Hairy leukemic cells which hyperexpress Ii do not demonstrate Ii genome alterations by restriction endonuclease...

The finding of increased expression and apparently altered processing of Ii in hairy leukemic cells led us to test for Ii genomic alteration by Southern-type Ii cDNA hybridization to leukemic spleen DNA cleaved with a series of restriction endonucleases. Some insertions, deletions, or point mutations, potentially detectable by this technique, might correlate to alteration in expression and function of Ii (and indirectly, class II antigens). No changes in genomic structure of Ii were detected in DNA isolated from spleens of five patients with hairy cell leukemia, compared with DNA preparations from peripheral blood cells of nineteen healthy blood donors. These experiments were consistent with the view that gross structural alteration of the Ii genome had not occurred in hairy leukemic cells.