Mitochondrial stress releases mitochondrial DNA (mtDNA) into the cytosol, thereby triggering the type Ι interferon (IFN) response. Mitochondrial outer membrane permeabilization, which is required for mtDNA release, has been extensively studied in apoptotic cells, but little is known about its role in live cells. We found that oxidatively stressed mitochondria release short mtDNA fragments via pores formed by the voltage-dependent anion channel (VDAC) oligomers in the mitochondrial outer membrane. Furthermore, the positively charged residues in the N-terminal domain of VDAC1 interact with mtDNA, promoting VDAC1 oligomerization. The VDAC oligomerization inhibitor VBIT-4 decreases mtDNA release, IFN signaling, neutrophil extracellular traps, and disease severity in a mouse model of systemic lupus erythematosus. Thus, inhibiting VDAC oligomerization is a potential therapeutic approach for diseases associated with mtDNA release.

Latency-associated transcript (LAT) sequences regulate herpes simplex virus (HSV) latency and reactivation from sensory neurons. We found a HSV-2 LAT-related microRNA (miRNA) designated miR-I in transfected and infected cells in vitro and in acutely and latently infected ganglia of guinea pigs in vivo. miR-I is also expressed in human sacral dorsal root ganglia latently infected with HSV-2. miR-I is expressed under the LAT promoter in vivo in infected sensory ganglia. We also predicted and identified a HSV-1 LAT exon-2 viral miRNA in a location similar to miR-I, implying a conserved mechanism in these closely related viruses. In transfected and infected cells, miR-I reduces expression of ICP34.5, a key viral neurovirulence factor. We hypothesize that miR-I may modulate the outcome of viral infection in the peripheral nervous system by functioning as a molecular switch for ICP34.5 expression.HSV ͉ latency-associated transcript ͉ latency ͉ reactivation ͉ human H erpes simplex virus 1 and 2 (HSV-1 and HSV-2) are closely related human herpes viruses. HSV-1 and HSV-2 establish lifelong incurable latency in and reactivate preferentially from trigeminal ganglia and dorsal root ganglia to cause oro-facial and genital herpes, respectively. Although infections are usually mild, these viruses can cause severe disease including encephalitis and neonatal herpes, and HSV-2 infection is a risk factor for HIV acquisition. The only readily detectable viral transcript during latency of both HSV-1 and HSV-2 is the noncoding latency-associated transcript (LAT), which is transcribed from within the long repeats of the viral genome ( Fig. 1) (1). A Ϸ8-kb primary LAT is spliced, yielding a stable Ϸ2-kb LAT intron (2). Deletion of the LAT promoter in both HSV-1 and HSV-2 reduces the efficiency of reactivation (3-5), and substitution of HSV-1 LAT for native HSV-2 LAT sequences confers an HSV-1 reactivation phenotype (6). The HSV-1 LAT is currently believed to act in part by increasing the establishment or maintenance of latency, likely via an effect on the survival of acutely infected neurons (7), which may be mediated by inhibition of apoptosis in infected neurons (8). The molecular function of HSV-2 LAT remains largely unknown.miRNAs are a family of 21Ϸ24-nt noncoding RNAs that regulate gene expression based on sequence similarity to their targets. Mammalian viruses including EBV, Kaposi's sarcoma-associated herpesvirus, human cytomegalovirus, and SV40 encode viral miRNAs (9). Viral encoded miRNAs were predicted for HSV-1 (10, 11) and also for HSV-2 (10). However, no miRNAs have been identified in HSV-2 or HSV-1 LAT sequences. Results HSV-2 LAT Exon 2 Encodes a miRNA.To find miRNAs within the HSV-2 LAT region, a plasmid containing the LAT sequence and its promoter (pSSK) and a mutant plasmid expressing LAT under control of the CMV-IE promoter (pCMV-SSK) were transfected into 293 cells. Small RNAs isolated from the transfected cells were cloned and sequenced. A 22-23-nt HSV-2 RNA sequence (designated HSV-2 miR-I) appeared at a frequenc...

We hypothesize that innate immune signals from infectious organisms and/or injured tissues may activate peripheral neuronal pain signals. In this study, we demonstrated that toll-like receptors 3/7/9 (TLRs) are expressed by human dorsal root ganglion neurons (DRGNs) and in cultures of primary mouse DRGNs. Stimulation of murine DRGNs with TLR ligands induced expression and production of proinflammatory chemokines and cytokines CCL5 (RANTES), CXCL10 (IP10), interleukin-1alpha, interleukin-1beta, and prostaglandin E2 (PGE2), which have previously been shown to augment pain. Further, TLR ligands up-regulated the expression of a nociceptive receptor transient receptor potential vanilloid type 1 (TRPV1), and enhanced calcium flux by TRPV1 expressing DRGNs. Using a tumor-induced temperature sensitivity model, we showed that in vivo administration of a TLR9 antagonist, known as a suppressive ODN, blocked tumor-induced temperature sensitivity. Taken together, these data indicate that stimulation of peripheral neurons by TLR ligands can induce nerve pain.

Herpes simplex virus 2 (HSV-2), the principal causative agent of recurrent genital herpes, is a highly prevalent viral infection worldwide. Limited information is available on the amount of genomic DNA variation between HSV-2 strains because only two genomes have been determined, the HG52 laboratory strain and the newly sequenced SD90e low-passage-number clinical isolate strain, each from a different geographical area. In this study, we report the nearly complete genome sequences of 34 HSV-2 lowpassage-number and laboratory strains, 14 of which were collected in Uganda, 1 in South Africa, 11 in the United States, and 8 in Japan. Our analyses of these genomes demonstrated remarkable sequence conservation, regardless of geographic origin, with the maximum nucleotide divergence between strains being 0.4% across the genome. In contrast, prior studies indicated that HSV-1 genomes exhibit more sequence diversity, as well as geographical clustering. Additionally, unlike HSV-1, little viral recombination between HSV-2 strains could be substantiated. These results are interpreted in light of HSV-2 evolution, epidemiology, and pathogenesis. Finally, the newly generated sequences more closely resemble the low-passage-number SD90e than HG52, supporting the use of the former as the new reference genome of HSV-2. IMPORTANCEHerpes simplex virus 2 (HSV-2) is a causative agent of genital and neonatal herpes. Therefore, knowledge of its DNA genome and genetic variability is central to preventing and treating genital herpes. However, only two full-length HSV-2 genomes have been reported. In this study, we sequenced 34 additional HSV-2 low-passage-number and laboratory viral genomes and initiated analysis of the genetic diversity of HSV-2 strains from around the world. The analysis of these genomes will facilitate research aimed at vaccine development, diagnosis, and the evaluation of clinical manifestations and transmission of HSV-2. This information will also contribute to our understanding of HSV evolution. Herpes simplex virus 1 (HSV-1) and herpes simplex virus 2 (HSV-2) are two closely related human species of herpesviruses in the genus Simplexvirus of the family Herpesviridae (1). HSV-1 is mostly associated with orofacial infections, while HSV-2 is generally associated with genital herpes. Both viruses cause significant human disease, so knowledge of the structure of their DNA genomes and the extent of their genetic variation is very important. A high overall GC content and the presence of highly reiterated repeat regions in both noncoding and coding portions of the genome complicate sequence determination (2).The HSV linear double-stranded DNA genomes consist of two covalent linked components, the long (L) and short (S) components, which invert relative to each other by intramolecular recombination (1). The L component consists of unique sequences (U L ) bounded by inverted repeats (R L and R L =), and the S component consists of unique sequences (U S ) bounded by inverted repeats (R S and R S =) (3). The termini con...