Intramuscular Vaccination of Mice with the Human Herpes Simplex Virus Type-1(HSV-1) 1 VC2 Vaccine Unlike its Parental Strain HSV-1(F) Confers Full Protection Against Lethal 2 Ocular Immunopathogenesis by the Human Clinical Strain HSV-1(McKrae)
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ABSTRACT: Live attenuated vaccine against herpes simplex ocular infections
Project description:Herpes simplex virus type-1 (HSV-1) can cause severe ocular infection and blindness. We have previously shown that the HSV-1 VC2 vaccine strain is protective in mice and guinea pigs against genital herpes infection following vaginal challenge with HSV-1 or HSV-2. In this study, we evaluated the efficacy of VC2 intramuscular vaccination in mice against herpetic keratitis following ocular challenge with lethal human clinical strain HSV-1(McKrae). VC2 vaccination in mice produced superior protection and morbidity control in comparison to its parental strain HSV-1(F). Specifically, after HSV-1(McKrae) ocular challenge, all VC2 vaccinated- mice survived, while 30% of the HSV-1(F)- vaccinated and 100% of the mock-vaccinated mice died post challenge. VC2-vaccinated mice did not exhibit any symptoms of ocular infection and completely recovered from initial conjunctivitis. In contrast, HSV-1(F)-vaccinated mice developed time-dependent progressive keratitis characterized by corneal opacification, while mock-vaccinated animals exhibited more severe stromal keratitis characterized by immune cell infiltration and neovascularization in corneal stroma with corneal opacification. Cornea in VC2-immunized mice exhibited significantly increased infiltration of CD3+ T lymphocytes and decreased infiltration of Iba1+ macrophages in comparison to mock- or HSV-1(F)-vaccinated groups. VC2 immunization produced higher virus neutralization titers than HSV-1(F) post challenge. Furthermore, VC-vaccination significantly increased the CD4 T central memory (TCM) subsets and CD8 T effector memory (TEM) subsets in the draining lymph nodes following ocular HSV-1 (McKrae) challenge, then mock- or HSV-1(F)-vaccination. These results indicate that VC2 vaccination produces a protective immune response at the site of challenge to protect against HSV-1-induced ocular pathogenesis.
Project description:Herpes simplex virus type-1 (HSV-1) ocular infection is one of the leading causes of infectious blindness in developed countries. The resultant herpetic keratitis (HK) is caused by an exacerbated reaction of the adaptive immune response that persists beyond virus clearance causing substantial damage to the cornea. Intramuscular immunization of mice with the HSV-1(VC2) live-attenuated vaccine strain has been shown to protect mice against lethal ocular challenge. Herein, we show that following ocular challenge, VC2 vaccinated animals control ocular immunopathogenesis in the absence of neutralizing antibodies on ocular surfaces. Ocular protection is associated with enhanced intracorneal infiltration of γδ T cells compared to mock-vaccinated animals. The observed γδ T cellular infiltration was inversely proportional to the infiltration of neutrophils, the latter associated with exacerbated tissue damage. Inhibition of T cell migration into ocular tissues by the S1P receptors agonist FTY720 produced significant ocular disease in vaccinated mice and marked increase in neutrophil infiltration. These results indicate that ocular challenge of mice immunized with the VC2 vaccine induce a unique ocular mucosal response that leads into the infiltration of γδ T cells resulting in the amelioration of infection-associated immunopathogenesis.
Project description:Herpes simplex virus (HSV) infections manifest as recurrent oral or genital mucosal lesions, meningoencephalitis, corneal blindness, and perinatal disease. Subunit vaccines have advanced into the clinic without success. None were tested preclinically in male mice. We compared a single-cycle candidate vaccine deleted in HSV-2 glycoprotein D (ΔgD-2) and subunit gD-2 or gD-1 protein vaccines in a male murine skin model. The ΔgD-2 provided complete protection against 10 times the lethal dose of HSV-1 or HSV-2 clinical isolates, and no latent virus was detected, whereas gD-1- and gD-2-adjuvanted proteins provided little or no protection. Protection correlated with Fc receptor activating but not neutralizing antibody titers.
Project description:Despite the availability of antiviral chemotherapy, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections remain a severe global health problem. Of particular concern is the growing incidence of drug resistance in immunocompromised patients, which stresses the urgency to develop new effective treatment alternatives. We have developed a humanized monoclonal antibody (mAb hu2c) that completely abrogates viral cell-to-cell spread, a key mechanism by which HSV-1/2 escapes humoral immune surveillance. Moreover, mAb hu2c neutralized HSV fully independent of complement and/or immune effector cell recruitment in a highly efficient manner. Prophylactic and therapeutic administration of mAb hu2c completely prevented infection-related mortality of severely immunodeficient mice being challenged with a lethal dose of HSV-1. The high neutralization capacity of mAb hu2c was fully maintained toward clinical HSV isolates being multiresistant to standard antiviral drugs, and infection was fully resolved in 7/8 nonobese diabetic/SCID mice being infected with a multidrug resistant HSV-1 patient isolate. Immunohistochemical studies revealed no significant cross-reactivity of the antibody toward human tissues. These features warrant further clinical development of mAb hu2c as an immunotherapeutic compound for the management of severe and particularly drug-resistant HSV infections.
Project description:Human herpes simplex viruses (HSV) 1 and 2 are extremely common human pathogens with overlapping disease spectra. Infections due to HSV-1 and HSV-2 are distinguished in clinical settings using sequence-based "typing" assays. Here we describe a case of HSV mistyping caused by a previously undescribed HSV-1 × HSV-2 recombination event in UL27, the HSV gene that encodes glycoprotein B. This is the first documented case of HSV mistyping caused by an HSV-1 × HSV-2 recombination event and the first description of an HSV interspecies recombination event in UL27, which is frequently used as a target for diagnostics and experimental therapeutics. We also review the primer and probe target sequences for a commonly used HSV typing assay from nearly 700 HSV-1 and HSV-2 samples and find that about 4% of HSV-1 samples have a single nucleotide change in at least one of these loci, which could impact assay performance. Our findings illustrate how knowledge of naturally occurring genomic variation in HSV-1 and HSV-2 is essential for the design and interpretation of molecular diagnostics for these viruses.
Project description:Herpes simplex virus type 1 and 2 (HSV-1 and HSV-2, respectively) are prevalent human pathogens of clinical relevance that establish long-life latency in the nervous system. They have been considered, along with the Herpesviridae family, to exhibit a low level of genetic diversity during viral replication. However, the high ability shown by these viruses to rapidly evolve under different selective pressures does not correlates with that presumed genetic stability. High-throughput sequencing has revealed that heterogeneous or plaque-purified populations of both serotypes contain a broad range of genetic diversity, in terms of number and frequency of minor genetic variants, both in vivo and in vitro. This is reminiscent of the quasispecies phenomenon traditionally associated with RNA viruses. Here, by plaque-purification of two selected viral clones of each viral subtype, we reduced the high level of genetic variability found in the original viral stocks, to more genetically homogeneous populations. After having deeply characterized the genetic diversity present in the purified viral clones as a high confidence baseline, we examined the generation of de novo genetic diversity under culture conditions. We found that both serotypes gradually increased the number of de novo minor variants, as well as their frequency, in two different cell types after just five and ten passages. Remarkably, HSV-2 populations displayed a much higher raise of nonconservative de novo minor variants than the HSV-1 counterparts. Most of these minor variants exhibited a very low frequency in the population, increasing their frequency over sequential passages. These new appeared minor variants largely impacted the coding diversity of HSV-2, and we found some genes more prone to harbor higher variability. These data show that herpesviruses generate de novo genetic diversity differentially under equal in vitro culture conditions. This might have contributed to the evolutionary divergence of HSV-1 and HSV-2 adapting to different anatomical niche, boosted by selective pressures found at each epithelial and neuronal tissue.
Project description:To date, no vaccine that is safe and effective against herpes simplex virus 2 (HSV-2) disease has been licensed. In this study, we evaluated a DNA prime-formalin-inactivated-HSV-2 (FI-HSV2) boost vaccine approach in the guinea pig model of acute and recurrent HSV-2 genital disease. Five groups of guinea pigs were immunized and intravaginally challenged with HSV-2. Two groups were primed with plasmid DNAs encoding the secreted form of glycoprotein D2 (gD2t) together with two genes required for viral replication, either the helicase (UL5) and DNA polymerase (UL30) genes or the single-stranded DNA binding protein (UL29) and primase (UL52) genes. Both DNA-primed groups were boosted with FI-HSV2 formulated with monophosphoryl lipid A (MPL) and alum adjuvants. Two additional groups were primed with the empty backbone plasmid DNA (pVAX). These two groups were boosted with MPL and alum (MPL-alum) together with either formalin-inactivated mock HSV-2 (FI-Mock) or with FI-HSV2. The final group was immunized with gD2t protein in MPL-alum. After challenge, 0/9 animals in the group primed with UL5, UL30, and gD2t DNAs and all 10 animals in the mock-immunized control group (pVAX-FI-Mock) developed primary lesions. All mock controls developed recurrent lesions through day 100 postchallenge. Only 1 guinea pig in the group primed with pVAX DNA and boosted with FI-HSV2 (pVAX-FI-HSV2 group) and 2 guinea pigs in the group primed with UL5, UL30, and gD2t DNAs and boosted with FI-HSV2 (UL5, UL30, gD2t DNA-FI-HSV2 group) developed recurrent lesions. Strikingly, the UL5, UL30, gD2t DNA-FI-HSV2 group showed a 97% reduction in recurrent lesion days compared with the mock controls, had the highest reduction in days with recurrent disease, and contained the lowest mean HSV-2 DNA load in the dorsal root ganglia.
Project description:During lytic herpes simplex virus (HSV) infections, the half-lives of host and viral mRNAs are regulated by the HSV virion host shutoff (Vhs) protein (UL41). The sequences of the UL41 polypeptides of HSV type 1 (HSV-1) strain KOS and HSV-2 strain 333 are 87% identical. In spite of this similarity, HSV-2 strains generally shut off the host more rapidly and completely than HSV-1 strains. To examine type-specific differences in Vhs function, we compared the Vhs activities of UL41 alleles from HSV-1(KOS) and HSV-2(333) by assaying the ability of a transfected UL41 allele to inhibit expression of a cotransfected reporter gene. Both HSV-1 and HSV-2 alleles inhibited reporter gene expression over a range of vhs DNA concentrations. However, 40-fold less of the HSV-2 allele was required to yield the same level of inhibition as HSV-1, indicating that it is significantly more potent. Examination of chimeric UL41 alleles containing various combinations of HSV-1 and HSV-2 sequences identified three regions of the 333 polypeptide which increase the activity of KOS when substituted for the corresponding amino acids of the KOS protein. These are separated by two regions which have no effect on KOS activity, even though they contain 43 of the 74 amino acid differences between the parental alleles. In addition, alleles encoding a full-length KOS polypeptide with a 32-amino-acid N-terminal extension retain considerable activity. The results begin to identify which amino acid differences are responsible for type-specific differences in Vhs activity.
Project description:Herpes simplex virus type 1 (HSV-1) strain KOS has been extensively used in many studies to examine HSV-1 replication, gene expression, and pathogenesis. Notably, strain KOS is known to be less pathogenic than the first sequenced genome of HSV-1, strain 17. To understand the genotypic differences between KOS and other phenotypically distinct strains of HSV-1, we sequenced the viral genome of strain KOS. When comparing strain KOS to strain 17, there are at least 1,024 small nucleotide polymorphisms (SNPs) and 172 insertions/deletions (indels). The polymorphisms observed in the KOS genome will likely provide insights into the genes, their protein products, and the cis elements that regulate the biology of this HSV-1 strain.
Project description:Herpes simplex virus 1 (HSV-1), also known as Human herpesvirus 1, is a highly prevalent human neurotropic pathogen that causes a variety of diseases, including lethal encephalitis. Here, we report the genome sequence of the HSV-1 strain SC16.