Active vaccination with vaccinia virus A33 protects mice against lethal vaccinia and ectromelia viruses but not against cowpoxvirus; elucidation of the specific adaptive immune response.

Vaccinia virus protein A33 (A33VACV) plays an important role in protection against orthopoxviruses, and hence is included in experimental multi-subunit smallpox vaccines. In this study we show that single-dose vaccination with recombinant Sindbis virus expressing A33VACV, is sufficient to protect mice against lethal challenge with vaccinia virus WR (VACV-WR) and ectromelia virus (ECTV) but not against cowpox virus (CPXV), a closely related orthopoxvirus. Moreover, a subunit vaccine based on the cowpox virus A33 ortholog (A33CPXV) failed to protect against cowpox and only partially protected mice against VACV-WR challenge.

Chimeric vaccine composed of viral peptide and mammalian heat-shock protein 60 peptide protects against West Nile virus challenge.

The protective efficacy and immunogenicity of a chimeric peptide against West Nile virus (WNV) was evaluated. This virus is the aetiological agent of West Nile fever, which has recently emerged in the western hemisphere. The rapid spread of WNV throughout North America, as well as the constantly changing epidemiology and transmission of the virus by blood transfusion and transplantation, have raised major public-health concerns.

Tail scarification with Vaccinia virus Lister as a model for evaluation of smallpox vaccine potency in mice.

Since smallpox eradication by the WHO during the 1980s, potency of new vaccines is compared to vaccines that were used during the eradication campaign. In this work we characterize the tail scarification technique in mice as a model for scarification in humans. Similar to humans, mice develop "clinical take" which is dependent on the vaccination dose.

T7 phage display of Ep15 peptide for the detection of WNV IgG.

West Nile virus (WNV) is one of the major emerging infectious diseases in North America. WNV belongs to the genus Flavivirus, and its rapid and extensive global spread has highlighted the necessity for accurate and specific assays for diagnosis of WNV infection. This study presents the first phage displayed peptide based ELISA for detection of WNV immunoglobulin G (IgG).

Newcastle disease vaccines.

Newcastle disease (ND) is a worldwide problem with severe economic implications, affecting chickens, turkeys and other birds. Newcastle disease virus (NDV), a member of the Paramyxoviridae group can cause disease of diverse severity in accordance with environmental factors. NDV strains are classified according to their virulence into three categories.

Prophylactic and therapeutic efficacy of human intravenous immunoglobulin in treating West Nile virus infection in mice.

West Nile virus (WNV) is a mosquito-borne disease found most commonly in Africa, West Asia, and the Middle East, where up to 40% of the human population possesses antibodies. It is an emerging disease in the United States. Humans infected with WNV develop a febrile illness that can progress to meningitis or encephalitis.

The effect of chronic emotional stress on the humoral immune response to Porphyromonas gingivalis in mice.

Previous studies have shown that psychological stress plays a significant role in the outcome of infectious diseases, but data related to the effect of stress on periodontal infection is limited. The present study was designed to test the impact of emotional stress on the humoral immune response to the periodontal pathogen Porphyromonas gingivalis in a mouse model of local inflammation. Chambers constructed from titanium wire were implanted in the subcutaneous dorsolumbar region of mice.

Inhalation anesthetic-induced neuroinvasion by an attenuated strain of West Nile virus in mice.

There are contradictory reports regarding the effects of inhalation anesthetics on the immune system. Measurable immune responses have been studied in vitro, but little is known about the in vivo effects in the intact organism. We used an attenuated, non-neuroinvasive, nonlethal strain of the encephalitic West Nile virus, termed WN-25, which can become lethal in combination with environmental stressors, to study possible modulatory immune effects of inhalation anesthetics in mice.

CNS penetration by noninvasive viruses following inhalational anesthetics.

The effects of inhalational anesthetics on brain penetration by the neurovirulent noninvasive West Nile virus (WN-25) were studied in mice. WN-25 injected intracerebrally causes encephalitis and kills adult mice, but when injected intraperitoneally (i.p.

Androstenetriol and androstenediol. Protection against lethal radiation and restoration of immunity after radiation injury.

Androstenetriol (AET) and Androstenediol (AED) upregulate host immunity, leading to increased resistance against infections. AET augments IL-2, IL-3, IFN gamma levels, and counteracts hydrocortisone immune suppression. AET and AED at a dose of 0.

Viral neuroinvasion as a marker for BBB integrity following exposure to cholinesterase inhibitors.

Exposure to the nerve agent soman, an irreversible cholinesterase (ChE) inhibitor, results in changes in blood-brain barrier permeability attributed to its seizure-induced activity. However, smaller BBB changes may be independent of convulsions. Such minor injury may escape detection.

A live attenuated West Nile virus strain as a potential veterinary vaccine.

This article reviews the development of two attenuated West Nile virus (WNV) variants, WNI-25 and WNI-25A. These variants have lost the neuroinvasion trait of the parental virus. Attenuation was achieved through serial passages in mosquito cells and neutralization escape from WNV-specific monoclonal antibody.

Experimental stress suppresses recruitment of macrophages but enhanced their P. gingivalis LPS-stimulated secretion of nitric oxide.

Background: Epidemiological studies have suggested that stress can alter the onset and progression of periodontal disease. However, the mechanisms involved are not clear. The present study was designed to examine whether the functional response of mouse macrophages stimulated by Porphyromonas gingivalis lipopolysaccharide (LPS) is affected by experimental stress, and to investigate the role of corticosterone (CS) in the stress-related effects.

The role of host immunocompetence in neuroinvasion of Sindbis virus.

Viral infections of the central nervous system (CNS) following peripheral inoculation of Sindbis viruses were studied. The use of viral strains, which vary in their neuroinvasive and neurovirulent properties, and various strains of mice, which differ in immunocompetence, revealed several pathways of viral neuroinvasion in adult mice. A genetic-trait dependent mechanism was exhibited by the neuroinvasive viruses, showing a similar pattern in all mice strains tested.

Androstenediol and dehydroepiandrosterone protect mice against lethal bacterial infections and lipopolysaccharide toxicity.

The protective effects of the hormones androstenediol (androstene-3beta, 17beta,-diol; AED) and dehydroepiandrosterone (5-androsten-3beta-ol-17-one; DHEA) on the pathophysiology of two lethal bacterial infections and endotoxin shock were examined. The infections included a gram-positive organism (Enterococcus faecalis) and a gram-negative organism (Pseudomonas aeruginosa). Both hormones protected mice from the lethal bacterial infections and from lipopolysaccharide (LPS) challenge.

The effect of stress on the inflammatory response to Porphyromonas gingivalis in a mouse subcutaneous chamber model.

Background: The impact of emotional stress on the outcome of infectious diseases was studied in animal models and humans, but data related to the effect of stress on periodontal infection are limited. Using the subcutaneous chamber model in mice, the present study was carried out to investigate the effect of stress on the host response to Porphyromonas gingivalis.

Methods: Mice with subcutaneous chambers (2 per animal) were divided into 4 treatment groups: cold-stress; isolation-stress; corticosterone (CS)-injected; and controls.

Cold stress-induced neuroinvasiveness of attenuated arboviruses is not solely mediated by corticosterone.

In previous studies we have shown that various stress paradigms can induce the penetration of noninvasive, attenuated viruses into the central nervous system (CNS). Since glucocorticoids levels are elevated during stress, we compared the effect of cold stress and corticosterone (CS) injection on neuroinvasiveness of a non-invasive encephalitic virus, WN-25 (West Nile). Exposure of inoculated mice to cold stress or CS resulted in high viremia and a marked increase in mortality when compared to control untreated mice.

West Nile virus neuroinvasion and encephalitis induced by macrophage depletion in mice.

The encephalitic West Nile virus and its nonneuroinvasive variant, WN-25, were used to study the effect of macrophage depletion on viral invasion of the central nervous system. The in vivo elimination of macrophages was achieved by use of liposome-encapsulated drug dichloromethylene diphosphonate. Depletion of macrophages had an exacerbating effect on the course of the viral infection, exhibited by higher and extended viremia and accelerated development of encephalitis and death.

Dehydroepiandrosterone augments M1-muscarinic receptor-stimulated amyloid precursor protein secretion in desensitized PC12M1 cells.

Epidemiologic studies suggest that the age-related decline in dehydroepiandrosterone (DHEA) levels may be associated with Alzheimer's disease (AD). Cholinergic markers also decline with age, and are associated with AD pathology. Activation of m1AChR-transfected PC12 cells (PC12M1) with cholinergic agonists results in secretion of Alzheimer's beta-amyloid precursor protein (APP) which in turn reduces beta-amyloid production.

Protective effects of melatonin in mice infected with encephalitis viruses.

We examined the effect of the pineal neurohormone melatonin (MLT) on protection from viral encephalitis. The antiviral activity of MLT was evaluated in normal mice inoculated with Semliki Forest virus (SFV) and in stressed mice injected with the attenuated non-invasive West Nile virus (WN-25). Administration of MLT (s.

Loss of active neuroinvasiveness in attenuated strains of West Nile virus: pathogenicity in immunocompetent and SCID mice.

The neuropathogenicity of West Nile virus (WNV) and two derived attenuated strains WN25 and WN25A, was studied in young adult ICR mice and in severe combined immunodeficient (SCID) mice. Similarity in serology and RNA fingerprints were found between WNV and WN25. The viral envelope proteins of the attenuates differed from WNV in their slower mobility in SDS-PAGE due probably to the presence of N-linked glycan.

Dehydroepiandrosterone protects mice inoculated with West Nile virus and exposed to cold stress.

The protective effect of pretreatment with dehydroepiandrosterone (DHEA) on stress-enhanced viral encephalitis was studied in mice exposed to cold following inoculation with West Nile virus (WNV). Exposure of WNV-inoculated mice to cold water (1 +/- 0.5 degrees C, 5 minutes/day for 8 days) resulted in a mortality rate of 83% as compared to 50% in nonstressed mice (p < 0.