title: HLA-DPB1 supertype-associated protection from childhood leukaemia: relationship to leukaemia karyotype and implications for prevention.
abstract: Most childhood B cell precursor (BCP) acute lymphoblastic leukaemia (ALL) cases carry the reciprocal translocation t(12;21)(p13;q22) ( approximately 25%), or a high hyperdiploid (HeH) karyotype (30%). The t(12;21) translocation leads to the expression of a novel fusion gene, TEL-AML1 (ETV6-RUNX1), and HeH often involves tri- and tetrasomy for chromosome 21. The presence of TEL-AML1+ and HeH cells in utero prior to the development of leukaemia suggests that these lesions play a critical role in ALL initiation. Based on our previous analysis of HLA-DP in childhood ALL, and evidence from in vitro studies that TEL-AML1 can activate HLA-DP-restricted T cell responses, we hypothesised that the development of TEL-AML1+ ALL might be influenced by the child's DPB1 genotype. To test this, we analysed the frequency of six HLA-DPB1 supertypes in a population-based series of childhood leukaemias (n = 776) classified by their karyotype (TEL-AML1+, HeH and others), in comparison with newborn controls (n = 864). One DPB1 supertype (GKD) conferred significant protection against TEL-AML1+ ALL (odds ratio (OR), 95% confidence interval (95% CI): 0.42, 0.22-0.81; p < 0.005) and HeH ALL (OR; 95% CI: 0.44, 0.30-0.65; p < 0.0001). These negative associations were almost entirely due to a single allele, DPB1*0101. Our results suggest that DPB1*0101 may afford protection from the development of TEL-AML1+ and HeH BCP ALL, possibly as the result of a DP-restricted immune response to BCP ALL-associated antigen(s), the identification of which could have important implications for the design of prophylactic vaccines.
authors.affiliation: Cancer Immunogenetics Laboratory, St Mary's Hospital, University of Manchester, Manchester, M13 0JH, UK. gmtaylor@manchester.ac.uk
authors.forename: Malcolm
authors.initials: M
authors.lastname: Taylor
authors.forename: Christine
authors.initials: C
authors.lastname: Harrison
authors.forename: Tim
authors.initials: T
authors.lastname: Eden
authors.forename: Jillian
authors.initials: J
authors.lastname: Birch
authors.forename: Mel
authors.initials: M
authors.lastname: Greaves
authors.forename: Tracy
authors.initials: T
authors.lastname: Lightfoot
authors.forename: Adiba
authors.initials: A
authors.lastname: Hussain
mesh_terms: D002648:Child; D002869:Chromosome Aberrations; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006682:HLA-DP Antigens / Q000235:genetics*; D059868:HLA-DP beta-Chains; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000517:prevention & control*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D006682:HLA-DP Antigens; D059868:HLA-DP beta-Chains; D015514:Oncogene Proteins, Fusion; C071170:HLA-DPB1 antigen; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein