Presence of HLA‐G‐Expressing Cells Modulates the Ability of Peripheral Blood Mononuclear Cells to Release Cytokines

Abstract
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.