Enhanced expression of IFI16 and RIG-I in human third-trimester placentas following HSV-1 infection.

The innate immune response in the placenta depends on the ability of maternal immune cells and fetal trophoblast cells to detect and eliminate invading pathogens through germline-encoded pattern recognition receptors (PRRs). In the present study, we analysed the transcripts and protein expression of interferon (IFN)-inducible protein (IFI)16, melanoma differentiation-associated protein 5 (MDA5), RIG-I-like receptor (RIG-I) and Toll-like receptor (TLR)-3 in third-trimester human placentas and investigated cytokine profiles generated during herpes simplex type 1 (HSV-1) infection. Decidual and chorionic villous biopsies (38-42 weeks of gestation) were obtained from healthy women immediately after a caesarean section. The expression of the DDX58 (RIG-I), IFIH1 (MDA5), IFI16 and TLR3 transcripts was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Extracellular cytokine and PRRs levels were then quantified by enzyme-linked immunosorbent assays (ELISAs). All examined PRRs genes, including DDX58, IFIH1, IFI16 and TLR3, were expressed constitutively at the mRNA and protein levels in the placental biopsies. The concentration of the IFI16 protein was increased in HSV-1-infected decidual and chorionic villous explants compared to those of mock-infected tissues (P = 0·029). Higher protein expression levels of RIG-I in both the maternal and fetal parts of the placenta were found (P = 0·009 and P = 0·004, respectively). In addition, increased production of IFN-ß by HSV-1-infected tissues was noticed (P = 0·004 for decidua, P = 0·032 for chorionic villi). No significant differences in the IFN-α, interleukin (IL)-6 and IL-8 levels were found. These results showed that HSV-1 infection can enhance the expression of IFI16 and RIG-I proteins in the human term placenta.

Cytomegalovirus DNA is highly prevalent in the blood of patients with asthma and is associated with age and asthma traits.

Cytomegalovirus (CMV) IgG antibodies have been associated with inflammaging and immunosenescence. We aimed to assess the presence of CMV DNA in the blood of adult and elderly patients with bronchial asthma to establish potential association of CMV DNAemia with asthma and asthma characteristics. Eighty-five elderly asthmatics, 74 younger asthma patients, and 114 age-matched controls were recruited. The CMV DNA was detected using commercial artus assay in 10.7% of asthma patients, but was negative in all control individuals. The secondary assay identified CMV DNA in 41.5% of asthmatics and 13.3% of control subjects (P < .001). Presence of CMV DNA was associated with an increased risk of asthma and CMV DNA copy numbers correlated with some asthma traits, including respiratory parameters and exhaled breath nitric oxide. We conclude that CMV infection is associated with asthma and may contribute to the pathogenesis of asthmatic inflammation.

Mixed infections with distinct cytomegalovirus glycoprotein B genotypes in Polish pregnant women, fetuses, and newborns.

The purpose of this investigation was to describe a distribution of cytomegalovirus (CMV) single and multiple genotypes among infected pregnant women, their fetuses, and newborns coming from Central Poland, as well as congenital cytomegaly outcome. The study involved 278 CMV-seropositive pregnant women, of whom 192 were tested for viral DNAemia. Human cytomegalovirus (HCMV) genotyping was performed for 18 of 34 pregnant women carrying the viral DNA and for 12 of their 15 offspring with confirmed HCMV infections. Anti-HCMV antibodies levels were assessed by chemiluminescence immunoassay (CLIA) and enzyme-linked fluorescence assay (ELFA) tests. Viral DNA loads and genotypes were determined by real-time polymerase chain reaction (PCR) assays for the UL55 gene. In the pregnant women, we identified HCMV gB1, gB2, gB3, and gB4 genotypes. Single gB2, gB3, or gB4 genotypes were observed in 14 (77.8 %) women, while multiple gB1-gB2 or gB2-gB3 genotypes were observed in four (22.2 %). Maternal HCMV genotypes determined the genotypes identified in their fetuses and newborns (p ≤ 0.050). Half of them were infected with single HCMV gB1, gB2, or gB3 genotypes and the other half with multiple gB1-gB2 or gB2-gB3 genotypes. Single and multiple genotypes were observed in both asymptomatic and symptomatic congenital cytomegaly, although no gB3 genotype was identified among asymptomatic cases. In Central Poland, infections with single and multiple HCMV strains occur in pregnant women, as well as in their fetuses and neonates, with both asymptomatic and symptomatic infections. HCMV infections identified in mothers seem to be associated with the viral genotypes in their children.

Decrease in 3-nitrotyrosine in the amniotic fluid of women with cytomegalovirus infection.

The aim of this study was to assess oxidative stress in pregnant women infected with cytomegalovirus on the basis of 3-nitrotyrosine levels in amniotic fluid (AF). The 3-nitrotyrosine (3-NT) level in AF was measured using the competitive ELISA method. The study groups were as follows: group I consisted of women with IgM and/or IgA; group II were women with only IgG anti-CMV antibodies and group III were seronegative women, used as the control group. Age, gestational age and socioeconomic status were also assessed. The average level of 3-nitrotyrosine in group II and the control group was similar: 53.14 nM 3-NT and 49.78 nM 3-NT, respectively. However, in group I, the lowest level 3-NT in AF was observed - 39.17 nM 3-NT and statistical analysis showed significant differences in levels of 3-NT between group I and the control group (p < 0.01). We conclude that significantly lower levels of 3-nitrotyrosine in pregnant women with CMV infection may indicate an increase in the antioxidant defence mechanisms in these patients.

Distribution of UL144, US28 and UL55 genotypes in Polish newborns with congenital cytomegalovirus infections.

Human cytomegalovirus (HCMV) is the most common congenital infection. HCMV strains display genetic variability in different regions. Distribution of HCMV genotypes in the population of congenitally infected newborns from Central Poland and viral load in newborns' blood is described and discussed. HCMV isolates were analysed by sequencing at three sites on the genome: the UL144 tumour necrosis factor-alpha (TNFα)-like receptor gene, the US28 beta-chemokine receptor gene and the UL55 envelope glycoprotein B (gB) gene. The newborns' blood was examined for HCMV DNA with a nested (UL144, UL55) or heminested (US28) polymerase chain reaction, and the genotypes were determined by sequence analysis. HCMV DNA was detectable in 25 out of 55 examined newborns born by HCMV-infected mothers (45.5%). The blood viral load in mother-infant pairs was determined. Most of the newborns had identical virus genotype, gB2 (96%), UL144 B1 (88%) and US28 A2 (84%). These genotypes were detected in all newborns with asymptomatic congenital infection. The occurrence of UL144 B1 or US28 A2 genotypes in the babies examined was significant in comparison to other genotypes (p=0.0002 and p=0.040 respectively). There was no association between specific gB subtypes in all patients groups (p=0.463). There was no correlation between HCMV genotypes and the outcome.

Constitutive and induced cytokine production by human placenta and amniotic membrane at term.

Results of our previous study on the immunity of human placenta and amniotic membranes revealed that in majority of cases these organs present constitutive non-specific antiviral immunity in the organ culture (OC) system. It is possible that interferons (IFNs), tumour necrosis factors (TNFs) and interleukin 6 (IL-6) may be responsible for the antiviral effect. Here, the constitutive and lipopolysaccharide (LPS)-induced production of these cytokines and, additionally, interleukin 10 (IL-10) were determined in OC of chorionic villi, decidua and amniotic membranes. Significant amounts of constitutive TNF-alpha (2-64 U/ml), IL-6 (200-12,000 U/ml) and IL-10 (1-70 ng/ml) were detected in the maternal decidua and chorionic villi of placenta. Amniotic membranes produced lower concentrations of the cytokines. LPS increased the production of cytokines from two- to eightfold. In contrast, activity of IFN released spontaneously was found only in four of 50 placentae and amniotic membranes. LPS and Newcastle disease virus (NDV) induced IFN production in the OC system. However, the increase of IFN after induction was also very small (up to 32 U/ml). Individual differentiation in the cytokines production was observed among placentas and amniotic membranes. TNF was identified as type alpha with addition TNF-beta, IFN as type alpha, beta and gamma.

Antiviral nonspecific immunity of human placenta at term: possible role of endogenous tumor necrosis factors and interferons.

The antiviral immunity of human placenta and amniotic membrane in an organ culture (OC) system was studied. Freshly isolated explants of most of the placentas at term and the amniotic membranes were found to be relatively resistant to herpes simplex virus type 1 (HSV-1), encephalomyocarditis virus (EMCV), and vesicular stomatitis virus (VSV) infections. After in vitro aging, however, the OC acquired the sensitivity to the viruses. In about 66%-90% of placentas, resistance of freshly isolated explants to the infection was observed. This indicates that the placentas displayed a constitutive immunity against the viruses. To study the role of endogenous cytokines in antiviral immunity, we added specific antibodies neutralizing IFN and TNF activities to VSV-infected OC and checked their influence on viral replication. Increases of 10-fold to 100-fold of VSV replication in the OC treated with anti-TNF-alpha, anti-IFN-alpha, anti-IFN-gamma or anti-IFN-beta sera were observed. The results indicate the importance of the endogenous cytokines in placental and amniotic membrane immunity. However, we did not observe a simple correlation between the spontaneous IFN and TNF production and the level of resistance against viruses. In view of the results, the participation of TNF and IFN in the constitutively expressed immunity of human placenta is of a more complex nature.

Effect of exogenous tumor necrosis factor alpha, interleukin 6 and interferons on vesicular stomatitis virus replication in human placenta and amniotic membrane organ cultures.

Effects of exogenous cytokines on replication of vesicular stomatitis virus (VSV) in amniotic membrane and placental organ cultures (OC) were studied. We compared the effects observed in OC and established human carcinoma cell lines: A549 and HEp-2. Recombinant human tumor necrosis factor alpha (rHuTNF-alpha), added to amniotic membrane, villous, or decidual OC at concentrations of 30 to 3000 U/ml, potentiated VSV replication by 10-1000 fold. Addition of 5 to 10000 U/ml of recombinant human interleukin 6 (rHuIL-6) to OC from 5 placentas was without effect on VSV growth, except one culture in which enhanced VSV replication has been observed. rHuTNF-alpha was found to have no effect on VSV growth in HEp-2 and A549 cell cultures. In contrast, the placental OC were sensitive to antiviral activity of natural interferons (IFNs): alpha, beta and recombinant IFN-gamma, although A549 cells were 5 to 10 fold more responsive to the cytokines.

[Immunologic function of the placenta and endothelium in virus infection; non-specific immunity]. / Immunologiczne funkcje lozyska i sróblonka w zakazeniach wirusowych; nieswoiste mechanizmy obronne.

A placenta constitutes a specific immune system that can protect a fetus against viral infections. We examined TNF, IFN and IL-6 production in organ cultures of human placenta and amniotic membrane. VSV replication and the cytokine production (TNF, IFN, IL-6) by human umbilical cord vein organ cultures and isolated endothelial cells were compared. We suggest that the local production of cytokines is responsible for the antiviral activity of placenta and endothelium.