Genetic and molecular definition of complementation group D in MHC class II deficiency.
Four complementation groups, A, B, C and D, have been described among cell lines defective in the coordinate expression of MHC class II genes. These include cell lines established from patients affected with MHC class II deficiency and experimentally generated mutant cell lines. Group D, in contrast to the other groups, was for a long time represented only by the 6.1.6 mutant cell line. The gene responsible for the defect in this group, RFXAP , recently was cloned and found to be mutated in the 6.1.6 cell line and in three patients. Here we report fusion experiments in several new HLA class II-deficient patients, completing the classification of the majority of known patients into the four complementation groups. Patients from five unrelated families were classified in complementation group D, while nine others fall into complementation groups A and B. None of the patients defined a new complementation group. Full correction of MHC class II expression was obtained in cells from patients belonging to group D by transfection with the RFXAP cDNA. The RFXAP coding region was found to be mutated in all patients. Mutations were found to be recurrent since only three different mutations have been found in the eight unrelated families reported to date.
Fondaneche
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MC
INSERM U429, Hôpital Necker-Enfants Malades, 149 rue de Sèvres, 15015 Paris, France. Geneva, Switzerland, Department of Pediatrics,
Villard
J
J
Wiszniewski
W
W
Jouanguy
E
E
Etzioni
A
A
Le Deist
F
F
Peijnenburg
A
A
Casanova
J L
JL
Reith
W
W
Mach
B
B
Fischer
A
A
Lisowska-Grospierre
B
B
D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics; D001402:B-Lymphocytes; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics; D005347:Fibroblasts; D015870:Gene Expression / Q000276:immunology*; D005802:Genes, MHC Class II; D005816:Genetic Complementation Test; D006681:HLA-D Antigens / Q000235:genetics; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis* / Q000235:genetics*; D006801:Humans; D009154:Mutation / Q000235:genetics; D000071701:Regulatory Factor X Transcription Factors; D014162:Transfection / Q000276:immunology
D000944:Antigens, Differentiation, B-Lymphocyte; D004268:DNA-Binding Proteins; C416189:H2-M antigens; D006681:HLA-D Antigens; C084245:HLA-DM antigens; D000949:Histocompatibility Antigens Class II; C093524:RFX5 protein, human; D000071701:Regulatory Factor X Transcription Factors; C045084:invariant chain