The next generation of needle-free mucosal vaccines is being rationally designed according to rules that govern the way in which the epitopes are recognized by and stimulate the genital mucosal immune system. We hypothesized that synthetic peptide epitopes extended with an agonist of Toll-like receptor 2 (TLR-2), that are abundantly expressed by dendritic and epithelial cells of the vaginal mucosa, would lead to induction of protective immunity against genital herpes. To test this hypothesis, we intravaginally (IVAG) immunized wild-type B6, TLR-2 (TLR2 −/−) or myeloid differentiation factor 88 deficient (MyD88 −/−) mice with a herpes simplex virus type 2 (HSV-2) CD8 + T-cell peptide epitope extended by a palmitic acid moiety (a TLR-2 agonist). IVAG delivery of the lipopeptide generated HSV-2-specific memory CD8 + cytotoxic T cells both locally in the genital tract draining lymph nodes and systemically in the spleen. Moreover, lipopeptide-immunized TLR2 −/− and MyD88 −/− mice developed significantly less HSV-specific CD8 + T-cell response, earlier death, faster disease progression, and higher vaginal HSV-2 titers compared to lipopeptide-immunized wild-type B6 mice. IVAG immunization with self-adjuvanting lipid-tailed peptides appears to be a novel mucosal vaccine approach, which has attractive practical and immunological features.

Previously, we reported NELL-1 as a novel molecule overexpressed during premature cranial suture closure in patients with craniosynostosis (CS), one of the most common congenital craniofacial deformities. Here we describe the creation and analysis of transgenic mice overexpressing Nell-1. Nell-1 transgenic animals exhibited CS-like phenotypes that ranged from simple to compound synostoses. Histologically, the osteogenic fronts of abnormally closing/closed sutures in these animals revealed calvarial overgrowth and overlap along with increased osteoblast differentiation and reduced cell proliferation. Furthermore, anomalies were restricted to calvarial bone, despite generalized, non-tissue-specific overexpression of Nell-1. In vitro, Nell-1 overexpression accelerated calvarial osteoblast differentiation and mineralization under normal culture conditions. Moreover, Nell-1 overexpression in osteoblasts was sufficient to promote alkaline phosphatase expression and micronodule formation. Conversely, downregulation of Nell-1 inhibited osteoblast differentiation in vitro. In summary, Nell-1 overexpression induced calvarial overgrowth resulting in premature suture closure in a rodent model. Nell-1, therefore, has a novel role in CS development, perhaps as part of a complex chain of events resulting in premature suture closure. On a cellular level, Nell-1 expression may modulate and be both sufficient and required for osteoblast differentiation

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f Herpesvirus entry mediator (HVEM) is one of several cell surface proteins herpes simplex virus (HSV) uses for attachment/entry. HVEM regulates cellular immune responses and can also increase cell survival. Interestingly, latency-associated transcript (LAT), the only viral gene consistently expressed during neuronal latency, enhances latency and reactivation by promoting cell survival and by helping the virus evade the host immune response. However, the mechanisms of these LAT activities are not well understood. We show here for the first time that one mechanism by which LAT enhances latency and reactivation appears to be by upregulating HVEM expression. HSV-1 latency/reactivation was significantly reduced in Hvem ؊/؊ mice, indicating that HVEM plays a significant role in HSV-1 latency/reactivation. Furthermore, LAT upregulated HVEM expression during latency in vivo and also when expressed in vitro in the absence of other viral factors. This study suggests a mechanism whereby LAT upregulates HVEM expression potentially through binding of two LAT small noncoding RNAs to the HVEM promoter and that the increased HVEM then leads to downregulation of immune responses in the latent microenvironment and increased survival of latently infected cells. Thus, one of the mechanisms by which LAT enhances latency/reactivation appears to be through increasing expression of HVEM.

The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) is the only HSV-1 gene transcript abundantly expressed throughout latency. LAT null mutants have a significantly reduced reactivation phenotype. LAT's antiapoptosis activity is the major LAT factor involved in supporting the wild-type reactivation phenotype. During HSV-1 latency, some ganglionic neurons are surrounded by CD8 T cells, and it has been proposed that these CD8 T cells help maintain HSV-1 latency by suppressing viral reactivations. Surprisingly, despite injection of cytotoxic lytic granules by these CD8 T cells into latently infected neurons, neither apoptosis nor neuronal cell death appears to occur. We hypothesized that protection of latently infected neurons against cytotoxic CD8 T-cell killing is due to LAT's antiapoptosis activity. Since CD8 T-cell cytotoxic lytic granule-mediated apoptosis is critically dependent on granzyme B (GrB), we examined LAT's ability to block GrB-induced apoptosis. We report here that (i) LAT can interfere with GrB-induced apoptosis in cell cultures, (ii) LAT can block GrB-induced cleavage (activation) of caspase-3 both in cell culture and in a cell-free in vitro cell extract assay, and (iii) LAT can protect C1300 and Neuro2A cells from cytotoxic CD8 T-cell killing in vitro. These findings support the hypothesis that LAT's antiapoptosis activity can protect latently infected neurons from being killed by CD8 T-cell lytic granules in vivo.Herpes simplex virus type 1 (HSV-1) is ubiquitous worldwide. Estimates of the percentage of adults that harbor latent HSV-1 range from just under 50% to over 90% (6,7,13,19,44,47,61,69). HSV-1 can infect mucosal sites, in particular the eyes, mouth, and genitals. Following primary infection at the periphery, the virus travels up axons and becomes latent in sensory neurons of the host's peripheral nervous system (PNS). HSV-1 latency is lifelong. Sporadic spontaneous reactivations of the virus from the PNS can result in return of infectious virus to the original peripheral site of infection. This reactivated virus, in the absence of clinical disease, is shed from mucosal surfaces and can be transmitted to others. Less often, viral reactivations and shedding result in recurrent pathology at the site of the original infection, such as genital lesions, cold sores in and around the mouth, and corneal disease that can lead to loss of vision. In the United States, recurrent HSV-1-induced corneal disease is the leading cause of corneal blindness due to an infectious agent (48, 59). In addition, HSV-1 causes a severe form of focal necrotizing encephalitis that affects over 2,000 people in the United States each year (20,40,67,68). Reactivations of HSV-1, rather than primary infections, are responsible for most incidences of HSV-1-induced disease and the majority of viral transmissions. Thus, understanding the molecular mechanisms of the HSV-1 latencyreactivation cycle is critical for developing methods of preventing both viral spread and HSV-1-induced disease.During neuro...