Marco Redaelli

Immunization of knock-out α/β interferon receptor mice against lethal bluetongue infection with a BoHV-4-based vector expressing BTV-8 VP2 antigen.

New effective tools for vaccine strategies are necessary to limit the spread of bluetongue, an insect-transmitted viral disease of domestic and wild ruminants. In the present study, BoHV-4-based vector cloned as a bacterial artificial chromosome (BAC) was engineered to express the bluetongue virus (BTV) immune-dominant glycoprotein VP2 provided of a heterologous signal peptide to its amino terminal and a trans-membrane domain to its carboxyl terminal (IgK-VP2gDtm), to allow the VP2 expression targeting to the cell membrane fraction. Based on adult α/β interferon receptor knockout (IFNAR(-/-)) mice, a newly generated bluetongue laboratory animal model, a pre-challenge experiment was performed to test BoHV-4 safety on such immune-compromised animal. BoHV-4 infected IFNAR(-/-) mice did not show clinical signs even following the inoculation of BoHV-4 intra-cerebrally, although many areas of the brain got transduced. IFNAR(-/-) mice intraperitoneally inoculated twice with BoHV-4-A-IgK-VP2gDtm at different time points developed serum neutralizing antibodies against BTV and showed a strongly reduced viremia and a longer survival time when challenged with a lethal dose of BTV-8. The data acquired in this pilot study validate BoHV-4-based vector as a safe and effective heterologous antigen carrier/producer for the formulation of enhanced recombinant immunogens for the vaccination against lethal bluetongue.

One nose, one brain: contribution of the main and accessory olfactory system to chemosensation

The accessory olfactory system is present in most tetrapods. It is involved in the perception of chemical stimuli, being implicated also in the detection of pheromones. However, it is sensitive also to some common odorant molecules, which have no clear implication in intraspecific chemical communication. The accessory olfactory system may complement the main olfactory system and may contribute different perceptual features to the construction of a unitary representation, which merges the different chemosensory qualities. Crosstalk between the main and accessory olfactory systems occurs at different levels of central processing, in brain areas where the inputs from the two systems converge. Interestingly, centrifugal projections from more caudal brain areas are deeply involved in modulating both main and accessory sensory processing. A high degree of interaction between the two systems may be conceived and partial overlapping appears to occur in many functions. Therefore, the central chemosensory projections merge inputs from different organs to obtain a complex chemosensory picture.

Herpes simplex virus type 1 thymidine kinase–armed bovine herpesvirus type 4–based vector displays enhanced oncolytic properties in immunocompetent orthotopic syngenic mouse and rat glioma models

Gliomas are devastating tumors of the brain resistant to therapies. Although some therapies can prolong the survival time among the affected persons, gliomas are not curable and new therapeutic approaches need to be investigated. Oncolytic viruses seem to represent an interesting alternative, because anticancer agents and new viral agents have to be explored to identify the one with the best characteristics. Bovine herpesvirus type 4 (BoHV-4) is a gammaherpesvirus with a striking tropism and permissive replication toward cancer cells and rat, mouse, and human glioma cells. However, BoHV-4 does not replicate into the normal brain parenchyma. The BoHV-4 genome was cloned as a bacterial artificial chromosome to easily manipulate this large genome and be used as a viral vector platform. In the present study, a herpes simplex virus type 1 thymidine kinase suicide gene-armed BoHV-4 was constructed, characterized, and proven to be highly efficient in killing by apoptosis glioma cells in vitro when co-administered with the pro-drug ganciclovir (GCV). When the armed BoHV-4/GCV therapeutic approach was tested in immunocompetent orthotopic syngenic mouse and rat glioma models in vivo, a significant increase in survival among the treated animals was achieved, and some animals were completely cured. The BoHV-4-based vector represents a promising alternative oncolytic virus for glioma and, perhaps, other types of cancer treatment that merit further investigation. This article represents the result of a mutual interaction between human medical science and veterinary science, a combination of scientific knowledge often neglected.

Urinary Volatile Molecules Vary in Males of the 2 European Subspecies of the House Mouse and Their Hybrids

Mice recognize other mice by identifying chemicals that confer a molecular signature to urinary marks. Such molecules may be involved in species recognition, and previous behavioral studies have related divergence of sexual preference between 2 subspecies of the house mouse (Mus musculus musculus and Mus musculus domesticus) to urinary odors. To characterize the differences between odors of males of the 2 subspecies and their first-generation offspring, the urinary volatile molecules were examined via gas chromatography coupled to mass spectrometry. Seven molecules were present in the samples from mice of at least one group. Their quantity varied among groups: M. m. domesticus showed a quantitatively richer panel of odorants in their urine when compared with M. m. musculus. The hybrids showed a more complex picture that was not directly related to one or the other parental subspecies. These quantitative differences may contribute to the specificity of the odorant bouquet of the 2 subspecies.

Molecular targets in glioblastoma

Glioblastoma is the most lethal brain tumor. The poor prognosis results from lack of defined tumor margins, critical location of the tumor mass and presence of chemo- and radio-resistant tumor stem cells. The current treatment for glioblastoma consists of neurosurgery, followed by radiotherapy and temozolomide chemotherapy. A better understanding of the role of molecular and genetic heterogeneity in glioblastoma pathogenesis allowed the design of novel targeted therapies. New targets include different key-role signaling molecules and specifically altered pathways. The new approaches include interference through small molecules or monoclonal antibodies and RNA-based strategies mediated by siRNA, antisense oligonucleotides and ribozymes. Most of these treatments are still being tested yet they stay as solid promises for a clinically relevant success.

Age and isolation influence steroids release and chemical signaling in male mice.

Social interactions in mice involve olfactory signals, which convey information about the emitter. In turn, the mouse social and physiological status may modify the release of chemical cues. In this study, the influences of age and social isolation on the endocrine response and the release of chemical signals were investigated in male CD1 mice, allocated into four groups: Young Isolated (from weaning till 60days; N=6), Adult Isolated (till 180days; N=6), Young Grouped (6 mice/cage; till 60days; N=18), Adult Grouped (6 mice/cage; till 180days; N=18). Mice were transferred in a clean cage to observe the micturition pattern and then sacrificed. Body and organs weights, serum testosterone, dehydroepiandrosterone, corticosterone and the ratio Major Urinary Protein/creatinine were measured. Urinary volatile molecules potentially involved in pheromonal communication were identified. Androgen secretion was greater in isolated mice (P<0.05), suggesting a greater reactivity of the Hypothalamic-Pituitary-Gonadal axis. Grouped mice presented a higher degree of adrenal activity, and young mice showed a higher serum corticosterone (P<0.05) suggesting a greater stimulation of the Hypothalamic-Pituitary-Adrenal axis. The micturition pattern typical of dominant male, consisting in voiding numerous droplets, was observed in Young Isolated mice only, which showed a higher protein/creatinine ratio (P<0.05). Urinary 2-s-butyl-thiazoline was higher in both Young and Adult Isolated mice (P<0.005). Young Isolated mice showed the most prominent difference in both micturition pattern and potentially active substance emission, while long term isolation resulted in a less extreme phenotype; therefore social isolation had a higher impact on young mice hormone and pheromone release.

Altered behavioral aspects of aged mice lacking the cellular prion protein

The biological function of the prion protein, which is intimately involved in the onset of prion diseases, remains unclear. To understand whether the prion protein could play a role in animal behavior, a battery of tests was applied to young and aged mice that express, or not, the prion protein. In contrast to the similar results obtained in all young animals, we found that aged mice lacking the prion protein reacted to new and stressful environments differently than their wild-type counterparts. This may suggest that, upon aging, the absence of the prion protein results in altered neural processing at the basis of adaptation to new situations.

The effect of angiotensin-converting enzyme inhibition by captopril on respiratory mechanics in healthy rats.

Context: Angiotensin stimulates smooth-muscle contraction. Accordingly, angiotensin-converting enzyme (ACE) inhibition is expected to decrease airway resistance. Objectives: To measure the effects of ACE inhibition on respiratory mechanics in healthy mammals. Materials and methods: We measured respiratory mechanics before and after i.p. ACE inhibitor captopril (100 mg/kg) in normal anaesthetised rats. The end-inflation occlusion method allowed the measurements of respiratory system elastance and ohmic and viscoelastic pressure dissipations. Respiratory system hysteresis and the elastic and resistive work of breathing were calculated. Results: Captopril induced a reduction of the ohmic and the total respiratory system resistances, while respiratory system hysteresis and elastance did not change. Accordingly, a reduction of the resistive and of the total work of breathing was observed. Conclusions: The captopril-induced reduction of airway resistance indicates that angiotensin modulates bronchomotor tone in basal conditions. ACE inhibition may positively affect respiratory system mechanics and work of breathing.

Bovine herpesvirus 4 based vector as a potential oncolytic-virus for treatment of glioma

The application of gene therapy for malignant gliomas is still under study and the use of specific vectors represents an important contribution. Here, we investigated bovine herpesvirus 4 (BoHV-4), which is non-pathogenic if injected into the rodent brain. We show that the vector can infect mouse, rat and human glioma cell lines and primary cultures obtained from human glioblastoma in vitro. BoHV-4 was injected into a tumour grown in rat brain. Although virus expression was scattered across the tumour mass, it was mainly located in the peripheral area of larger gliomas. These data support BoHV-4 as a candidate vector for glioma treatment.

Mice Recognize Recent Urine Scent Marks by the Molecular Composition

Male mice mark the territory with urine scent marks that are frequently renewed to maintain the territory ownership. We measured the response of male mice to small spots of urine deposed either 0, 5, 11, 22, 45, 90 min, or 24 h before testing and show that mice loose interest in sniffing scent marks as they become older and older. We asked what scent features tell a mouse how recent a scent mark is, and therefore, we studied the molecule-to-behavior relationship by correlating 6 behavioral variables--the number of sniffing acts, the latency to the first sniff, the number of urine marks, the latency to the first mark, the area of the marks, and the number of fecal pellets-to 2,4-dehydro-exo-brevicomin, linalool, 2-sec-butyl-4,5-dihydrothiazole, 2,4-dimethylphenol, 4-ethylphenol, and 6,10-dimethyl-5,9-undecadien-2-one released from urine spots over the time, identified, and quantified by gas chromatography and mass spectrometry. Canonical correlation between the molecular and the behavioral principal components was strong (R(1) = 0.96, P = 0.026). The principal component based on 2,4-dehydro-exo-brevicomin, linalool, and 2-sec-butyl-4,5-dihydrothiazole correlated negatively with countermarking and positively with the sniffing behavior, suggesting a semantic feature of fresh male mouse urine.