title: Effect of HLA genotype or CTLA-4 polymorphism on cytokine response in healthy children.
abstract: Type 1 diabetes (T1D) is considered to be a T-cell-mediated autoimmune disease in which genetic predisposition is affected by HLA class II alleles and polymorphisms in cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene. We tested the hypothesis whether these T1D-related gene polymorphisms modulate cytokine response and thus contribute to the development of autoimmunity. The study includes 67 non-diabetic children, typed for HLA class II alleles and CTLA-4 polymorphisms (+49A/G, CT60A/G, CTBC217_1C/T). We measured cytokine secretion of peripheral blood mononuclear cells after stimulation with tetanus toxoid (TT), polio virus, coxsackie virus B4, pertussis toxin (PT) and phytohemagglutinin (PHA). We saw higher IL-13 response to TT in individuals with DR3-DQ2 haplotype (P = 0.002). HLA class II protective haplotype, DR2-DQ6, showed association with increased production of IFN-gamma (P < 0.001) and IL-2 (P = 0.005) in response to polio virus. In children with the autoimmunity-related homozygous genotypes CTLA-4 +49G/G, CT60G/G and CTBC217_1T/T, we found enhanced PT- and PHA-induced IFN-gamma production (P < 0.05). The cytokine responses to studied antigens were weakly modified by HLA class II risk haplotypes, and children with T1D-associated HLA risk haplotypes are not specifically inclined to develop an immune response in general. Higher IFN-gamma and IL-2 response to enterovirus in children with HLA class II protective haplotype DR2-DQ6 could be of importance in the protection from T1D-associated enterovirus infections. All autoimmunity related CTLA-4 polymorphisms were associated with enhanced IFN-gamma. This suggests impaired downregulation of cellular immunity by these CTLA-4 polymorphisms.
authors.affiliation: Division of Pediatrics and Diabetes Research Center, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden. jenny.wallden@imk.liu.se
authors.forename: J
authors.initials: J
authors.lastname: Walldén
authors.forename: J
authors.initials: J
authors.lastname: Ilonen
authors.forename: M
authors.initials: M
authors.lastname: Roivainen
authors.forename: J
authors.initials: J
authors.lastname: Ludvigsson
authors.forename: O
authors.initials: O
authors.lastname: Vaarala
mesh_terms: D000483:Alleles; D015703:Antigens, CD / Q000235:genetics*; D060908:CTLA-4 Antigen; D002478:Cells, Cultured; D002675:Child, Preschool; D015331:Cohort Studies; D016207:Cytokines / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology; D015536:Down-Regulation; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006680:HLA Antigens / Q000235:genetics*; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006720:Homozygote; D006801:Humans; D007963:Leukocytes, Mononuclear; D011110:Polymorphism, Genetic; D011897:Random Allocation; D013548:Sweden
chemical_list: D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D016207:Cytokines; D006680:HLA Antigens; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains