Nectin-2 Acts as a Viral Entry Mediated Molecule That Binds to Human Herpesvirus 6B Glycoprotein B

Human herpesvirus 6B (HHV-6B) is a T-lymphotropic virus and the etiological agent of exanthem subitum. HHV-6B is present in a latent or persistent form after primary infection and is produced in the salivary glands or transmitted to this organ. Infected individuals continue to secrete the virus in their saliva, which is thus considered a source for virus transmission. HHV-6B primarily propagates in T cells because its entry receptor, CD134, is mainly expressed by activated T cells. The virus then spreads to the host’s organs, including the salivary glands, nervous system, and liver. However, CD134 expression is not detected in these organs. Therefore, HHV-6B may be entering cells via a currently unidentified cell surface molecule, but the mechanisms for this have not yet been investigated. In this study, we investigated a CD134-independent virus entry mechanism in the parotid-derived cell line HSY. First, we confirmed viral infection in CD134-membrane unanchored HSY cells. We then determined that nectin cell adhesion molecule 2 (nectin-2) mediated virus entry and that HHV-6B-insensitive T-cells transduced with nectin-2 were transformed into virus-permissive cells. We also found that virus entry was significantly reduced in nectin-2 knockout parotid-derived cells. Furthermore, we showed that HHV-6B glycoprotein B (gB) interacted with the nectin-2 V-set domain. The results suggest that nectin-2 acts as an HHV-6B entry-mediated protein.

Valganciclovir as Add-On Therapy Modifies the Frequency of NK and NKT Cell Subpopulations in Disseminated Kaposi Sarcoma Patients

Human herpesvirus-8 infection (HHV-8) is the causative agent of Kaposi sarcoma (KS) and is highly prevalent among people living with HIV (KS/HIV). It has been reported that valganciclovir (VGC) reduces HHV-8 replication in KS/HIV patients. However, currently it is unclear if VGC modifies the frequency and induces changes in markers of immune regulation of immune cells necessary to eliminate HHV8-infected cells, such as Natural Killer (NK) and NK T cells (NKT). This study evaluated the effect of VGC used as antiviral HHV8 therapy in KS patients on the frequency of NK and NKT subpopulations based on the CD27 and CD57 expression, and the immunosenescence markers, PD-1 and KLRG1. Twenty KS/HIV patients were followed-up at baseline (W0), 4 (W4), and 12 weeks (W12) of the study protocol. Among them, 10 patients received a conventional treatment scheme (CT), solely antiretroviral therapy (ART), and 10 patients received a modified treatment regime (MT), including VGC plus ART. In both groups, bleomycin/vincristine was administrated according to the treating physician’s decision. The soluble levels of IL-15, PD-L1, PD-L2, and E-cadherin were quantified across the follow-up. Our results showed that the higher IL-15 levels and lower NK frequencies cells in KS/HIV patients reach almost normal values with both treatments regimes at W12. CD27+ NK and NKT cell frequencies increased since W4 on KS/HIV patients with MT. Furthermore, PD-1 expression decreased while KLRG1 increased on NK and NKT subpopulations at W12, and it is accompanied by increased PD-L1 plasma level since W4. Our study highlights the disruption of NK and NKT subpopulations in patients with KS/HIV and explores VGC treatment’s contribution to immune reconstitution during the first weeks of treatment.

Cryotherapy Treatment of Cutaneous Kaposi Sarcoma in a Patient With B-Cell Chronic Lymphocytic Leukemia: A Case Report and Short Review of the Literature

Introduction. Kaposi sarcoma (KS) is a low-grade mesenchymal tumor involving the blood and the lymphatic vessels that primarily effaces the skin and is mediated by human herpesvirus-8 (HHV-8) in more than 90% of patients. There are 4 distinct types of KS. Compared with the classic and AIDS-related variants, chronic lymphocytic leukemia (CLL) associated with KS is a relatively rare clinical condition; thus, only a few cases have been reported. Case Report. This report presents a case study of an 87-year-old patient with B-cell CLL and cutaneous KS managed with cryotherapy, along with a short review of the literature. Conclusions. Considering that the method is relatively simple and with few adverse effects, cryotherapy may represent a simple and safe treatment method for cutaneous KS. However, more studies should be conducted to further evaluate the effectiveness of cryotherapy as a promising treatment for cutaneous KS.

Detection of Nocardia by 16S Ribosomal RNA Gene PCR and Metagenomic Next-Generation Sequencing (mNGS)

In this study, the aim was to investigate the discriminatory power of molecular diagnostics based on mNGS and traditional 16S ribosomal RNA PCR among Nocardia species. A total of fourteen clinical isolates from patients with positive Nocardia cultures and clinical evidence were included between January 2017 and June 2020 in HeNan Provincial People’s Hospital. DNA extraction and 16S rRNA PCR were performed on positive cultures, and pathogens were detected by mNGS in these same samples directly. Among the 14 Nocardia isolates, four species were identified, and N. cyriacigeorgica (8 cases) is the most common species. Twelve of the 14 Nocardia spp. isolates were identified by the two methods, while two strains of N. cyriacigeorgica were not identified by mNGS. All tested isolates showed susceptibility to trimethoprim-sulfamethoxazole (SXT), amikacin and linezolid. Apart from Nocardia species, other pathogens such as Acinetobacter baumannii, Klebsiella pneumonia, Aspergillus, Enterococcus faecalis, Human herpesvirus, etc., were detected from the same clinical samples by mNGS. However, these different pathogens were considered as colonization or contamination. We found that it is essential to accurately identify species for determining antibiotic sensitivity and, consequently, choosing antibiotic treatment. 16S rRNA PCR was useful for identification of nocardial infection among species, while this technique needs the clinicians to make the pre-considerations of nocardiosis. However, mNGS may be a putative tool for rapid and accurate detection and identification of Nocardia, beneficial for applications of antimicrobial drugs and timely adjustments of medication.

Liver Fibrosis and Steatosis in Virally Suppressed HIV-Infected Patients with Cytomegalovirus Seropositivity

Background: Cytomegalovirus (CMV) is a human herpesvirus common in people with human immunodeficiency virus (HIV). In a patient with immunocompetence, long periodic asymptomatic CMV might affect to develop the abnormal liver function and contribute to non-AIDS defining morbidity, including chronic liver disease. This study aims to know the prevalence of liver fibrosis and steatosis in virally suppressed HIV infected patients with CMV reactive and summarize the correlation of clinical presentation with liver fibrosis and steatosis in these subjects.Method: A cross-sectional study in HIV Integrated Care Unit, Cipto Mangunkusumo Hospital, was conducted from April 2019 until June 2020. Subjects enrolled in this study were suppressed HIV patients aged between 30-40 years with positive IgG CMV and already using stable ART for at least one year. Transient elastography measured the liver stiffness. Patients with liver stiffness above 7 kPa were defined as having significant liver fibrosis. In addition, Spearman correlation was conducted to evaluate the correlation of clinical presentation of subjects related to liver fibrosis and steatosis. Results: A total of subjects was included in this study. Dominantly male (62.5%) with average age 38 ± 4.68 years. The median amount of CMV DNA was 466 (17-21284) copy/ml. Significant Fibrosis was found in 17/80 (21%) subjects. In this study, clinical parameters correlated with liver fibrosis were insulin, glucose fasting, Homa IR, triglyceride, HDL, and platelet. A medium positive correlation was found in insulin, and Homa IR, with coefficient correlation for insulin, was r = 0.475, p 0.001; and coefficient correlation for Homa IR was r = 0 .487, p 0.001.Conclusion: The prevalence of liver fibrosis was 12% in these subjects. In addition, insulin and Homa IR had a positive correlation with increasing liver fibrosis.

Investigation of Inherited Chromosomally Integrated Human Herpesvirus-6A+ and -6B+ in a Patient with Ulipristal Acetate-Induced Fulminant Hepatic Failure

Inherited chromosomally integrated (ici) human herpes virus 6 (HHV-6) is estimated to occur in 0.6–2.7% of people worldwide. HHV-6 comprises two distinct species: HHV-6A and HHV-6B. Both HHV-6A and HHV-6B integration have been reported. Several drugs are capable of activating iciHHV-6 in tissues, the consequences of which are poorly understood. We report herein a case of a woman with iciHHV-6A+ and iciHHV-6B+, who developed ulipristal acetate (a selective progesterone receptor modulator)-induced fulminant hepatic failure that required liver transplantation. We confirmed the presence of ~one copy per cell of both HHV-6A and HHV-6B DNA in her hair follicles using multiplex HHV-6A/B real-time PCR and demonstrated the Mendelian inheritance of both iciHHV-6A and iciHHV-6B in her family members over three generations. Because of the rarity of this presentation, we discuss herein the possible links between reactivated HHV-6 from iciHHV-6A and/or iciHHV-6B and adverse drug reactions, suggesting that iciHHV-6 could be screened before the introduction of any hepatotoxic drugs to exclude HHV-6 active disease or combined idiosyncratic drug-induced liver injury in these patients.

Some opportunistic infections in the structure of premature birth causes

Aim. To determine the structure and detection rate of some opportunistic infections in premature birth.Materials and methods. The study was carried out at the premises of the Research Institute of Maternity and Childhood Protection and the Pathology Department of the Khabarovsk Perinatal Center. We studied 62 placentas from women whose pregnancy ended prematurely and placentas and organ samples (heart, lungs, liver, and kidneys) from 14 premature infants who died in the early neonatal period. Thirty placentas of women who delivered full-term live babies were classified as a control group. Genomes of Chlamydia trachomatis, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma species (Ureaplasma urealyticum + Ureaplasma parvum), Cytomegalovirus, Herpes simplex virus, Human herpesvirus 4 type, Human herpesvirus 6 type, Parvovirus B19, Listeria monocytogenes, Streptococcus agalactiae, Streptococcus species, Streptococcus pyogenes, Haemophilus influenza, Klebsiella pneumoniae, Candida albicans were detected by polymerase chain reaction (PCR) in samples of placental tissue and samples of internal organs of deceased newborns. Results. The rate of opportunistic agent detection in the placentas from women with preterm birth made 59.6% and in the sectional material from premature newborns who died in the early neonatal period (78.6%), which figures exceeded the same indicator in the control group (30.0%) respectively, by 2.0 (p=0.007) and 2.6 (p=0.002), respectively. In 47.9±7.2% of cases of all positive results, the material from women with preterm birth presented with various combinations of two, three, and four infectious agents, having common pathogenic links, which contributes to the aggravation of pathogenic processes, comorbidity or multimorbidity. According to the detection rates, in terms of total monoinfections and mixed infection components, pathogens detected during preterm birth were distributed as follows: U. urealyticum ‒ 34,2±5,4%; S. agalactiae ‒ 17,1±4,3%; M. hominis ‒ 15,8±4,1%; S. species (S. sanguis, S. salivarius, S. mitis, S. mutans) ‒ 13,1±3,8%; Cytomegalovirus ‒ 11,8±3,7%; Human herpesvirus 4 type – 9,2±3,3%; M. genitalium ‒ 2,6±1,8%. Conclusion. PCR testing showed that placentas from women whose pregnancy ended prematurely and samples of placenta and organs of premature infants who died in the early neonatal period presented with opportunistic agents colonizing female genital tract (streptococci, mycoplasmas) or ubiquitous herpesviruses persistent and reproduced in human lymphocytes (Cytomegalovirus, Human herpesvirus 4 type). Associations of microorganisms that cause comorbidity or multimorbidity account for a significant portion of the infectious agents detected. The context for a microbiota-integrated opportunistic agent to transform into a pathogenic strain, identification of transformation predictors, and possible tools to correct the disorders – all these require further research.

A panel of KSHV mutants in the polycistronic kaposin locus for precise analysis of individual protein products

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the cause of several human cancers including the endothelial cell (EC) malignancy, Kaposi’s sarcoma. Unique KSHV genes absent from other human herpesvirus genomes, the “K-genes”, are important for KSHV replication and pathogenesis. Among these, the kaposin transcript is highly expressed in all phases of infection, but its complex polycistronic nature has hindered functional analysis to date. At least three proteins are produced from the kaposin transcript: Kaposin A (KapA), B (KapB), and C (KapC). To determine the relative contributions of kaposin proteins during KSHV infection, we created a collection of mutant viruses unable to produce kaposin proteins individually or in combination. In previous work, we showed KapB alone recapitulated the elevated proinflammatory cytokine transcripts associated with KS via the disassembly of RNA granules called processing bodies (PBs). Using the new ΔKapB virus, we showed that KapB was necessary for this effect during latent KSHV infection. Moreover, we observed that despite the ability of all kaposin-deficient latent iSLK cell lines to produce virions, all displayed low viral episome copy number, a defect that became more pronounced after primary infection of naïve ECs. For ΔKapB, provision of KapB in trans failed to complement the defect, suggesting a requirement for the kaposin locus in cis . These findings demonstrate that our panel of kaposin-deficient viruses enables precise analysis of the respective contributions of individual kaposin proteins to KSHV replication. Moreover, our mutagenesis approach serves as a guide for the functional analysis of other complex multicistronic viral loci. Importance Kaposi’s sarcoma-associated herpesvirus (KSHV) expresses high levels of the kaposin transcript during both latent and lytic phases of replication. Due to its repetitive, GC-rich nature and polycistronic coding capacity, until now no reagents existed to permit a methodical analysis of the role of individual kaposin proteins in KSHV replication. We report the creation of a panel of recombinant viruses and matched producer cell lines that delete kaposin proteins individually or in combination. We demonstrate the utility of this panel by confirming the requirement of one kaposin translation product to a key KSHV latency phenotype. This study describes a new panel of molecular tools for the KSHV field to enable precise analysis of the roles of individual kaposin proteins during KSHV infection.