Unusual apparently constitutive interferons and antagonists in human placental blood.

Abstract

We have detected seemingly uninduced interferons (IFNs) Chromatographic Products. Sephadex G-25 medium in pre-packed PD 10 columns, concanavalin A (Con A)-Sepharose and Blue Sepharose CL-6B (group-specific adsorbents), cyanogen bromide-activated Sepharose 4B, and activated CH-Sepharose 4B (coupling gels for antiserum immobilization), and acrylamide were purchased from Pharmacia. The standard proteins used for calibration of the slab gels were also from Pharmacia.Biological Preparations. Human placentas were collected shortly after caesarian section between the 37th week (calculated on the basis of amenorrhea and sonar exploration) and delivery. Most of the women were in the 39th week, corresponding to a fetal age of 37 weeks. In two additional cases, products of therapeutic abortion by vacuum aspiration in the 10th and 17th weeks of development were studied.Fetal membranes were separated from the placenta, washed carefully one to five times in 500 ml of saline (0.15 M NaCl, pH 7), then incubated with Eagle's minimal essential medium (MEM), supplemented with 10%o heat-inactivated newborn calf serum, at 370C for 18 hr.Blood from the umbilical cord was collected. The whole placenta was then compressed for 3 hr under 0.15 kg/cm2 (15 kPa) to squeeze out the blood, which was analyzed.Cells and Viruses. Human diploid fibroblasts (F7000, Flow Laboratories) were grown in Eagle's basal medium (BME) supplemented with nonessential amino acids, 2 mM glutamine, and 10% heat-inactivated fetal calf serum. Human amnion (WISH), bovine kidney (MDBK), and mouse L929 cells, in continuous cultivation, and rat fibroblasts (REF) in secondary subcultures, were grown in Eagle's MEM supplemented with 10% heat-inactivated newborn calf serum. Normal rat kidney (NRK) cells were grown in RPMI 1629 medium, supplemented with 10% fetal calf serum and 4 mM glutamine.Vesicular stomatitis virus (VSV), Indiana strain, and encephalomyocarditis (EMC) virus were grown on L929 cells and titrated by plaque-forming unit assay. EMC virus titer was also evaluated by human erythrocyte (O+ group) agglutination.Affinity Chromatography on Con A-Sepharose. IFN preparations were applied to a Sephadex G-25 M PD 10 column (1.5 x 5 cm), previously equilibrated with 0.02 M sodium phosphate, pH 7.2/1 M NaCl (buffer EO) and eluted with the same buffer. The breakthrough active fractions (5 ml) were applied on 5 ml of Con A-Sepharose in a column (IBF 11, 1.14 x 10 cm) equilibrated with buffer EO at room temperature at a flow rate of 4.5 ml/hr, according to a previously described procedure (10,11 5010The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Interferon Production by Cultured Human Trophoblasts and Choriocarcinoma Cell Lines Induced by Sendai Virus

“…The IFN produced by Sendai virus-induced trophoblasts seems to be distinct from that released from Sendai virus-infected human amniotic membrane (Duc-Goiran et al, 1983) and from that detected in human placental blood (Duc-Goiran et al, 1985). The latter two IFNs consist of ~ and B species as well as three other species neutralized to almost the same extent by IFN-~ and IFN-fl antibodies.…”

Constitutive and trophoblast-specific expression of a class of bovine interferon genes.

“…The discovery that the bovine TP-1 promoter was active in JAR cells was surprising since these cells do not normally produce IFN unless induced by virus. IFN production by human placental tissues has been widely reported (1), and suggestions of a human placental-specific IFN have been made (47)(48)(49). Antiviral activity suggestive of IFN is associated with the conceptus and placenta in mice (50,51), hamsters (52), and pigs (27).…”

Characterization Of Sendai Virus-Induced Human Placental Trophoblast Interferons

“…Several workers (Chard et al, 1986;Duc-Goiran et al, 1985;Bocci et al, 1985) have reported the presence of IFN<t and -fl in amniotic fluids and specimens from placentae, however the cellular origins of these IFNs have not been identified. Besides IFN-~ and -fl, Chin et al (1986) have reported that IFN-~ is produced by placental lymphocytes, monocytes and granulocytes after phytohaemagglutinin and interleukin 2 stimulation.…”