Herpes Simplex Virus Infection Research Articles

A bioinformatic approach to identify pathogenic variants for Stevens-Johnson syndrome.

Stevens-Johnson syndrome (SJS) produces a severe hypersensitivity reaction caused by Herpes simplex virus or mycoplasma infection, vaccination, systemic disease, or other agents. Several studies have investigated the genetic susceptibility involved in SJS. To provide further genetic insights into the pathogenesis of SJS, this study prioritized high-impact, SJS-associated pathogenic variants through integrating bioinformatic and population genetic data. First, we identified SJS-associated single nucleotide polymorphisms from the genome-wide association studies catalog, followed by genome annotation with HaploReg and variant validation with Ensembl. Subsequently, expression quantitative trait locus (eQTL) from GTEx identified human genetic variants with differential gene expression across human tissues. Our results indicate that two variants, namely rs2074494 and rs5010528, which are encoded by the HLA-C (human leukocyte antigen C) gene, were found to be differentially expressed in skin. The allele frequencies for rs2074494 and rs5010528 also appear to significantly differ across continents. We highlight the utility of these population-specific HLA-C genetic variants for genetic association studies, and aid in early prognosis and disease treatment of SJS.

Modern approaches to the therapy of genital herpes in women

Genital herpes (GH) is a common sexually transmitted disease caused by the herpes simplex virus (HSV). It is characterized by lifelong infection and periodic reactivation. Until recently, GH was more often caused by HSV type 2 (HSV-2), but now it very common infection cases by HSV type 1 (HSV-1) and in some countries are even more common than HSV-2. More than 400 million people currently have GH caused by HSV-2 in the world. In the United States nearly one in five adults (approximately 40 million people) are infected with HSV-2. About 1 million new infections occur every year.Recently, much attention has been paid to the issue of new approaches to GH therapy in women. The problem is extremely urgent, since this infection is very common in the world. The main causes of GH are HSV-1 and HSV-2.Approaches to the treatment of GH differ depending on the type of virus (HSV-1 or HSV-2), as well as the absence or presence of clinical manifestations. The analysis of literature data shows that is there are two ways of GH treatment: episodic antiviral therapy, when patients undergo short courses of antiviral therapy during GH relapse, or suppressive antiviral therapy, when patients take medication daily to prevent relapses.Our clinical experience allows us to recommend the ukrainian drug Virostat (manufacturer “Kyiv Vitamin Plant”) for the treatment of HSV infection in women. The scheme of treatment with the Virostat depends on whether these are the first manifestations of infection or its recurrence.There are no approved vaccines for the treatment and prevention of GH, therefore, active prevention and early diagnosis increase the chances of safe and effective treatment of GH in women of different age groups and at different stages of the disease.

Oral ulcer and skin lesions: a tell-tale sign of pemphigus vulgaris

Aim: The aim of this case presentation was to highlight the importance of the awareness of two different coexisting pathologies, as well as emphasise that early diagnosis and prompt management are essential to manage pemphigus vulgaris. Pemphigus vulgaris is a rare, life-threatening autoimmune disease characterised by the presence of blisters on the surface of oral mucosa caused by antibodies against adhesion molecules on the cell surface of keratinocytes. Coexistence with various conditions, notably herpes simplex virus, is noteworthy. Case report: We report a case of a middle-aged female who presented with non-healing oral ulceration that turned out to be herpes simplex virus, consequently triggering pemphigus vulgaris. Histopathology and immunofluorescence were suggestive of pemphigus vulgaris, but immunohistochemistry and polymerase chain reaction were indicative of herpes simplex virus infection. Conclusion: The coexistence of a viral infection with pemphigus vulgaris poses a therapeutic challenge.

Dual impacts of a glycan shield on the envelope glycoprotein B of HSV-1: evasion from human antibodies in vivo and neurovirulence.

Identification of the mechanisms of viral evasion from human antibodies is crucial both for understanding viral pathogenesis and for designing effective vaccines. Here we show in cell cultures that an N-glycan shield on the herpes simplex virus 1 (HSV-1) envelope glycoprotein B (gB) mediated evasion from neutralization and antibody-dependent cellular cytotoxicity due to pooled γ-globulins derived from human blood. We also demonstrated that the presence of human γ-globulins in mice and immunity to HSV-1 induced by viral infection in mice significantly reduced replication in their eyes of a mutant virus lacking the glycosylation site but had little effect on the replication of its repaired virus. These results suggest that an N-glycan shield on a specific site of HSV-1 envelope gB mediated evasion from human antibodies in vivo and from HSV-1 immunity induced by viral infection in vivo. Notably, we also found that an N-glycan shield on a specific site of HSV-1 gB was significant for HSV-1 neurovirulence and replication in the central nervous system of naïve mice. Thus, we have identified a critical N-glycan shield on HSV-1 gB that has dual impacts, namely evasion from human antibodies in vivo and viral neurovirulence. IMPORTANCE Herpes simplex virus 1 (HSV-1) establishes lifelong latent and recurrent infections in humans. To produce recurrent infections that contribute to transmission of the virus to new human host(s), the virus must be able to evade the antibodies persisting in latently infected individuals. Here, we show that an N-glycan shield on the specific site of the envelope glycoprotein B (gB) of HSV-1 mediates evasion from pooled γ-globulins derived from human blood both in cell cultures and mice. Notably, the N-glycan shield on the specific site of gB was also significant for HSV-1 neurovirulence in naïve mice. Considering the clinical features of HSV-1 infection, these results suggest that the glycan shield not only facilitates recurrent HSV-1 infections in latently infected humans by evading antibodies but is also important for HSV-1 pathogenesis during the initial infection.

P76 Management of aciclovir-resistant mucocutaneous herpes simplex virus infection: a systematic review

Abstract Aciclovir resistance results in immunocompromised hosts due to long-term antiviral therapy and ongoing viral replication. Aciclovir resistance in herpes simplex virus (HSV) poses a major concern, as this can lead to chronic and recalcitrant infection that significantly impacts on the quality of life. While different treatment options exist, there are currently no standardized clinical treatment guidelines for mucocutaneous aciclovir-resistant (ACV-R) HSV infection. This systematic review seeks to identify safe and effective treatments for mucocutaneous ACV-R HSV infection. For this systematic review, PubMed/MEDLINE and Embase were searched in September 2022 for all articles published between 1 January 1980 and 1 September 2022. Studies were included if they described the use of a medication for the treatment of mucocutaneous ACV-R HSV infection. From the initial search that yielded 1066 studies, 86 met the inclusion criteria and were selected. Of the 86 studies, 6 were clinical trials and 80 were case reports/series. A total of 318 patients were included in our review. Foscarnet [intravenous (IV) and topical] was studied in 5 clinical trials and 25 case reports/series, leading to complete response in most patients, with adverse effects including renal toxicity and electrolyte abnormalities. Vidarabine (IV) was found to be inferior to foscarnet in a clinical trial and reported in two case reports. Common side-effects included nausea, anaemia and renal impairment. Trifluridine (topical) was studied in a clinical trial and a case report, showing complete response in some patients. Cidofovir (IV, topical, intralesional) was studied in 21 case reports/series, showing complete response in most patients, with renal impairment as the most common adverse effect. Imiquimod (topical) was studied in eight case reports/series, showing complete response and no side-effects. Pritelivir (oral) was reported in two case reports/series, showing complete response and no side-effects. Combination treatment was reported in 10 case reports/series with variable clinical response. Our review also identified reports of less widely used treatments. These include artesunate, zidovudine, varicella-zoster virus vaccine, leflunomide and surgical excision, which achieved variable response rates but have not been widely studied. While foscarnet and cidofovir have the most robust evidence, IV administration of these agents is associated with significant side-effects and may be limiting. Intralesional and topical formulations of cidofovir, trifluridine and imiquimod are alternative options appropriate for outpatient management. Pritelivir is a novel and promising treatment of mucocutaneous ACV-R HSV infection.

BI03 (P76) Management of aciclovir-resistant mucocutaneous herpes simplex virus infection: a systematic review

Abstract Aciclovir resistance results in immunocompromised hosts due to long-term antiviral therapy and ongoing viral replication. Aciclovir resistance in herpes simplex virus (HSV) poses a major concern, as this can lead to chronic and recalcitrant infection that significantly impacts on quality of life. While different treatment options exist, there are currently no standardized clinical treatment guidelines for mucocutaneous aciclovir-resistant (ACV-R) HSV infection. This systematic review seeks to identify safe and effective treatments for mucocutaneous ACV-R HSV infection. For this systematic review, PubMed/MEDLINE and Embase were searched in September 2022 for all articles published between 1 January 1980 and 1 September 2022. Studies were included if they described the use of medications for the treatment of mucocutaneous ACV-R HSV infection. From the initial search that yielded 1066 studies, 86 met the inclusion criteria and were selected. Of the 86 studies, six were clinical trials and 80 were case reports/series. A total of 318 patients were included in our review. Foscarnet [intravenous (IV) and topical] was studied in five clinical trials and 25 case reports/series, leading to complete response in most patients, with adverse effects including renal toxicity and electrolyte abnormalities. Vidarabine (IV) was found to be inferior to foscarnet in a clinical trial and reported in two case reports. Common side-effects included nausea, anaemia and renal impairment. Trifluridine (topical) was studied in a clinical trial and a case report, showing complete response in some patients. Cidofovir (IV, topical, intralesional) was studied in 21 case reports/series, showing complete response in most patients, with renal impairment as the most common adverse effect. Imiquimod (topical) was studied in eight case reports/series, showing complete response and no side-effects. Pritelivir (oral) was reported in two case reports/series, showing complete response and no side-effects. Combination treatment was reported in 10 case reports/series with variable clinical response. Our review also identified reports of less widely used treatments. These include artesunate, zidovudine, varicella-zoster virus vaccine, leflunomide and surgical excision, which achieved variable response rates but have not been widely studied. While foscarnet and cidofovir have the most robust evidence, IV administration of these agents is associated with significant side-effects and may be limiting. Intralesional and topical formulations of cidofovir, trifluridine and imiquimod are alternative options appropriate for outpatient management. Pritelivir is a novel and promising treatment of mucocutaneous ACV-R HSV infection.

P-459 Sexually transmitted infections in women and fecundability – A prospective cohort study

Abstract Study question Does a previous infection with Chlamydia trachomatis (CT) or genital herpes simplex virus (HSV) affect fecundability, and does recency of infection play a role? Summary answer Previous infection with CT or HSV in women was not appreciably associated with fecundability. However, a recent CT infection was associated with slightly lower fecundability. What is known already Worldwide, 1 million people contract sexually transmitted infections (STIs) every day. CT and genital HSV infections are among the most common STIs. Untreated CT in women can cause pelvic inflammatory disease (PID), which can lead to scarring and narrowing of the fallopian tubes and the lower uterus, thus complicating the ability to conceive. Also, an association between genital HSV in women and PID has been suggested. However, it is uncertain to what extent CT and HSV infections in women are associated with fecundability, defined as the per-cycle probability of conception, and whether recency of the infection plays a role. Study design, size, duration We conducted a prospective cohort study of female participants included in two Danish preconception cohorts: SnartGravid.dk (‘Soon Pregnant’, 2007-2011) and SnartForældre.dk (‘Soon Parents’, 2011-ongoing). At enrollment, participants had to be non-pregnant, aged 18-45 years, in a relationship with a male partner, not using contraception or fertility treatment, and trying to conceive. Participants completed a baseline questionnaire and bimonthly follow-up questionnaires until conception or up to 12 months after study entry. Participants/materials, setting, methods We analyzed data from 10475 women. At study entry, participants reported if they had ever been diagnosed (including year of first diagnosis) with CT or HSV. Fecundability ratios (FRs) were calculated using proportional probability regression models and 95% confidence intervals (CIs). The analyses were adjusted for age, income, educational attainment, other STIs, and smoking, reported at study entry. The reference groups were either women with no CT or no HSV diagnosis. Main results and the role of chance At study entry, 2603 (24.9%) of participants reported a history of infection with CT, and 766 (7.3%) with HSV. Using life table methods, 84.7% of participants conceived within 12 cycles of follow-up. Compared with the reference group, the adjusted FR for women ever diagnosed with CT was 0.98 (CI: 0.93-1.04) and 0.96 (CI: 0.88-1.06) for women ever diagnosed with HSV. Compared with the reference group, a recent CT infection was associated with slightly lower fecundability: adjusted FRs for women diagnosed 0-2 years, 2-5 years, and more than 5 years before study entry were 0.84 (CI: 0.71-0.99), 1.01 (CI: 0.90-1.12), and 1.00 (CI: 0.93-1.07), respectively. The association between recency of a HSV infection compared to the reference group was less evident: adjusted FRs for 0-2 years, 2-5 years, and more than 5 years since study entry were 0.93 (CI: 0.72-1.21), 0.97 (CI: 0.77-1.22), and 0.91 (0.75-1.09), respectively. Limitations, reasons for caution Misclassification of exposure is possible, as CT and HSV infections are often asymptomatic and hence undiagnosed. In addition, self-report may have resulted in misclassification of infection type and year. Further, we lacked information on severity or frequency of infections. Wider implications of the findings Women diagnosed with STIs often experience psychological distress concerning their future ability to conceive. Our finding of no overall association between previous diagnoses of CT or HSV may reassure women wanting to conceive. Still, testing for STIs remains important because untreated infections can damage the female reproductive system. Trial registration number Not applicable

Sexually transmitted infections in Spain: Current status.

Sexually Transmitted Infections (STI) are a major public health problem. The problems inherent to their diagnosis, treatment and prevention have to do not only with their nature, but also with organizational issues and overlapping competencies of the different health authorities in Spain. The real situation of STI in Spain, at present, is poorly known. For this reason, the Scientific Committee on COVID and Emerging Pathogens of the Illustrious Official College of Physicians of Madrid (ICOMEM) has formulated a series of questions on this subject which were distributed, not only among the members of the Committee, but also among experts outside it. The central health authorities provide very high and increasing figures for gonococcal infection, syphilis, Chlamydia trachomatis infection and lymphogranuloma venereum (LGV). Both HIV infection and Monkeypox are two important STI caused by viruses in our environment, to which it should be added, mainly, Herpes simplex virus (HSV) and Human papillomavirus (HPV) infections. Emerging microorganisms such as Mycoplasma genitalium pose not only pathogenic challenges but also therapeutic problems, as in the case of N. gonohrroeae. The pathways that patients with suspected STI follow until they are adequately diagnosed and treated are not well known in Spain. Experts understand that this problem is fundamentally managed in public health institutions, and that Primary Care and Hospital Emergency Services, together with some institutions that deal monographically with this problem, are the recipients of most of these patients. One of the most serious difficulties of STI lies in the availability of the microbiological tests necessary for their diagnosis, particularly in this era of outsourcing of microbiology services. Added to this is the increased cost of implementing the latest generation of molecular techniques and the difficulties of transporting samples. It is clear that STI are not diseases to which the entire population is equally exposed and it is necessary to have a better knowledge of the risk groups where to focus the necessary interventions adapted to their characteristics. It should not be forgotten that STI are also a problem in the pediatric age group and that their presence can be a marker of sexual abuse with all that this implies in terms of health care and medicolegal activity. Finally, STI are infections that are associated with a high cost of care for which we have very little information. The possibility of expanding the automatic performance of laboratory tests for STI surveillance through laboratory routines is encountering ethical and legal problems that are not always easy to solve. Spain has created a ministerial area of specific attention to STI and there are plans to improve the diagnosis, treatment and prevention of these problems, but we still lack the necessary evidence on their impact. We cannot forget that these are diseases that transcend the individual and constitute a Public Health problem.

Herpes Pseudotumor Mimicking Cervical Cancer With Lymph Node Metastasis in an Immunocompetent Patient.

Anogenital herpes simplex virus (HSV) infection can rarely manifest as a pseudotumor, which some have termed "hypertrophic herpes." Almost all cases are in immunocompromised patients, typically with human immunodeficiency virus/acquired immune deficiency syndrome. This presentation often mimics malignancy clinically. We present a case of cervical HSV pseudotumor with associated lymphadenopathy in an immunocompetent woman, mimicking locally advanced cervical cancer. The lesion resolved with acyclovir therapy. We emphasize that (1) clinically suspected malignancy must be confirmed by pathologic examination; (2) infectious mimics must be considered when microscopic examination fails to confirm a clinically suspected anogenital malignancy, particularly in patients with compromised or unknown immune status; (3) morphologic hallmarks of infection may be focal; (4) co-infection with multiple sexually transmitted infections can occur, particularly in immunocompromised patients, and HSV or other infection does not per se exclude concurrent human papillomavirus-associated neoplasia; and (5) anogenital HSV pseudotumor should prompt clinical evaluation for human immunodeficiency virus or other immunosuppression.

Incidence Rates of Infections, Malignancies, Thromboembolism, and Cardiovascular Events in an Alopecia Areata Cohort from a US Claims Database.

Alopecia areata (AA) is an autoimmune disease with an underlying immuno-inflammatory pathogenesis. Treatments can include systemic corticosteroids and immunomodulators (such as Janus kinase inhibitors); these medications may be associated with a risk of some adverse events. However, large-scale observational studies of baseline incidence rates (IRs) of infection, cardiovascular disease, malignancy, and thromboembolism in US patients with AA, including those with alopecia totalis or alopecia universalis (AT/AU), are limited. This real-world, US claims-based study aimed to estimate the incidence of events in patients with AA compared with matched patients without AA. Patients aged ≥ 12years enrolled in the Optum Clinformatics Data Mart database from 1 October 2016 to 30 September 2020, with ≥ 2 AA diagnosis codes were included in the AA cohort. Patients without AA were age-, sex-, and race-matched 3:1 to patients with AA. Baseline comorbidities were evaluated during the 12-month period pre-index date. Incident cases of serious/herpes infections, malignancies, major adverse cardiovascular events (MACE), and thromboembolic events were evaluated post-index date. Data are presented using descriptive statistics, proportional percentages, frequencies, and IRs (calculated with 95% CI). Overall, 8784 patients with AA, 599 of whom had AT/AU, were matched to 26,352 patients without AA. IRs per 1000 person-years among the AA and non-AA cohorts, respectively, were 18.5 and 20.6 for serious infections, 19.5 and 9.7 for herpes simplex infections, 7.8 and 7.6 for herpes zoster infections, 12.5 and 11.6 for primary malignancies, 16.0 and 18.1 for MACE, and 4.9 and 6.1 for venous thromboembolisms. Compared with patients with non-AT/AU AA, patients with AT/AU largely had higher IRs for most baseline comorbidities and outcome events evaluated. Patients with AA had a higher IR of herpes simplex infection than the matched non-AA cohort. Patients with AT/AU generally had higher rates of outcome events than patients without AT/AU.

Management of oral herpes simplex virus infections: The problem of resistance. A narrative review.

Herpes Simplex Virus (HSV) type 1 (HSV-1) and type 2 (HSV-2) are among the most common human viral pathogens, affecting several billion people worldwide. Although in healthy patients clinical signs and symptoms of HSV infection are usually mild and self-limiting, HSV-infections in immunocompromised patients are frequently more aggressive, persistent, and even life-threatening. Acyclovir and its derivatives are the gold standard antiviral drugs for the prevention and treatment of HSV infections. Although the development of acyclovir resistance is a rather uncommon condition, it may be associated with serious complications, especially in immunocompromised patients. In this review, we aim to address the problem of drug resistant HSV infection and discuss the available alternative therapeutic interventions. All relative studies concerning alternative treatment modalities of acyclovir resistant HSV infection published in PubMed between 1989 to 2022 were reviewed. Long-term treatment and prophylaxis with antiviral agents predisposes to drug resistance, especially in immunocompromised patients. Cidofovir and foscarnet could serve as alternative treatments in these cases. Although rare, acyclovir resistance may be associated with severe complications. Hopefully, in the future, novel antiviral drugs and vaccines will be available in order to avoid the existing drug resistance.

Cathelicidin-derived antiviral peptide inhibits herpes simplex virus 1 infection.

Herpes simplex virus 1 (HSV-1) is a widely distributed virus. HSV-1 is a growing public health concern due to the emergence of drug-resistant strains and the current lack of a clinically specific drug for treatment. In recent years, increasing attention has been paid to the development of peptide antivirals. Natural host-defense peptides which have uniquely evolved to protect the host have been reported to have antiviral properties. Cathelicidins are a family of multi-functional antimicrobial peptides found in almost all vertebrate species and play a vital role in the immune system. In this study, we demonstrated the anti-HSV-1 effect of an antiviral peptide named WL-1 derived from human cathelicidin. We found that WL-1 inhibited HSV-1 infection in epithelial and neuronal cells. Furthermore, the administration of WL-1 improved the survival rate and reduced viral load and inflammation during HSV-1 infection via ocular scarification. Moreover, facial nerve dysfunction, involving the abnormal blink reflex, nose position, and vibrissae movement, and pathological injury were prevented when HSV-1 ear inoculation-infected mice were treated with WL-1. Together, our findings demonstrate that WL-1 may be a potential novel antiviral agent against HSV-1 infection-induced facial palsy.

Inhibitory effect of zinc oxide nanoparticles and fibrillar chitosan‐zinc oxide nanostructures against herpes simplex virus infection

AbstractAlthough zinc ions have a strong antiviral impact against viral infections, they have a high level of toxicity in cell culture and in animal models. In the current work, ZnO nanoparticles (ZnO NPs) and fibrillar chitosan‐ZnO nanostructures (CS‐ZnO NSs) were synthesized in order to evaluate their cytotoxicity and inhibitory impact against HSV (herpes simplex virus) replication in vitro using the MTT, plaque, and Real‐time PCR methods. Also, different characterization approaches such as FE‐SEM, XRD, FTIR and fluorescence microscope were used to evaluate prepared NPs. The findings revealed that CS‐ZnO NSs exhibit negligible cytotoxicity in cells, whereas ZnO NPs were exceedingly harmful at high doses. Also, CS‐ZnO NSs could considerably internalize cells and reduce virus titration in HSV‐infected cells. Furthermore, their inhibitory effect against HSV replication was quite effective, which may be more related to the antiviral activity of chitosan and ZnO. In conclusion, the new fibrillar chitosan‐ZnO NS was prepared with the least toxicity for host cells.

Febbre e gengivostomatite: non è sempre solo herpes simplex

Gingivostomatitis is a clinical condition frequently diagnosed by the family paediatrician and it generally shows a viral aetiology. In particular, primary herpes simplex infection is the most frequent cause of gingivostomatitis in toddlers and it typically presents with fever and gingival/oral inflammation and ulcerations. Besides, gingivostomatitis and fever can be present at the onset of acute myeloid leukaemia (AML), a rare type of childhood cancer with an incidence of 7 cases per 1 million children < 15 years. This paper describes the case of a 3-year-old boy who presented with fever and gingivostomatitis initially misdiagnosed as a primary herpetic infection, while it turned out to be a clinical onset of an AML with hyperleukocytosis, a condition at high-risk of mortality.

Association between atopic dermatitis, autoimmune illnesses, Epstein-Barr virus, and cytomegalovirus.

Atopic dermatitis (AD) is a Th2-driven inflammatory skin disease that has been associated with other autoimmune illnesses (AI) and has a well-known predisposition to infection with herpes simplex virus infection. Yet, few studies have evaluated the association between atopic dermatitis, autoimmune illness, and other human herpes virus (HHV) infections such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV). We aimed to evaluate the association between AD, specific AIs, CMV, and EBV in a random sample of the Optum Clinformatics Data Mart database, a US administrative claims database. AD was defined based on ICD diagnostic codes. Patients with AD were exact matched to those without AD on sex, age at enrollment, time observed in the dataset and census division. Our outcomes of interest were rheumatoid arthritis (RA), Crohn's disease (CD), ulcerative colitis (UC), multiple sclerosis (MS), CMV, and EBV infection as defined by specific ICD codes. Logistic regression models were used to examine the association between AD and our outcomes of interest [odds ratio (95% confidence intervals)]. Our full cohort included 40,141,017 patients. In total, 601,783 patients with AD were included. As expected, patients with AD had a higher prevalence of asthma and seasonal allergies versus controls. Individuals with AD have an increased risk of EBV, CMV, RA, CD, UC, and MS. While we cannot demonstrate a causal association, the observed associations between AD and AI may be in part mediated by these types of HHV (i.e., CMV and EBV), a finding that merits further study.

Herpes simplex virus infection among neonates suspected of invasive bacterial infection: a population-based cohort study

ObjectiveTo estimate the incidence of neonatal herpes simplex virus (HSV) infection and the number of neonates with suspected invasive bacterial infection (IBI) needed to treat (NNT) with acyclovir to ensure...

Memory T cells possess an innate-like function in local protection from mucosal infection.

Mucosal infections pose a significant global health burden. Antigen-specific tissue-resident T cells are critical to maintaining barrier immunity. Previous studies in the context of systemic infection suggest that memory CD8+ T cells may also provide innate-like protection against antigenically unrelated pathogens independent of T cell receptor engagement. Whether bystander T cell activation is also an important defense mechanism in the mucosa is poorly understood. Here, we investigated whether innate-like memory CD8+ T cells could protect against a model mucosal virus infection, herpes simplex virus 2 (HSV-2). We found that immunization with an irrelevant antigen delayed disease progression from lethal HSV-2 challenge, suggesting that memory CD8+ T cells may mediate protection despite the lack of antigen specificity. Upon HSV-2 infection, we observed an early infiltration, rather than substantial local proliferation, of antigen-nonspecific CD8+ T cells, which became bystander-activated only within the infected mucosal tissue. Critically, we show that bystander-activated CD8+ T cells are sufficient to reduce early viral burden after HSV-2 infection. Finally, local cytokine cues within the tissue microenvironment after infection were sufficient for bystander activation of mucosal tissue memory CD8+ T cells from mice and humans. Altogether, our findings suggest that local bystander activation of CD8+ memory T cells contributes a fast and effective innate-like response to infection in mucosal tissue.

Detection of herpes simplex virus in oral tongue squamous cell carcinoma.

Introduction: Oral tongue squamous cell carcinoma (OTSCC) is the most common cancer of the oral cavity. Contradictory results have been observed on the involvement of herpes simplex virus 1 (HSV-1) in oral squamous cell carcinomas. Here, we aimed to study the predominance of HSV-1 or HSV-2 in oral HSV infections and to investigate the presence of HSV-1 in OTSCC and its effect on carcinoma cell viability and invasion. Methods: The distribution of HSV types one and two in diagnostic samples taken from suspected oral HSV infections was determined from the Helsinki University Hospital Laboratory database. We then analysed 67 OTSCC samples for HSV-1 infection using immunohistochemical staining. We further tested the effects of HSV-1 using six concentrations (0.00001-1.0 multiplicity of infection [MOI]) on viability and two concentrations (0.001 and 0.1 MOI) on invasion of highly invasive metastatic HSC-3 and less invasive primary SCC-25 OTSCC cell lines using MTT and Myogel-coated Transwell invasion assays. Results: Altogether 321 oropharyngeal samples were diagnosed positive for HSV during the study period. HSV-1 was the predominant (97.8%) HSV type compared with HSV-2 (detected in 2.2% of samples). HSV-1 was also detected in 24% of the OTSCC samples and had no association with patient survival or recurrence. OTSCC cells were viable even after 6days with low viral load (0.00001, 0.0001, 0.001 MOI) of HSV-1. In both cell lines, 0.001 MOI did not affect cell invasion. However, 0.1 MOI significantly reduced cell invasion in HSC-3 cells. Discussion: HSV-1 infection is predominant compared with HSV-2 in the oral cavity. HSV-1 is detected in OTSCC samples without clinical significance, and OTSCC cell survival or invasion was not affected at low doses of HSV-1.

Identification of oxysterol synthetic analogs as a novel class of late-stage inhibitors of herpes simplex virus 2 replication

Genital herpes, most frequently caused by herpes simplex virus 2 (HSV-2) infection, is one of the most prevalent sexually transmitted infections. The current rationale for the treatment of HSV-2 infection involves nucleoside analogs (e.g. acyclovir) to suppress reactivation. Enzymatic oxysterols are endogenous 27-carbon atoms molecules produced by enzymatic cholesterol oxidation, and recently emerged as a broad-spectrum host targeting antivirals. In this study, we screened selected members of an in-house synthesized library of oxysterol analogs for their activity against HSV-2, identifying three compounds, named PFM064, PFM067, and PFM069, endowed with 50% effective concentrations (EC50) in the micromolar range, without exerting any apparent cytotoxicity. Moreover, the results obtained showed the ability of the novel derivatives to inhibit both cell-to-cell fusion induced by HSV-2, and the production of an intracellular viral progeny. Further experiments performed with PFM067 (which was selected for more-in-depth studies as the most effective synthetic analog) showed that these molecules act in a late stage of HSV-2 replicative cycle, by sequestering viral glycoproteins in the Golgi compartment, and likely inhibiting the nuclear egress of neo-synthetized viral capsids.Taken together, these results point to PFM067 as a promising chemical scaffold for the development of novel herpetic antivirals.

Encephalitis and poor neuronal death-mediated control of herpes simplex virus in human inherited RIPK3 deficiency

Inborn errors of TLR3-dependent type I IFN immunity in cortical neurons underlie forebrain herpes simplex virus-1 (HSV-1) encephalitis (HSE) due to uncontrolled viral growth and subsequent cell death. We report an otherwise healthy patient with HSE who is compound heterozygous for nonsense (R422*) and frameshift (P493fs9*) RIPK3 variants. Receptor interacting protein kinase 3 (RIPK3) is a ubiquitous cytoplasmic kinase regulating cell death outcomes, including apoptosis and necroptosis. In vitro, the R422* and P493fs9* RIPK3 proteins impair cellular apoptosis and necroptosis upon TLR3, TLR4 or TNFR1 stimulation, and ZBP1/DAI-mediated necroptotic cell death following HSV-1 infection. The patient's fibroblasts display no detectable RIPK3 expression. Following TNFR1 or TLR3 stimulation, the patient's cells do not undergo apoptosis or necroptosis. Following HSV-1 infection, the cells support excessive viral growth despite normal induction of antiviral IFN-β and interferon-stimulated genes (ISGs). This phenotype is, nevertheless, rescued by the application of exogenous type I IFN. The patient's human pluripotent stem cell (hPSC)-derived cortical neurons display impaired cell death and enhanced viral growth following HSV-1 infection, as do isogenic RIPK3- knockout hPSC-derived cortical neurons. Inherited RIPK3 deficiency therefore confers a predisposition to HSE, by impairing the cell death-dependent control of HSV-1 in cortical neurons independently of type I IFN immunity.