Objective To compare the levels of indoleamine 2,3-dioxygenase (IDO) in the peripheral blood mononuclear cells(PBMCs) from HIV-1 infected and HIV-1 negative individuals and in human tumor cells in the presence or absence of TLR ligand stimulation.Methods TaqMan probe real-time RT-PCR method for human IDO mRNA was established; IDO mRNA levels in the PBMCs from HIV-1+ and HIV-1-individuals were tested; IDO mnRNA levels in mucosal origin(T84,Caco-2,Hela) and leukocyte origin(THP-1,MT-4) tumor cells before and after exposure to agonists for TLR4,TLR7/8 and TLR9 were examined.Results It was found that a high level of IDO mRNA could be found in HIV-1+ individuals( 103.42 copy IDO mRNA/106 copy GAPDH mRNA) ; however,some high risk HIV-1-individuals may have also a high level of IDO mRNA.Some of the tumor cells could express higher level of IDO mRNA after exposure to TLR agonist.Conclusion This study indicated a role for IDO in the viral persistence and tumor formation in HIV/AIDS and further studies were warranted.

OBJECTIVETo study the expression of Toll-like receptors (TLRs) mRNA in human trophoblast HTR-8/SVneo cells and the changes in indoleamine 2,3-dioxygenase (IDO) mRNA expression in response to TLR ligand stimulation.

METHODSThe expressions of TLRs and IDO mRNA in human HTR-8/SVneo cells were tested by RT-PCR, and the changes in IDO mRNA levels after exposure to TLR3, TLR4, TLR7/8, and TLR9 ligands were quantitatively analyzed with real-time PCR.

RESULTSIDO and TLR1-10 mRNAs were expressed in HTR-8/SVneo cells. As the cell culture time extended, IDO mRNA expression level tended to increase within 48 h. After stimulation with the TLR ligands, the expression of TLR-3 mRNA was down-regulated while the expression of TLR-4, 7, 8, and 9 mRNA up-regulated. Stimulation of the cells with poly(I:C) lowered the expression of IDO mRNA while IFN-γ increased its expression.

CONCLUSIONSThe expression of IDO mRNA is associated with the nutrition of the maternal-fetal interface. Stimulation with the TLR ligands affects the expression of IDO and TLR mRNA expressions in the cells, which verifies the functional activity of TLRs and suggests a role of IDO in TLR pathway-dependent antiviral immunity.

Cell Line ; Female ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; genetics ; metabolism ; Interferon-gamma ; pharmacology ; Ligands ; Poly I-C ; pharmacology ; RNA, Messenger ; metabolism ; Toll-Like Receptors ; genetics ; metabolism ; Trophoblasts ; cytology ; metabolism