Well Put Together-A Guide to Accessorizing with the Herpesvirus gH/gL Complexes.

Herpesviruses are enveloped, double-stranded DNA viruses that infect a variety of hosts across the animal kingdom. Nine of these establish lifelong infections in humans, for which there are no cures and few vaccine or treatment options. Like all enveloped viruses, herpesviruses enter cells by fusing their lipid envelopes with a host cell membrane. Uniquely, herpesviruses distribute the functions of receptor engagement and membrane fusion across a diverse cast of glycoproteins. Two glycoprotein complexes are conserved throughout the three herpesvirus subfamilies: the trimeric gB that functions as a membrane fusogen and the heterodimeric gH/gL, the role of which is less clearly defined. Here, we highlight the conserved and divergent functions of gH/gL across the three subfamilies of human herpesviruses by comparing its interactions with a broad range of accessory viral proteins, host cell receptors, and neutralizing or inhibitory antibodies. We propose that the intrinsic structural plasticity of gH/gL enables it to function as a signal integration machine that can accept diverse regulatory inputs and convert them into a "trigger" signal that activates the fusogenic ability of gB.

Systematic Determination of Herpesvirus in Free-Ranging Cetaceans Stranded in the Western Mediterranean: Tissue Tropism and Associated Lesions.

The monitoring of herpesvirus infection provides useful information when assessing marine mammals' health. This paper shows the prevalence of herpesvirus infection (80.85%) in 47 cetaceans stranded on the coast of the Valencian Community, Spain. Of the 966 tissues evaluated, 121 tested positive when employing nested-PCR (12.53%). The largest proportion of herpesvirus-positive tissue samples was in the reproductive system, nervous system, and tegument. Herpesvirus was more prevalent in females, juveniles, and calves. More than half the DNA PCR positive tissues contained herpesvirus RNA, indicating the presence of actively replicating virus. This RNA was most frequently found in neonates. Fourteen unique sequences were identified. Most amplified sequences belonged to the Gammaherpesvirinae subfamily, but a greater variation was found in Alphaherpesvirinae sequences. This is the first report of systematic herpesvirus DNA and RNA determination in free-ranging cetaceans. Nine (19.14%) were infected with cetacean morbillivirus and all of them (100%) were coinfected with herpesvirus. Lesions similar to those caused by herpesvirus in other species were observed, mainly in the skin, upper digestive tract, genitalia, and central nervous system. Other lesions were also attributable to concomitant etiologies or were nonspecific. It is necessary to investigate the possible role of herpesvirus infection in those cases.

Susceptibility of Goldfish to Cyprinid Herpesvirus 2 (CyHV-2) SH01 Isolated from Cultured Crucian Carp.

Cyprinid herpesvirus 2 (CyHV-2), a member of the Alloherpesviridae family belonging to the genus Cyprinivirus, is a fatal contagious aquatic pathogen that affects goldfish (Carassius auratus) and crucian carp (Carassius carassius). Although crucian carp and goldfish belong to the genus Carassius, it is unclear whether they are susceptible to the same CyHV-2 isolate. In addition, the origin of the crucian carp-derived CyHV-2 virus isolate remains unclear. CyHV-2 SH01 was isolated during herpesviral hematopoietic necrosis disease (HVHN) outbreaks in crucian carp at a local fish farm near Shanghai. CyHV-2 SH01 was confirmed by PCR and Western blot analysis of kidney, spleen, muscle, and blood tissue from the diseased crucian carp. Moreover, histopathological and ultra-pathological analyses revealed pathological changes characteristic of CyHV-2 SH01 infection in the tissues of the diseased crucian carp. In the present study, goldfish and crucian carp were challenged with CyHV-2 SH01 to elucidate viral virulence. We found that CyHV-2 SH01 could cause rapid and fatal disease progression in goldfish and crucian carp 24 h post-injection at 28 °C. Experimental infection of goldfish by injection indicated that the average virus titer in the kidney of the goldfish was 103.47 to 103.59 copies/mg. In addition, tissues exhibited the most prominent histopathological changes (cellular wrinkling and shrinkage, cytoplasmic vacuolation, fusion of the gill lamellae, and hepatic congestion) in CyHV-2 SH01-infected goldfish and crucian carp. Thus, crucian carp and goldfish showed a high sensitivity, with typical symptoms, to HVHN disease caused by CyHV-2 SH01.

Viruses Infecting the European Catfish (Silurus glanis).

In aquaculture, disease management and pathogen control are key for a successful fish farming industry. In past years, European catfish farming has been flourishing. However, devastating fish pathogens including limiting fish viruses are considered a big threat to further expanding of the industry. Even though mainly the ranavirus (Iridoviridea) and circovirus (Circoviridea) infections are considered well- described in European catfish, more other agents including herpes-, rhabdo or papillomaviruses are also observed in the tissues of catfish with or without any symptoms. The etiological role of these viruses has been unclear until now. Hence, there is a requisite for more detailed information about the latter and the development of preventive and therapeutic approaches to complete them. In this review, we summarize recent knowledge about viruses that affect the European catfish and describe their origin, distribution, molecular characterisation, and phylogenetic classification. We also highlight the knowledge gaps, which need more in-depth investigations in the future.

Emerging Viral Pathogens in Sturgeon Aquaculture in Poland: Focus on Herpesviruses and Mimivirus Detection.

Recently, Poland has become a leading producer of sturgeon meat and caviar in Europe and is one of the largest in the world. The growing importance of this branch of aquaculture means that diseases of these fish, especially viral ones, are becoming the object of interest for ichthyopathologists. In recent years, there have been increasing reports of health problems in the dynamically developing sturgeon farming. The greatest risk appears to be emerging infectious diseases that are caused by viruses and that can become a serious threat to the development of the aquaculture industry and the success of sturgeon restitution programs undertaken in many European countries, including Poland. In this paper, an attempt was made to determine the spread of the two most important groups of viruses in Polish sturgeon farming: These include the herpesviruses and sturgeon nucleocytoplasmic large DNA viruses (sNCLDV), in particular, mimiviruses. In the years 2016-2020, 136 samples from nine farms were collected and tested by using the WSSK-1 cell line, PCR and Real Time PCR methods. All results were negative for herpesviruses. Out of the samples, 26% of the samples have been tested positive for mimiviruses. Sanger sequencing of mimiviruses demonstrated their affiliation with AciV-E. The sequence characterization confirmed the presence of both V1 and V2 lineages in Polish fish facilities, but variant V2 seems to be more widespread, as is observed in other European countries.

Berberine in Human Oncogenic Herpesvirus Infections and Their Linked Cancers.

Human herpesviruses are known to induce a broad spectrum of diseases, ranging from common cold sores to cancer, and infections with some types of these viruses, known as human oncogenic herpesviruses (HOHVs), can cause cancer. Challenges with viral latency, recurrent infections, and drug resistance have generated the need for finding new drugs with the ability to overcome these barriers. Berberine (BBR), a naturally occurring alkaloid, is known for its multiple biological activities, including antiviral and anticancer effects. This paper comprehensively compiles all studies that have featured anti-HOHV properties of BBR along with promising preventive effects against the associated cancers. The mechanisms and pathways induced by BBR via targeting the herpesvirus life cycle and the pathogenesis of the linked malignancies are reviewed. Approaches to enhance the therapeutic efficacy of BBR and its use in clinical practice as an anti-herpesvirus drug are also discussed.

Inhibition of selective autophagy by members of the herpesvirus ubiquitin-deconjugase family.

Autophagy is an important component of the innate immune response that restricts infection by different types of pathogens. Viruses have developed multiple strategies to avoid autophagy to complete their replication cycle and promote spreading to new hosts. Here, we report that the ubiquitin deconjugases encoded in the N-terminal domain of the large tegument proteins of Epstein-Barr virus (EBV), Kaposi Sarcoma herpesvirus (KSHV) and human cytomegalovirus (HCMV), but not herpes simplex virus-1 (HSV-1), regulate selective autophagy by inhibiting the activity of the autophagy receptor SQSTM1/p62. We found that all the homologs bind to and deubiquitinate SQSTM1/p62 but with variable efficiency, which correlates with their capacity to prevent the colocalization of light chain 3 (LC3) with SQSTM1/p62 aggregates and promote the accumulation of a model autophagy substrate. The findings highlight important differences in the strategies by which herpesviruses interfere with selective autophagy.

Molecular Detection of Human Herpes Viruses in Suspected Measles Serum Samples from Senegal, 2014 to 2017.

Herpesviruses are known to cause a diversity of clinical syndromes, ranging from minor cutaneous lesions to life-threatening illnesses, especially in immunocompromised hosts. Here, we investigate retrospectively the contribution of five human herpesviruses, including herpes simplex virus Cytomegalovirus (CMV), the Epstein-Barr virus (EBV), human herpesvirus 6, and varicella zoster virus (VZV) in serum samples collected from measles suspected patients with at least fever and rash. Sera specimens were first tested for serological evidence of measles and rubella virus infection by ELISA, and DNA extracted from an aliquot of each clinical specimen for molecular detection of human herpes viruses by RT-qPCR. A total of 3,358 specimens have been collected and tested for herpes viruses. Nearly half of the overall suspected cases were children younger than 5 years (49.4%). Of the 3,358 sera tested by ELISA, 227 (6.7%) were measles laboratory confirmed and 152 (4.5%) rubella laboratory confirmed. Herpes viruses were detected in 1763 (52.5%), and VZV was the most common with 44.3%, followed by EBV with 10.7%. Coinfections were found in 352 (20%) cases, and the most common co-detections were VZV/EBV or VZV/CMV (169 and 81 cases, respectively). A clear seasonal pattern of VZV, EBV, and CMV identification was observed, with the highest incidence between February and April each year. Results of this investigation provide more insights into cutaneous rash syndrome etiologies in patients sampled in the framework of measles/rubella surveillance in Senegal, which is useful for the guidance of both case definition revision and clinical practice as well as for public health policy.

Clinical Manifestations and Epigenetic Regulation of Oral Herpesvirus Infections.

The oral cavity is often the first site where viruses interact with the human body. The oral epithelium is a major site of viral entry, replication and spread to other cell types, where chronic infection can be established. In addition, saliva has been shown as a primary route of person-to-person transmission for many viruses. From a clinical perspective, viral infection can lead to several oral manifestations, ranging from common intraoral lesions to tumors. Despite the clinical and biological relevance of initial oral infection, little is known about the mechanism of regulation of the viral life cycle in the oral cavity. Several viruses utilize host epigenetic machinery to promote their own life cycle. Importantly, viral hijacking of host chromatin-modifying enzymes can also lead to the dysregulation of host factors and in the case of oncogenic viruses may ultimately play a role in promoting tumorigenesis. Given the known roles of epigenetic regulation of viral infection, epigenetic-targeted antiviral therapy has been recently explored as a therapeutic option for chronic viral infection. In this review, we highlight three herpesviruses with known roles in oral infection, including herpes simplex virus type 1, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus. We focus on the respective oral clinical manifestations of these viruses and their epigenetic regulation, with a specific emphasis on the viral life cycle in the oral epithelium.

The Role of ND10 Nuclear Bodies in Herpesvirus Infection: A Frenemy for the Virus?

Nuclear domains 10 (ND10), a.k.a. promyelocytic leukemia nuclear bodies (PML-NBs), are membraneless subnuclear domains that are highly dynamic in their protein composition in response to cellular cues. They are known to be involved in many key cellular processes including DNA damage response, transcription regulation, apoptosis, oncogenesis, and antiviral defenses. The diversity and dynamics of ND10 residents enable them to play seemingly opposite roles under different physiological conditions. Although the molecular mechanisms are not completely clear, the pro- and anti-cancer effects of ND10 have been well established in tumorigenesis. However, in herpesvirus research, until the recently emerged evidence of pro-viral contributions, ND10 nuclear bodies have been generally recognized as part of the intrinsic antiviral defenses that converge to the incoming viral DNA to inhibit the viral gene expression. In this review, we evaluate the newly discovered pro-infection influences of ND10 in various human herpesviruses and analyze their molecular foundation along with the traditional antiviral functions of ND10. We hope to shed light on the explicit role of ND10 in both the lytic and latent cycles of herpesvirus infection, which is imperative to the delineation of herpes pathogenesis and the development of prophylactic/therapeutic treatments for herpetic diseases.

Highly divergent herpesviruses in threatened river dolphins from Brazil.

River dolphins are a highly threatened polyphyletic group comprised of four odontocete families: Iniidae, Pontoporiidae, Lipotidae, and Platanistidae, the first two endemic to South America. To address the knowledge gap regarding infectious agents in this cetacean group, we surveyed the presence of herpesviruses by PCR in skin and/or blood samples of live-captured Amazon (Inia geoffrensis, n = 25) and Bolivian (Inia boliviensis, n = 22) river dolphins of the Amazon basin and in selected tissue samples of franciscanas (Pontoporia blainvillei, n = 27) stranded or bycaught in southeastern Brazil. Additionally, available franciscana tissue samples were examined by histopathology. Herpesvirus DNA was amplified in 13 Bolivian river dolphins (59.1%, 95% CI 38.5-79.6%) and 14 franciscanas (51.9%, 95% CI 33.0-70.7%). All Amazon river dolphins were herpesvirus-negative. Two different herpesviruses were found in Bolivian river dolphins: a previously known gammaherpesvirus detected in blood and/or skin samples of all positive individuals and a novel alphaherpesvirus in the skin of one animal. A new gammaherpesvirus was found in several franciscana samples-the first herpesvirus recorded in Pontoporiidae. Intranuclear inclusion bodies consistent with herpesvirus were observed in the lymph node of one franciscana. The high divergence among the obtained herpesviruses and those previously described can be explained by viral-host coevolution, and by the fact that these populations are fairly isolated.

High abundance of human herpesvirus 8 in wastewater from a large urban area.

AIMS: This study assesses the diversity and abundance of Human Herpesviruses (HHVs) in the influent of an urban wastewater treatment plant using shotgun sequencing, metagenomic analysis and qPCR. METHODS AND RESULTS: Influent wastewater samples were collected from the three interceptors that serve the City of Detroit and Wayne, Macomb and Oakland counties between November 2017 to February 2018. The samples were subjected to a series of processes to concentrate viruses which were further sequenced and amplified using qPCR. All nine types of HHV were detected in wastewater. Human Herpesvirus 8 (HHV-8), known as Kaposi's sarcoma herpesvirus, which is only prevalent in 5-10% of USA population, was found to be the most abundant followed by HHV-3 or Varicella-zoster virus. CONCLUSIONS: The high abundance of HHV-8 in the Detroit metropolitan area may be attributed to the HIV-AIDS outbreak that was ongoing in Detroit during the sampling period. SIGNIFICANCE AND IMPACT OF THE STUDY: The approach described in this paper can be used to establish a baseline of viruses secreted by the community as a whole. Sudden changes in the baseline would identify changes in community health and immunity.

Inhibitors of APE1 redox function effectively inhibit γ-herpesvirus replication in vitro and in vivo.

APE1 is a multi-functional protein with a redox function in its N-terminal domain and an apurinic/apyrimidinic endonuclease activity in the C-terminal domain. APE1 redox function plays an important role in regulating cell proliferation and survival through activating specific transcriptional activators. APE1 redox function is also found to be associated with some cancer occurrence. In this study, we demonstrated that APE1 redox function is essential for Epstein-Barr virus (EBV) lytic replication as the silencing of APE1 expression or treatment with APE1 redox inhibitors C10 and E3330 can inhibit EBV lytic replication and virion production. Furthermore, C10 and E3330 also inhibit MHV-68 replication in vitro and in vivo. C10 and E3330 were able to significantly reduce the loss of pulmonary alveoli and thickening of alveolar septa in mice caused by MHV-68 infection. Altogether, (i) APE1 redox function is validated as a new antiviral target; (ii) APE1 redox inhibitors, especially C10, have potentials to be used for the treatment of γ-herpesvirus infection and associated diseases; (iii) MHV-68 is validated to be a surrogate for the study of the pathogenesis and therapy of EBV and KSHV infection in vivo.

Multiple DNA viruses identified in multimammate mouse (Mastomys natalensis) populations from across regions of sub-Saharan Africa.

The multimammate mouse (Mastomys natalensis; M. natalensis) serves as the main reservoir for the zoonotic arenavirus Lassa virus (LASV), and this has led to considerable investigation into the distribution of LASV and other related arenaviruses in this host species. In contrast to the situation with arenaviruses, the presence of other viruses in M. natalensis remains largely unexplored. In this study, herpesviruses and polyomaviruses were identified and partially characterized by PCR methods, sequencing, and phylogenetic analysis. In tissues sampled from M. natalensis populations in Côte d'Ivoire and Mali, six new DNA viruses (four betaherpesviruses, one gammaherpesvirus and one polyomavirus) were identified. Phylogenetic analysis based on glycoprotein B amino acid sequences showed that the herpesviruses clustered with cytomegaloviruses and rhadinoviruses of multiple rodent species. The complete circular genome of the newly identified polyomavirus was amplified by PCR. Amino acid sequence analysis of the large T antigen or VP1 showed that this virus clustered with a known polyomavirus from a house mouse (species Mus musculus polyomavirus 1). These two polyomaviruses form a clade with other rodent polyomaviruses, and the newly identified virus represents the third known polyomavirus of M. natalensis. This study represents the first identification of herpesviruses and the discovery of a novel polyomavirus in M. natalensis. In contrast to arenaviruses, we anticipate that these newly identified viruses represent a low zoonotic risk due to the normally highly restricted specificity of members of these two DNA virus families to their individual mammalian host species.

Prevalence of feline herpesvirus-1, feline calicivirus, Chlamydia felis, and Bordetella bronchiseptica in a population of shelter cats on Prince Edward Island.

The prevalence of the causative agents of feline upper respiratory tract disease (URTD) has been previously documented in many regions worldwide, but has yet to be reported in eastern Canada. The objectives of this study were to determine the prevalence of feline herpesvirus-1 (FHV-1), feline calicivirus (FCV), Chlamydia felis (C. felis), and Bordetella bronchiseptica (B. bronchiseptica) in a population of shelter cats with clinical signs related to URTD on Prince Edward Island, Canada; to compare the prevalence of FHV-1 and FCV as detected by polymerase chain reaction (PCR) and virus isolation (VI) in this population; and lastly, to determine whether factors, such as co-infections, time of year, concurrent feline leukemia virus (FeLV)- or feline immunodeficiency virus (FIV)-positive status, or clinical signs, were associated with prevalence of particular pathogens. Conjunctival, nasal mucosal, and oropharyngeal swabs were collected from 82 cats with clinical signs consistent with URTD. Samples were pooled in transport medium and PCR was used to detect FHV-1, FCV, and C. felis and VI was also used to detect FHV-1 and FCV. A separate swab was submitted for aerobic bacterial culture to detect B. bronchiseptica. Feline herpesvirus-1 (FHV-1) was the most prevalent in this population, followed by C. felis, B. bronchiseptica, and FCV. Of the 4 cats that were positive for B. bronchiseptica, 3 were concurrently positive for FHV-1. All positive B. bronchiseptica cultures were resistant to cefovecin. The prevalence for FHV-1 was lowest in autumn (seasons P < 0.001) and was positively associated with the presence of nasal discharge (P = 0.018) and coughing (P = 0.043).

La prévalence des agents causals de maladies du tractus respiratoire supérieur félin (URTD) a été préalablement documentée dans plusieurs régions du monde mais n'a pas encore été rapportée dans l'est du Canada. Les objectifs de la présente étude étaient de déterminer la prévalence d'herpès virus félin-1 (FHV-1), du calicivirus félin (FCV), de Chlamydia felis et de Bordetella bronchiseptica dans une population de chats de refuge de l'Île-du-Prince-Édouard, Canada avec des signes cliniques reliés au URTD; de comparer la prévalence de FHV-1 et FCV telle que détecter par réaction d'amplification en chaîne par la polymérase (PCR) et l'isolement viral (VI) dans ces populations; et finalement, déterminer si des facteurs, tels que les co-infections, la période de l'année, le statut concomitant positif pour le virus de la leucémie féline (FeLV) ou le virus de l'immunodéficience féline (FIV) ou les signes cliniques étaient associés avec la prévalence d'un agent pathogène en particulier. Des écouvillons de la conjonctive, de la muqueuse nasale et de l'oropharynx furent obtenus de 82 chats avec des signes cliniques compatibles avec URTD. Les échantillons étaient regroupés dans un milieu de transport et la PCR utilisée pour détecter FHV-1, FCV et C. felis et l'isolement viral fut également utilisé pour détecter FHV-1 et FCV. Un écouvillon séparé fut soumis pour culture bactérienne aérobie afin de détecter B. bronchiseptica. Le FHV-1 était le plus prévalent dans cette population, suivi par C. felis, B. bronchiseptica et FCV. Des quatre chats qui étaient positifs pour B. bronchiseptica, trois étaient positifs également pour FHV-1. Tous les isolats de B. bronchiseptica obtenus étaient résistants au céfovecin. La prévalence de FHV-1 était à son plus bas en automne (P < 0,001 pour les saisons) et était associée positivement avec la présence d'écoulement nasal (P = 0,018) et de la toux (P = 0,043).(Traduit par Docteur Serge Messier).

HERQ-9 Is a New Multiplex PCR for Differentiation and Quantification of All Nine Human Herpesviruses.

Infections with the nine human herpesviruses (HHVs) are globally prevalent and characterized by lifelong persistence. Reactivations can potentially manifest as life-threatening conditions for which the demonstration of viral DNA is essential. In the present study, we developed HERQ-9, a pan-HHV quantitative PCR designed in triplex reactions to differentiate and quantify each of the HHV-DNAs: (i) herpes simplex viruses 1 and 2 and varicella-zoster virus; (ii) Epstein-Barr virus, human cytomegalovirus, and Kaposi's sarcoma-associated herpesvirus; and (iii) HHV-6A, -6B, and -7. The method was validated with prequantified reference standards as well as with mucocutaneous swabs and cerebrospinal fluid, plasma, and tonsillar tissue samples. Our findings highlight the value of multiplexing in the diagnosis of many unsuspected, yet clinically relevant, herpesviruses. In addition, we report here frequent HHV-DNA co-occurrences in clinical samples, including some previously unknown. HERQ-9 exhibited high specificity and sensitivity (LOD95s of ∼10 to ∼17 copies/reaction), with a dynamic range of 101 to 106 copies/µl. Moreover, it performed accurately in the coamplification of both high- and low-abundance targets in the same reaction. In conclusion, we demonstrated that HERQ-9 is suitable for the diagnosis of a plethora of herpesvirus-related diseases. Besides its significance to clinical management, the method is valuable for the assessment of hitherto-unexplored synergistic effects of herpesvirus coinfections. Furthermore, its high sensitivity enables studies on the human virome, often dealing with minute quantities of persisting HHVs.IMPORTANCE By adulthood, almost all humans become infected by at least one herpesvirus (HHV). The maladies inflicted by these microbes extend beyond the initial infection, as they remain inside our cells for life and can reactivate, causing severe diseases. The diagnosis of active infection by these ubiquitous pathogens includes the detection of DNA with sensitive and specific assays. We developed the first quantitative PCR assay (HERQ-9) designed to identify and quantify each of the nine human herpesviruses. The simultaneous detection of HHVs in the same sample is important since they may act together to induce life-threatening conditions. Moreover, the high sensitivity of our method is of extreme value for assessment of the effects of these viruses persisting in our body and their long-term consequences on our health.

Co-infections of human herpesviruses (CMV, HHV-6, HHV-7 and EBV) in non-transplant acute leukemia patients undergoing chemotherapy.

BACKGROUND: Human herpesviruses (HHVs) remain latent after primary infection and can be reactivated in response to immunosuppression and chemotherapy. Little is known about their incidence, potential relationships, risk factors and clinical impact in non-transplant leukemia patients. This study investigated prospectively incidence, risk factors, clinical impact and possible association of HHVs-(1-7) infections in patients with newly diagnosed acute leukemia. METHODS: Study design involved longitudinal sampling before chemotherapy and in different phases of chemotherapy: post-induction, post-remission, and post-salvage during 2016-2018. A total of 734 plasma samples from 95 patients were analyzed by a qualitative, multiplex PCR for HHVs detection and a quantitative real-time PCR was used for cytomegalovirus (CMV) quantification. HHVs-(1-6) IgG and IgM antibodies were tested using immunoassays. Risk factors were analyzed by binary logistic regression and relationships between viruses were analyzed using the Chi-square or Fisher's exact test as appropriate. RESULTS: The overall seroprevalences of HHV-(1-6) IgG were high (> 80%). At least one herpes viral agent was detected in 60 patients (63.3%). CMV was the most commonly detected virus in the different phases of chemotherapy (19.4%), followed by HHV-6 (9.7%), HHV-7 (5.2%) and EBV (2.7%). HSV-1/2 and VZV DNA were not detected. Twenty-seven patients (28.4%) had more than one virus detected in the follow-up, with 23 who were co-infected. CMV/HHV-6 was the most frequent co-infection (69.5%, 16/23). HHV-6 infection (p = 0.008) was identified as a risk factor for CMV infection while salvage treatment (p = 0.04) and CMV infection (p = 0.007) were found to be independent risk factors for HHV-6 infection. CMV co-infection was associated with severe lymphopenia with an absolute lymphocyte count (ALC) (< 500/µL) (p = 0.009), rash (p = 0.011), pneumonia (p = 0.016) and opportunistic infections [bacteremia, p < 0.001 and invasive fungal infection, (p = 0.024)] more frequently than CMV mono-viral infections. CONCLUSIONS: Our data suggest that co-infection with HHVs, especially CMV and HHV-6, may contribute to the development of serious clinical manifestations with profound lymphopenia, pneumonia rash and increased risk for bacterial and fungal co-infections. These findings may suggest the synergistic effect of HHVs associated infection.

Search for polyoma-, herpes-, and bornaviruses in squirrels of the family Sciuridae.

BACKGROUND: Squirrels (family Sciuridae) are globally distributed members of the order Rodentia with wildlife occurrence in indigenous and non-indigenous regions (as invasive species) and frequent presence in zoological gardens and other holdings. Multiple species introductions, strong inter-species competition as well as the recent discovery of a novel zoonotic bornavirus resulted in increased research interest on squirrel pathogens. Therefore we aimed to test a variety of squirrel species for representatives of three virus families. METHODS: Several species of the squirrel subfamilies Sciurinae, Callosciurinae and Xerinae were tested for the presence of polyomaviruses (PyVs; family Polyomaviridae) and herpesviruses (HVs; family Herpesviridae), using generic nested polymerase chain reaction (PCR) with specificity for the PyV VP1 gene and the HV DNA polymerase (DPOL) gene, respectively. Selected animals were tested for the presence of bornaviruses (family Bornaviridae), using both a broad-range orthobornavirus- and a variegated squirrel bornavirus 1 (VSBV-1)-specific reverse transcription-quantitative PCR (RT-qPCR). RESULTS: In addition to previously detected bornavirus RNA-positive squirrels no more animals tested positive in this study, but four novel PyVs, four novel betaherpesviruses (BHVs) and six novel gammaherpesviruses (GHVs) were identified. For three PyVs, complete genomes could be amplified with long-distance PCR (LD-PCR). Splice sites of the PyV genomes were predicted in silico for large T antigen, small T antigen, and VP2 coding sequences, and experimentally confirmed in Vero and NIH/3T3 cells. Attempts to extend the HV DPOL sequences in upstream direction resulted in contiguous sequences of around 3.3 kilobase pairs for one BHV and two GHVs. Phylogenetic analysis allocated the novel squirrel PyVs to the genera Alpha- and Betapolyomavirus, the BHVs to the genus Muromegalovirus, and the GHVs to the genera Rhadinovirus and Macavirus. CONCLUSIONS: This is the first report on molecular identification and sequence characterization of PyVs and HVs and the detection of bornavirus coinfections with PyVs or HVs in two squirrel species. Multiple detection of PyVs and HVs in certain squirrel species exclusively indicate their potential host association to a single squirrel species. The novel PyVs and HVs might serve for a better understanding of virus evolution in invading host species in the future.

Herpesviruses and the Unfolded Protein Response.

Herpesviruses usurp cellular stress responses to promote viral replication and avoid immune surveillance. The unfolded protein response (UPR) is a conserved stress response that is activated when the protein load in the ER exceeds folding capacity and misfolded proteins accumulate. The UPR aims to restore protein homeostasis through translational and transcriptional reprogramming; if homeostasis cannot be restored, the UPR switches from "helper" to "executioner", triggering apoptosis. It is thought that the burst of herpesvirus glycoprotein synthesis during lytic replication causes ER stress, and that these viruses may have evolved mechanisms to manage UPR signaling to create an optimal niche for replication. The past decade has seen considerable progress in understanding how herpesviruses reprogram the UPR. Here we provide an overview of the molecular events of UPR activation, signaling and transcriptional outputs, and highlight key evidence that herpesviruses hijack the UPR to aid infection.

Antibodies to Human Herpesviruses in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients.

Myalgic encephalomyelitis, also referred to as chronic fatigue syndrome (ME/CFS) is a debilitating disease characterized by myalgia and a sometimes severe limitation of physical activity and cognition. It is exacerbated by physical and mental activity. Its cause is unknown, but frequently starts with an infection. The eliciting infection (commonly infectious mononucleosis or an upper respiratory infection) can be more or less well diagnosed. Among the human herpesviruses (HHV-1-8), HHV-4 (Epstein-Barr virus; EBV), HHV-6 (including HHV-6A and HHV-6B), and HHV-7, have been implicated in the pathogenesis of ME/CFS. It was therefore logical to search for serological evidence of past herpesvirus infection/reactivation in several cohorts of ME/CFS patients (all diagnosed using the Canada criteria). Control samples were from Swedish blood donors. We used whole purified virus, recombinant proteins, and synthetic peptides as antigens in a suspension multiplex immunoassay (SMIA) for immunoglobulin G (IgG). The study on herpesviral peptides based on antigenicity with human sera yielded novel epitope information. Overall, IgG anti-herpes-viral reactivities of ME/CFS patients and controls did not show significant differences. However, the high precision and internally controlled format allowed us to observe minor relative differences between antibody reactivities of some herpesviral antigens in ME/CFS versus controls. ME/CFS samples reacted somewhat differently from controls with whole virus HHV-1 antigens and recombinant EBV EBNA6 and EA antigens. We conclude that ME/CFS samples had similar levels of IgG reactivity as blood donor samples with HHV-1-7 antigens. The subtle serological differences should not be over-interpreted, but they may indicate that the immune system of some ME/CFS patients interact with the ubiquitous herpesviruses in a way different from that of healthy controls.