1. Identification of HLA-A*0111N: A Synonymous Substitution, Introducing an Alternative Splice Site in Exon 3, Silenced the Expression of an HLA-A Allele
- Author
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Arend Mulder, Jan G. van den Tweel, Judith Reinders, Marcel G. J. Tilanus, Anne Dormoy, Erik H. Rozemuller, Henny G. Otten, Anna J.S. Houben, and Eefke Petersen
- Subjects
Male ,Sequence analysis ,DNA Mutational Analysis ,Immunology ,Biology ,Exon ,Humans ,Immunology and Allergy ,Gene Silencing ,Serotyping ,Alleles ,Genetics ,HLA-A Antigens ,Alternative splicing ,Exons ,Sequence Analysis, DNA ,General Medicine ,Middle Aged ,C957T ,Flow Cytometry ,Null allele ,Molecular biology ,HLA-A ,Alternative Splicing ,Amino Acid Substitution ,RNA splicing ,Synonymous substitution - Abstract
A new variant of the HLA-A*010101 allele designated as HLA-A*0111N, previously known as HLA-A*010101var, was identified in a patient requiring a stem-cell transplantation. The patient was typed by serologic methods as HLA-A2 homozygous and by sequence-based typing (SBT) as A*010101,020601. Flow-cytometric (FCM) analysis with 11 human monoclonal antibodies (mAbs) for the A1 molecule confirmed lack of any cell membrane expression of the A*0111N allele. One-dimensional isoelectric focusing (1D-IEF) of total cell lysate from the patient’s cells revealed no cell surface and cytoplasmic A1 protein expression, whereas the HLA-A2 molecule was identified by both FCM analysis and 1D-IEF. DNA sequence analysis showed the presence of a synonymous substitution from G to T at position 597 in codon 175. RNA SBT revealed a deletion of 24 bp in exon 3, position 596 through 619, encoding codons 175 through 182 of the HLA-A*0111N allele. The synonymous substitution introduced a new splice site, resulting in an efficient splicing, because no classical A1 protein could be detected in the patient. This alternative splicing prevented the translation into a correct and stable class I molecule expression on the cell surface.
- Published
- 2005