Characterization of a TGFβ-responsive Human Trophoblast-derived Cell Line

The placenta is formed by developing trophoblast cells to facilitate fluid, gas and nutrient exchange with the mother. Inappropriate trophoblast responsiveness can lead to life threatening complications during pregnancy including intrauterine growth retardation, pre-eclampsia, spontaneous abortion and malignancy that could lead to fetal loss. Transforming growth factor beta (TGFβ) is a multifunctional cytokine required for embryonic development and is an important regulator of human trophoblast function. Although TGFβ is critical for placental and embryonic development, there are currently no established TGFβ-responsive human trophoblast-derived cell lines available to study the mechanisms by which TGFβ regulates trophoblast function. Our studies have examined the transformed human trophoblast-derived cell line, ED27, to determine if it is responsive to TGFβ. Our data indicate that TGFβ dose responsively and reversibly inhibits cell growth in ED27cells and induces classic TGFβ response genes, fibronectin and plasminogen activator inhibitor 1 (PAI-1). TGFβ also induces an inhibitor of trophoblast invasion, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in ED27cells. Our studies have identified a human trophoblast-derived cell line that parallels isolated primary human trophoblasts in their responses to TGFβ. This cell line may provide us with the opportunity to determine TGFβ-mediated responses on human trophoblast functions not previously possible

Characterization of a TGFβ-responsive Human Trophoblast-derived Cell Line

The placenta is formed by developing trophoblast cells to facilitate fluid, gas and nutrient exchange with the mother. Inappropriate trophoblast responsiveness can lead to life threatening complications during pregnancy including intrauterine growth retardation, pre-eclampsia, spontaneous abortion and malignancy that could lead to fetal loss. Transforming growth factor beta (TGFβ) is a multifunctional cytokine required for embryonic development and is an important regulator of human trophoblast function. Although TGFβ is critical for placental and embryonic development, there are currently no established TGFβ-responsive human trophoblast-derived cell lines available to study the mechanisms by which TGFβ regulates trophoblast function. Our studies have examined the transformed human trophoblast-derived cell line, ED27, to determine if it is responsive to TGFβ. Our data indicate that TGFβ dose responsively and reversibly inhibits cell growth in ED27cells and induces classic TGFβ response genes, fibronectin and plasminogen activator inhibitor 1 (PAI-1). TGFβ also induces an inhibitor of trophoblast invasion, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in ED27cells. Our studies have identified a human trophoblast-derived cell line that parallels isolated primary human trophoblasts in their responses to TGFβ. This cell line may provide us with the opportunity to determine TGFβ-mediated responses on human trophoblast functions not previously possible

CD1d-Reactive T-Cell Activation Leads to Amelioration of Disease Caused by Diabetogenic Encephalomyocarditis Virus

A subset of CD161 (NK1) T cells express an invariant Vα14Jα281TCR-α chain (Vαinvt T cells) and produce Th2 and Th1cytokines rapidly in response to CD1d, but their physiological function(s) remain unclear. We have found that CD1d-reactive T cells mediate to resistance against the acute, cytopathic virus diabetogenic encephalomyocarditis virus (EMCV-D) in relatively Th1-biased,C57BL/6-based backgrounds. We show now that these results generalize toTh2-biased, hypersensitive BALB/c mice. CD1d-KO BALB/c mice were more susceptible to EMCV-D. Furthermore, α-galactosylceramide(α-GalCer), a CD1d-presented lipid antigen that specifically activates Vαinvt T cells, protected wild-type (WT) mice against EMCV-D-induced encephalitis, myocarditis, and diabetes. In contrast, neither CD1d-KO nor Jα281-KO mice were protected byα-GalCer. Finally, disease in Jα281-KO mice was comparable to WT,indicating for the first time equivalent roles for CD1d-reactiveVαinvt and noninvariant T cells in resistance to acute viral infection. A model for how CD1d-reactive T cells can initiate immune responses, which synthesizes current results, is presented

CD1d-Reactive T-Cell Activation Leads to Amelioration of Disease Caused by Diabetogenic Encephalomyocarditis Virus

A subset of CD161 (NK1) T cells express an invariant Vα14Jα281TCR-α chain (Vαinvt T cells) and produce Th2 and Th1cytokines rapidly in response to CD1d, but their physiological function(s) remain unclear. We have found that CD1d-reactive T cells mediate to resistance against the acute, cytopathic virus diabetogenic encephalomyocarditis virus (EMCV-D) in relatively Th1-biased,C57BL/6-based backgrounds. We show now that these results generalize toTh2-biased, hypersensitive BALB/c mice. CD1d-KO BALB/c mice were more susceptible to EMCV-D. Furthermore, α-galactosylceramide(α-GalCer), a CD1d-presented lipid antigen that specifically activates Vαinvt T cells, protected wild-type (WT) mice against EMCV-D-induced encephalitis, myocarditis, and diabetes. In contrast, neither CD1d-KO nor Jα281-KO mice were protected byα-GalCer. Finally, disease in Jα281-KO mice was comparable to WT,indicating for the first time equivalent roles for CD1d-reactiveVαinvt and noninvariant T cells in resistance to acute viral infection. A model for how CD1d-reactive T cells can initiate immune responses, which synthesizes current results, is presented

Innate Immune Response to Encephalomyocarditis Virus Infection Mediated by CD1d

CD1d-reactive natural killer T (NKT) cells can rapidly produce T helper type 1 (Th1) and/or Th2 cytokines, can activate antigen-presenting cell (APC) interleukin-12 (IL-12) production, and are implicated in the regulation of adaptive immune responses. The role of the CD1d system was assessed during infection with encephalomyocarditis virus (EMCV-D), a picornavirus that causes acute diabetes, paralysis and myocarditis. EMCV-D resistance depends on IL-12-mediated interferon-γ (IFN-γ) production. CD1d-deficient mice, which also lack CD1d-reactive NKT cells, were substantially more sensitive to infection with EMCV-D. Infected CD1d knockout mice had decreased IL-12 levels in vitro and in vivo, and indeed were protected by treatment with exogenous IL-12. IFN-γ production in CD1d knockout mice was decreased compared with that in wild-type (WT) mice in response to EMCV-D in vitro, although differences were not detected in vivo. Treatment with anti-asialo-GM1 antibody, to deplete NK cells, caused a marked increase in susceptibility of WT mice to EMCV-D infection, whereas CD1d knockout mice were little affected, suggesting that NK-cell-mediated protection is CD1d-dependent. Therefore, these data indicate that CD1d is essential for optimal responses to acute picornaviral infection. We propose that CD1d-reactive T cells respond to early immune signals and function in the innate immune response to a physiological viral infection by rapidly augmenting APC IL-12 production and activating NK cells