Expression patterns of lectin-like natural killer receptors, inhibitory CD94/NKG2A, and activating CD94/NKG2C on decidual CD56bright natural killer cells differ from those on peripheral CD56dim natural killer cells.
The balance of inhibitory and activating natural killer (NK) receptors on maternal decidual NK cells, most of which are CD56bright, is thought to be crucial for the proper growth of trophoblasts in placenta. A lectin-like NK receptor, CD94/NKG2, is the receptor for human leukocyte antigen (HLA)-E, which is expressed on trophoblasts. To clarify the mechanism regulating the activity of decidual NK cells during pregnancy, we investigated the expression patterns of inhibitory NK receptor, CD94/NKG2A, and activating receptor, CD94/NKG2C, on decidual NK cells in an early stage of normal pregnancy and compared them with those on peripheral NK cells, most of which are CD56dim. The rate of NKG2A-positive cells was significantly higher for decidual CD56bright NK cells than for peripheral CD56dim NK cells, but the rates of NKG2C-positive cells were comparable between the two cell types. Interestingly, peripheral CD56dim NK cells reciprocally expressed inhibitory NKG2A and activating NKG2C, but decidual CD56bright NK cells that expressed activating NKG2C simultaneously expressed inhibitory NKG2A. The co-expression of inhibitory and activating NKG2 receptors may fine-tune the immunoregulatory functions of the decidual NK cells to control the trophoblast invasion in constructing placenta.
Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Maki
M
Kusumi
Takahiro
T
Yamashita
Tomoyuki
T
Fujii
Takeshi
T
Nagamatsu
Shiro
S
Kozuma
Yuji
Y
Taketani
D019002:CD56 Antigen / Q000096:biosynthesis / Q000276:immunology*; D003656:Decidua / Q000166:cytology / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type / Q000276:immunology; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D / Q000096:biosynthesis / Q000276:immunology*; D011247:Pregnancy; D011956:Receptors, Cell Surface / Q000276:immunology; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000276:immunology; D055607:Receptors, Natural Killer Cell; D014327:Trophoblasts / Q000166:cytology / Q000276:immunology
D019002:CD56 Antigen; C400041:CLEC2D protein, human; C527054:KLRC1 protein, human; C527059:KLRC2 protein, human; C497869:KLRD1 protein, human; D037181:Lectins, C-Type; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D055607:Receptors, Natural Killer Cell