title: Definition of a novel complementation group in MHC class II deficiency.
abstract: In this study we analyzed fibroblasts derived from an MHC class II deficiency patient (type III bare lymphocyte syndrome). Northern blot analysis showed that upon induction with IFN-gamma these fibroblasts did not express HLA class II genes and displayed a strongly reduced level of HLA class I gene expression when compared with fibroblasts of a healthy individual. However, when analyzed by RT-polymerase chain reaction (PCR), residual expression could be detected for HLA-DRA, DPB, and DQA, but not for HLA-DRB, DPA, and DQB. The lack of HLA-DRB transcripts in the patient fibroblasts and the high degree of sequence polymorphism of HLA-DRB were exploited in the further analysis of these fibroblasts. Thus far, at least three, and probably four, complementation groups have been defined among patient-derived and experimentally-derived MHC class II-negative cell lines. Transient heterokaryons between the patient fibroblasts and representative B-lymphoblastoid cell lines from each of the complementation groups were analyzed by RT-PCR and Southern blotting, using HLA-DRB-specific primers and biotin-labeled sequence specific oligonucleotides, respectively. These analyses showed that the fibroblasts of this particular patient belonged to a novel complementation group in MHC class II deficiency.
authors.affiliation: Department of Immunohematology and Bloodbank, University Hospital Leiden, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Peijnenburg
authors.forename: B
authors.initials: B
authors.lastname: Godthelp
authors.forename: A
authors.initials: A
authors.lastname: van Boxel-Dezaire
authors.forename: P J
authors.initials: PJ
authors.lastname: van den Elsen
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D005816:Genetic Complementation Test; D006684:HLA-DR Antigens / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016511:Severe Combined Immunodeficiency / Q000235:genetics*
chemical_list: D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D007371:Interferon-gamma