Relationship Between Toll-like Receptor 4 Gene Polymorphism And Related Signaling Factors And Legionela Infection

Objective:①Investigate ralationship between Toll-like receptor 4(TLR4) gene (2244G→A) polymorphism and legionella infection.②To explore the relationship between MyD88 mRNA and legionella infection;to explore the ralationship between TLR4 (2244G→A) polymorphism and MyD88 mRNA .③To explore the relationship between IFN-β,IL-10 and legionella infection;to explore the ralationship between TLR4 (2244G→A) polymorphism and IFN-β,IL-10.Methods:①16Sr ribosome gene of Legionella was amplified by polymerase chain reaction(PCR) and antigen of Legionella pneumophila serogroup 1 strains was detcted by EIA for pulmonary infected patient's urine.The diagnostic criteria of Legionella infection was the positive result for Lp1 antigen or16Sr ribosome gene of Legionella in urine.②Polymerase chain reaction- restriction fragment length polymorphism(PCR-RFLP) was used to analyze the TLR4(2244G→A) gene polymorphisms of 25 legionella infected patients,66 other pulmonary infected patients caused by other non gram negative bacteria and 102 healthy individuals.③R eal-time RT-PCR was used to detect MyD88 mRNA expression in legionella infected patients ,case controls and healthy controls. To search for the relationship between MyD88 mRNA and legionella infection,TLR4 gene (2244G→A) polymorphism and MyD88 mRNA.④E LISA was used to detect the concentration of IFN-β,IL-10 in legionella infected patients,case controls and healthy controls. To search for the relationship between IFN-β,IL-10 and legionella infection,TLR4 gene (2244G→A) polymorphism and IFN-β, IL-10. Results①A allele frequency of healthy contro(l44.6%)is higher than legionella infected patients(34%) and case control(36.4%), but there was no significant difference (χ2=3.243,p=0.198).There was no significant difference among three groups of TLR4(2244G→A) three genetypes frequencies(χ2=6.003,p=0.199).There was no significant difference among three groups of TLR4(2244G→A) GG/GA and AA genetypes frequencies(p=0.076).There was significant difference between healthy control and legionella infected patients of TLR4(2244G→A) GG/GA and AA genetypes frequencies(p=0.044).②There was significant difference among three groups of MyD88 mRNA expression(F=6.625, p =0.002); The MyD88 mRNA of case control was higher than healthy control(p =0.000), The MyD88 mRNA of legionella infected patients was higher than healthy control, but there was no significant difference(p =0.095), There was no significant difference between legionella infected patients and case control of MyD88 mRNA(p =0.436). There was no significant difference among TLR4 gene (2244G→A) three genotypes of MyD88 mRNA expression in three group(sp =0.408,p =0.235,p =0.174). The MyD88 mRNA of AA genetype group was higher thanGG/GA genetype group in case control and healthy control, but there was no significant difference(Z= -1.461, p=0.144;Z=-1.791, p=0. 073).③T here was significant difference among three groups of the concentration of IFN-β(F=12.884,p=0.000),the concentration of IFN-βof legionella infected patients and case control was higher than healthy control(p =0.001, p =0.000 ),there was no significant difference between legionella infected patients and case control of the concentration of IFN-β(p =0.982);There was no significant difference among three groups of the concentration of IL-10(F=1.835, p =0.166).There was no significant difference amang TLR4 (2244G→A) three genotypes of the concentration of IFN-βand IL-10 in three groups ( p=0.506, p=0.497, p=0.260; p=0.399, p=0.1, p =0.223).The concentration of IFN-βof AA genetype group was lower than GG/GA genetype group in case control and healthy control, but there was no significant differenc(eZ=-1.155, p=0.248;Z=-1.617, p=0.106); The concentration of IL-10 of AA genetype group was higher than GG/GA genetype group in case control, there was significant difference(Z=-2.132, p=0.032), The concentration of IL-10 of AA genetype group was higher than GG/GA genetype groups in healthy control, there was no significant difference(Z=-0.981, p=0.326). Conclusion①There was difference among three groups of TLR4(2244G→A) GG/GA and AA genetype frequencies, A allele frequency of healthy control is higher than legionella infected patients.Indicate that TLR4(2244G→A) polymorphism may be associated with legionella infection.②The MyD88 mRNA of legionella infected patients and case control was higher than healthy control, indicate that legionella and other non gram negative bacteria infection may increase the MyD88 mRNA expression;The MyD88 mRNA of AA genetype group was higher thanGG/GA genetype group in case control and healthy control. Indicate that TLR4(2244G→A) polymorphism may be associated with MyD88 mRNA expression.③The concentration of IFN-βand IL-10 of legionella infected patients and case control was higher than healthy control, indicate that legionella and other non gram negative bacteria infection may increase IFN-βand IL-10 expression; The conce- ntration of IFN-βof AA genetype group was lower than GG/GA genetype group in case control and healthy control,the concentration of IL-10 of AA genetype group was higher than GG/GA genetype group in case control and healthy control . Indicate that TLR4(2244G→A) polymorphism may be associated with IFN-βand IL-10 expression.