HLA-G promotes myeloid-derived suppressor cell accumulation and suppressive activity during human pregnancy through engagement of the receptor ILT4.
Article Details
- CitationCopy to clipboard
Kostlin N, Ostermeir AL, Spring B, Schwarz J, Marme A, Walter CB, Poets CF, Gille C
HLA-G promotes myeloid-derived suppressor cell accumulation and suppressive activity during human pregnancy through engagement of the receptor ILT4.
Eur J Immunol. 2017 Feb;47(2):374-384. doi: 10.1002/eji.201646564. Epub 2016 Dec 9.
- PubMed ID
- 27859042 [ View in PubMed]
- Abstract
Establishing and maintaining maternal-fetal tolerance is essential for a successful pregnancy; failure of immunological adaptation to pregnancy leads to severe complications such as abortion or preterm delivery. Myeloid-derived suppressor cells (MDSCs) are innate immune cells that suppress T-cell responses, expand during pregnancy and thus may play a role in tolerance induction. Human leucocyte antigen G (HLA-G) is a major histocompatibility complex (MHC) I molecule with immune-modulatory properties, which is expressed during pregnancy. Here, we investigated the impact of HLA-G on MDSCs accumulation and activation in pregnant women. We demonstrate that granulocytic MDSCs (GR-MDSCs) express receptors for HLA-G, namely immunoglobulin-like transcript (ILT) 2 and 4, and that ILT4-expression by GR-MDSCs is regulated during pregnancy. Stimulation with soluble HLA-G (sHLA-G) increased suppressive activity of GR-MDSCs, induced MDSCs from peripheral blood mononuclear cells (PBMCs) and led to phosphorylation of the signal transducer and activator of transcription 3 (STAT3) and induction of indoleamine-2,3-dioxygenase (IDO) in myeloid cells. Effects of sHLA-G on MDSC accumulation were mediated through ILT4. These results suggest an interaction between MDSCs and HLA-G in humans as a potential mechanism for maintaining maternal-fetal tolerance. Modulating MDSC function during pregnancy via HLA-G might provide new opportunities for a therapeutic manipulation of immunological pregnancy complications.