Therapeutic prime/pull vaccination of HSV-2-infected guinea pigs with the ribonucleotide reductase 2 (RR2) protein and CXCL11 chemokine boosts antiviral local tissue-resident and effector memory CD4+ and CD8+ T cells and protects against recurrent genital herpes.

Following acute herpes simplex virus type 2 (HSV-2) infection, the virus undergoes an asymptomatic latent infection of sensory neurons of dorsal root ganglia (DRG). Chemical and physical stress cause intermittent virus reactivation from latently infected DRG and recurrent virus shedding in the genital mucosal epithelium causing genital herpes in symptomatic patients. While T cells appear to play a role in controlling virus reactivation from DRG and reducing the severity of recurrent genital herpes, the mechanisms for recruiting these T cells into DRG and the vaginal mucosa (VM) remain to be fully elucidated. The present study investigates the effect of CXCL9, CXCL10, and CXCL11 T-cell-attracting chemokines on the frequency and function of DRG- and VM-resident CD4+ and CD8+ T cells and its effect on the frequency and severity of recurrent genital herpes in the recurrent herpes guinea pig model. HSV-2 latent-infected guinea pigs were immunized intramuscularly with the HSV-2 ribonucleotide reductase 2 (RR2) protein (Prime) and subsequently treated intravaginally with the neurotropic adeno-associated virus type 8 expressing CXCL9, CXCL10, or CXCL11 chemokines to recruit CD4+ and CD8+ T cells into the infected DRG and VM (Pull). Compared to the RR2 therapeutic vaccine alone, the RR2/CXCL11 prime/pull therapeutic vaccine significantly increased the frequencies of functional tissue-resident and effector memory CD4+ and CD8+ T cells in both DRG and VM tissues. This was associated with less virus in the healed genital mucosal epithelium and reduced frequency and severity of recurrent genital herpes. These findings confirm the role of local DRG- and VM-resident CD4+ and CD8+ T cells in reducing virus shedding at the vaginal site of infection and the severity of recurrent genital herpes and propose the novel prime-pull vaccine strategy to protect against recurrent genital herpes.IMPORTANCEThe present study investigates the novel prime/pull therapeutic vaccine strategy to protect against recurrent genital herpes using the latently infected guinea pig model. In this study, we used the strategy that involves immunization of herpes simplex virus type 2-infected guinea pigs using a recombinantly expressed herpes tegument protein-ribonucleotide reductase 2 (RR2; prime), followed by intravaginal treatment with the neurotropic adeno-associated virus type 8 expressing CXCL9, CXCL10, or CXCL11 T-cell-attracting chemokines to recruit T cells into the infected dorsal root ganglia (DRG) and vaginal mucosa (VM) (pull). We show that the RR2/CXCL11 prime-pull therapeutic vaccine strategy elicited a significant reduction in virus shedding in the vaginal mucosa and decreased the severity and frequency of recurrent genital herpes. This protection was associated with increased frequencies of functional tissue-resident (TRM cells) and effector (TEM cells) memory CD4+ and CD8+ T cells infiltrating latently infected DRG tissues and the healed regions of the vaginal mucosa. These findings shed light on the role of tissue-resident and effector memory CD4+ and CD8+ T cells in DRG tissues and the VM in protection against recurrent genital herpes and propose the prime-pull therapeutic vaccine strategy in combating genital herpes.

HSV-infection-related herpetic anogenital ulcer disease among PLWH in southeastern US: electronic medical record based analysis.

ObjectivesThe southeastern US is a domestic epicentre for incident HIV with high prevalence of herpes simplex virus (HSV) coinfection. We estimated the incidence rates (IR) of symptomatic herpetic anogenital ulcer disease (HAUD) and assessed its associations with demographic and clinical characteristics, specifically with immunological markers using median, nadir and trajectory CD4 counts. METHODS: Electronic medical records (EMR) of over 7000 people living with HIV (PLWH) attending one of the leading HIV clinics in the southeastern US between 2006 and 2018 were reviewed and analysed. IR of HSV-related HAUD were estimated per 10 000 person years. Joinpoint regressions were performed to examine temporal changes in the trends of IR. All IR and trends were stratified by gender and race. Six CD4 trajectory groups were constructed using the group-based trajectory modelling. Multivariable logistic models were conducted to assess the associations of CD4 counts (nadir, median CD4 and newly defined CD4 trajectory), separately with HAUD. RESULTS: Of the 4484 PLWH eligible individuals (3429 men, 1031 women and 24 transgender), we observed 425 patients with HSV-related HAUD. The mean log10viral load was higher in HAUD than HAUD-free groups, whereas the median nadir CD4 count (cells/uL) was higher in the non-cases than the case groups (p<0.05). HAUD were more frequent in women than men. Median CD4 (<200 cell/uL) was associated with HAUD (OR=2.1), but there were no significant associations with nadir CD4. Significant associations with declining and sustained low CD4 counts trajectory patterns were observed with HAUD. CONCLUSIONS: There were significant differences between men and women with incident HAUD among PLWH. EMR-based studies can provide innovative trajectory models that can potentially be helpful in guiding screening and clinical care of HAUD among high-risk PLWH.

Intrinsic Antiviral Activity of Optineurin Prevents Hyperproliferation of a Primary Herpes Simplex Virus Type 2 Infection.

Very little knowledge exists on virus-specific host cell intrinsic mechanisms that prevent hyperproliferation of primary HSV type 2 (HSV-2) genital infections. In this study, we provide evidence that the Nemo-related protein, optineurin (OPTN), plays a key role in restricting HSV-2 infection both in vitro and in vivo. Contrary to previous reports regarding the proviral role of OPTN during Sendai virus infection, we demonstrate that lack of OPTN in cells causes enhanced virus production. OPTN deficiency negatively affects the host autophagy response and results in a marked reduction of CCL5 induction. OPTN knockout (OPTN-/-) mice display exacerbated genital disease and dysregulated T cell frequencies in infected tissues and lymph nodes. A human transcriptomic profile dataset provides further credence that a strong positive correlation exists between CCL5 upregulation and OPTN expression during HSV-2 genital infection. Our findings underscore a previously unknown OPTN/CCL5 nexus that restricts hyperproliferative spread of primary HSV-2 infection, which may constitute an intrinsic host defense mechanism against herpesviruses in general.

Trivalent nucleoside-modified mRNA vaccine yields durable memory B cell protection against genital herpes in preclinical models.

Nucleoside-modified mRNA vaccines have gained global attention because of COVID-19. We evaluated a similar vaccine approach for preventing a chronic, latent genital infection rather than an acute respiratory infection. We used animal models to compare an HSV-2 trivalent nucleoside-modified mRNA vaccine with the same antigens prepared as proteins, with an emphasis on antigen-specific memory B cell responses and immune correlates of protection. In guinea pigs, serum neutralizing-antibody titers were higher at 1 month and declined far less by 8 months in mRNA- compared with protein-immunized animals. Both vaccines protected against death and genital lesions when infected 1 month after immunization; however, protection was more durable in the mRNA group compared with the protein group when infected after 8 months, an interval representing greater than 15% of the animal's lifespan. Serum and vaginal neutralizing-antibody titers correlated with protection against infection, as measured by genital lesions and vaginal virus titers 2 days after infection. In mice, the mRNA vaccine generated more antigen-specific memory B cells than the protein vaccine at early times after immunization that persisted for up to 1 year. High neutralizing titers and robust B cell immune memory likely explain the more durable protection by the HSV-2 mRNA vaccine.

Immunoregulatory Functions of Interferons During Genital HSV-2 Infection.

Herpes simplex virus type 2 (HSV-2) infection is one of the most prevalent sexually transmitted infections that disproportionately impacts women worldwide. Currently, there are no vaccines or curative treatments, resulting in life-long infection. The mucosal environment of the female reproductive tract (FRT) is home to a complex array of local immune defenses that must be carefully coordinated to protect against genital HSV-2 infection, while preventing excessive inflammation to prevent disease symptoms. Crucial to the defense against HSV-2 infection in the FRT are three classes of highly related and integrated cytokines, type I, II, and III interferons (IFN). These three classes of cytokines control HSV-2 infection and reduce tissue damage through a combination of directly inhibiting viral replication, as well as regulating the function of resident immune cells. In this review, we will examine how interferons are induced and their critical role in how they shape the local immune response to HSV-2 infection in the FRT.

Tissue-Resident-Memory CD8+ T Cells Bridge Innate Immune Responses in Neighboring Epithelial Cells to Control Human Genital Herpes.

Tissue-resident-memory T cells (TRM) populate the body's barrier surfaces, functioning as frontline responders against reencountered pathogens. Understanding of the mechanisms by which CD8TRM achieve effective immune protection remains incomplete in a naturally recurring human disease. Using laser capture microdissection and transcriptional profiling, we investigate the impact of CD8TRM on the tissue microenvironment in skin biopsies sequentially obtained from a clinical cohort of diverse disease expression during herpes simplex virus 2 (HSV-2) reactivation. Epithelial cells neighboring CD8TRM display elevated and widespread innate and cell-intrinsic antiviral signature expression, largely related to IFNG expression. Detailed evaluation via T-cell receptor reconstruction confirms that CD8TRM recognize viral-infected cells at the specific HSV-2 peptide/HLA level. The hierarchical pattern of core IFN-γ signature expression is well-conserved in normal human skin across various anatomic sites, while elevation of IFI16, TRIM 22, IFITM2, IFITM3, MX1, MX2, STAT1, IRF7, ISG15, IFI44, CXCL10 and CCL5 expression is associated with HSV-2-affected asymptomatic tissue. In primary human cells, IFN-γ pretreatment reduces gene transcription at the immediate-early stage of virus lifecycle, enhances IFI16 restriction of wild-type HSV-2 replication and renders favorable kinetics for host protection. Thus, the adaptive immune response through antigen-specific recognition instructs innate and cell-intrinsic antiviral machinery to control herpes reactivation, a reversal of the canonical thinking of innate activating adaptive immunity in primary infection. Communication from CD8TRM to surrounding epithelial cells to activate broad innate resistance might be critical in restraining various viral diseases.

Epidemiology of herpes simplex virus type 2 in Latin America and the Caribbean: systematic review, meta-analyses and metaregressions.

OBJECTIVE: To characterise epidemiology of herpes simplex virus type 2 (HSV-2) in Latin America and the Caribbean. METHODS: HSV-2 reports were systematically reviewed and synthesised, and findings were reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Meta-analyses and metaregressions were conducted. FINDING: 102 relevant reports were identified including 13 overall incidence measures, 163 overall (and 402 stratified) seroprevalence measures, and 7 and 10 proportions of virus detection in genital ulcer disease and in genital herpes, respectively. Pooled mean seroprevalence was 20.6% (95% CI 18.7% to 22.5%) in general populations, 33.3% (95% CI 26.0% to 41.0%) in intermediate-risk populations, 74.8% (95% CI 70.6% to 78.8%) in female sex workers, and 54.6% (95% CI 47.4% to 61.7%) in male sex workers, men who have sex with men and transgender people. In general populations, seroprevalence increased from 9.6% (95% CI 7.1% to 12.4%) in those aged <20 years to 17.9% (95% CI 13.6% to 22.5%) in those aged 20-30, 27.6% (95% CI 21.4% to 34.2%) in those aged 30-40 and 38.4% (95% CI 32.8% to 44.2%) in those aged >40. Compared with women, men had lower seroprevalence with an adjusted risk ratio (ARR) of 0.68 (95% CI 0.60 to 0.76). Seroprevalence declined by 2% per year over the last three decades (ARR of 0.98, 95% CI 0.97 to 0.99). Pooled mean proportions of HSV-2 detection in GUD and genital herpes were 41.4% (95% CI 18.9% to 67.0%) and 91.1% (95% CI 82.7% to 97.2%), respectively. CONCLUSIONS: One in five adults is HSV-2 infected, a higher level than other world regions, but seroprevalence is declining. Despite this decline, HSV-2 persists as the aetiological cause of nearly half of GUD cases and almost all of genital herpes cases.

A sustained type I IFN-neutrophil-IL-18 axis drives pathology during mucosal viral infection.

Neutrophil responses against pathogens must be balanced between protection and immunopathology. Factors that determine these outcomes are not well-understood. In a mouse model of genital herpes simplex virus-2 (HSV-2) infection, which results in severe genital inflammation, antibody-mediated neutrophil depletion reduced disease. Comparative single-cell RNA-sequencing analysis of vaginal cells against a model of genital HSV-1 infection, which results in mild inflammation, demonstrated sustained expression of interferon-stimulated genes (ISGs) only after HSV-2 infection primarily within the neutrophil population. Both therapeutic blockade of IFNα/ß receptor 1 (IFNAR1) and genetic deletion of IFNAR1 in neutrophils concomitantly decreased HSV-2 genital disease severity and vaginal IL-18 levels. Therapeutic neutralization of IL-18 also diminished genital inflammation, indicating an important role for this cytokine in promoting neutrophil-dependent immunopathology. Our study reveals that sustained type I interferon (IFN) signaling is a driver of pathogenic neutrophil responses and identifies IL-18 as a novel component of disease during genital HSV-2 infection.

Herpes simplex virus (HSV) is a human pathogen that causes genital herpes, an incurable disease that results in recurrent sores and inflammation. Infection with HSV induces a strong antiviral immune response, which results in large numbers of immune cells arriving at these lesions. But while some of these cells help to control viral replication, others might contribute to the inflammation that drives the disease. One of the first immune cells to respond to infection are neutrophils. Although neutrophils are generally protective, especially against bacteria and fungi, they have also been implicated in tissue damage and severe inflammation during viral infections. But what determines whether a neutrophil will help to fight off an infection or increase disease severity is still an open question. To investigate this, Lebratti, Lim et al. studied mice that had been infected with the genital herpes virus HSV-2, which is known to cause significant amounts of inflammation in mice. The experiments revealed that a signaling molecule called type I interferon, which is thought to be antiviral, causes neutrophils at the site of the infection to produce proteins, such as IL-18, which trigger an inflammatory reaction. Lebratti, Lim et al. found that type I interferon and IL-18 had shifting roles during the course of infection. In the early stages, both molecules had a protective effect, confirming results from previous studies. However, as the infection progressed, sustained levels of type I interferon signaling in neutrophils led to excess amounts of IL-18. Lebratti, Lim et al. discovered that blocking interferon signaling or decreasing the levels of IL-18 later during infection unexpectedly reduced the severity of the disease and resulted in less genital tissue damage. Further experiments also showed that mice infected with another genital herpes virus called HSV-1 did not experience sustained levels of type I interferon. This may explain why this virus causes less severe disease in mice. Understanding how the immune system reacts to viruses could reveal new targets for treatments of genital herpes. At the moment, there is little information about IL-18 production during genital herpes in humans. So, the next step is to see whether neutrophils behave in the same way and whether IL-18 can be detected during human disease. It is possible that the same immune components could promote disease in other infections too. If so, this work may help uncover new drug targets for other viral diseases.

Endogenous Retroviruses Provide Protection Against Vaginal HSV-2 Disease.

Endogenous retroviruses (ERVs) are genomic sequences that originated from retroviruses and are present in most eukaryotic genomes. Both beneficial and detrimental functions are attributed to ERVs, but whether ERVs contribute to antiviral immunity is not well understood. Here, we used herpes simplex virus type 2 (HSV-2) infection as a model and found that Toll-like receptor 7 (Tlr7-/-) deficient mice that have high systemic levels of infectious ERVs are protected from intravaginal HSV-2 infection and disease, compared to wildtype C57BL/6 mice. We deleted the endogenous ecotropic murine leukemia virus (Emv2) locus on the Tlr7-/- background (Emv2-/-Tlr7-/-) and found that Emv2-/-Tlr7-/- mice lose protection against HSV-2 infection. Intravaginal application of purified ERVs from Tlr7-/- mice prior to HSV-2 infection delays disease in both wildtype and highly susceptible interferon-alpha receptor-deficient (Ifnar1-/-) mice. However, intravaginal ERV treatment did not protect Emv2-/-Tlr7-/- mice from HSV-2 disease, suggesting that the protective mechanism mediated by exogenous ERV treatment may differ from that of constitutively and systemically expressed ERVs in Tlr7-/- mice. We did not observe enhanced type I interferon (IFN-I) signaling in the vaginal tissues from Tlr7-/- mice, and instead found enrichment in genes associated with extracellular matrix organization. Together, our results revealed that constitutive and/or systemic expression of ERVs protect mice against vaginal HSV-2 infection and delay disease.

Pharmacological Inhibition of IRE-1 Alpha Activity in Herpes Simplex Virus Type 1 and Type 2-Infected Dendritic Cells Enhances T Cell Activation.

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections are life-long and highly prevalent in the human population. These viruses persist in the host, eliciting either symptomatic or asymptomatic infections that may occur sporadically or in a recurrent manner through viral reactivations. Clinical manifestations due to symptomatic infection may be mild such as orofacial lesions, but may also translate into more severe diseases, such as ocular infections that may lead to blindness and life-threatening encephalitis. A key feature of herpes simplex viruses (HSVs) is that they have evolved molecular determinants that hamper numerous components of the host's antiviral innate and adaptive immune system. Importantly, HSVs infect and negatively modulate the function of dendritic cells (DCs), by inhibiting their T cell-activating capacity and eliciting their apoptosis after infection. Previously, we reported that HSV-2 activates the splicing of the mRNA of XBP1, which is related to the activity of the unfolded protein response (UPR) factor Inositol-Requiring Enzyme 1 alpha (IRE-1α). Here, we sought to evaluate if the activation of the IRE-1α pathway in DCs upon HSV infection may be related to impaired DC function after infection with HSV-1 or HSV-2. Interestingly, the pharmacological inhibition of the endonuclease activity of IRE-1α in HSV-1- and HSV-2-infected DCs significantly reduced apoptosis in these cells and enhanced their capacity to migrate to lymph nodes and activate virus-specific CD4+ and CD8+ T cells. These findings suggest that the activation of the IRE-1α-dependent UPR pathway in HSV-infected DCs may play a significant role in the negative effects that these viruses exert over these cells and that the modulation of this signaling pathway may be relevant for enhancing the function of DCs upon infection with HSVs.

Analysis of ALS-related proteins during herpes simplex virus-2 latent infection.

BACKGROUND: Genetics have provided hints on potential molecular pathways involved in neurodegenerative diseases (NDD). However, the number of cases caused exclusively by genetic alterations is low, suggesting an important contribution of environmental factors to NDDs. Among these factors, viruses like herpes simplex viruses (HSV-2), capable of establishing lifelong infections within the nervous system (NS), are being proposed to have a role in NDDs. Despite promising data, there is a significant lack of knowledge on this and an urgent need for more research. METHODS: We have set up a mouse model to study HSV latency and its associated neuroinflammation in the spinal cord. The goal of this model was to observe neuroinflammatory changes caused by HSV latent infections, and if those changes were similar to alterations observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients. RESULTS: In infected spinal cords, we have observed a strong leukocyte infiltration and a severe alteration of microglia close to motor neurons. We have also analyzed ALS-related proteins: we have not found changes in TDP-43 and Fus in neurons, but interestingly, we have found decreased protein levels of C9orf72, of which coding gene is severely altered in some familial forms of ALS and is critical for microglia homeostasis. CONCLUSIONS: Latent infection of HSV in the spinal cord showed altered microglia and leukocyte infiltration. These inflammatory features resembled to those observed in the spinal cord of ALS patients. No changes mimicking ALS neuropathology, such as TDP-43 cytoplasmic inclusions, were found in infected spinal cords, but a decrease in protein levels of C9orf72 was observed. Then, further studies should be required to determine whether HSV-2 has a role in ALS.

Subclinical Genital Herpes Shedding in HIV/Herpes Simplex Virus 2-Coinfected Women during Antiretroviral Therapy Is Associated with an Increase in HIV Tissue Reservoirs and Potentially Promotes HIV Evolution.

Antigen (Ag)-specific immune responses to chronic infections, such as herpes simplex virus type 2 (HSV-2) in HIV/HSV-coinfected persons, may sustain HIV tissue reservoirs by promoting T-cell proliferation but are poorly studied in women on antiretroviral therapy (ART). Mixed anogenital swabs and cervical secretions were self-collected by nine HIV/HSV-2-coinfected women during ART for 28 days to establish subclinical HSV DNA shedding rates and detection of HIV RNA by real-time PCR. Typical herpes lesion site biopsy (TLSB) and cervical biopsy specimens were collected at the end of the daily sampling period. Nucleic acids (NA) isolated from biopsy specimens had HIV quantified and HIV envC2-V5 single-genome amplification (SGA) and T-cell receptor (TCR) repertoires assessed. Women had a median CD4 count of 537 cells/µl (IQR: 483 to 741) at enrollment and HIV plasma viral loads of <40 copies/ml. HSV DNA was detected on 12% of days (IQR: 2 to 25%) from anogenital specimens. Frequent subclinical HSV DNA shedding was associated with increased HIV DNA tissue concentrations and increased divergence from the most recent common ancestor (MRCA), an indicator of HIV replication. Distinct predominant TCR clones were detected in cervical and TLSB specimens in a woman with frequent HSV DNA shedding, with mixing of minor variants between her tissues. In contrast, more limited TCR repertoire mixing was observed in two women with less frequent subclinical HSV DNA shedding. Subclinical HSV shedding in HIV/HSV-coinfected women during ART may sustain HIV tissue reservoirs via Ag exposure or HIV replication. This study provides evidence supporting further study of interventions targeting suppression of Ag-specific immune responses as a component of HIV cure strategies.IMPORTANCE Persons with HIV infection are frequently coinfected with chronic herpesviruses, which periodically replicate and produce viable herpes virions, particularly in anogenital and cervical tissues. Persistent protein expression results in proliferation of CD8+ and CD4+ T cells, and the latter could potentially expand and sustain HIV tissue reservoirs. We found HSV genital shedding rates were positively correlated with HIV DNA concentrations and HIV divergence from ancestral sequences in tissues. Our work suggests that immune responses to common coinfections, such as herpesviruses, may sustain HIV tissue reservoirs during suppressive ART, suggesting future cure strategies should study interventions to suppress replication or reactivation of chronic herpes infections.

Herpes Simplex Virus Type 2 Inhibits Type I IFN Signaling Mediated by the Novel E3 Ubiquitin Protein Ligase Activity of Viral Protein ICP22.

Type I IFNs play an important role in innate immunity against viral infections by inducing the expression of IFN-stimulated genes (ISGs), which encode effectors with various antiviral functions. We and others previously reported that HSV type 2 (HSV-2) inhibits the synthesis of type I IFNs, but how HSV-2 suppresses IFN-mediated signaling is less understood. In the current study, after the demonstration of HSV-2 replication resistance to IFN-ß treatment in human epithelial cells, we reveal that HSV-2 and the viral protein ICP22 significantly decrease the expression of ISG54 at both mRNA and protein levels. Likewise, us1 del HSV-2 (ICP22-deficient HSV-2) replication is more sensitive to IFN-ß treatment, indicating that ICP22 is a vital viral protein responsible for the inhibition of type I IFN-mediated signaling. In addition, overexpression of HSV-2 ICP22 inhibits the expression of STAT1, STAT2, and IFN regulatory factor 9 (IRF9), resulting in the blockade of ISG factor 3 (ISGF3) nuclear translocation, and mechanistically, this is due to ICP22-induced ubiquitination of STAT1, STAT2, and IRF9. HSV-2 ICP22 appears to interact with STAT1, STAT2, IRF9, and several other ubiquitinated proteins. Following further biochemical study, we show that HSV-2 ICP22 functions as an E3 ubiquitin protein ligase to induce the formation of polyubiquitin chains. Taken together, we demonstrate that HSV-2 interferes with type I IFN-mediated signaling by degrading the proteins of ISGF3, and we identify HSV-2 ICP22 as a novel E3 ubiquitin protein ligase to induce the degradation of ISGF3. Findings in this study highlight a new mechanism by which HSV-2 circumvents the host antiviral responses through a viral E3 ubiquitin protein ligase.

Herpes Simplex virus type 2 seroprevalence and risk factors among adolescents and youth with HIV-1 in Northern, Tanzania.

INTRODUCTION: Herpes Simplex virus type 2 (HSV-2) infection is associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) acquisition and transmission. Individuals co-infected with HIV-1 and HSV-2 may have longer lasting, more frequent and severe outbreaks of herpes symptoms. Previous studies have assessed HSV-2 seroprevalence and associated risk factors in adult populations. However, there is limited data on the HSV-2 seroprevalence among adolescents and youth living with HIV-1. The study aimed to determine the HSV-2 seroprevalence and associated risk factors among adolescents and youth living with HIV-1 at referral hospital setting in Northern Tanzania. METHODOLOGY: A cross-sectional survey was conducted between February and July 2017 among HIV-1-infected individuals aged 10-24 years attending the Child -Centred Family Care Clinic at Kilimanjaro Christian Medical Centre. Blood specimens from 180 individuals were collected for ELISA-based detection of HSV-2 antibodies. Associations between risk factors and HSV-2 seroprevalence were analysed by univariate and multivariate logistic regression models. RESULTS: The overall HSV-2 seroprevalence was 18% (32/180). A significant HSV-2 seroprevalence was noted among adolescents and youth, who reported having had sexual intercourse than those who never had sexual intercourse (28.9% vs 13.3%, p = 0.02). Youths aged 20-24 had six folds higher risk of HSV-2 seroprevalence compared to those aged 10-14 years (AOR = 5.97 95% CI 1.31 - 27.19, p = 0.02). CONCLUSIONS: Our study found that HSV-2 seroprevalence increased by age among adolescents and youth living with HIV-1. Age-specific approaches might play an important role in interventions targeting HSV-2 infection.

Vaccines to prevent genital herpes.

Genital herpes increases the risk of acquiring and transmitting Human Immunodeficiency Virus (HIV), is a source of anxiety for many about transmitting infection to intimate partners, and is life-threatening to newborns. A vaccine that prevents genital herpes infection is a high public health priority. An ideal vaccine will prevent both genital lesions and asymptomatic subclinical infection to reduce the risk of inadvertent transmission to partners, will be effective against genital herpes caused by herpes simplex virus types 1 and 2 (HSV-1, HSV-2), and will protect against neonatal herpes. Three phase 3 human trials were performed over the past 20 years that used HSV-2 glycoproteins essential for virus entry as immunogens. None achieved its primary endpoint, although each was partially successful in either delaying onset of infection or protecting a subset of female subjects that were HSV-1 and HSV-2 uninfected against HSV-1 genital infection. The success of future vaccine candidates may depend on improving the predictive value of animal models by requiring vaccines to achieve near-perfect protection in these models and by using the models to better define immune correlates of protection. Many vaccine candidates are under development, including DNA, modified mRNA, protein subunit, killed virus, and attenuated live virus vaccines. Lessons learned from prior vaccine studies and select candidate vaccines are discussed, including a trivalent nucleoside-modified mRNA vaccine that our laboratory is pursuing. We are optimistic that an effective vaccine for prevention of genital herpes will emerge in this decade.

IL-17C/IL-17RE: Emergence of a Unique Axis in TH17 Biology.

Therapeutic targeting of IL-17A and its receptor IL-17RA with antibodies has turned out to be a tremendous success in the treatment of several autoimmune conditions. As the IL-17 cytokine family consists of six members (IL-17A to F), it is intriguing to elucidate the biological function of these five other molecules to identify more potential targets. In the past decade, IL-17C has emerged as quite a unique member of this pro-inflammatory cytokine group. In contrast to the well-described IL-17A and IL-17F, IL-17C is upregulated at very early timepoints of several disease settings. Also, the cellular source of the homodimeric cytokine differs from the other members of the family: Epithelial rather than hematopoietic cells were identified as the producers of IL-17C, while its receptor IL-17RE is expressed on TH17 cells as well as the epithelial cells themselves. Numerous investigations led to the current understanding that IL-17C (a) maintains an autocrine loop in the epithelium reinforcing innate immune barriers and (b) stimulates highly inflammatory TH17 cells. Functionally, the IL-17C/RE axis has been described to be involved in the pathogenesis of several diseases ranging from infectious and autoimmune conditions to cancer development and progression. This body of evidence has paved the way for the first clinical trials attempting to neutralize IL-17C in patients. Here, we review the latest knowledge about identification, regulation, and function of the IL-17C/IL-17receptor E pathway in inflammation and immunity, with a focus on the mechanisms underlying tissue injury. We also discuss the rationale for the translation of these findings into new therapeutic approaches in patients with immune-mediated disease.

Multivalent DNA vaccine protects against genital herpes by T-cell immune induction in vaginal mucosa.

Genital herpes is one of the most common sexually transmitted infections (STIs), and it is mainly caused by the neurotropic herpes simplex virus (HSV-2). Not only does this infection cause ulcers, but HSV-2 can also stay in a latent state in the nervous system of the host throughout their lifespan. As a result, many people do not know that they harbor this infection. Moreover, HSV-2 serves as a major risk factor for human immunodeficiency virus (HIV) infection and can be transmitted to the fetus. Despite the high risk of infection and adverse effects, attempts at development of an effective vaccine for HSV-2 have not yet been successful. In this study, we developed a DNA vaccine for HSV-2 (SL-V20). This multivalent DNA vaccine effectively reduced the pathological symptoms of infection and induced efficient elimination of the virus in a mouse model. Intramuscular injection of SL-V20 led to induction of an HSV-2-specific T-cell response in the vagina, the major infection site, and in draining lymph organs. Dendritic cells (DCs), especially basic leucine zipper ATF-like transcription factor 3 (Baft3)+ DCs and partially interferon regulatory factor 4 (Irf4)+ DCs, were involved in this T-cell-mediated protective response, while B cells were dispensable for these prophylactic effects. This study demonstrates that SL-V20 offers a novel and effective vaccine against vaginal HSV-2 infection and may be applicable to patients, pending validation in clinical studies.

Cutting Edge: The Use of Topical Aminoglycosides as an Effective Pull in "Prime and Pull" Vaccine Strategy.

The presence of tissue-resident memory T cells at barrier tissues is critical for long-lasting protective immune responses. Previous work has shown that tissue-resident memory T cells can be established by "pulling" virus-specific effector T cells from circulation to the genital mucosa via topical vaginal application of chemokines in mice. Once established, these cells protect hosts against genital herpes infection. We recently showed that vaginal application of aminoglycoside antibiotics induces robust activation of the IFN signaling pathway, including upregulation of chemokine expression within the tissue in mice. In this study, we show that a single topical application of neomycin, an inexpensive and vaginally nontoxic antibiotic, is sufficient to pull CD8 T cells to the vaginal mucosa and provide protection against genital herpes infection in mice.

Tissue-resident T cell-derived cytokines eliminate herpes simplex virus-2-infected cells.

The mechanisms underlying rapid elimination of herpes simplex virus-2 (HSV-2) in the human genital tract despite low CD8+ and CD4+ tissue-resident T cell (Trm cell) density are unknown. We analyzed shedding episodes during chronic HSV-2 infection; viral clearance always predominated within 24 hours of detection even when viral load exceeded 1 × 107 HSV DNA copies, and surges in granzyme B and IFN-γ occurred within the early hours after reactivation and correlated with local viral load. We next developed an agent-based mathematical model of an HSV-2 genital ulcer to integrate mechanistic observations of Trm cells in in situ proliferation, trafficking, cytolytic effects, and cytokine alarm signaling from murine studies with viral kinetics, histopathology, and lesion size data from humans. A sufficiently high density of HSV-2-specific Trm cells predicted rapid elimination of infected cells, but our data suggest that such Trm cell densities are relatively uncommon in infected tissues. At lower, more commonly observed Trm cell densities, Trm cells must initiate a rapidly diffusing, polyfunctional cytokine response with activation of bystander T cells in order to eliminate a majority of infected cells and eradicate briskly spreading HSV-2 infection.

A vaccine containing highly purified virus particles in adjuvant provides high level protection against genital infection and disease in guinea pigs challenged intravaginally with homologous and heterologous strains of herpes simplex virus type 2.

Infection with Herpes Simplex Viruses (HSVs) represents a significant health burden worldwide with HSV-1 and HSV-2 causing genital disease and HSV-2 contributing to human immunodeficiency virus acquisition. Despite great need, there is currently no licensed vaccine against HSV. In this report, we evaluated the protective efficacy of a vaccine containing highly purified, inactivated HSV-2 particles (with and without additional recombinant glycoprotein D) formulated with a monophosphoryl lipid A/Alhydrogel adjuvant in a guinea pig HSV genital model. The key results from 3 independent studies were: (1) vaccination consistently provided significant 3-3.5 Log10 reductions in vaginal HSV-2 titers on day 2 postchallenge; (2) following homologous or heterologous challenge with two U.S. isolates, all vaccine groups showed complete protection against lesion formation, significant 3 Log10 reductions in day 2 virus shedding, enhanced virus clearance, significant reductions in HSV-2 DNA within ganglia, and no detectable shedding (<2 PFU) or latent viral DNA in some immunized animals; (3) following challenge with a third heterologous strain, vaccination provided complete protection against primary and recurrent lesions, significant reductions in primary virus shedding, a 50% reduction in recurrent shedding days, and undetectable latent virus in the ganglia and spinal cords of most animals; and (4) adding glycoprotein D provided no enhanced protection relative to that elicited by the inactivated HSV-2 particles alone. Together, these data provide strong support for further development of this exceedingly protective and highly feasible vaccine candidate for human trials.