Association between human herpesvirus infection and cervical carcinoma: a systematic review and meta-analysis

BACKGROUND

Cervical cancer (CC) is one of the most common gynecologic tumors among women around the world. Although the etiological role of human papillomavirus (HPV) in CC is well established, other factors in CC carcinogenesis remains unclear. Here, we performed a systematic review and meta-analysis to explore the association between infections of human herpesvirus (HHVs) and CC risk.

METHODS

Embase and PubMed databases were utilized to search the relevant studies. The revised JBI Critical Appraisal Tool was used to assess the quality of the included studies. Prevalence and odds ratios (ORs) with 95% confidence intervals (CI) were calculated to evaluate the association between viral infection and CC or precancerous cervical lesions (PCL).

RESULTS

Totally 67 eligible studies involving 7 different HHVs were included in meta-analysis. We found an increased risk of CC or PCL that was associated with the overall infection of HHVs (CC, OR = 2.74, 95% CI 2.13-3.53; PCL, OR = 1.95, 95% CI 1.58-2.41). Subgroup analysis showed a trend towards positive correlations between herpes simplex virus type 2 (HSV-2) infection and CC (OR = 3.01, 95% CI 2.24 to 4.04) or PCL (OR = 2.14, 95% CI 1.55 to 2.96), and the same is true between Epstein-Barr virus (EBV) infection and CC (OR = 4.89, 95% CI 2.18 to 10.96) or PCL (OR = 3.55, 95% CI 2.52 to 5.00). However, for HSV-1 and cytomegalovirus (HCMV), there was no association between viral infection and CC or PCL. By contrast, the roles of HHV-6, HHV-7, and Kaposi sarcoma-associated herpesvirus (KSHV) in cervical lesions were unclear due to the limited number of studies.

CONCLUSIONS

This study provided evidence that HHVs infection as a whole increase the risk of CC incidence. In addition, some types of HHVs such as EBV and HSV-2 may serve as potential targets in the development of new interventions or therapeutic strategies for cervical lesions.

Transmission dynamics of human herpesvirus 6A, 6B and 7 from whole genome sequences of families

While hundreds of thousands of human whole genome sequences (WGS) have been collected in the effort to better understand genetic determinants of disease, these whole genome sequences have less frequently been used to study another major determinant of human health: the human virome. Using the unmapped reads from WGS of over 1000 families, we present insights into the human blood DNA virome, focusing particularly on human herpesvirus (HHV) 6A, 6B, and 7. In addition to extensively cataloguing the viruses detected in WGS of human whole blood and lymphoblastoid cell lines, we use the family structure of our dataset to show that household drives transmission of several viruses, and identify the Mendelian inheritance patterns characteristic of inherited chromsomally integrated human herpesvirus 6 (iciHHV-6). Consistent with prior studies, we find that 0.6% of our dataset's population has iciHHV, and we locate candidate integration sequences for these cases. We document genetic diversity within exogenous and integrated HHV species and within integration sites of HHV-6. Finally, in the first observation of its kind, we present evidence that suggests widespread de novo HHV-6B integration and HHV-7 integration and reactivation in lymphoblastoid cell lines. These findings show that the unmapped read space of WGS is a promising source of data for virology research.

L-lysine: its antagonism with L-arginine in controlling viral infection. Narrative Literature Review

Knowledge about viral characteristics, mechanisms of entry into the host cell and multiplication/dissemination can help in the control and treatment of viral pathologies. Several nutritional factors linked to the host may favor viral multiplication and their control, may lead to new prophylactic alternatives and/or antiviral therapies. The objective of this review is to discuss the relationship between the amino acid L-lysine and the control of viral infections, aiming at a possible therapeutic property. This research used databases such as PubMed, Web of Science, Scielo, Medline and Google Scholar, as well as searching for references cited by journals. The time frame covered the period between 1964 and January 2022. The observed studies have shown that the usual antiviral therapies are not able to interfere with the viruses in their latent state, however, they can interfere with the adhesion and fusion of viral particles or the production of proteins, which play an important role in viral epidemiology and control, particularly in the initial moment and in the reactivation. Lysine is an amino acid that can interfere mainly in the formation of capsid proteins and DNA by a competitive antagonism with amino acid arginine, which is an essential amino acid for some viruses and also by promoting the increase of arginase, increasing the catabolism of arginine. Although there is evidence of the importance of L-lysine in viral control, more studies are needed, with a view to new antiviral therapies.

Persistent viremia in an immunocompetent patient with inherited chromosomally integrated HHV-6B

Human herpesvirus-6 (HHV-6), the virus which causes roseola, has traditionally been associated with benign and self-limited childhood illness. However, HHV-6 establishes lifelong latency and can reactivate in immunocompromised adult patients. In about 1% of cases, it integrates into the human genome as inherited chromosomally integrated HHV-6 (iciHHV-6). We report the case of a 70-year-old man presenting with altered mental status and agitation. His infectious workup revealed a cerebrospinal fluid sample positive for HHV-6 with virus detectable in the blood as well. He was subsequently treated with ganciclovir. HHV-6 viremia (DNAemia) persisted, and the antiviral medications were switched to foscarnet under the assumption of treatment failure due to drug resistance. After several admissions to the hospital for the same complaint, and after noticing that DNAemia persisted despite adequate treatment for HHV-6, infectious disease specialists ordered testing for chromosomally integrated virus. Test results confirmed the presence of iciHHV-6, explaining his consistently elevated serum viral load. Primary HHV-6 infection in adults causes a transient increase in viral load with resolution and clearance after a few weeks while iciHHV-6 is characterized by persistent detection of viral DNA at a high copy number. Individuals with iciHHV-6 can develop HHV-6 disease and are at increased risk for active viral replication when treated with immunosuppressive medications, but only mRNA testing, which is not widely available can differentiate between latent and active infection. This makes the decision to treat challenging in this patient population. When faced with a positive HHV-6 DNA result in the setting of equivocal symptoms, clinicians should consider the possibility of chromosomally integrated virus rather than drug-resistant virus in order to reduce exposure to potentially toxic antiviral medications.

Human herpesvirus-encoded MicroRNA in host-pathogen interaction

Human herpesviruses (HHV) are ubiquitous, linear dsDNA viruses that establish lifelong latency, disrupted by sporadic reactivation. HHV have evolved diverse ingenious mechanisms to evade robust host defenses. Incorporation of unique stem loop sequences that generate viral microRNAs (v-miRs) exemplifies one such evolutionary adaptation in HHV. These noncoding RNAs can control cellular and viral transcriptomes highlighting their ability in shaping host-HHV interactions. We summarize recent developments in functional characterization of HHV-encoded miRNAs in shaping the outcome of host-pathogen interaction. Non-immunogenic dissemination of v-miRs through exosomes confer added advantage to HHV in incessant modulation of host microenvironment. This review delineates the mechanistic role of v-miRs in facilitating viral persistence and tropism by targeting genes associated with cellular (apoptosis, angiogenesis, cell migration, etc.) and viral life cycle (latency, lytic and reactivation). Burgeoning evidences indicate plausible association of v-miRs in various immune-mediated diseases (nasopharyngeal carcinoma, neurological disorders, periodontal diseases, etc.) and herpesvirus-related malignancies indicating their broad-spectrum impact on host cellular pathways. We propose to exploit tisssue and systemic levels of v-miRs as diagnostic and prognostic markers for cancers and immune-mediated diseases. Therapeutic targeting of v-miRs will advance the promising outcomes of preclinical discoveries to bedside application.

A multiplex real-time PCR quantitation of human herpesvirus-6, 7, 8 viruses: application in blood transfusions

Background

In recent years, fluorescent quantitative polymerase chain reaction assays for detecting viral DNA are in widespread use throughout the world. However, considering the wide distribution of new herpesvirus among the population, we constructed a method to detect HHV-6, 7, and 8 simultaneously.

Methods

The blood samples of 74 blood donors and 45 pityriasis rosea patients were collected. The recombinant plasmids containing U67, U36, and orf65 were constructed to optimize the PCR reaction system. The forward and reverse primers and probe sequences of HHV-6 were as follows: TAAATATCGATGCCGCTCTG, ACGTTCTAGCCATCTTCTTTG, CGCAAACGACAAAGCCA. The forward and reverse primers and probe sequences of HHV-7 were as follows: TTAGACATCTTACACGACAGC, CAGCTTTTCGAACTTGTCAC, TTCATCGGGTACGTCCA. The forward and reverse primers and probe sequences of HHV-8 were as follows: GCGACATATTTCCCTGATCC, CCAACTTTAAGGTGAGAGACC, CATGCGAGCCACCAG. Through the detection of housekeeping genes, DNA sequencing, and optimization of the PCR reaction system, the triple fluorescent quantitative PCR detection system was constructed. Blood samples of blood transfusion staff and pityriasis rosea patients were detected.

Results

The correlations of HHV-6, 7, and 8 between single and multiplex PCR are 0.980, 0.987, 0.965, respectively. In 74 blood donor samples, 16.2% of HHV-6 and 55% of HHV-7 were positive (viral load > 3 log10 copies/ml) according to multiplex real-time PCR. In 45 patients suspected of pityriasis rosea (PR) infection, 40% HHV-6, 73.3% positive cases are found.

Conclusion

With the safety of blood transfusion being a major concern of the public, this method will show good specificity and sensitivity in blood transfusion screening.

Pathobiology and treatment of viral keratitis

Keratitis is one of the most prevalent ocular diseases manifested by partial or total loss of vision. Amongst infectious (viz., microbes including bacteria, fungi, amebae, and viruses) and non-infectious (viz., eye trauma, chemical exposure, and ultraviolet exposure, contact lens) risk factors, viral keratitis has been demonstrated as one of the leading causes of corneal opacity. While many viruses have been shown to cause keratitis (such as rhabdoviruses, coxsackieviruses, etc.), herpesviruses are the predominant etiologic agent of viral keratitis. This chapter will summarize current knowledge on the prevalence, diagnosis, and pathobiology of viral keratitis. Virus-mediated immunomodulation of host innate and adaptive immune components is critical for viral persistence, and dysfunctional immune responses may cause destruction of ocular tissues leading to keratitis. Immunosuppressed or immunocompromised individuals may display recurring disease with pronounced severity. Early diagnosis of viral keratitis is beneficial for disease management and response to treatment. Finally, we have discussed current and emerging therapies to treat viral keratitis.

Viral Hepatitis Other than A, B, and C: Evaluation and Management

Viral hepatitis can cause a wide spectrum of clinical presentations from a benign form with minimal or no symptoms to acute liver failure or death. Hepatitis D coinfection and superinfection have distinct clinical courses, with the latter more likely leading to chronic infection. Management of chronic hepatitis D virus is individualized because of the paucity of treatment options and significant side effect profile of currently available treatments. Sporadic cases of hepatitis E caused by contaminated meats are becoming increasingly prevalent in immunocompromised hosts. Human herpesviruses are an important cause of disease also in immunocompromised individuals.

Human cytomegalovirus pTRS1 stimulates cap-independent translation

Human cytomegalovirus (HCMV) manipulates multiple cellular processes to facilitate virus replication, including the control of mRNA translation. We previously showed that the HCMV TRS1 protein (pTRS1) promotes cap-dependent mRNA translation independent of its ability to antagonize the antiviral protein PKR. Here we find that pTRS1 enhances internal ribosome entry site (IRES) activity using a novel circular RNA reporter that lacks an mRNA cap and poly(A) tail. Additionally, pTRS1 expression increases the activity of cellular IRESs that control the expression of proteins needed for efficient HCMV replication. We find that the ability of pTRS1 to enhance cap-independent translation is separable from its ability to antagonize PKR, but requires the pTRS1 RNA binding domain. Together these data show that pTRS1 stimulates cap-independent translation and suggest a role for pTRS1 in alternative translation initiation pathways during HCMV infection.

Quadruplex real-time PCR for rapid detection of human alphaherpesviruses

Infections with the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) as well as with the varicella-zoster virus (VZV) may take a serious course. Thus, rapid and reliable detection of these alphaherpesviruses is urgently needed. For this, we established a qualitative quadruplex real-time polymerase chain reaction (PCR) covering HSV-1, HSV-2, VZV and endogenous human glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The PCR was validated with quality assessment samples and pre-characterized clinical samples including swabs, blood and cerebrospinal as well as respiratory fluids. For comparison, nucleic acids (NA) of selected samples were extracted manually and automatically. The protocol takes approx. 90 min, starting with the preparation of NA until the report of results. The oligonucleotide and hydrolysis probe sequences specifically detect and distinguish HSV-1 (530 nm), HSV-2 (705 nm) and VZV (560 nm) DNA. The detection limit was estimated with 100-500 copies/ml HSV-1 and HSV-2/VZV, respectively. All quality assessment samples as well as all the patient samples were classified correctly. Parallel detection of GAPDH (670 nm) DNA was implemented to demonstrate correct sampling, but was uncertain in case of swabs. To this end, alphaherpesvirus-free human DNA was also added directly into the mastermix to exclude PCR inhibition. The established protocol for parallel detection and differentiation of alphaherpesviruses is fast, highly specific as well as rather sensitive. It will facilitate HSV-1/2 and VZV diagnostics and may be further improved by opening the 670 nm channel for a combined extraction and PCR inhibition control.

Association between human herpes virus seropositivity and frailty in the elderly: A systematic review and meta-analysis

Frailty is an emerging geriatric syndrome characterized by decreased physiologic reserve and increased vulnerability to environmental factors. Several studies have examined the association between persistent cytomegalovirus (CMV) infection and poor clinical outcomes in the elderly, but the results are often contradictory. Here, we performed a systematic review and meta-analysis to analyze the association between human herpesvirus seropositivity [CMV, Epstein-Barr virus (EBV), Varicella zoster virus (VZV), and Herpes simplex virus (HSV)] and frailty in elderly people. Searches were performed in PubMed, SCOPUS, Lilacs, IBECS, and Web of Science databases. We used the odds ratio (OR) as a measure of the association between herpesvirus infections and frailty. Summary estimates were calculated using random-effects models. Six studies were included in the present systematic review. The data from 2559 elderly subjects were analyzed; 1571 of the subjects had ages between 60 and 79 years, and 988 of the subjects were older than 80. We found an association between CMV seropositivity and frailty in the elderly aged 60-79 years (OR 2.33, CI 95% 1.48-3.67) but not in the oldest-old subjects (OR 0.67, CI 95% 0.42-1.05). Moreover, no association was found between EBV, VZV, and HSV infections and frailty. Current evidence suggests an association between CMV seropositivity and frailty in individuals aged 60-79 years old.

Human Herpesvirus 8 and Lymphoproliferative Disorders

The spectrum of lymphoproliferative disorders linked to human herpesvirus 8 (HHV-8) infection has constantly been increasing since the discovery of its first etiologic association with primary effusion lymphoma (PEL). PEL is a rapidly progressing non-Hodgkin’s B-cell lymphoma that develops in body cavities in an effusional form. With the increase in the overall survival of PEL patients, as well as the introduction of HHV-8 surveillance in immunocompromised patients, the extracavitary, solid counterpart of PEL was later identified. Moreover, virtually all plasmablastic variants of multicentric Castleman’s disease (MCD) developing in HIV-1-infected individuals harbor HHV-8, providing a strong etiologic link between MCD and this oncogenic herpesvirus. Two other pathologic conditions develop in HIV-1-infected persons concomitantly with MCD: MCD with plasmablastic clusters and HHV-8-positive diffuse large B-cell lymphoma not otherwise specified (HHV-8+ DLBCL NOS), the first likely representing an intermediate stage preceding the full neoplastic form. MCD in leukemic phase has also been described, albeit much less commonly. The germinotropic lymphoproliferative disorder (GLPD) may resemble extracavitary PEL, but develops in immune competent HHV8-infected individuals, and, unlike the other disorders, it responds well to conventional therapies. Almost all HHV-8-mediated lymphoproliferative disorders are the result of an interaction between HHV-8 infection and a dysregulated immunological system, leading to the formation of inflammatory niches in which B cells, at different developmental stages, are infected, proliferate and may eventually shift from a polyclonal state to a monoclonal/neoplastic disorder. Herein, we describe the association between HHV-8 and lymphoproliferative disorders and highlight the predominant distinctive features of each disease.

Lymphoproliferative Syndromes Associated with Human Herpesvirus-6A and Human Herpesvirus-6B

Human herpesvirus 6A and 6B (HHV-6A and HHV-6B) have been noted since their discovery for their T-lymphotropism. Although it has proven difficult to determine the extent to which HHV-6A and HHV-6B are involved in the pathogenesis of many diseases, evidence suggests that primary infection and reactivation of both viruses may induce or contribute to the progression of several lymphoproliferative disorders, ranging from benign to malignant and including infectious mononucleosis-like illness, drug induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS), and nodular sclerosis Hodgkin's lymphoma. Herein, we discuss the conditions associated with the lymphoproliferative capacity of HHV-6, as well as the potential mechanisms behind them. Continued exploration on this topic may add to our understanding of the interactions between HHV-6 and the immune system and may open the doors to more accurate diagnosis and treatment of certain lymphoproliferative disorders.

The eIF4AIII RNA helicase is a critical determinant of human cytomegalovirus replication

Human cytomegalovirus (HCMV) was recently shown to encode a large number of spliced mRNAs. While the nuclear export of unspliced viral transcripts has been extensively studied, the role of host mRNA export factors in HCMV mRNA trafficking remains poorly defined. We found that the eIF4AIII RNA helicase, a component of the exon junction complex, was necessary for efficient virus replication. Depletion of eIF4AIII limited viral DNA accumulation, export of viral mRNAs from the nucleus, and the production of progeny virus. However eIF4AIII was dispensable for the association of viral transcripts with ribosomes. We found that pateamine A, a natural compound that inhibits both eIF4AI/II and eIF4AIII, has potent antiviral activity and inhibits HCMV replication throughout the virus lytic cycle. Our results demonstrate that eIF4AIII is required for efficient HCMV replication, and suggest that eIF4A family helicases may be a new class of targets for the development of host-directed antiviral therapeutics.

The Sordid Affair Between Human Herpesvirus and HIV

Both human immunodeficiency virus (HIV) and human herpesvirus (HHV) infections persist lifelong, and almost all individuals infected with HIV are also infected with ≥1 HHV. These coinfections are not independent processes or benign. In this review, we discuss how HHVs, and cytomegalovirus in particular, interact with concurrent HIV infection, and we describe the next steps necessary to understand and address these connections.

Spontaneous fatal Human herpesvirus 1 encephalitis in two domestic rabbits (Oryctolagus cuniculus)

Despite the particular susceptibility of the rabbit to experimental infection with Human herpesvirus 1 (HHV-1) and the high seroprevalence of HHV-1 in human beings, reports of natural infection in pet rabbits are rare. The current report describes 2 cases of HHV encephalitis in pet rabbits in North America. Antemortem clinical signs included seizures, ptyalism, and muscle tremors. Results of complete blood cell count and plasma biochemistry panel were unremarkable except for a mild leukocytosis in both cases. Both rabbits died after a short period of hospitalization. Rabbit 1 presented mild optic chiasm hemorrhage on gross examination, while rabbit 2 had no gross lesions. Histologic findings for both cases included lymphocytic and/or lymphoplasmacytic encephalitis with necrosis and the presence of intranuclear inclusion bodies in neurons and glial cells. Polymerase chain reaction (PCR) analysis of affected brain tissue using primers specific for Human herpesvirus 1 and 2 confirmed diagnosis of HHV encephalitis for rabbit 1. Immunohistochemical staining (poly- and monoclonal) and PCR analysis using primers specific to HHV-1 confirmed the diagnosis of HHV-1 encephalitis for rabbit 2. The owner of rabbit 2 was suspected to be the source of infection due to close contact during an episode of herpes labialis. Given the high susceptibility of rabbits to experimental HHV-1, high seroprevalence of HHV-1 in human beings, and severity of clinical disease in this species, clinician awareness and client education is important for disease prevention. Human herpesvirus 1 encephalitis should be considered as a differential diagnosis for rabbits with neurologic disease.

Fever, rash, and systemic symptoms: understanding the role of virus and HLA in severe cutaneous drug allergy

Drug hypersensitivity syndromes such as abacavir hypersensitivity and the severe cutaneous adverse drug reactions have been associated with significant short- and long-term morbidity and mortality. More recently, these immunologically mediated and previously unpredictable diseases have been shown to be associated with primarily class I but also class II HLA alleles. The case of the association of HLA-B*57:01 and abacavir hypersensitivity has created a translational roadmap for how this knowledge can be used in the clinic to prevent severe reactions. Although many hurdles exist to the widespread translation of such HLA screening approaches, our understanding of how drugs interact with the major histocompatibility complex has contributed to the discovery of new models that have provided considerable insights into the immunopathogenesis of severe cutaneous adverse drug reactions and other T-cell-mediated drug hypersensitivity syndromes. Future translation of this knowledge will facilitate the development of preclinical toxicity screening to significantly improve efficacy and safety of drug development and design.