Vernet-Der Garabedian
B
B
Treton
D
D
Galanaud
P
P
Richard
Y
Y
D000328:Adult; D000917:Antibody Formation; D015703:Antigens, CD / Q000032:analysis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001323:Autoantibodies / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008297:Male; D009157:Myasthenia Gravis / Q000276:immunology* / Q000473:pathology; D011961:Receptors, Fc / Q000032:analysis; D017455:Receptors, IgE; D011978:Receptors, Nicotinic / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013934:Thymectomy; D013950:Thymus Gland / Q000276:immunology* / Q000473:pathology
D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; D001323:Autoantibodies; D007376:Interleukin-2; D011961:Receptors, Fc; D017455:Receptors, IgE; D011978:Receptors, Nicotinic; D015847:Interleukin-4