HLA-DR-associated invariant chain is highly expressed in chronic lymphocytic leukemia.
Total RNA extracted from peripheral blood lymphocytes of a patient with B-cell chronic lymphocytic leukemia (CLL) and the poly (A+) RNA was purified. A cDNA library was constructed and approximately 4,000 clones were screened in order to identify genes preferentially expressed in CLL. A relatively low repetition frequency characterizes the majority of the abundant mRNA species present in CLL lymphocytes. One clone, corresponding to the mRNA encoding the HLA-DR-associated invariant chain, was selected and its expression was examined in different leukemic cell populations and in normal tissues. DNA-RNA hybridization studies showed that the invariant chain mRNA (In-mRNA) is detectable in RNA preparations from human blood cells and their precursors, whereas no In-mRNA is found in several other tissues examined. Among various normal and leukemic leukocyte populations, the highest levels of In-mRNA are found in CLL. Therefore, a role of In-chain mRNA as a marker of CLL is proposed. Our data support a relationship between high levels of invariant chain mRNA and the out of cycle condition of CLL peripheral blood lymphocytes.
Narni
F
F
Kudo
J
J
Mars
W
W
Calabretta
B
B
Florine
D L
DL
Barlogie
B
B
Saunders
G F
GF
D002999:Clone Cells; D003101:Collodion; D004591:Electrophoresis, Polyacrylamide Gel; D005374:Filtration / Q000295:instrumentation; D014644:Genetic Variation; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D007945:Leukemia, Lymphoid / Q000097:blood*; D009693:Nucleic Acid Hybridization; D010209:Paper; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics
D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D012333:RNA, Messenger; D003101:Collodion