Cytokines Interleukin 4 (IL-4) and Interleukin 10 (IL-10) Gene Polymorphisms as Potential Host Susceptibility Factors in Virus-Induced Encephalitis

Yu, Ying; Chen, Ying; Wang, Feng-Ling; Sun, Jing; Li, Hai-Jun; Liu, Jia-Ming

Using direct sequencing, our study determined the genotypes of IL-4 rs2243283, IL-4 rs2243288, IL-10 rs1800871, and IL-10 rsl800872 and analyzed the correlation of IL-4 and IL-10 gene polymorphisms with the susceptibility to virus-induced encephalitis, suggesting that IL-4 rs2227288 and IL-10 rs1800872 might enhance the risk for virus-induced encephalitis. Previous studies have suggested that IL-4 and IL-10 were 2 cytokines that have a relationship to encephalitis [15] [16] [17] 37] . Initially, we found during this study that the A allele, and GA, AA, and GA + AA genotypes in IL-4 rs2227288 were risk factors for virus-induced encephalitis. According to Anovazzi et al., there were strong relationships between the alleles, genotypes, and haplotypes of IL-4 gene polymorphisms and chronic periodontitis [38] . It was suggested that the IL-4-590 T/T and IL-4-33 T/T genotypes were potentially correlated with resistance to therapy in hepatitis C virus patients, and the CT/TT genotypes of IL-4 C-589T was correlated with wheezing without actually having a cold in African Americans infants [39, 40] . The etiology of systemic lupus erythematosus (SLE) and elevated risk for SLE were revealed as having correlations with IL-4 gene in a previous study [41] , and another study indicated that the IL-4-590 C/T polymorphisms might participate in controlling parasitemia and the result could affect the severity of malaria [42] . Promoter polymorphisms of IL-4, an immune-regulatory Th2 cytokine, were proposed as being related to T2DM and might play a role in the susceptibility to T2DM [43] . Furthermore, IL-4 polymorphisms potentially contribute to evaluation of severity of rheumatoid arthritis (RA), and IL-4-590 promoter polymorphism might be correlated with elevated risk and increased activity of RA [44] . An SNP of IL-4 rs2243250 was demonstrated as being correlated with increased risk of development of Clostridium difficile infection in patients with inflammatory bowel disease [45] .