A recombinant herpes virus expressing influenza hemagglutinin confers protection and induces antibody-dependent cellular cytotoxicity.

Despite widespread yearly vaccination, influenza leads to significant morbidity and mortality across the globe. To make a more broadly protective influenza vaccine, it may be necessary to elicit antibodies that can activate effector functions in immune cells, such as antibody-dependent cellular cytotoxicity (ADCC). There is growing evidence supporting the necessity for ADCC in protection against influenza and herpes simplex virus (HSV), among other infectious diseases. An HSV-2 strain lacking the essential glycoprotein D (gD), was used to create ΔgD-2, which is a highly protective vaccine against lethal HSV-1 and HSV-2 infection in mice. It also elicits high levels of IgG2c antibodies that bind FcγRIV, a receptor that activates ADCC. To make an ADCC-eliciting influenza vaccine, we cloned the hemagglutinin (HA) gene from an H1N1 influenza A strain into the ΔgD-2 HSV vector. Vaccination with ΔgD-2::HAPR8 was protective against homologous influenza challenge and elicited an antibody response against HA that inhibits hemagglutination (HAI+), is predominantly IgG2c, strongly activates FcγRIV, and protects against influenza challenge following passive immunization of naïve mice. Prior exposure of mice to HSV-1, HSV-2, or a replication-defective HSV-2 vaccine (dl5-29) does not reduce protection against influenza by ΔgD-2::HAPR8 This vaccine also continues to elicit protection against both HSV-1 and HSV-2, including high levels of IgG2c antibodies against HSV-2. Mice lacking the interferon-α/ß receptor and mice lacking the interferon-γ receptor were also protected against influenza challenge by ΔgD-2::HAPR8 Our results suggest that ΔgD-2 can be used as a vaccine vector against other pathogens, while also eliciting protective anti-HSV immunity.

Artificial light at night alters delayed-type hypersensitivity reaction in response to acute stress in Siberian hamsters.

Several physiological and behavioral processes rely on precisely timed light information derived from the natural solar cycle. Using this information, traits have adapted to allow individuals within specific niches to optimize survival and reproduction, but urbanization by humans has significantly altered natural habitats. Nighttime light exposure alters immune function in several species, which could lead to decreased fitness or survival, particularly in the face of an environmental challenge. We exposed male Siberian hamsters (Phodopus sungorus) to five lux of light at night for four weeks, and then administered six hours of acute restraint stress. Delayed-type hypersensitivity (DTH) response was assessed immediately following stress. Acute restraint increased the DTH reaction in dark nights, but exposure to nighttime light prevented this response. Exposure to light at night prolonged the DTH response in non-stressed control hamsters. These results suggest that light pollution may significantly alter physiological responses in Siberian hamsters, particularly in response to a salient environmental challenge such as stress.

Capturing Structural Variants of Herpes Simplex Virus Genome in Full Length by Oxford Nanopore Sequencing.

Genome sequencing and assembly of viral genomes within the Herpesviridae family, particularly herpes simplex virus (HSV), have been challenging due to the large size (~154 Kb), high GC content (68%), and nucleotide variations arising during replication. Oxford Nanopore Technology (ONT) has been successful in obtaining read lengths ranging from 100 Kb up to 2.3 Mb. We have optimized DNA extraction and sequencing with ONT to capture the whole genome of HSV-1 as a single read. Although previous studies described the presence of four different genome isomers of HSV, we provided the first report on capturing all four variants' full-length genome as single reads. These isomers were found to be present in almost equal proportion in the sequenced DNA preparation. IMPORTANCE With the advent of next-generation sequencing platforms, genome sequencing of viruses can be performed in a relatively shorter time frame in even the most austere conditions. Ultralong read sequencing platforms, such as Oxford Nanopore Technology (ONT), have made it possible to capture the full-length genome of DNA viruses as a single read. By optimizing ONT for this purpose, we captured the genome (~154 Kb) of a clinical strain of herpes simplex virus 1 (HSV-1). Additionally, we captured full-length sequences of the four isomers of lab-grown HSV-1 virus and were able to determine the frequency of each within the isogenic population. This method will open new directions in studying the significance of these isomers and their clinical relevance to HSV-1 infections. It will also improve basic studies on the recombination and replication of this virus.

Genetic variation in total number and locations of GnRH neurons identified using in situ hybridization in a wild-source population.

The evolution of brain function in the regulation of physiology may depend in part upon the numbers and locations of neurons. Wild populations of rodents contain natural genetic variation in the inhibition of reproduction by winter-like short photoperiod, and it has been hypothesized that this functional variation might be due in part to heritable variation in the numbers or location of gonadotropin releasing hormone (GnRH) neurons. A naturally variable wild-source population of white-footed mice was used to develop lines artificially selected for or against mature gonads in short, winter-like photoperiods. We compared a selection line that is reproductively inhibited in short photoperiod (Responsive) to a line that is weakly inhibited by short photoperiod (Nonresponsive) for differences in counts of neurons identified using in situ hybridization for GnRH mRNA. There was no effect of photoperiod, but there were 60% more GnRH neurons in total in the Nonresponsive selection line than the Responsive selection line. The lines differed specifically in numbers of GnRH neurons in more anterior regions, whereas numbers of GnRH neurons in posterior areas were not statistically different between lines. We compare these results to those of an earlier study that used immunohistochemical labeling for GnRH neurons. The results are consistent with the hypothesis that the selection lines and natural source population contain significant genetic variation in the number and location of GnRH neurons. The variation in GnRH neurons may contribute to functional variation in fertility that occurs in short photoperiods in the laboratory and in the wild source population in winter.

Fluoxetine Facilitates Fear Extinction Through Amygdala Endocannabinoids.

Pharmacologically elevating brain endocannabinoids (eCBs) share anxiolytic and fear extinction-facilitating properties with classical therapeutics, including the selective serotonin reuptake inhibitor, fluoxetine. There are also known functional interactions between the eCB and serotonin systems and preliminary evidence that antidepressants cause alterations in brain eCBs. However, the potential role of eCBs in mediating the facilitatory effects of fluoxetine on fear extinction has not been established. Here, to test for a possible mechanistic contribution of eCBs to fluoxetine's proextinction effects, we integrated biochemical, electrophysiological, pharmacological, and behavioral techniques, using the extinction-impaired 129S1/Sv1mJ mouse strain. Chronic fluoxetine treatment produced a significant and selective increase in levels of anandamide in the BLA, and an associated decrease in activity of the anandamide-catabolizing enzyme, fatty acid amide hydrolase. Slice electrophysiological recordings showed that fluoxetine-induced increases in anandamide were associated with the amplification of eCB-mediated tonic constraint of inhibitory, but not excitatory, transmission in the BLA. Behaviorally, chronic fluoxetine facilitated extinction retrieval in a manner that was prevented by systemic or BLA-specific blockade of CB1 receptors. In contrast to fluoxetine, citalopram treatment did not increase BLA eCBs or facilitate extinction. Taken together, these findings reveal a novel, obligatory role for amygdala eCBs in the proextinction effects of a major pharmacotherapy for trauma- and stressor-related disorders and anxiety disorders.