Quantitative expression of HLA class I molecules in acute non-lymphoblastic leukaemia cells.
The present study concerns a panel of 33 acute non lymphoblastic leukaemia (ANLL) patients, previously typed for HLA-A,B serological specificities and including samples with a normal HLA-A,B phenotype (3,4 detected specificities) as well as samples with missing and extra specificities. Samples were analysed at the protein and/or RNA level in order to verify whether the observed typing anomalies were due to a modified quantitative expression of class I molecules. The number of HLA-A,B assigned specificities correlated significantly with the cell surface class I expression detected by indirect immunofluorescence using the monomorphic anti-class I MoAb W6/32 (Spearman rank correlation test, P < 0.01) and with the amount of class I Heavy Chain (HC, P < 0.05) and beta-2-microglobulin (beta 2m, P < 0.05) evaluated by Western blot in whole cell extracts. The RNA analysis suggested a HC-beta 2m coordinated down regulation at the mRNA level in a patient with no assigned HLA-A,B specificities. Another patient with no detectable HLA-A,B specificities showed a low expression selectively of the beta 2m protein. The results reported here demonstrate a heterogenous quantitative HLA class I expression in ANLL blasts, analogous to results reported for solid tumours.
D'Alfonso
S
S
Dipartimento di Genetica, Biologia e Chimica Medica, Università di Torino, Italy.
Savoia
P
P
Pitti
G
G
Peruccio
D
D
Pozzi
C
C
Crepaldi
T
T
Falda
M
M
Ficara
F
F
Resegotti
L
L
Momigliano Richiardi
P
P
D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000235:genetics; D015973:Gene Expression Regulation, Leukemic; D015234:HLA-A Antigens / Q000096:biosynthesis* / Q000235:genetics; D015235:HLA-B Antigens / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000276:immunology*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D014411:Neoplastic Stem Cells / Q000276:immunology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D001613:beta 2-Microglobulin / Q000096:biosynthesis / Q000235:genetics
D000951:Antigens, Neoplasm; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D001613:beta 2-Microglobulin