Seminal plasma and CD4+ T‑cell cytokine profiles in the in vitro fertilization success

Background: Abnormal female immune response is one of the potential causes of unexplained infertility (UI). Seminal plasma (SP) is an important regulator of female immune responses during pregnancy. This study investigated a SP effect on the expression of CD4+ T‑cell‑related cytokines in a group of UI woman candidates for in vitro fertilization (IVF) and healthy fertile women. Materials and Methods: This was a semi‑experimental study that performed on 20 UI couples (ten unsuccessful and ten successful IVF outcomes) and 10 fertile couples as the healthy group. CD4+ T‑cells were separated from peripheral blood mononuclear cells of women by magnetic‑activated cell sorting technique and incubated with (stimulated condition) or without (unstimulated condition) SP of their husbands. After incubation, real‑time polymerase chain reaction method was used to investigate interleukin (IL)‑23, IL‑17, IL‑4, IL‑10, transforming growth factor (TGF)‑β, and interferon (IFN)‑γ gene expression. Mann–Whitney U‑test, Kruskal–Wallis test, and Wilcoxon signed‑rank test were used for statistical analysis. Results: Baseline TCD4+ mRNA levels of IL‑23 (P = 0.03) and TGF‑β (P = 0.01) were different between healthy and infertile groups. However, IL‑17, IL‑4, IFN‑γ, and IL‑10 were expressed similarly regardless of fertility status. Comparing mRNA expression before and after SP exposure, our results have shown that relative expression of IL‑23 significantly increased in successful (P = 0.04) and unsuccessful IVF groups (P = 0.01), whereas IL‑10 expression increased only in the IVF failure group (P = 0.01). Conclusion: SP can make a positive effect on IVF outcome through alteration in CD4 + T‑cell‑related cytokines expression, especially IL‑10 and IL‑23.