Cytokine gene polymorphism and Chlamydia trachomatis-specific immune responses

Chlamydia trachomatis-induced fallopian tube damage leading to tubal factor infertility (TFI) is linked with TNF, IL-10, and probably IFNG gene polymorphisms. The aim of this study was to clarify the contribution of these cytokine gene polymorphisms to interindividual variation in C trachomatis-specific immune responses and the cross-regulation of secreted cytokines and single nucleotide polymorphisms (SNPs). Cytokine polymorphisms (IL-10 -1082A/G, -819T/C, and -592A/C, IFNG +874T/A, and TNF -308G/A) were genotyped by polymerase chain reaction in 139 women. C trachomatis-specific immune responses were measured using lymphocyte proliferation (LP) induced by C trachomatis E and F strains and chlamydial heat shock protein 60 antigens. Cytokine secretion was measured in culture supernatants of infected and uninfected mononuclear leukocytes. IL-10 -1082/-819/-592 and IFNG +874 SNPs were associated with the intensity of LP responses to C trachomatis antigens. These cytokines also interact with each other and a cumulative effect of IL-10 -1082 and IFNG +874 genotypes was seen in LP responses to C trachomatis antigens. Our data suggest that interleukin-10 and interferon-γ regulate C trachomatis-specific immune responses in humans and that genetic variation in the expression of their coding genes explains interindividual variation in host immune responses to C trachomatis infection.