scholarly journals The Placental Response to Guinea Pig Cytomegalovirus Depends Upon the Timing of Maternal Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Zachary W. Berkebile ◽  
Dira S. Putri ◽  
Juan E. Abrahante ◽  
Davis M. Seelig ◽  
Mark R. Schleiss ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Digital Pcr ◽  
Maternal Infection ◽  
Junctional Zone ◽  
Viral Loads ◽  
Susceptibility To Infection ◽  
Increased Risk ◽  
Guinea Pig Cytomegalovirus ◽  
Infected Cells ◽  
Adverse Pregnancy

Human cytomegalovirus (HCMV) infects the placenta, and these placental infections can cause fetal injury and/or demise. The timing of maternal HCMV infection during pregnancy is a determinant of fetal outcomes, but how development affects the placenta’s susceptibility to infection, the likelihood of placental injury post-infection, and the frequency of transplacental HCMV transmission remains unclear. In this study, guinea pig cytomegalovirus (GPCMV) was used to model primary maternal infection and compare the effects of infection at two different times on the placenta. When guinea pigs were infected with GPCMV at either 21- or 35-days gestation (dGA), maternal and placental viral loads, as determined by droplet digital PCR, were not significantly affected by the timing of maternal infection. However, when the transcriptomes of gestational age-matched GPCMV-infected and control placentas were compared, significant infection-associated changes in gene expression were only observed after maternal infection at 35 dGA. Notably, transcripts associated with immune activation (e.g. Cxcl10, Ido1, Tgtp1, and Tlr8) were upregulated in the infected placenta. A GPCMV-specific in situ hybridization assay detected rare infected cells in the main placenta after maternal infection at either time, and maternal infection at 35 dGA also caused large areas of GPCMV-infected cells in the junctional zone. As GPCMV infection after mid-gestation is known to cause high rates of stillbirth and/or fetal growth restriction, our results suggest that the placenta becomes sensitized to infection-associated injury late in gestation, conferring an increased risk of adverse pregnancy outcomes after cytomegalovirus infection.

scholarly journals Targeted Mutagenesis of Guinea Pig Cytomegalovirus Using CRISPR/Cas9-Mediated Gene Editing

2016 ◽  
Vol 90 (15) ◽  
pp. 6989-6998 ◽  
Author(s):  
Craig J. Bierle ◽  
Kaitlyn M. Anderholm ◽  
Jian Ben Wang ◽  
Michael A. McVoy ◽  
Mark R. Schleiss
Keyword(s):  
Guinea Pig ◽  
Viral Genome ◽  
Genetic Manipulation ◽  
Spontaneous Mutation ◽  
Lytic Replication ◽  
Targeted Mutagenesis ◽  
Bacterial Artificial Chromosomes ◽  
Artificial Chromosomes ◽  
Guinea Pig Cytomegalovirus ◽  
Infected Cells

ABSTRACTThe cytomegaloviruses (CMVs) are among the most genetically complex mammalian viruses, with viral genomes that often exceed 230 kbp. Manipulation of cytomegalovirus genomes is largely performed using infectious bacterial artificial chromosomes (BACs), which necessitates the maintenance of the viral genome inEscherichia coliand successful reconstitution of virus from permissive cells after transfection of the BAC. Here we describe an alternative strategy for the mutagenesis of guinea pig cytomegalovirus that utilizes clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated genome editing to introduce targeted mutations to the viral genome. Transient transfection and drug selection were used to restrict lytic replication of guinea pig cytomegalovirus to cells that express Cas9 and virus-specific guide RNA. The result was highly efficient editing of the viral genome that introduced targeted insertion or deletion mutations to nonessential viral genes. Cotransfection of multiple virus-specific guide RNAs or a homology repair template was used for targeted, markerless deletions of viral sequence or to introduce exogenous sequence by homology-driven repair. As CRISPR/Cas9 mutagenesis occurs directly in infected cells, this methodology avoids selective pressures that may occur during propagation of the viral genome in bacteria and may facilitate genetic manipulation of low-passage or clinical CMV isolates.IMPORTANCEThe cytomegalovirus genome is complex, and viral adaptations to cell culture have complicated the study of infectionin vivo. Recombineering of viral bacterial artificial chromosomes enabled the study of recombinant cytomegaloviruses. Here we report the development of an alternative approach using CRISPR/Cas9-based mutagenesis in guinea pig cytomegalovirus, a small-animal model of congenital cytomegalovirus disease. CRISPR/Cas9 mutagenesis can introduce the same types of mutations to the viral genome as bacterial artificial chromosome recombineering but does so directly in virus-infected cells. CRISPR/Cas9 mutagenesis is not dependent on a bacterial intermediate, and defined viral mutants can be recovered after a limited number of viral genome replications, minimizing the risk of spontaneous mutation.

scholarly journals Repair of a Mutation Disrupting the Guinea Pig Cytomegalovirus Pentameric Complex Acquired during Fibroblast Passage Restores Pathogenesis in Immune-Suppressed Guinea Pigs and in the Context of Congenital Infection

2016 ◽  
Vol 90 (17) ◽  
pp. 7715-7727 ◽  
Author(s):  
Michael A. McVoy ◽  
Jian Ben Wang ◽  
Dirk P. Dittmer ◽  
Craig J. Bierle ◽  
Elizabeth C. Swanson ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Guinea Pig ◽  
Viral Entry ◽  
Guinea Pigs ◽  
Congenital Infection ◽  
Artificial Chromosome ◽  
Cell Types ◽  
Content Type ◽  
Viral Loads ◽  
Guinea Pig Cytomegalovirus

ABSTRACTGuinea pig cytomegalovirus (GPCMV) provides a valuable model for congenital cytomegalovirus transmission. Salivary gland (SG)-passaged stocks of GPCMV are pathogenic, while tissue culture (TC) passage in fibroblasts results in attenuation. Nonpathogenic TC-derived virus N13R10 (cloned as a bacterial artificial chromosome [BAC]) has a 4-bp deletion that disruptsGP129, which encodes a subunit of the GPCMV pentameric complex (PC) believed to govern viral entry into select cell types, andGP130, an overlapping open reading frame (ORF) of unknown function. To determine if this deletion contributes to attenuation of N13R10, markerless gene transfer inEscherichia coliwas used to construct virus r129, a variant of N13R10 in which the 4-bp deletion is repaired. Virions from r129 were found to contain GP129 as well as two other PC subunit proteins, GP131 and GP133, whereas these three PC subunits were absent from N13R10 virions. Replication of r129 in fibroblasts appeared unaltered compared to that of N13R10. However, following experimental challenge of immunocompromised guinea pigs, r129 induced significant weight loss, longer duration of viremia, and dramatically higher (up to 1.5 × 106-fold) viral loads in blood and end organs compared to N13R10. In pregnant guinea pigs, challenge with doses of r129 virus of ≥5 × 106PFU resulted in levels of maternal viremia, congenital transmission, pup viral loads, intrauterine growth restriction, and pup mortality comparable to that induced by pathogenic SG virus, although higher doses of r129 were required. These results suggest that theGP129-GP130mutation is a significant contributor to attenuation of N13R10, likely by abrogating expression of a functional PC.IMPORTANCETissue culture adaptation of cytomegaloviruses rapidly selects for mutations, deletions, and rearrangements in the genome, particularly for viruses passaged in fibroblast cells. Some of these mutations are focused in the region of the genome encoding components of the pentameric complex (PC), in particular homologs of human cytomegalovirus (HCMV) proteins UL128, UL130, and UL131A. These mutations can attenuate the course of infection when the virus is reintroduced into animals for vaccine and pathogenesis studies. This study demonstrates that a deletion that arose during the process of tissue culture passage can be repaired, with subsequent restoration of pathogenicity, using BAC-based mutagenesis. Restoration of pathogenicity by repair of a frameshift mutation in GPCMV geneGP129using this approach provides a valuable genetic platform for future studies using the guinea pig model of congenital CMV infection.

scholarly journals Dramatic Effects of 2-Bromo-5,6-Dichloro-1-β-d-Ribofuranosyl Benzimidazole Riboside on the Genome Structure, Packaging, and Egress of Guinea Pig Cytomegalovirus

2004 ◽  
Vol 78 (4) ◽  
pp. 1623-1635 ◽  
Author(s):  
Daniel E. Nixon ◽  
Michael A. McVoy
Keyword(s):  
Guinea Pig ◽  
Inhibitory Concentration ◽  
Unit Length ◽  
Genome Structure ◽  
Nuclease Digestion ◽  
Guinea Pig Cytomegalovirus ◽  
Infected Cells ◽  
Terminal Structure ◽  
The Right ◽  
Striking Contrast

ABSTRACT The halogenated benzimidazoles BDCRB (2-bromo-5,6-dichloro-1-β-d-riborfuranosyl benzimidazole riboside) and TCRB (2,5,6-trichloro-1-β-d-riborfuranosyl benzimidazole riboside) were the first compounds shown to inhibit cleavage and packaging of herpesvirus genomes. Both inhibit the formation of unit length human cytomegalovirus (HCMV) genomes by a poorly understood mechanism (M. R. Underwood et al., J. Virol. 72:717-715, 1998; P. M. Krosky et al., J. Virol. 72:4721-4728, 1998). Because the simple genome structure of guinea pig cytomegalovirus (GPCMV) provides a useful model for the study of herpesvirus DNA packaging, we investigated the effects of BDCRB on GPCMV. GPCMV proved to be sensitive to BDCRB (50% inhibitory concentration = 4.7 μM), although somewhat less so than HCMV. In striking contrast to HCMV, however, a dose of BDCRB sufficient to reduce GPCMV titers by 3 logs (50 μM) had no effect on the quantity of GPCMV genomic DNA that was formed in infected cells. Electron microscopy revealed that this DNA was in fact packaged within intranuclear capsids, but these capsids failed to egress from the nucleus and failed to protect the DNA from nuclease digestion. The terminal structure of genomes formed in the presence of BDCRB was also altered. Genomes with ends lacking a terminal repeat at the right end, which normally exist in an equimolar ratio with those having one copy of the repeat at the right end, were selectively eliminated by BDCRB treatment. At the left end, BDCRB treatment appeared to induce heterogeneous truncations such that 2.7 to 4.9 kb of left-end-terminal sequences were missing. These findings suggest that BDCRB induces premature cleavage events that result in truncated genomes packaged within capsids that are permeable to nuclease. Based on these and other observations, we propose a model for duplication of herpesvirus terminal repeats during the cleavage and packaging process that is similar to one proposed for bacteriophage T7 (Y. B. Chung, C. Nardone, and D. C. Hinkle, J. Mol. Biol. 216:939-948, 1990).

The Need for Personalized Risk-Stratified Approaches to Treatment for Gestational Diabetes: A Narrative Review

2021 ◽  
Author(s):  
Shamil D. Cooray ◽  
Jacqueline A. Boyle ◽  
Georgia Soldatos ◽  
Shakila Thangaratinam ◽  
Helena J. Teede
Keyword(s):  
Gestational Diabetes ◽  
Pregnancy Outcomes ◽  
Population Based ◽  
Adverse Pregnancy Outcomes ◽  
Therapeutic Interventions ◽  
Clinical Prediction Model ◽  
Increased Risk ◽  
Adverse Pregnancy ◽  
The Individual ◽  
Personalized Risk

AbstractGestational diabetes mellitus (GDM) is common and is associated with an increased risk of adverse pregnancy outcomes. However, the prevailing one-size-fits-all approach that treats all women with GDM as having equivalent risk needs revision, given the clinical heterogeneity of GDM, the limitations of a population-based approach to risk, and the need to move beyond a glucocentric focus to address other intersecting risk factors. To address these challenges, we propose using a clinical prediction model for adverse pregnancy outcomes to guide risk-stratified approaches to treatment tailored to the individual needs of women with GDM. This will allow preventative and therapeutic interventions to be delivered to those who will maximally benefit, sparing expense, and harm for those at a lower risk.

scholarly journals Adverse Pregnancy Outcomes by Degree of Maternal Serum Analyte Elevation: A Retrospective Cohort Study

2020 ◽  
Vol 10 (04) ◽  
pp. e369-e379
Author(s):  
Amanda Yeaton-Massey ◽  
Rebecca J. Baer ◽  
Larry Rand ◽  
Laura L. Jelliffe-Pawlowski ◽  
Deirdre J. Lyell
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Screening Program ◽  
Maternal Serum ◽  
Obstetric Complication ◽  
Patient Counseling ◽  
Increased Risk ◽  
Antenatal Management ◽  
Adverse Pregnancy

Abstract Objective The aim of this study was to evaluate rates of preterm birth (PTB) and obstetric complication with maternal serum analytes > 2.5 multiples of the median (MoM) by degree of elevation. Study Design Retrospective cohort study of singleton live-births participating in the California Prenatal Screening Program (2005–2011) examining PTB and obstetric complication for α-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3), and inhibin A (INH) by analyte subgroup (2.5 to < 6.0, 6.0 to < 10.0, and ≥ 10.0 MoM vs. < 2.5 MoM). Results The risk of obstetric complication increased with increasing hCG, AFP, and INH MoM, and were greatest for AFP and INH of 6.0 to <10.0 MoM. The greatest risk of any adverse outcome was seen for hCG MoM ≥ 10.0, with relative risk (RR) of PTB < 34 weeks of 40.8 (95% confidence interval [CI]: 21.7–77.0) and 13.8 (95% CI: 8.2–23.1) for obstetric complication. Conclusions In euploid, structurally normal fetuses, all analyte elevations > 2.5 MoM confer an increased risk of PTB and, except for uE3, obstetric complication, and risks for each are not uniformly linear. These data can help guide patient counseling and antenatal management.

scholarly journals Adolescent, Pregnant, and HIV-Infected: Risk of Adverse Pregnancy and Perinatal Outcomes in Young Women from Southern Mozambique

2021 ◽  
Vol 10 (8) ◽  
pp. 1564
Author(s):  
Clara Pons-Duran ◽  
Aina Casellas ◽  
Azucena Bardají ◽  
Anifa Valá ◽  
Esperança Sevene ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Maternal Morbidity ◽  
Low Birthweight ◽  
Negative Binomial ◽  
Perinatal Outcomes ◽  
Sub Saharan Africa ◽  
P Value ◽  
Increased Risk ◽  
Adverse Pregnancy ◽  
The Impact

Sub-Saharan Africa concentrates the burden of HIV and the highest adolescent fertility rates. However, there is limited information about the impact of the interaction between adolescence and HIV infection on maternal health in the region. Data collected prospectively from three clinical trials conducted between 2003 and 2014 were analysed to evaluate the association between age, HIV infection, and their interaction, with the risk of maternal morbidity and adverse pregnancy and perinatal outcomes in women from southern Mozambique. Logistic regression and negative binomial models were used. A total of 2352 women were included in the analyses; 31% were adolescents (≤19 years) and 29% HIV-infected women. The effect of age on maternal morbidity and pregnancy and perinatal adverse outcomes was not modified by HIV status. Adolescence was associated with an increased incidence of hospital admissions (IRR 0.55, 95%CI 0.37–0.80 for women 20–24 years; IRR 0.60, 95%CI 0.42–0.85 for women >25 years compared to adolescents; p-value < 0.01) and outpatient visits (IRR 0.86, 95%CI 0.71–1.04; IRR 0.76, 95%CI 0.63–0.92; p-value = 0.02), and an increased likelihood of having a small-for-gestational age newborn (OR 0.50, 95%CI 0.38–0.65; OR 0.43, 95%CI 0.34–0.56; p-value < 0.001), a low birthweight (OR 0.40, 95%CI 0.27–0.59; OR 0.37, 95%CI 0.26–0.53; p-value <0.001) and a premature birth (OR 0.42, 95%CI 0.24–0.72; OR 0.51, 95%CI 0.32–0.82; p-value < 0.01). Adolescence was associated with an increased risk of poor morbidity, pregnancy and perinatal outcomes, irrespective of HIV infection. In addition to provision of a specific maternity care package for this vulnerable group interventions are imperative to prevent adolescent pregnancy.

scholarly journals POS0737 LOW PRECONCEPTIONAL COMPLEMENT LEVEL IS RELATED WITH ADVERSE OBSTETRIC OUTCOME IN A MULTICENTRIC COHORT OF PREGNANCY IN PATIENTS WITH APS AND APL POSITIVITY

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 619.2-620
Author(s):  
D. Lini ◽  
C. Nalli ◽  
L. Andreoli ◽  
F. Crisafulli ◽  
M. Fredi ◽  
...  
Keyword(s):  
Pregnancy Outcome ◽  
Complement Activation ◽  
Pregnancy Complications ◽  
Antiphospholipid Antibodies ◽  
Pregnancy Loss ◽  
Adverse Pregnancy Outcome ◽  
Obstetric Outcome ◽  
Complement Level ◽  
Increased Risk ◽  
Adverse Pregnancy

Background:The role of complement in the antiphospholipid (aPL) related pathology has been widely studied in animal models. Antiphospholipid antibodies can induce fetal loss in experimental animals but mice deficient in specific complement components (C4, C3, C5) appear somehow protected. In addition, in pregnant mice injected with aPL, antibody deposition has been found at decidual level causing focal necrosis, apoptosis and neutrophil infiltrates and supporting aPL pathogenetic potential. On the other hand, human studies did find hypocomplementemia associated to pregnancy complications in patients with obstetric antiphospholipid syndrome (APS). These results, however, are not unanimously confirmed and, in addition, some studies only show increased levels of complement activation products (i.e. Bb) and not decreased levels of C3 and/or C4. A recently study focusing on complement level in early pregnancy and before pregnancy showed a significant correlation with pregnancy complications and loss in a large cohort of primary APS.Objectives:To investigate if the simple detection of low C3 and/or C4 could be considered a risk factor for adverse pregnancy outcome in APS and aPL carriers pregnancies.Methods:We performed a multicentric study including patients from 10 Italian and 1 Russian Centers. Data on pregnancies in women with primary APS (n=434) and asymptomatic carriers with persistently positive aPL but not fulfilling clinical criteria for APS (n=218) were retrospectively collected. Serum C3 and C4 levels were evaluated by nephelometry; hypocomplementemia was defined by local laboratory reference values. Statistical analysis was performed using GraphPad.Results:Preconceptional complement levels and gestational outcome were available for 107 (25%) pregnancies in APS out of 434 and for 196 (90%) pregnancies in aPL carriers women out of 218. In pregnancies with low preconceptional C3 and/or C4, a significantly higher prevalence of pregnancy losses was observed (p=0.019). A subgroup analysis focusing on triple aPL positive patients was also performed. Preconceptional low C3 and/or C4 levels were found to be associated with an increased rate of pregnancy loss (p = 0.027) in this subgroup also. Otherwise, adverse pregnancy outcomes in single or double aPL positive women were not related to preconception complement levels (p = 0.44) (Table 1). Of note, all the pregnancy losses in the triple positive group occurred in patients treated with low dose aspirin and low molecular weight heparin from the time of positive pregnancy test.Conclusion:Our findings confirm that decreased complement levels before pregnancy are associated with increased risk of adverse outcome. This has been seen only in in women with triple aPL positivity, indeed single or double positivity does not show this trend. Complement levels are cheap and easy to be measured therefore they could represent a useful aid to identify patients at increased risk of pregnancy loss. test positivity.References:[1]De Carolis S, et al. Complementemia and obstetric outcome in pregnancy with antiphospholipid syndrome. Lupus (2012) 21:776–8.[2]Kim MY, et al. Complement activation predicts adverse pregnancy outcome in patients with systemic lupus erythematosus and/or antiphospholipid antibodies. Ann Rheum Dis (2018) 77:549–55.[3]Fredi M, et al. Risk Factors for Adverse Maternal and Fetal Outcomes in Women With Confirmed aPL Positivity: Results From a Multicenter Study of 283 Pregnancies. Front Immunol. 2018 May 7;9:864.Triple aPL positivitySingle or double aPL positivityGestational outcomeLow C3/C4 (n=49)Normal C3/C4(n=17)pLow C3/C4 (n=57)Normal C3/C4(n=165)pTerm live birth (>37w)15 (31%)6 (35%)ns34 (60%)110 (67%)nsPreterm live birth (≤37w)22 (45%)11 (65%)ns15 (26%)38 (23%)nsPregnancy losses (abortion and miscarriages)12 (24%)0 (0%)0.0278 (14%) 17 (10%)nsDisclosure of Interests:None declared

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