Association Between Tlr4/11367 Gene Polymorphism In 3' Untranslated Region And Diseases Related To Wheezing In Infants

PARTⅠAssociation between TLR4/11367 gene polymorphism in 3'untranslated region and diseases related to clinical phenotype of wheezing in infantsObjective: To investigate the correlation among the polymorphism of 3'untranslated region of TLR4/11367 gene and susceptibility to diseases related to wheezing,the levels of sputum cytokines, etiology and clinical phenotypes.Methods: The polymorphisms of TLR4 gene 3'UTR 11367G/C were genotyped with the method of single-tube bi-directional allele specific amplification (SB-ASA). The levels of cytokines were measured by enzyme-linked immunosorbent assay (ELISA). Immunofluorescence method is used to test respiratory syncytial virus.Result: The G/C polymorphisms (GG and GC genotypes) were identified in 11367 region of TLR4 gene. There were significant asscociations in the distribution of genetypes and allele frequencies between wheezing subjects and controls (P=0.002). The level of IL-8 in GG genotype of wheezing groups is higher than GC, and this relationship also exists in the positive rates of pathogen infections. However, clinical phenotypes of subjects did not show significant differences.Conclusion: This study confirmed the association between TLR4 polymorphisms at 3'UTR and susceptibility to wheezing, and it might be associated with the level of IL-8 in airway secretions and susceptibility to RSV and bacterial infections.PARTⅡThe influence of TLR4/11367 gene polymorphism in 3'untranslated region on TLR4 protein expression of peripheral blood monouclear cellsObjective: Explore the TLR4/11367 gene polymorphism in 3'untranslated region on PBMC cultured in TLR4 protein expression.Methods: TLR4 expression level was measured by flow cytometry using PBMC culture model of healthy children with or without RSV stimulation, respectively, IL-8 production in the cultured after stimulated by RSV was also measured.Results: 1) The expression of GG and GC genotypes granulocyte in control group on TLR4 intensity were varied, but there was no significant difference (P> 0.05). Compared with the control group, TLR4 expression was significantly increased in RSV stimulation (both fluorescence intensity values were 5.02±1.56, 3.16±0.39, P <0.05), two kinds of genotypes granulocyte TLR4 expression had significant difference (P<0.05), GG homozygotes in which increased expression of TLR4 significantly higher than the GC genotype. 2) Compared with the control group, the levels of IL-8 expression increased significantly in RSV stimulation of PBMC supernatants with peripheral blood (P <0.05), in which the IL-8 secretion of RSV stimulation in GG homozygous significantly higher than GC genotype (P= 0.001).Conclusion: The TLR4 polymorphisms at 3'UTR may influenced the TLR4 expression, and it might be associated with IL-8 response to RSV stimulation.