Systemic AL kappa chain amyloidosis in a captive Bornean orangutan (Pongo pygmaeus).

Systemic amyloid light-chain (AL) amyloidosis is an infrequent disease in which amyloid fibrils derived from the immunoglobulin light chain are deposited in systemic organs, resulting in functional impairment. This disease has been notably uncommon in animals, and nonhuman primates have not been reported to develop it. In this study, we identified the systemic AL kappa chain amyloidosis in a captive Bornean orangutan (Pongo pygmaeus) and analyzed its pathogenesis. Amyloid deposits were found severely in the submucosa of the large intestine, lung, mandibular lymph nodes, and mediastinal lymph nodes, with milder lesions in the liver and kidney. Mass spectrometry-based proteomic analysis revealed an abundant constant domain of the immunoglobulin kappa chain in the amyloid deposits. Immunohistochemistry further confirmed that the amyloid deposits were positive for immunoglobulin kappa chains. In this animal, AL amyloidosis resulted in severe involvement of the gastrointestinal submucosa and lymph nodes, which is consistent with the characteristics of AL amyloidosis in humans, suggesting that AL amyloid may have a similar deposition mechanism across species. This report enhances the pathological understanding of systemic AL amyloidosis in animals by providing a detailed characterization of this disease based on proteomic analysis.

Unique genomic sequences in a novel Mycobacterium avium subsp. hominissuis lineage enable fine scale transmission route tracing during pig movement.

Mycobacterium avium subsp. hominissuis (MAH) is one of the most prevalent mycobacteria causing non-tuberculous mycobacterial disease in humans and animals. Of note, MAH is a major cause of mycobacterial granulomatous mesenteric lymphadenitis outbreaks in pig populations. To determine the precise source of infection of MAH in a pig farm and to clarify the epidemiological relationship among pig, human and environmental MAH lineages, we collected 50 MAH isolates from pigs reared in Japan and determined draft genome sequences of 30 isolates. A variable number of tandem repeat analysis revealed that most pig MAH isolates in Japan were closely related to North American, European and Russian human isolates but not to those from East Asian human and their residential environments. Historical recombination analysis revealed that most pig isolates could be classified into SC2/4 and SC3, which contain MAH isolated from pig, European human and environmental isolates. Half of the isolates in SC2/4 had many recombination events with MAH lineages isolated from humans in East Asia. To our surprise, four isolates belonged to a new lineage (SC5) in the global MAH population. Members of SC5 had few footprints of inter-lineage recombination in the genome, and carried 80 unique genes, most of which were located on lineage specific-genomic islands. Using unique genetic features, we were able to trace the putative transmission route via their host pigs. Together, we clarify the possibility of species-specificity of MAH in addition to local adaptation. Our results highlight two transmission routes of MAH, one exposure on pig farms from the environment and the other via pig movement. Moreover, our study also warns that the evolution of MAH in pigs is influenced by MAH from patients and their residential environments, even if the MAH are genetically distinct.

Onchocerca flexuosa. sp. (Nematoda: Filarioidea) in Japanese Wild Sika Deer (Cervus nippon): Pathological and molecular identification.

Subcutaneous nodular onchocercosis was detected and investigated in 17 Japanese Sika deer (Cervus nippon), captured in Gifu and Shiga Prefectures/Japan, in the period between 2016 and 2017. The worms were found in all the seventeen deer within characteristics subcutaneous nodules dispersed mainly in the back (especially in the lumbar region and flanks), with few scattered nodules were located at the forelimbs and neck. The all collected nodules were examined stereo-microscopically. The parasites were extracted from the nodules and identified through morphological and histopathological examinations. Molecular identification through sequencing of the following genes; internal transcribed spacer subunit 2 (ITS2)-28S ribosomal RNA (28S rRNA), cytochrome c oxidase subunit 1 (cox1) and mitochondrially encoded NADH dehydrogenase subunit 2 (NAD2) were performed. The histopathological, molecular and phylogenetic analysis demonstrated that, the filarial nematode isolated from Gifu and Shiga Prefectures in Japan is O. flexuosa. This is the first report about presence of O. flexuosa in Japanese Sika deer (Cervus nippon) in Gifu and Shiga Prefectures. Supplementary Information: The online version supplementary material available at 10.1007/s12639-021-01453-3.

Systemic amyloidosis derived from EFEMP1 in a captive Tsushima leopard cat.

In animals, most cases of systemic amyloidosis are of amyloid A type, and the other types of systemic amyloidoses are rare. This study analyzed systemic amyloidosis in a 15-year-old female Tsushima leopard cat. Amyloid deposits strongly positive for Congo red staining were observed in the arterial walls as well as the interstitium in multiple organs. Mass spectrometry-based proteomic analysis with laser microdissection of amyloid deposits identified epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) as a prime amyloidogenic protein candidate. Immunohistochemistry showed that the amyloid deposits were positive for the N-terminal region of EFEMP1. From these results, the present case was diagnosed as EFEMP1-derived amyloidosis. It is the first such case in an animal. EFEMP1-derived amyloidosis in humans has recently been reported as a systemic amyloidosis, and it is known as an age-related venous amyloidosis. The present case showed different characteristics from human EFEMP1-derived amyloidosis, including the amyloid deposition sites and the amyloidogenic region of the EFEMP1 protein, suggesting a different pathogenesis between Tsushima leopard cat and human EFEMP1-derived amyloidosis.

Efficacy of Vaccination against Infection with Velogenic Newcastle Disease Virus Genotypes VI and VII 1.1 Strains in Japanese Quails.

Newcastle disease virus (NDV), a major pathogen of poultry worldwide, causes significant economic losses in the poultry industry. To characterize the ability of recently isolated virulent strains of NDV genotypes VI and VII to cause disease in quails, and to evaluate the efficacy of two NDV vaccines against such strains, Japanese quails were experimentally inoculated with either NDV genotype VI (Pigeon F-VI strain) or VII 1.1 (GHB-328 strain) with or without vaccination with inactivated NDV vaccine of genotype II (La Sota strain) or VII (KBNP strain). Mild to severe neurological signs developed in quails inoculated with the Pigeon F-VI strain from 3 to 14 days post infection (PI) and from 4 to 10 days PI in birds infected with the GHB-328 strain. The mortality rates were 46% and 33% for birds inoculated with NDV VI and NDV VII 1.1, respectively. The severity of histopathological changes depended on the viral isolates used. Vaccination with the La Sota or KBNP vaccine strain successfully protected quails against NDV-induced mortality and decreased the severity of clinical signs, pathological changes and cloacal viral shedding. This study showed that these virulent NDV isolates had mild to moderate pathogenicity in quails and that both vaccines protected against challenge with both virus strains. NDV vaccine genotype VII improved the level of protection against challenge with the VII 1.1 genotype compared with the classic vaccine, but failed to protect quails against challenge with the VI genotype.

Proteopathic lesions in the brain of a super-aged chimpanzee (Pan troglodytes).

The brain of a chimpanzee estimated to be 68 years old, the oldest reported so far, has been examined. Pathological analyses revealed the formation of mild tau-positive neuritic clusters and cytoplasmic α-synuclein aggregates, in addition to severe cerebral amyloid angiopathy and diffuse plaques, but no tangle lesions were observed.

Genomic features of Mycobacterium avium subsp. hominissuis isolated from pigs in Japan.

Mycobacterium avium subsp. hominissuis (MAH) is one of the most important agents causing non-tuberculosis mycobacterial infection in humans and pigs. There have been advances in genome analysis of MAH from human isolates, but studies of isolates from pigs are limited despite its potential source of infection to human. Here, we obtained 30 draft genome sequences of MAH from pigs reared in Japan. The 30 draft genomes were 4,848,678-5,620,788 bp in length, comprising 4652-5388 coding genes and 46-75 (median: 47) tRNAs. All isolates had restriction modification-associated genes and 185-222 predicted virulence genes. Two isolates had tRNA arrays and one isolate had a clustered regularly interspaced short palindromic repeat (CRISPR) region. Our results will be useful for evaluation of the ecology of MAH by providing a foundation for genome-based epidemiological studies.

Descriptive Pathological Study of Avian Schistosomes Infection in Whooper Swans (Cygnus cygnus) in Japan.

Cercarial dermatitis, or Swimmer's itch, is one of the emerging diseases caused by the cercariae of water-borne schistosomes, mainly Trichobilharzia spp. Since the zoonotic potential of Allobilharzia visceralis is still unknown, studies on this schistosome would be helpful to add knowledge on its possible role in causing human infections. In the present study, 54 whooper swans (Cygnus cygnus) from rescue/rehabilitation centers in Honshu, Japan, were necropsied to identify the cause of death. Grossly, 33 (61.11%) swans were severely emaciated and 23 (42.59%) had multiple reddened areas throughout the length of the intestine with no worms detected in the internal organs. Microscopically, adult schistosomes were found in the lumen of the mesenteric, serosal, portal, and testicular veins, in the capillaries of the intestinal lamina propria, and in the sinusoids of the adrenal gland, spleen, and liver of 23 (42.59%) swans. Hypertrophy of veins containing adult worms was identified in 15 (27.77%) swans, and vascular lumen obliteration was observed in 8 (14.81%) swans. Mild to severe villous atrophy and superficial enteritis were observed in 8 birds (14.81%), whereas bile pigments and hemosiderin were detected in the livers of 14 (25.92%) and 18 (33.33%) swans, respectively. In three swans (5.55%), schistosome parasites were found in the subcapsular veins of the testes. The schistosomes in the present study were assumed to be A. visceralis based on the microscopical and histological evidence of adult schistosomes found in the lumen of veins as well as the infection pathology, which was very similar to the schistosome-induced pathology previously reported in swans infected by A. visceralis in Europe and Australia. The swans examined herein most likely died from obstructive phlebitis associated with A. visceralis, but further molecular confirmation is required for identification of this species. However, the present study does not provide new data on the zoonotic potential, but only on the pathogenic potential of this schistosome in swans. Furthermore, our study provides a novel contribution to the description of the pathological effects of avian schistosomes infection in whooper swans in Japan.

Biochemical and Histopathological Alterations in Different Tissues of Rats Due to Repeated Oral Dose Toxicity of Cymoxanil.

Evaluating potential adverse health impacts caused by pesticides is an important parameter in human toxicity. This study focuses on the importance of subchronic toxicity assessment of cymoxanil fungicide in rats with special reference to target biochemical enzymes and histopathological changes in different tissues. In this regard, a 21-day toxicity study with repeated cymoxanil oral doses was conducted. It has been shown that low doses (0.5 mg/kg) were less effective than medium (1 mg/kg) and high (2 mg/kg) doses. Moreover, high dose dose-treated rats showed piecemeal necrosis in the liver, interstitial nephritis and tubular degeneration in the kidneys, interstitial pneumonia and type II pneumocyte hyperplasia in the lungs, gliosis, spongiosis, and malacia in the brain, and testicular edema and degeneration in the testes. Cymoxanil significantly increased AST, ALT, and ALP in serum and liver, indicating tissue necrosis and possible leakage of these enzymes into the bloodstream. Creatinine levels increased, indicating renal damage. Similarly, significant inhibition was recorded in brain acetylcholinesterase, indicating that both synaptic transmission and nerve conduction were affected. Importantly, these histopathological and biochemical alterations were dose-dependent. Taken together, our study reported interesting biochemical and histopathological alterations in different rat tissues following repeated toxicity with oral doses of cymoxanil. Our study suggests future studies on different pesticides at different concentrations that would help urge governments to create more restrictive regulations concerning these compounds' levels.

Comparative Study of the Pathogenesis of Rhinopneumonitis Induced by Intranasal Inoculation of Hamsters with Equine Herpesvirus-9, Equine Herpesvirus-1 strain Ab4p and Zebra-borne Equine Herpesvirus-1.

Equine herpesvirus-9 (EHV-9), equine herpesvirus-1 (EHV-1) and zebra-borne EHV-1 are members of the family Herpesviridae and cause encephalitis and rhinopneumonitis in a range of animal species. The aim of this study was to characterize and compare the rhinopneumonitis induced by experimental intranasal inoculation of groups of hamsters with EHV-9, EHV-1 strain Ab4p or zebra-borne EHV-1 viruses. Animals inoculated with EHV-9 had earlier and more severe neurological and respiratory signs than those inoculated with EHV-1 strain Ab4p or zebra-borne EHV-1. At 4-5 days post inoculation (dpi), hamsters inoculated with EHV-9 had significantly increased expression of open reading fame (ORF) 30, the viral gene encoding the DNA polymerase, in lung tissue. ORF 30 expression at these time points was higher in the hamsters infected with EHV-9 than in those inoculated with the other two viruses. Severe, mild or very mild rhinitis was seen in animals inoculated with EHV-1 strain Ab4p, EHV-9 and zebra-borne EHV-1, respectively. Viral antigen was detected in olfactory receptor neurons, inflammatory cells and desquamated epithelial cells in animals in all groups until 5 dpi. Tracheitis was also seen in all three virus-infected groups with viral antigen detected in tracheal epithelium. Inoculated hamsters developed interstitial pneumonia of increasing severity over the course of the experiment. Bronchopneumonia and vasculitis were also seen in all three infected groups. These results confirm that, in addition to their neurotropism, EHV-9 and zebra-borne EHV-1 are pneumotropic viruses. EHV-1 strain Ab4p caused more severe upper respiratory tract disease, but no significant differences were detected in the severity of pneumonia induced by each virus.

Correlation of Immunomodulatory Cytokine Expression with Histopathological Changes and Viral Antigen in a Hamster Model of Equine Herpesvirus-9 Encephalitis.

A group of hamsters (n = 25) was intranasally infected with equine herpesvirus-9 (EHV-9) and mRNA transcription levels of several proinflammatory (IFN-γ, TNF-α and IL-6) and anti-inflammatory (IL-4, IL-10 and TGF-ß) cytokines were investigated in brain tissue using RT-qPCR. These levels were correlated with the severity of sequential histopathological changes and intensity of immunohistochemical labelling of virus antigen in brain. Early and progressive upregulation of all the proinflammatory and anti-inflammatory cytokines investigated (P < 0.05) was correlated with increasing severity of encephalitis and viral antigen expression from 2 days post infection (dpi) with a peak at 4-5 dpi (P <0.05).

S-Methylcysteine (SMC) Ameliorates Intestinal, Hepatic, and Splenic Damage Induced by Cryptosporidium parvum Infection Via Targeting Inflammatory Modulators and Oxidative Stress in Swiss Albino Mice.

Cryptosporidiosis has been proposed to be one of the major causes of diarrhoeal disease in humans worldwide that possesses zoonotic concern. Thereby, this study investigated the potential effects of s-Methylcysteine (SMC) on the parasite in vivo followed by the measurement of cytokines, oxidative stress parameters, and an investigation of the major histopathological changes. Sixty male Swiss albino mice weighing 20-25 g were allocated equally into five groups and orally administered saline only (control), SMC only (SMC50) (50 mg/kg b.w.), and 104Cryptosporidium parvum oocysts per mouse via an esophageal tube (C + ve untreated). The fourth and fifth groups (C + SMC25, C + SMC50) administrated 104C. parvum oocysts combined with SMC25 (low dose) and 50 (high dose) mg/kg b.w., respectively. At days 7 and 14 post-infection (PI), the feces was collected from each group in order to count C. parvum oocysts. After two weeks of treatment, the animals were euthanized and the serum was collected for biochemical analysis. Next, the intestinal, spleen, and liver sections were dissected for histopathological examination. The results revealed lower oocyst numbers in the C + SMC25 and C + SMC50 groups compared to the infected untreated group. Moreover, higher doses of SMC treatment significantly reduced the enteritis induced by C. parvum in a dose-dependent manner. The hepatic lesions were also mitigated as demonstrated in C + SMC25 and C + SMC50 groups unlike the infected group via lowering the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes and increasing albumin and globulin serum levels. SMC administration also reduced cytokines production (SAP, TNF-α, IL-6, and IFN-γ) mediated by Cryptosporidium infection in contrast to the infected untreated group. There were marked lymphoid depletion and amyloidosis observed in the infected untreated group, while the treated groups showed obvious increase in the lymphoid elements. Moreover, the scoring of intestinal parasites, hepatic, and splenic lesions in the SMC-treated groups exhibited significantly lower pathological lesions in different organs in a dose-dependent manner, compared to the infected untreated group. Our results also revealed a significant change in the malondialdehyde content with an elevation of glutathione and superoxide dismutase in the intestines collected from C + SMC25 and C + SMC50 mice relative to the untreated group. Taken together, our results indicated that SMC could be a promising effective compound for treating and declining C. parvum infestation via restoring structural alterations in different tissues, enhancing antioxidant enzymes, and suppressing the cytokines liberation.

Suppression of inflammatory genes expression in the injured host intestinal wall during Mesocestoides vogae tetrathyridium larvae migration.

Mesocestoides vogae is a cestode parasite of the family Mesocestoididae (order Cyclophyllidea). Its larvae, tetrathyridium, are approximately 1 mm long and 300 µm wide and infect a wide range of host species including humans. Tetrathyridium migrate through the intestinal wall to invade the peritoneal cavity. Despite intestinal penetration by such a large-sized parasite, symptomatic intestinal disorders are not common during the migration period. In this study, the dynamics of tetrathyridia migration and their pathogenicity towards intestinal tissues were examined in mice infected orally with these parasites. Most tetrathyridia were found to migrate through the intestinal wall, moving into the peritoneal cavity or liver 24 to 48 hours after the oral infections. Next, the pathogenicity of tetrathyridium in the intestinal wall was histopathologically evaluated, and tissue injury from tetrathyridium migration was confirmed. Inflammatory foci were observed as tetrathyridium migration tracks from 48 hours after oral infection; however, the number of inflammatory foci had decreased by half more than 48 hours later. Therefore, we examined the gene expression levels of the macrophage driving cytokine, IL-1ß, and the eosinophil recruiting chemokine, CCL11, by quantitative reverse-transcriptase PCR. The expression levels of these genes in the infected group were significantly lower than those of the non-infected group at 48 hours post-infection. Although the immunomodulating ability of the excretory-secretory products released from tetrathyridium has been previously shown by in vitro assays, the significance of this ability in their lifecycle has remained unclear. In this study, we discovered that tetrathyridium causes temporal inflammation in the intestinal wall during penetration and large-scale migration in this organ, but tetrathyridium simultaneously suppresses the host's inflammatory gene expression, might to be a strategy that reduces inflammatory responses and increases survival of the parasite.

Time Course-Dependent Study on Equine Herpes Virus 9-Induced Abortion in Syrian Hamsters.

This study aimed to follow the time-course pathogenesis of EHV-9 abortion in early and late trimesters. Twenty-seven pregnant hamster dams were divided into three groups: (G1) control, (G2) EHV-9-inoculated on the 5th day (early trimester), and (G3) EHV-9-inoculated on the 10th day of gestation (late trimester). Dams were sacrificed at different time points during gestation and examined for viremia and viral DNA in different fetal and maternal tissues and pathological changes in fetal tissue, placenta, and cytokines. Animals in G3 showed a marked increase in the number of dead fetuses than those in G2. Histopathological findings of G2 showed early band coagulative necrosis of maternal spaces and stromal decidual cells. Necrotic changes were observed within the decidua basalis, spongiotrophoblast layer, and labyrinth. First, the virus was localized within mononuclear leukocytes in the decidua capsularis and basalis, and within the necrotic chorionic villi and cervical epithelium. G3 demonstrated degenerative changes within the chorionic villi and trophospongium. The virus antigen was observed within the chorionic villi, trophoblasts, mononuclear cells, and fetal tissues. In conclusion, EHV-9 induced abortion mostly occurs through necrosis of the chorionic villi and cannot cross through the capsular placenta in the early trimester but can through the developed decidual placentation.

AA Amyloid Deposition in the Central and Peripheral Nervous Systems in Flamingos.

AA amyloidosis is characterized by amyloid deposition in systemic organs, but amyloid deposition in the central nervous system (CNS) or peripheral nervous system (PNS) is rare. In this study, AA amyloidosis was observed in 31 of 48 flamingos that died at a Japanese zoo. Almost all cases developed AA amyloidosis secondary to inflammatory diseases such as enteritis. Affected flamingos had AA amyloid deposition around blood vessels in periventricular white matter of the brain and in peripheral nerves. In addition, cerebral Aß amyloidosis was observed in one of the 31 cases with AA amyloidosis. In conclusion, flamingos in the zoo commonly developed systemic amyloidosis with frequent amyloid deposition in the CNS and PNS, which seems to be a unique distribution in this avian species. Comparative pathological analyses in flamingos may help elucidate the pathogenesis of amyloid neuropathy.

Melatonin and Mesenchymal Stem Cells as a Key for Functional Integrity for Liver Cancer Treatment.

Hepatocellular carcinoma (HCC) is the most common hepatobiliary malignancy with limited therapeutic options. On the other hand, melatonin is an indoleamine that modulates a variety of potential therapeutic effects. In addition to its important role in the regulation of sleep-wake rhythms, several previous studies linked the biologic effects of melatonin to various substantial endocrine, neural, immune and antioxidant functions, among others. Furthermore, the effects of melatonin could be influenced through receptor dependent and receptor independent manner. Among the other numerous physiological and therapeutic effects of melatonin, controlling the survival and differentiation of mesenchymal stem cells (MSCs) has been recently discussed. Given its controversial interaction, several previous reports revealed the therapeutic potential of MSCs in controlling the hepatocellular carcinoma (HCC). Taken together, the intention of the present review is to highlight the effects of melatonin and mesenchymal stem cells as a key for functional integrity for liver cancer treatment. We hope to provide solid piece of information that may be helpful in designing novel drug targets to control HCC.

Avipoxvirus infection in two captive Japanese cormorants (Phalacrocorax capillatus).

Cormorant fishing is a traditional Japanese fishing method using captive Japanese cormorants (Phalacrocorax capillatus). Between June and July 2017, an avian pox outbreak was reported in captive cormorant populations throughout several distant cities in Japan. We examined the lesions obtained from two such affected cormorants, which were raised in distant cities. The affected cormorants were grossly characterized by the development of cutaneous nodules around the base of the beak. Histopathologically, these nodules consisted of marked epidermal hyperplasia with ballooning degeneration of spinous cells and eosinophilic intracytoplasmic inclusions (Bollinger bodies). The lesions displayed 4b core protein (P4b) of Avipoxvirus (APV) and DNA polymerase genes, which were detected by PCR. Moreover, the nucleotide sequences detected from both cormorants were found to be identical. No identical sequence was found in any international database. These findings suggest that both examined cormorants were infected with an identical APV, which has never been previously reported. According to the phylogenetic analysis, the detected sequences were observed to cluster in subclade A3, which consists mainly of the sequences detected from several marine birds, including other cormorant species. This observation suggests that the viruses might be maintained in Japanese cormorants in nature.

New Insights Into Potential Benefits of Bioactive Compounds of Bee Products on COVID-19: A Review and Assessment of Recent Research.

The recent emergence of COVID-19 represents one of the biggest challenges facing the world today. Despite the recent attempts to understand the epidemiological pattern and pathogenesis of the disease, detailed data about the physiology and pathology of the disease is still out of reach. Moreover, the lack of a widespread vaccine prompts an urgent call for developing a proper intervention strategy against the virus. Importantly, identification of novel molecules that target replication of the virus represents one of the promising strategies for the control this pandemic crisis. Among others, honey bee products contain numerous bioactive compounds such as propolis and several phenolic compounds that possess a wide range of therapeutic properties for combating various pathological disorders and infectious agents. The intention of the present review is to highlight the stages of SARS-CoV-2 lifecycle, the molecular mechanisms explaining the health benefits of honey bee products on COVID-19 physiology and pathology and the possible limitations. Further future research is suggested to explore more about bee natural bioactive compounds as potential candidates against SARS-CoV-2.

Protection conferred by a vaccine derived from an inactivated Egyptian variant of infectious bronchitis virus: a challenge experiment.

The current study investigated the protective efficacy of a formalin-inactivated infectious bronchitis virus (IBV) vaccine derived from the field strain KP729422, which exhibits low S1 spike protein sequence homology (77.1-79.8%) with the currently used vaccine strains in Egypt. Two-week-old, specific-pathogen-free chickens were subcutaneously inoculated with a single dose of the vaccine containing 106.7 50% embryo infective dose (EID50) of the inactivated virus. At 6 weeks of age, the chickens were challenged with 104 EID50 of the same virus strain via the oculonasal route. In comparison with the unvaccinated challenged group, the vaccinated chickens had significantly higher IBV-neutralizing antibody titers and exhibited efficient protection against challenge on the basis of tracheal ciliary activity. However, the challenge virus was recovered from the kidneys and tracheas of these chickens at rates of 40% and 60%, respectively. These findings suggest that a single application of the vaccine may provide sufficient clinical and respiratory protection, but may not ensure complete protection against infection by the challenge virus.

Tumour necrosis factor-related apoptosis-inducing ligand induces apoptosis in canine hemangiosarcoma cells in vitro.

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is an apoptosis-inducing cytokine that shows potential therapeutic value for human neoplasms, and is effective in some canine tumours; however, its potential for killing canine hemangiosarcoma (HSA) cells is unknown. Thus, we evaluated the proapoptotic effect of TRAIL in nine canine HSA cell lines. Cells (JuA1, JuB2, JuB2-1, JuB4, Re11, Re12, Re21, Ud2 and Ud6) were cultured with three recombinant human TRAILs (rhTRAILs): TRAIL-TEC derived from Escherichia coli, TRAIL-TL derived from mammalian cells and isoleucine zipper recombinant human TRAIL (izTRAIL) containing an isoleucine-zippered structure that facilitates trimerization. TRAIL-TEC did not decrease the cell viability in any of the cell lines tested, whereas the other two rhTRAILs effectively decreased the viability of all cell lines as assessed by the WST-1 assay. In canine HSA cells, izTRAIL induced apoptosis more effectively than TRAIL-TL. In JuB4, Re12, and Ud6 cells, izTRAIL increased the activation of caspase-3 and caspase-8 and caused poly (ADP-ribose) polymerase degradation. Moreover, izTRAIL treatment increased the proportion of Annexin V+/ Propidium iodide (PI)- apoptotic cells and nuclear fragmentation in izTRAIL-sensitive cells. These results show that rhTRAIL can induce apoptosis in canine HSA cells, but the sensitivity of TRAIL was different depending on the cell lines. Therefore, TRAIL could be an effective therapeutic agent against canine HSA, but the specific mechanism of resistance should be determined to clarify under what conditions this treatment would be most effective.