Interleukin-2 Production by Cultured Human Granulosa Cells

Problem: Ovarian hyperstimulation syndrome (OHSS) is similar to vascular leak syndrome (VLS), which may be attributable to the massive increase in systemic inflammatory cytokines. The hyperstimulated human ovaries were demonstrated to contain interleukin (IL)-2, which, in turn, was suggested to activate the systemic inflammatory response characteristic of OHSS. As the source of follicular fluid IL-2 is still unclear, in the present study, we sought to validate the presence of IL-2 and IL-2 mRNA expression in human luteinized granulosa cells. Method of Study: IL-2 nuclear expression was detected using real-time PCR and immunofluorescence staining of human luteinized granulosa cell from 6 patients undergoing in vitro fertilization treatment. Calretinin immunofluorescence staining was used as a marker of granulosa cells. Results: IL-2-positive immunofluorescence staining was detected within nuclei of granulosa cells, together with positive stain for calretinin, confirming the presence of granulosa cell. Moreover, IL-2 gene expression was demonstrated in luteinized granulosa cells by real-time PCR. Conclusion: In the present study, we provided firm evidence for the IL-2 production by human luteinized granulosa cells, as demonstrated by the presence of IL-2 and IL-2 mRNA expression in luteinized granulosa cells. Further studies are justified in an attempt to clarify the regulation and the cause-and-effect relationship between IL-2 production by the hyperstimulated ovaries and OHSS.