Interleukin-10 receptors are expressed by basement membrane anchored, alpha(6) integrin(+) cytotrophoblast cells in early human placenta.
Cytotrophoblast cells produce interleukin (IL)-10 and express IL-10 receptor mRNA in culture. Furthermore, IL-10 dramatically reduces the synthesis of matrix metalloproteinase (MMP)-9 and the invasivity of cytotrophoblast cells in vitro, suggesting that an autocrine regulatory role in vivo is also possible. To test this hypothesis we investigated the expression of IL-10 receptor protein by first trimester cytotrophoblasts both in vitro and in situ, using flow cytometry and immunohistochemistry. Flow cytometric analyses demonstrated that 75-80% of cytotrophoblasts are able to bind labelled IL-10, suggesting that these cells possess IL-10 receptors in vitro. Serial sections of early human placentae stained for either alpha(5) and alpha(6) integrin subunits, or for IL-10 receptors respectively, revealed that placental cytotrophoblasts possess cell surface IL-10 receptors not only in vitro, but also in vivo. IL-10 receptors were present mainly on alpha(6) integrin expressing villous cytotrophoblast cells and on alpha(6)-positive cells of invasive cell columns located nearest the villous stroma. Differentiated trophoblasts (i.e. alpha(5)-positive cells and villous syncytiotrophoblasts) showed no reactivity. This differential expression of IL-10 receptors suggests that IL-10 might suppress the invasivity of undifferentiated cytotrophoblast cells, in vivo, preserving their non-invasive state in an autocrine manner. The possible involvement in cytotrophoblast proliferation and/or differentiation is also discussed.
Szony
B J
BJ
Department of Obstetrics and Gynaecology, WHO Collaborative Centre for Research in Human Reproduction, Albert Szent-Györgyi Medical University, Szeged, H-6725, Hungary.
Bata-Csörgo
Z
Z
Bártfai
G
G
Kemény
L
L
Dobozy
A
A
Kovács
L
L
D015703:Antigens, CD / Q000378:metabolism*; D001485:Basement Membrane / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D039503:Integrin alpha6; D010920:Placenta / Q000166:cytology / Q000378:metabolism; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism; D018123:Receptors, Interleukin / Q000096:biosynthesis*; D053701:Receptors, Interleukin-10; D014327:Trophoblasts / Q000378:metabolism*
D015703:Antigens, CD; D039503:Integrin alpha6; D018123:Receptors, Interleukin; D053701:Receptors, Interleukin-10