Type III bare lymphocyte syndrome: lack of HLA class II gene expression and reduction in HLA class I gene expression.
The bare lymphocyte syndrome (BLS) consists of an association between a combined immunodeficiency disease and a significantly reduced expression of either human histocompatibility leukocyte antigens (HLA) class I (HLA-A, -B, -C) or HLA class II (HLA-DP, -DQ, -DR) at the cell surface. BLS type III, the more frequent form of this syndrome, is characterized by impaired expression of both class I and class II antigens on patients' cells, in particular on leukocytes. We describe herein the demonstration that expression of HLA class I molecules was reduced by approximately half on Epstein-Barr virus-transformed B cells (LCL) derived from type III BLS patients. HLA class I mRNA level was also decreased to the same extent. Expression of HLA class I molecules was also very significantly reduced at the surface of these fibroblasts as was mRNA specific for HLA class I. Simultaneously, the expression of HLA-DR molecules on LCL was even more greatly decreased, and the expression of HLA-DQ antigens was virtually abolished. Molecular analysis demonstrated an absence of mRNA for the alpha- and beta-chains of HLA-DQ and HLA-DR in the patients' lymphocytes. In general, such patients present with an association of an absence of expression of HLA class II antigens and a significantly reduced expression of HLA class I antigens. The mechanism of this association is still uncertain.
Sabatier
C
C
INSERM U. 80, Hôpital E-Herriot, Lyon, France.
Gimenez
C
C
Calin-Laurens
V
V
Rabourdin-Combe
C
C
Touraine
J L
JL
D002648:Child; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D005805:Genes, MHC Class I / Q000235:genetics*; D005802:Genes, MHC Class II / Q000235:genetics*; D006683:HLA-DQ Antigens / Q000235:genetics; D006684:HLA-DR Antigens / Q000235:genetics; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis; D016511:Severe Combined Immunodeficiency / Q000235:genetics*
D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D012333:RNA, Messenger