Cold sore susceptibility gene-1 genotypes affect the expression of herpes labialis in unrelated human subjects

A Comprehensive Overview of Epidemiology, Pathogenesis and the Management of Herpes Labialis

Herpes labialis remains exceedingly prevalent and is one of the most common human viral infections throughout the world. Recurrent herpes labialis evolves from the initial viral infection by herpes simplex virus type 1 (HSV-1) which subsequently presents with or without symptoms. Reactivation of this virus is triggered by psychosocial factors such as stress, febrile environment, ultraviolet light susceptibility, or specific dietary inadequacy. This virus infection is also characterized by uninterrupted transitions between chronic-latent and acute-recurrent phases, allowing the virus to opportunistically avoid immunity and warrant the transmission to other vulnerable hosts simultaneously. This review comprehensively evaluates the current evidence on epidemiology, pathogenesis, transmission modes, clinical manifestations, and current management options of herpes labialis infections.

Comparison of herpes simplex virus 1 genomic diversity between adult sexual transmission partners with genital infection

Herpes simplex virus (HSV) causes chronic infection in the human host, characterized by self-limited episodes of mucosal shedding and lesional disease, with latent infection of neuronal ganglia. The epidemiology of genital herpes has undergone a significant transformation over the past two decades, with the emergence of HSV-1 as a leading cause of first-episode genital herpes in many countries. Though dsDNA viruses are not expected to mutate quickly, it is not yet known to what degree the HSV-1 viral population in a natural host adapts over time, or how often viral population variants are transmitted between hosts. This study provides a comparative genomics analysis for 33 temporally-sampled oral and genital HSV-1 genomes derived from five adult sexual transmission pairs. We found that transmission pairs harbored consensus-level viral genomes with near-complete conservation of nucleotide identity. Examination of within-host minor variants in the viral population revealed both shared and unique patterns of genetic diversity between partners, and between anatomical niches. Additionally, genetic drift was detected from spatiotemporally separated samples in as little as three days. These data expand our prior understanding of the complex interaction between HSV-1 genomics and population dynamics after transmission to new infected persons.

[RETRACTED: High-throughput sequencing in diagnostics and prevention of herpes simplex virus infection (Herpesviridae, Alphaherpesvirinae, Simplexvirus, Human alphaherpesvirus 1)]

RETRACTEDHerpes simplex viruses types 1 (HSV-1) and 2 (HSV-2) are among the most common viruses in the human population. The clinical manifestations of HSV infection vary widely, which necessitates reliable molecular methods for the timely diagnosis of herpes virus infection, as well as for detection of mutations in the genes responsible for drug resistance. PCR is often unable to detect HSV isolates with nucleotide substitutions at the primer binding site. Sanger sequencing of the whole genome reveals mutations mainly at the consensus level, which accumulate at advanced stages of viral infection. High-throughput sequencing (HTS, next generation sequencing) offers an obvious advantage both in early diagnosis of herpes virus infection and identification of HSV variants.

Herpesviral Latency-Common Themes

Latency establishment is the hallmark feature of herpesviruses, a group of viruses, of which nine are known to infect humans. They have co-evolved alongside their hosts, and mastered manipulation of cellular pathways and tweaking various processes to their advantage. As a result, they are very well adapted to persistence. The members of the three subfamilies belonging to the family Herpesviridae differ with regard to cell tropism, target cells for the latent reservoir, and characteristics of the infection. The mechanisms governing the latent state also seem quite different. Our knowledge about latency is most complete for the gammaherpesviruses due to previously missing adequate latency models for the alpha and beta-herpesviruses. Nevertheless, with advances in cell biology and the availability of appropriate cell-culture and animal models, the common features of the latency in the different subfamilies began to emerge. Three criteria have been set forth to define latency and differentiate it from persistent or abortive infection: 1) persistence of the viral genome, 2) limited viral gene expression with no viral particle production, and 3) the ability to reactivate to a lytic cycle. This review discusses these criteria for each of the subfamilies and highlights the common strategies adopted by herpesviruses to establish latency.

The Role of C21orf91 in Herpes Simplex Virus Keratitis

Background and Objectives: This paper aims to describe the single nucleotide polymorphisms (SNPs) of C21orf91 rs1062202 and rs10446073 in patients with herpetic keratitis by evaluating corneal sub-basal nerves, as well as the density of Langerhans cells (LC) and endothelium cells (EC) during the acute phase of the disease. Materials and Methods: A prospective clinical study included 260 subjects: 70 with herpetic eye disease, 101 with previous history of herpes labialis—but no history of herpetic eye disease—and 89 with no history of any herpes simplex virus (HSV) diseases. All subjects underwent a complete ophthalmological examination including in vivo laser scanning confocal microscopy (LSCM) of the central cornea. C21orf91 rs1062202 and rs10446073 were genotyped using the real-time polymerase chain reaction (PCR) method with the Rotor-Gene Q real-time PCR quantification system. SNPs were determined using TaqMan genotyping assay, according to the manufacturer’s manual. Results: The C21orf91 rs10446073 genotype GT was more frequent in the HSV keratitis group, compared with healthy controls (20.0% vs. 7.9%), OR 2.929[1.11–7.716] (p < 0.05). The rs10446073 genotype TT was more frequent in healthy controls (12.4% vs. 1.4%), OR 22.0[2.344–260.48] (p < 0.05). The rs10446073 genotype GT increased the risk of EC density being less than 2551.5 cell/mm², OR 2.852[1.248–6.515] (p < 0.05). None of the SNPs and their genotypes influenced the LC density and corneal sub-basal nerve parameters (p > 0.05). Conclusions: Our study reports a new association between herpetic keratitis and human gene C21orf91, with the rs10446073 genotype GT being more common in herpetic keratitis patients and increasing the risk for the disease by a factor of 2.9.

Persistent Infection with Herpes Simplex Virus 1 and Alzheimer's Disease-A Call to Study How Variability in Both Virus and Host may Impact Disease

Increasing attention has focused on the contributions of persistent microbial infections with the manifestation of disease later in life, including neurodegenerative conditions such as Alzheimer’s disease (AD). Current data has shown the presence of herpes simplex virus 1 (HSV-1) in regions of the brain that are impacted by AD in elderly individuals. Additionally, neuronal infection with HSV-1 triggers the accumulation of amyloid beta deposits and hyperphosphorylated tau, and results in oxidative stress and synaptic dysfunction. All of these factors are implicated in the development of AD. These data highlight the fact that persistent viral infection is likely a contributing factor, rather than a sole cause of disease. Details of the correlations between HSV-1 infection and AD development are still just beginning to emerge. Future research should investigate the relative impacts of virus strain- and host-specific factors on the induction of neurodegenerative processes over time, using models such as infected neurons in vitro, and animal models in vivo, to begin to understand their relationship with cognitive dysfunction.

Viral Genetics Modulate Orolabial Herpes Simplex Virus Type 1 Shedding in Humans

BACKGROUND

Orolabial herpes simplex virus type 1 (HSV-1) infection has a wide spectrum of severity in immunocompetent persons. To study the role of viral genotype and host immunity, we characterized oral HSV-1 shedding rates and host cellular response, and genotyped viral strains, in monozygotic (MZ) and dizygotic (DZ) twins.

METHODS

A total of 29 MZ and 22 DZ HSV-1-seropositive twin pairs were evaluated for oral HSV-1 shedding for 60 days. HSV-1 strains from twins were genotyped as identical or different. CD4+ T-cell responses to HSV-1 proteins were studied.

RESULTS

The median per person oral HSV shedding rate was 9% of days that a swab was obtained (mean, 10.2% of days). A positive correlation between shedding rates was observed within all twin pairs, and in the MZ and DZ twins. In twin subsets with sufficient HSV-1 DNA to genotype, 15 had the same strain and 14 had different strains. Viral shedding rates were correlated for those with the same but not different strains. The median number of HSV-1 open reading frames recognized per person was 16. The agreement in the CD4+ T-cell response to specific HSV-1 open reading frames was greater between MZ twins than between unrelated persons (P = .002).

CONCLUSION

Viral strain characteristics likely contribute to oral HSV-1 shedding rates.

Herpes Simplex Virus Disease Management and Diagnostics in the Era of High-Throughput Sequencing

Herpes simplex virus (HSV) serotypes 1 and 2 are among the most widespread human viruses. HSV disease has a complex phenotype, with symptoms that can range from mild lesions to encephalitis. In the clinical setting, this diversity of outcomes poses a major challenge, making timely disease diagnosis and treatment challenging. High-throughput sequencing (HTS) has been one of the breakthrough technologies in the modern era of molecular biology, and it is revolutionizing the study of pathogen biology and clinical diagnostics. Here, we review recent studies that have used HTS to answer questions related to the evolution of drug resistance, transmission and spread, virulence marker identification, and the design of better antiviral therapeutics for HSV. We also highlight practical considerations for handling computational analysis of HSV genomes and adoption of HTS as a routine diagnostic procedure in the clinical laboratories.