David M. Svinarich

Macrophage Inflammatory Protein‐1α in Term and Preterm Parturtition: Effect of Microbial Invasion of the Amniotic Cavity

PROBLEM: This study was conducted to determine whether: (1) gestational age, parturition, and microbial invasion of the amniotic cavity (MIAC) are associated with changes in amniotic fluid concentrations of immunoreactive macrophage inflammatory protein‐1α; (2) amniotic fluid concentrations of macrophage inflammatory protein‐1α are correlated with the white blood cell count and the concentrations of interleukin‐8 in amniotic fluid.

Decreased Gene Expression of Endothelial Nitric Oxide Synthase in Newborns with Persistent Pulmonary Hypertension

Previous studies in adults have shown that chronic pulmonary hypertension is associated with decreased endothelial nitric oxide synthase (eNOS) expression in pulmonary arteries. However, the role of decreased eNOS expression in persistent pulmonary hypertension of the newborn (PPHN) is unknown. We investigated the hypothesis that umbilical vein endothelial cells cultured from infants with PPHN will have decreased eNOS expression. Umbilical cords were collected from meconium-stained infants at birth, and endothelial cells were isolated if the infants developed PPHN. Endothelial cells were grown in primary culture, and total RNA was isolated. cDNA was reverse transcribed from mRNA and amplified by PCR. An expected product of approximately 550 bp was found in all control infants but only in two of the six infants with PPHN. Identity of the PCR product was confirmed by Southern hybridization to a separate internal eNOS-specific probe. Amplification ofβ-actin cDNA, an internal control, was detected in all controls and in all infants with PPHN, including the four infants without the eNOS band. There was no difference in the course and outcome of patients with presence or absence of the eNOS band. However, there was an acidotic arterial blood pH(7.19-7.29) and intrapartum fetal heart rate decelerations in all four infants without eNOS expression. In conclusion, eNOS mRNA was detected in all normal term infants but was notably absent in the majority of infants with PPHN in this pilot study. The development of PPHN is multifactorial, and a decrease in eNOS gene expression may occur in some infants. Whether the decreased eNOS transcript is a cause of PPHN or a result of intrapartum stress remains to be determined. (Pediatr Res 44:00-00, 1998)

Detection of Human Defensins in the Placenta

PROBLEM: The placenta is a highly selective barrier against the hematogenous dissemination of infectious agents. Despite the presence of seemingly intact physical and immunologic barriers, infections nonetheless occur. These observations prompted the examination of placental tissue, amnion, and chorion for previously unrecognized protective mechanisms.

Induction and postranslational expression of G-CSF and RANTES in a first trimester trophoblast cell line by lipopolysaccharide.

PROBLEM: Comparatively little is known about the capacity of first trimester trophoblasts to respond to an infection and coordinate an immune response. This study characterizes the LPS induction of G‐CSF and RANTES in a first trimester trophoblast cell line.

Ethanol-induced expression of cytokines in a first-trimester trophoblast cell line.

OBJECTIVES Altered cytokine expression at the fetoplacental interface may be a potential mechanism for the development of fetal immune dysfunction in children with fetal alcohol syndrome. This study was conducted to determine whether first-trimester trophoblasts respond to ethanol exposure by the induction of specific cytokines. STUDY DESIGN HTR-8/SVneo trophoblast cells were cultured in vitro in the presence of either ethanol (0.5% [vol/vol]), lipopolysaccharide (1 microg/mL), or ethanol and lipopolysaccharide. Expression of granulocyte colony-stimulating factor, regulated on activation normal T cell expressed and secreted, and interleukin-6 was examined by Northern analysis and enzyme-linked immunosorbent assay. RESULTS Culture in the presence of ethanol, lipopolysaccharide, or lipopolysaccharide and ethanol resulted in the increased transcription and secretion of granulocyte colony-stimulating factor, regulated on activation normal T cell expressed and secreted, and interleukin-6 at significantly greater levels (P < .01) than control cultures. CONCLUSIONS Human first-trimester trophoblasts express high levels of cytokines when cultured in the presence of ethanol. Trophoblasts may therefore be an important exogenous source of cytokines for the fetus, and altered cytokine levels during early gestation may have an adverse effect on the development of the fetal immune system.

Induction and posttranslational expression of cytokines in a first-trimester trophoblast cell line by lipopolysaccharide

OBJECTIVES The response to infection by human first-trimester trophoblasts is a poorly understood event. This study was undertaken to determine whether first-trimester trophoblasts are capable of responding to an infection stimulus and mediating an immune response. STUDY DESIGN HTR-8/SVneo cells were exposed to lipopolysaccharide (1 microgram/ml) or media alone for either 0, 2, 4, 6, 8, or 24 hours. Northern analysis was conducted by use of a panel of antisense cytokine probes. Enzyme-linked immunosorbent assays specific for either interleukin-1 alpha, interleukin-6, interleukin-8, or transforming growth factor-beta 1 were conducted on corresponding cell culture supernatants, and the kinetics of expression were determined. RESULTS Interleukin-1 alpha, interleukin-6, interleukin-8, and transforming growth factor-beta 1 transcription occurred maximally between 2 and 8 hours of culture in media containing lipopolysaccharide, with a subsequent diminution of response. Enzyme-linked immunosorbent assay analysis corroborated lipopolysaccharide induction seen at the level of transcription, with significant posttranslational expression of these cytokines being detected between 2 and 24 hours in culture (p < 0.01). CONCLUSIONS Expression of the proinflammatory cytokines interleukin-1 alpha, interleukin-6, interleukin-8 and transforming growth factor-beta 1 strongly support the contention that human first-trimester trophoblasts are capable of responding to an infection stimulus and eliciting an immune response through cytokine-based immune signaling.

The mouse lysyl oxidase gene (Lox) resides on chromosome 18.

Lysyl oxidase initiates crosslink formation of the connective tissue matrix. This enzyme can also revert the ras phenotype in mouse NIH 3T3-transformed cells. Even though lysyl oxidase may participate in many different biological processes, its chromosomal assignment in the mouse genome remains to be addressed. Southern analysis of a panel of Chinese hamster x mouse somatic cell hybrids was utilized to assign the lysyl oxidase gene (Lox) to mouse Chromosome 18.

Human trophoblast cell adhesion to extracellular matrix protein, entactin.

PROBLEM: Trophoblast interaction with endometrial extracellular matrix (ECM) is crucial during human embryo implantation and placentation. Entactin, a ubiquitous basement membrane glycoprotein, plays a central role in ECM assembly, cell attachment, and chemotaxis. The present study was conducted to examine the possible role of entactin in promoting human trophoblast adhesion.

Detection of cytomegalovirus in the meconium of infected newborns by polymerase chain reaction.

OBJECTIVE: Congenital cytomegalovirus (CMV) infection is a leading cause of hearing loss and mental retardation throughout the world. Detection of the CMV DNA by polymerase chain reaction (PCR) offers a sensitive, rapid, and specific means of identification. Meconium, the stool formed in utero, may be an ideal specimen for CMV detection. The objective of this study was to develop a PCR-based methodology for the detection of CMV in the meconium of neonates. METHODS: Meconium was collected from 10 newborn infants (seven with positive viral cultures and three uninfected infants born to CMV-seropositive mothers). For each, DNA was isolated from meconium by organic extraction and attachment to a DNA-binding matrix, and PCR was performed using amplimers specific for the major intermediate early (MIE) and late antigenic (LA) regions of CMV. RESULTS: Gel electrophoresis demonstrated an anticipated PCR product of 250 base pairs (bp) corresponding to the MIE region of CMV in all infected and positive control meconium samples. Furthermore, a single band of 150 bp corresponding to the LA region of CMV was also amplified in several of the infected infants. Conversely, no amplification of these antigenic regions was noted in either uninfected infants born to CMV-seropositive mothers or negative controls. CONCLUSIONS: CMV is present within the meconium of infected neonates and is readily detectable by PCR.

Effect of imiquimod on cytokine induction in first trimester trophoblasts

OBJECTIVES: Imiquimod (IQ) is used clinically for the topical treatment of external genital warts. IQ is an immune response modifier and induces the expression of interferon-alpha and other cytokines in human Peripheral Blood Monocytes (PBMC). Trophoblasts have been previously shown to express inflammatory cytokines upon lipopolysaccharide (LPS) stimulation. The objective of this study was to evaluate the ability of IQ to induce transcription of cytokines in trophoblasts. METHODS: A transformed human first trimester trophoblast cell line, HTR-8/SVneo, was cultured in DMEM containing IQ at concentrations of 0 to 5.0 microg/ml. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) viability assays were conducted to control for any drug-induced cell death. Total RNA was isolated from trophoblasts at 0, 8 and 24 hours of culture and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was conducted using specific amplimers for the inflammatory cytokines interleukin (IL)-1alpha, IL-1beta, IL-6 and IL-8. RT-PCR of beta-actin was performed to control for equal RNA loading. RESULTS: RT-PCR was unable detect an increase in either IL-1alpha, IL-1beta, IL-6 or IL-8 mRNA in first trimester trophoblasts cultured in the presence of 0 to 5.0 microg/mL of IQ for up to 24 hours. RT-PCR confirmed equal RNA loading and MTT viability assays did not show loss of cell viability at concentrations of IQ up to 5.0 microg/ml. CONCLUSIONS: IQ, at the concentrations tested, did not induce the transcriptional expression of inflammatory cytokines in human first trimester trophoblasts. These data suggest that IQ would not induce the expression of inflammatory cytokines in placental trophoblasts.