UV irradiation of HSV-1 virions induces the differential recruitment of host intrinsic and innate immune regulators to infecting viral genomes

Recognition of virus-derived nucleic acids is a key process in the activation of immune defences to viral infection. However, the spatiotemporal recruitment of host immune regulators to infecting viral DNA (vDNA) genomes remains poorly defined. Here we utilize 5-Ethynyl-2’-deoxycytidine (EdC) nucleotide labelling of WT or UV-irradiated HSV-1 genomes in combination with click chemistry and high-resolution confocal microscopy imaging to investigate the recruitment and proximity of key intracellular immune regulators to infecting vDNA during HSV-1 infection.

We report that UV irradiation of HSV-1 virions restricts vDNA decompaction upon delivery to infected cells. UV treatment reduced the frequency in PML-NB recruitment to nuclear genomes relative to non-irradiated vDNA. These data demonstrate an important role of genome decompaction in the recruitment of intrinsic host factors to nuclear infecting vDNA. Additionally, UV-irradiated HSV-1 genomes favoured a premature cytosolic deposition phenotype, due to ineffective association with microtubules as shown by nocodazole treatment. The cytosolic UV irradiated vDNA showed enhanced association with both cGAS and STING. Interestingly, high-resolution Airyscan imaging identified a consistent unreported 3D interaction between both cGAS and STING, the strength of association of which was enhanced in the context of UV infection. This enhanced recruitment correlated with elevated levels of IFN-β transcription relative to non-irradiated vDNA, despite the presence of non-irradiated cytosolic genomes.

Our data demonstrates that UV irradiation of herpesviruses, a well-established procedure for virus inactivation, has multiple effects on genome structure and sub-cellular localisation that differentially influence the spatiotemporal recruitment of intrinsic and innate host immune regulators to infecting genomes.

The histone chaperone HIRA promotes the induction of host innate immune defences in response to HSV-1 infection

Host innate immune defences play a critical role in restricting the intracellular propagation and pathogenesis of invading viral pathogens. Here we show that the histone H3.3 chaperone HIRA (histone cell cycle regulator) associates with promyelocytic leukaemia nuclear bodies (PML-NBs) to stimulate the induction of innate immune defences against herpes simplex virus 1 (HSV-1) infection. Following the activation of innate immune signalling, HIRA localized at PML-NBs in a Janus-Associated Kinase (JAK), Cyclin Dependent Kinase (CDK), and Sp100-dependent manner. RNA-seq analysis revealed that HIRA promoted the transcriptional upregulation of a broad repertoire of host genes that regulate innate immunity to HSV-1 infection, including those involved in MHC-I antigen presentation, cytokine signalling, and interferon stimulated gene (ISG) expression. ChIP-seq analysis revealed that PML, the principle scaffolding protein of PML-NBs, was required for the enrichment of HIRA onto ISGs, identifying a role for PML in the HIRA-dependent regulation of innate immunity to virus infection. Our data identifies independent roles for HIRA in the intrinsic silencing of viral gene expression and the induction of innate immune defences to restrict the initiation and propagation of HSV-1 infection, respectively. These intracellular host defences are antagonized by the HSV-1 ubiquitin ligase ICP0, which disrupts the stable recruitment of HIRA to infecting viral genomes and PML-NBs at spatiotemporally distinct phases of infection. Our study highlights the importance of histone chaperones to regulate multiple phases of intracellular immunity to virus infection, findings that are likely to be highly pertinent in the cellular restriction of many clinically important viral pathogens.

Host innate immune defences play critical roles in the cellular restriction of invading viral pathogens and the stimulation of adaptive immune responses. A key component in the regulation of this arm of host immunity is the rapid induction of cytokine signalling and the expression of interferon stimulated gene products (ISGs), which confer a refractory antiviral state to limit virus propagation and pathogenesis. While the signal transduction cascades that activate innate immune defences are well established, little is known about the cellular host factors that expedite the expression of this broad repertoire of antiviral host genes in response to pathogen invasion. Here we show that HIRA, a histone H3.3 chaperone, associates with PML-NBs to stimulate the induction of innate immune defences in response to HSV-1 infection. Our study highlights the importance of histone chaperones in the coordinated regulation of multiple phases of host immunity in response to pathogen invasion and identifies a key role for HIRA in the induction of innate immunity to virus infection.

[POLYHEXAMETHYLENE BIGUANID HYDROCHLORIDE (BIGUANELLE) THERAPY OF BACTERIAL VAGINOSIS]

The aim of our study was to determine the efficacy and tolerability of local therapy with polyhexamethylene biguanid hydrochloride (BIGUANELLE) in women with anaerobic vaginal infection.

MATERIAL AND METHODS

We include in our study 23 women (18-50) with established by AMSEL criteria bacterial vaginosis. In all of the women at the beginning and at the end of the survey was performed gynecological examination and microbiological research (AMSEL). The therapeutic scheme at all women is with a single vaginal application of gynecological solution BIGUANELLE. Effectiveness of the treatment was evaluated according to clinical complaints and microbiological research (Amsel criteria: Ph 4.5 >; KOH (+); "clue cells"; specific vaginal fluorine). Tolerability of patients to treatment was assessed by questionnaire.

RESULTS

Clinical complaints of patients after the therapy decreased as follows: vaginal fluorine with 73.9%; odor--75%; pruritus--50%; discomfort--90%. Microbiological research and their evaluation by AMSEL, showed the therapeutic efficacy of the therapy in 16 (69.6%) of all (n-23) patients. At 7 (30.4%) women, the treatment remained without effect. At questionnaire answers, 73.9% patients were satisfied with the application of BIGUANELLE, 95.6% of them have implemented it easily, 95.6% of women believe that BIGUANELLE is more convenient to use in comparison with similar products which have a daily application, and none of the patients (100%) have any complaints in applying this gynecological solution.

CONCLUSIONS

BIGUANELLE showed good clinical efficacy in the treatment of bacterial vaginosis. It is easily applied and well tolerated by the patients.

Can oral anaerobic bacteria cause adverse pregnancy outcomes?

AIM

Maternal periodontal infection has been recognized as a risk factor for premature and low birthweight infants. It is suspected that pathogens causing periodontal disease may translocate to the amniotic cavity and so contribute to triggering an adverse pregnancy outcome. The aim of this study was to evaluate whether the presence of specific periodontal pathogens may influence the incidence of preterm labor and premature birth.

MATERIAL AND METHODS

This study was designed as a hospital-based case-control study. A total of 70 pregnant women, aged 18-40 with single live pregnancy were recruited from the Departement of Gynecolgy and Obstetrics at a General hospital in Sibenik, Croatia, between March 2013 to March 2014. The case group: 30 pregnant women who were hospitalised with signs of premature labor.

CONTROL GROUP

40 patients with normal pregnancy post-delivery up to 48 hrs, who had given birth at term, and the baby had a weight of more than 2500 gr. These women had undergone microbiological examination at the time of recruitment, microbial samples, paper point subgingival swabs were obtained in both groups and processed by anaerobic culturing. Standard procedures were used for culture and identification of bacteria. Information was collected on demographics, health behaviors, and obstetric and systemic diseases that may have influence the premature delivery.

RESULTS

The levels of periodontal pathogens tended to be higher in the premature (case group) labor compared to the term deliveries (control group). Levels of Porphyromonas gingivalis, Fuscobacterium nucleatum, Actinomyces actinomycetecomitans were statistically significantly higher in premature births as compared to term deliveries, adjusting for baseline levels. The joint effects of red and orange microbial clusters were significantly higher in the premature group compared to the term group.

CONCLUSIONS

The study shows a significant association betwen periodontal anaerobic infection and adverse pregnancy outcome. High levels of periodontal pathogens during pregnancy are associated with an increased risk for preterm delivery. Further studies elucidating the role of the microbial load and maternal immune response as related to pregnancy outcome seem merited.

Combination of two anti-stress procedures: our original 4-corner deltoid-like vaginal suspension and suburethral duplication sec. Lazarevski in patients with genital prolapse

AIM

The effectiveness of the combination of two anti-stress procedures: 1) our original 4-corner deltoid-like vaginal suspension; and 2) suburethral duplication sec. Lazarevski are analysed.

STUDY DESIGN

144 women, undergoing vaginal hysterectomy, combined with our original 4-corner deltoid-like vaginal suspension and suburethral duplication sec. Lazarevski were divided into: SUIGP group (n = 48) with stress urinary incontinence (SUI) and genital prolapse (GP); and GP group (n = 96) with GP. All operations were performed by the first author of this study.

RESULTS

At the last follow-up (mean 18.3 months for GP, and 18.7 months for SUIGP), point C was significantly higher in both groups and total vaginal length (tvl) longer in GP vs. preoperative positions (p < 0.05; p < 0.05; p < 0.05 respectively). There were no postoperative significant differences between groups. Regarding the severity of prolapse: stage I for anterior segment and stage 0 for most severe segment predominated in SUIGP (p < 0.05; p < 0.05 respectively). The recurrent prolapse was: 1) in anterior segment: stage I 6.25% in GP and 18.7% in SUIGP; stage II 6.25% in GP and 2.1% in SUIGP; 2) in posterior segment: stage I 18.7% in GP and 18.7% in SUIGP. There was no recurrent prolapse of the apical segment, and only one patient with stage III anterior segment. The recurrent SUI was 8.3% in SUIGP, and de novo SUI 1% in GP.

CONCLUSION

This proposed combination seems to be safe and effective (Tab. 8, Fig. 2, Ref. 24). Full Text (Free, PDF) www.bmj.sk.