Absence of HLA-G expression in macrophages of human decidua.
OBJECTIVE
Macrophages - together with natural killer (NK) cells - constitute the majority of bone marrow derived infiltrating cells in the decidua. As interferon-gamma (IFN-gamma), a cytokine produced by NK cells, has been reported to induce expression of human leukocyte antigen (HLA-G) in monocytic cells, suggesting expression of HLA-G on decidua macrophages potentially stimulated by IFN-gamma, the question arises whether decidua macrophages in normal pregnancy express HLA-G.


METHODS
The study was based on immunohistochemistry and flow cytometry. In order to exclude that potentially elusive soluble HLA-G was not detected by immunohistochemistry, we performed in addition RT-PCR of flow-sorted decidua macrophages.


RESULTS
Our findings indicate that HLA-G is not present on macrophages of first trimester or term decidua in either membrane-bound or soluble form. Transcripts for soluble HLA-G1 and -G2 were not detected.


CONCLUSIONS
We exclude a role of HLA-G on the surface of decidua macrophages or of soluble HLA-G1 or -G2 as a secretory product of decidua macrophages with regard to interaction with HLA-G receptors present in or outside the decidua.
Sedlmayr
Peter
P
Institute of Histology and Embryology, Karl-Franzens University, Graz, Austria. peter.sedlmayr@kfunigraz.ac.at
Morales
Pedro
P
Trummer
Silvia
S
Wascher
Karin
K
Azzola
Dagmar
D
Blaschitz
Astrid
A
Hammer
Astrid
A
Walcher
Wolfgang
W
Wintersteiger
Reinhold
R
Dohr
Gottfried
G
D002460:Cell Line; D003656:Decidua / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006680:HLA Antigens / Q000276:immunology / Q000378:metabolism*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D011247:Pregnancy; D011264:Pregnancy Trimesters; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I