ANALYSIS OF TRANSCRIPTS OF GENES LOCATED WITHIN THE HLA-D REGION IN B-CELLS FROM AN HLA-SEVERE COMBINED IMMUNODEFICIENCY INDIVIDUAL

The mRNA levels of LMP7, HLA-DMA, and HLA-DMB genes, all located withi n the HLA-D region, were analyzed in the ''bare lymphocyte'' line SJO, which had been shown to be characterized by a transcription defect of class II genes (DP, DQ, and DR). This was done using semiquantitative PCR amplification of cDNA generated from total RNA. The results show that the transcription of the LMP7 gene in SJO cells is equivalent to that in the control B-cell line Raji. In contrast, the HLA-DM gene tra nscripts were not present in the SJO cell line. This observation indic ates that the promoter similarity between the classic class II genes a nd HLA-DM is sufficient for the SJO defect to extend to the DM loci.