First-trimester human chorionic villi express both immunoregulatory and inflammatory cytokines: a role for interleukin-10 in regulating the cytokine network of pregnancy.
OBJECTIVE
T-helper 2 (TH2)-type cytokines [i.e., interleukin (IL)-6, IL-10, and IL-13] and transforming growth factor (TGF)-beta are expressed by the murine decidua and/or placenta and are likely to suppress inflammatory cytokine [i.e., IL-2, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-1 alpha, and IL-1 beta] production at the maternal-fetal interface. In addition, class I IFNs may protect the fetus from immunologic rejection and viral infections. This study examines the expression of inflammatory/immunoregulatory cytokines and IL-10 production by first-trimester chorionic villi.


METHODS
Gestational tissues (n = 5) were obtained following elective terminations performed between 7 and 9 weeks of gestation. Chorionic villous tissues were separated from fetal membranes and decidua, and total RNA was extracted. Cytokine expression was assessed by a reverse transcriptase-polymerase chain reaction technique. Chorionic villi (n = 9; 6-12 weeks gestation) were maintained in organ culture, and human chorionic gonadotropin (hCG) and IL-10 levels were determined by immunoradiometric and enzyme-linked immunosorbent assays, respectively.


RESULTS
IFN-gamma and IL-2 were generally not expressed by first-trimester chorionic villi. Low to moderate levels of expression were noted for IL-1 alpha, IL-1 beta, and TNF-alpha. High levels of mRNA were noted for IFN-alpha and IFN-beta, but IFN-tau was not expressed. In all tissues, TGF-beta 1 and IL-13 were either weakly expressed or not expressed. In contrast, moderate to high levels of IL-6 and IL-10 mRNA were detected in each chorionic villous sample. In chorionic villous explants obtained at 6-11 weeks gestation production of hCG and IL-10 was greatest during the first 24 hr ([hCG] = 6961 +/- 815 mIU/mL, [IL-10] = 92 +/- 11 pg/mL) and then declined through 72 hr.


CONCLUSIONS
TH1-type cytokines (IL-2, IFN-gamma) are not expressed by first-trimester chorionic villous tissues: This is possibly due to local production of IL-10. In contrast, macrophage-associated cytokines (IL-1 beta and TNF-alpha) are expressed and their regulation may be critical for fetal survival. Finally, class 1 IFNs expressed by early chorionic tissues may protect the fetus from maternal rejection and viral transmission.
Bennett
W A
WA
Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, USA.
Lagoo-Deenadayalan
S
S
Whitworth
N S
NS
Stopple
J A
JA
Barber
W H
WH
Hale
E
E
Brackin
M N
MN
Cowan
B D
BD
D000028:Abortion, Induced; D006063:Chorionic Gonadotropin / Q000096:biosynthesis; D002824:Chorionic Villi / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000502:physiology; D009924:Organ Culture Techniques; D011247:Pregnancy / Q000276:immunology*; D011261:Pregnancy Trimester, First; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
D006063:Chorionic Gonadotropin; D016207:Cytokines; D012333:RNA, Messenger; D016753:Interleukin-10