PROBLEM: Human leukocyte antigen-G (HLA-G) is thought to be at play in maternal-fetal immune interplay during pregnancy. Whether the expression of HLA-G protein on the target cells altered the release of cytokines from effector mononuclear cells was questioned. METHOD OF STUDY: The amounts of cytokines released from peripheral blood mononuclear cells (PBMC) cocultured with or without HLA-G-expressing target cells were compared. RESULTS: When cocultured with HLA-G-expressing target cell lines, the amounts of interleukin-3 (IL-3) and interleukin-lβ (IL-1β) released from PBMC were increased, whereas the amounts of tumor necrosis factor-α (TNF-α) were decreased.
CONCLUSIONS: Mononuclear cells, if cultured with HLA-G-expressing cells, modulate their ability to release cytokines, suggesting a role of HLA-G in triggering maternal-fetal immune interplay and thereby maintaining pregnancy.