Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Distemper”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

Immunological relationships between phocid and canine distemper virus studied with monoclonal antibodies.

The immunological relationships between distemper viruses, isolated from a seal and mink in Denmark and from a dog in Greenland, were investigated with 39 previously developed monoclonal antibodies (MAbs) directed against four major structural proteins of canine distemper virus (CDV). They were also investigated with 16 newly developed MAbs directed against the fusion (F) and large glycoprotein (named H in analogy with measles virus) of phocid distemper virus (PDV) isolated from a harbour seal (Phoca vitulina). These MAbs were reacted with the three different isolated viruses and with the LEC strain of measles virus, in ELISA and immunofluorescence tests. In addition, immunoprecipitation tests were carried out with some of the cross-reacting antibodies. All 55 MAbs reacted identically with distemper virus isolated from seals or mink. When the MAbs produced against CDV were tested, 37 of 39 antibodies reacted with a virus isolated from a sled dog diseased in an outbreak of distemper in Greenland prior to the epizootic among seals in the North Sea. Of the 39 antibodies, 25 reacted with PDV and distemper virus isolated from mink. Of these antibodies, only three of the nine antibodies directed against the H protein of CDV cross-reacted with PDV and distemper virus from mink. Eleven MAbs, reacting with six epitopes of the H protein of PDV, were produced. All 11 antibodies reacted with distemper virus from mink, two of the antibodies reacted with CDV and none reacted with measles virus. All five antibodies reacting with three different epitopes of the F protein of PDV reacted with distemper virus from mink and CDV. Of these five antibodies three, directed against two epitopes, reacted with measles virus. Of the two envelope proteins, the H protein shows pronounced immunological differences between PDV and CDV. In contrast, immunologically the F protein appears to be well conserved among morbilliviruses. It is concluded that the virus causing the epizootic in seals in the North Sea in 1988 may have infected mink on land, or, alternatively, the virus in the sea may have originated from virus-infected mink.

Animals↗

Response of gray foxes to modified live-virus canine distemper vaccines.

Ten gray foxes seronegative for canine distemper virus were vaccinated with 1 of 3 commercial modified live-virus canine distemper vaccines. Of 5 foxes receiving vaccine A (chicken tissue culture origin), 4 developed significant titers (greater than or equal to 1:100) of neutralizing antibody to canine distemper virus and remained clinically normal after vaccination. Two of 3 foxes vaccinated with vaccine B (canine cell line origin) and both foxes receiving vaccine C (canine cell line origin) died of vaccine-induced distemper. Five unvaccinated control foxes died of distemper after a known occasion for contact transmission of virus from a fox vaccinated with vaccine B. The results suggested that the chicken tissue culture origin modified live-virus canine distemper vaccine is probably safe for normal adult gray foxes, whereas the canine cell origin vaccines are hazardous. The results of this study tended to corroborate anecdotal experiences of veterinarians who have observed that gray foxes frequently die from distemper soon after vaccination with modified live-virus canine distemper vaccines.

Animals↗

A comparison of in situ hybridisation, reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ-RT-PCR for the detection of canine distemper virus RNA in Paget's disease.

Previous evidence implicating Paramyxoviruses in the aetiopathology of Paget's disease of bone has proved controversial. Whilst several groups have demonstrated Paramyxoviruses using techniques such as in situ hybridisation (ISH), reverse transcriptase-polymerase chain reaction (RT-PCR), and in situ-RT-PCR (IS-RT-PCR), others have found no evidence of viruses using only RT-PCR. To investigate this latter finding, we have now compared detection of canine distemper virus by ISH, RT-PCR (three different methods) and IS-RT-PCR, in 10 patients with Paget's disease, and samples of non-diseased bone from four patients. Canine distemper virus was detectable in six of the samples by ISH, but only in five of the samples by RT-PCR, using one of the methods. Neither of the other RT-PCR methods detected canine distemper virus. IS-RT-PCR demonstrated canine distemper virus in all 10 samples. There was no evidence of virus in the control samples. We have shown that the ability to detect canine distemper virus in bone is dependent on the technique used. IS-RT-PCR clearly showed that canine distemper virus was present in 100% of Pagetic samples, whereas canine distemper virus was only found in 60% by ISH and in 50% using one particular RT-PCR method. These results provide conclusive evidence that canine distemper virus is present within Pagetic bone, and provide a possible explanation for the failure of some groups to detect Paramyxovirus sequences. These findings also have wider implications for other studies investigating viral expression.

Distemper Virus, Canine↗

Incidence of and risk factors for adverse events associated with distemper and rabies vaccine administration in ferrets.

OBJECTIVE: To determine incidence of and risk factors for adverse events associated with distemper and rabies vaccine administration in ferrets. DESIGN: Retrospective cohort study. ANIMALS: 3,587 ferrets that received a rabies or distemper vaccine between January 1, 2002, and December 31, 2003. PROCEDURES: Electronic medical records were searched for possible vaccine-associated adverse events. Adverse events were classified by attending veterinarians as nonspecific vaccine reactions, allergic reactions, or anaphylaxis. Patient information that was collected included age, weight, sex, cumulative number of distemper and rabies vaccinations received, clinical signs, and treatment. The association between potential risk factors and occurrence of an adverse event was estimated with logistic regression. RESULTS: 30 adverse events were recorded. The adverse event incidence rates for administration of rabies vaccine alone, distemper vaccine alone, and rabies and distemper vaccines together were 0.51%, 1.00%, and 0.85%, respectively. These rates were not significantly different. All adverse events occurred immediately following vaccine administration and most commonly consisted of vomiting and diarrhea (52%) or vomiting alone (31%). Age, sex, and body weight were not significantly associated with occurrence of adverse events, but adverse event incidence rate increased as the cumulative number of distemper or rabies vaccinations received increased. In multivariate logistic regression analysis, only the cumulative number of distemper vaccinations received was significantly associated with the occurrence of an adverse event. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in ferrets, the risk of vaccine-associated adverse events was primarily associated with an increase in the number of distemper vaccinations.

Animals↗

Antemortem diagnosis of CDV infection by RT-PCR in distemper dogs with neurological deficits without the typical clinical presentation.

In dogs with neurological disturbances without myoclonus and extraneural signs, the clinical diagnosis of distemper is difficult perform. Considering the great infectious potential of the disease, the possibility of carrying out an antemortem diagnosis of distemper is important, particularly in hospitalized patients with neurological disease. The present study was carried out to evaluate RT-PCR for antemortem CDV detection in hospitalized dogs with neurological disturbances without the typical findings of distemper. We investigated five dogs with canine distemper virus (CDV) encephalomyelitis, in which the clinical diagnosis was not performed owing to the absence of characteristic signs of the disease, such as myoclonus and systemic signs. We observed an apparent high sensitivity of RT-PCR in urine samples for detection of CDV: four out of five urine samples were RT-PCR positive. The results of the present study suggest that urine is a good biological sample for antemortem CDV detection by RT-PCR in dogs with distemper encephalomyelitis in which the clinical diagnosis is likely to be difficult owing to the absence of suggestive distemper signs. The use of two different body fluids (urine and CSF) may increase the RT-PCR sensitivity for antemortem diagnosis of distemper in such cases.

Animals↗

Cytokine mRNA expression in whole blood samples from dogs with natural canine distemper virus infection.

Cytokines are soluble polypeptides with many physiological functions and a special role during infection and inflammation. Little is known about cytokine regulation in naturally occurring viral diseases of animals. Especially the role of cytokines in the development and progression of lesions in canine distemper virus (CDV) infection in dogs is largely unknown. Whole blood samples from 14 dogs with CDV infection and three dogs suffering from non-distemper diseases were examined for mRNA of pro-inflammatory cytokines such as interleukin-1beta (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-12 (IL-12), tumor necrosis factor-alpha (TNF), interferon-gamma (IFN), and the anti-inflammatory transforming growth factor-beta1 (TGF) using reverse transcription polymerase chain reaction (RT-PCR). Blood samples from the three dogs that showed no clinical abnormalities during a pre-vaccination physical examination served as control. CDV infection was confirmed by post-mortem immunohistochemistry for CDV nucleoprotein. The degree of immunoreactivity and the number of virus antigen positive organs were expressed as antigen index. IFN transcripts were not identified in any dog and IL-8 transcripts were present in RNA isolates from all 20 dogs. None of the other cytokines was detected in control animals. IL-1 and IL-6 were each found in one non-distemper dog and TGF transcripts were amplified in two dogs with non-distemper disease. The following transcripts were found in variable numbers in distemper dogs: IL-1 (7/14 dogs), IL-6 (3/14 dogs), IL-12 (3/14 dogs), TNF (8/14 dogs), and TGF (10/14 dogs) with multiple cytokines in ten dogs. No cytokine transcripts were detected in three distemper dogs. There was no obvious correlation between cytokine mRNA expression and respiratory and gastrointestinal tract diseases. In the CNS, demyelination was frequently associated with IL-1, IL-12, TNF and TGF mRNA expression in the blood. IL-6 transcripts were found only in animals with early CNS lesions and TGF was the only detectable cytokine in an animal with chronic demyelination. Lack of detectable cytokine transcripts in whole blood samples was associated with a high antigen index and viremia, indicating that an overwhelming virus infection may suppress cytokine production, possibly due to paralysis of the immune system. Simultaneous occurrence of pro- and anti-inflammatory cytokines in whole blood preparation from most of the dogs with distemper, indicated a complex most likely disease stage dependent orchestrated cytokine expression.

Animals↗

A canine distemper outbreak in Alaska: diagnosis and strain characterization using sequence analysis.

Vaccination with modified-live vaccines has been very effective in reducing the incidence of canine distemper, a disease that can be devastating in unvaccinated populations. A diagnostic submission to the Animal Health Diagnostic Laboratory at Michigan State University, East Lansing, Michigan, involved a case in which several hundred dogs in an Alaskan town died in a suspected canine distemper outbreak. Cytoplasmic and intranuclear eosinophilic inclusion bodies, consistent with canine distemper virus (CDV) infection, were found in urinary bladder, spleen, lung, and salivary gland. Direct fluorescent antibody test gave results that could be considered positive for canine distemper. Because of the condition of the tissues received, the histopathology and fluorescent antibody-staining results were suggestive but not conclusive of CDV. In this study, immunohistochemistry, reverse transcriptase-polymerase chain reaction (RT-PCR), and DNA sequencing were used to confirm the presence of canine distemper virus in these tissues and to perform molecular characterization of the virus. Immunohistochemistry showed the presence of the virus in spleen, lung, and salivary gland. Viral RNA was detected by RT-PCR in brain, spleen, liver, lung, and kidney, both with nucleoprotein and phosphoprotein (P)-gene-specific primers. Sequence alignment and phylogenetic analysis of a 540-bp P-gene fragment of the Alaskan strain with corresponding sequences of 2 vaccine and 7 wild-type CDV strains showed that the virus responsible for the outbreak was closely related to a virulent strain of distemper virus from Siberia.

Alaska↗

Canine distemper in black-footed ferrets (Mustela nigripes) from Wyoming.

In September and October 1985, six black-footed ferrets (Mustela nigripes) were captured from the only known population, located near Meeteetse, Wyoming for captive propagation. Two days following capture an adult male showed signs of canine distemper and an adult female displayed similar signs 7 days postcapture; these infections were undoubtedly acquired prior to capture. Subsequently the four remaining captive black-footed ferrets also developed canine distemper and all eventually died. Clinical signs included severe pruritus, hyperkeratosis and progressive loss of body condition. A few animals had intermittent diarrhea and respiratory disease. Intranuclear and intracytoplasmic inclusion bodies were numerous in epithelial tissues and two black-footed ferrets had a mild to moderate meningoencephalitis. Canine distemper virus was isolated from four animals and paramyxovirus nucleocapsids were observed by electron microscopy of feces from all affected black-footed ferrets. Antibodies to canine distemper virus were not detected in sera of sick black-footed ferrets. Antibodies to canine distemper virus were found in sera of badgers (Taxidea taxus) and coyotes (Canis latrans) collected in the Meeteetse area in 1986. Most free-ranging black-footed ferrets in the colony apparently died of canine distemper during the summer and fall of 1985. An attempt was made to capture all surviving animals in the affected area in order to abort the epizootic and provide black-footed ferrets for captive propagation.

Animals↗

Vaccination of black-footed ferret (Mustela nigripes) x Siberian polecat (M. eversmanni) hybrids and domestic ferrets (M. putorius furo)against canine distemper.

An inactivated canine distemper vaccine with adjuvant and a modified-live virus (MLV) vaccine were evaluated using black-footed ferret (Mustegla nigripes) x Siberian polecat (Mustela eversmanni) hybrids us surrogates for endangered black-footed ferrets. For comparative purposes, we also vaccinated domestic ferrets (Mustela putorius furo) with the MLV vaccine. Response to vaccination was measured by clinical observation, hematology, dynamics of serum virus neutralizing antibodies, and challenge with virulent canine distemper virus. No clinical signs attributable to the vaccines were observed. Transient leukopenia occurred in hybrid ferrets that received MLV vaccine and there was marked lymphopenia for approximately 52 days post-vaccination. Lymphopenia was present for approximately 21 days in domestic ferrets vaccinated with MLV vaccine. Neutralizing antibodies against canine distemper virus were detected 14 days post-vaccination in hybrids receiving MLV vaccine and most titers were > 1:1024 for the 791 days of the study. Antibody titers in hybrids vaccinated with the inactivated vaccine were significantly lower. All eight hybrid ferrets that received MLV vaccine survived challenge with virulent canine distemper virus without clinical disease. However, one of seven hybrids vaccinated with the inactivated vaccine developed canine distemper and was euthanized; two other hybrids became clinically ill but survived. The MLV vaccine may be useful in prevention of canine distemper in black-footed ferrets, but until additional studies of efficacy and safety are completed, use of the inactivated vaccine is appropriate.

Animals↗

Restricted canine distemper virus infection of oligodendrocytes.

BACKGROUND: Canine distemper virus, a morbillivirus induces multifocal demyelination in the central nervous system. The acute demyelination correlates with virus replication in brain cells, especially astrocytes. Observations in vivo and in vitro demonstrated degeneration of oligodendrocytes, the myelin producing cells. However, the mechanism of oligodendroglial degeneration in distemper remained unexplained. Infection of the myelin producing cells, the most obvious explanation for the phenomenon of demyelination, could not be supported by extensive searches for viral particles or antigens in these cells neither in vivo nor in vitro. EXPERIMENTAL DESIGN: In the present study, we combined in situ hybridization to visualize viral nucleic acid sequences with immunofluorescence for oligodendroglial antigens. RESULTS: The nonradioactive in situ hybridization technique in combination with contrast enhanced video microscopy allowed us to unequivocally demonstrate the presence of canine distemper virus nucleic acid sequences in cultured oligodendrocytes. Many oligodendrocytes close to infected foci in the brain cell cultures were found to contain viral nucleic acid sequences. Only 1% of the viral nucleic acid sequences containing oligodendrocytes also contained viral antigen. Canine distemper virus replication in these cells is clearly restricted. CONCLUSIONS: Different possibilities why oligodendrocytes do not support a productive virus infection and mechanisms by which such a restricted infection leads to oligodendroglial degeneration and ensuing demyelination are discussed. While our results have advanced our understanding of the pathogenesis of acute demyelination in distemper, they may also offer a possible explanation for the chronic progressive or even relapsing course of the disease. A restricted infection of the oligodendrocytes may be the mechanism by which canine distemper virus persists in the central nervous system. Virus persistence is probably a key event in many chronic viral induced inflammatory demyelinating diseases.

Animals↗

Canine distemper virus transcripts sequenced from pagetic bone.

Paget's disease is a chronic disease of the skeleton which is believed to be caused by a persistent virus of the paramyxovirus family. There is still conflict as to the precise identity of the virus(es) involved in causing this disease. Our previous results using in situ hybridisation have implicated distemper as a possible cause of this disease. In order to confirm these results, we have reverse transcribed RNA from pagetic bone and have specifically amplified for distemper and measles sequences using the polymerase chain reaction (PCR) technique. We have found that 8/13 of the patients examined had distemper and 1/10 cases had measles nucleic acids sequestered within their bone cells. One individual was found to have both viruses sequestered in his bone cells. Dideoxy sequencing of the distemper virus PCR products revealed 2% base pair changes in the nucleic acid sequences relative to the Onderstpoort strain of canine distemper. We can conclude that in Paget's disease, canine distemper and possible other paramyxoviruses reside in bone cells and that the persistent nature of the virus may be due to mutations in the viral genome.

Animals↗

[Antibody formation and resistance in dogs vaccinated intravenously and subcutaneously against distemper and Rubarth's disease].

The results of the vaccination of dogs with Canivac F (distemper vaccine) and Canivac FH (distemper) hepatitis vaccine, are presented. The Canivac F vaccine was injected intravenously (i.v.) to 8 dogs, intramuscularly (i.m.) to 1 dog and subcutaneously (s.c.) to 1 dog. The Canivac FH was administered i.v. to 19 dogs, i.m. to 1 dog and s.c. to 18 dogs. All the dogs displayed no-postvaccination signs. Distemper antibodies were observed in blood sera of all dogs vaccinated with Canivac F after 9-10 and 20-21 days. In sera of dogs vaccinated with Canivac FH, distemper, antibodies were present in 14 of 18 serum samples after 9-10 days and in 26 of 27 samples after 20-21 days. The antibody titre did not depend on the vaccination route. The peak of antibody titre was observed after 37 to 51 days after vaccination. The hepatitis antibodies in dogs vaccinated with Canivac FH were found in 15 of 17 animals after 9-10 days, and in all 27 dogs examined after 20-21 days. On the basis of an intracerebral challenge with virulent distemper virus and by intraperitoneal challenge with virulent dog's hepatitis virus (Rubarth's disease), it was demonstrated that all the vaccinated dogs acquired the full immunity. In addition, it was found that vaccinated dogs kept in the environment contaminated naturally with Rubarth's disease virus were also resistant to the disease. All the non-vaccinated dogs were still susceptible to distemper or hepatitis infections. On the strength of the analysis of the obtained results and our previous studies, it can be assumed that Canivac F and FH vaccines produced in Poland are harmless and show a high immunogenic activity.

Adenoviridae↗

Detection of canine distemper virus in dogs by real-time RT-PCR.

Canine distemper virus is the etiological agent of a severe disease in dogs and many other carnivores. Clinical diagnosis of canine distemper is difficult due to the broad spectrum of signs that may be confounded with other respiratory and enteric diseases of dogs. Accordingly, a laboratory confirmation is required for suspected cases. In this study a real-time RT-PCR assay was developed for detection and quantitation of canine distemper virus. The assay exhibited high specificity as all the negative controls (no-template-controls and samples from healthy sero-negative dogs) and other canine pathogens were not misdetected. Up to 1 x 10(2) copies of RNA were detected by the TaqMan assay, thus revealing a high sensitivity. Quantitative TaqMan was validated on clinical samples, including various tissues and organs collected from dogs naturally infected by canine distemper virus. Urines, tonsil, conjunctival swabs and whole blood were found to contain high virus loads and therefore proved to be suitable targets for detection of canine distemper virus RNA.

Animal Structures↗

Multiple sclerosis and canine distemper in Iceland.

Iceland offers a favourable opportunity to examine the suggested relationship between canine distemper and multiple sclerosis. Distemper is not enzootic in Iceland and distemper immunisation is not practised. However, importations result in occasional epizootics, three of which have occurred since 1909. Careful enumeration of multiple sclerosis indicates that there were 129 cases during the period 1946--65. When these cases are subdivided into six regions, by place of birth, regional period-prevalence rates were highest in two regions partially involved by distemper only once in the past 70 years. Also, there was substantial prevalence in a third region, encompassing Reykjavik, where the dog population has been kept very low for over 50 years. The Icelandic experience indicates that multiple sclerosis can occur at high incidence in the virtual absence of canine distemper or in the presence of a very small dog population.

Animals↗

Phenotypical characterization of T and B cell areas in lymphoid tissues of dogs with spontaneous distemper.

CD3, CD4, CD5, and CD8 antigen expression of T cells and IgG expression of B cells and canine distemper virus (CDV) antigen distribution were immunohistochemically examined in lymphoid tissues (lymph node, spleen, thymus, and tonsil) of control dogs and animals with spontaneous canine distemper. In addition, CNS tissue of all animals was studied for neuropathological changes and CDV antigen distribution. Based on the degree of depletion distemper dogs were classified into two groups. Group I represented animals with moderate to marked lymphoid depletion, while group II dogs displayed mild or no depletion. CDV antigen was mainly found in lymphocytes and macrophages of group I dogs, whereas CDV expression was most prominent in dendritic cells of group II animals. In group I dogs, a marked loss of CD3, CD4, CD5, CD8, and IgG expression was noticed, hereby loss of CD4+ cells was more prominent than depletion of CD8+ cells. In the lymphoid tissues of group II animals, a significant increase in the number of T and B cells was observed compared to group I dogs. The number of CD3+, CD4+, and CD8+ cells in group II dogs was similar to the findings in controls, however, CD5 and IgG expression was mildly reduced in T and B cell areas, respectively. Additionally, in groups I and II dogs, CD3+ and CD5- T cells were detected in T cell areas. Whether this cell population represents a cell type with autoimmune reactive potential remains to be determined. Surprisingly in group II animals, viral antigen was found predominantly in dendritic cells indicating a change in the cell tropism of CDV during chronic infection and a possible mechanism of viral persistence. The two patterns of lymphoid depletions correlated to two different types of canine distemper encephalitis (CDE). Group I dogs displayed acute non-inflammatory CDE, whereas group II dogs suffered from chronic inflammatory demyelinating CDE, indicating a pathogenic relationship between lymphocytic depletion and inflammatory brain lesions in distemper.

Animals↗

Interleukin-1beta, -6, -12 and tumor necrosis factor-alpha expression in brains of dogs with canine distemper virus infection.

Canine distemper virus infection in dogs is commonly associated with demyelinating central nervous system lesions. Investigations on viral protein expression by studying mRNA and protein distribution together with the characterization of CD4 and CD8 inflammatory cells and MHC class II up-regulation revealed a biphasic disease process. To further investigate the cellular interactions in the different plaque types the cerebella of 14 dogs with confirmed distemper infection were investigated for expression of interleukin (IL)-1beta, -6, -12 and tumor necrosis factor-alpha (TNF) by immunohistochemistry using rabbit polyclonal anti-cytokine antibodies. T-cells and astrocytes were identified with rabbit anti CD3- and GFAP-monoclonal and polyclonal antibodies, respectively; and microglia/macrophages were characterized by their ability to bind lectin from Bandeiraea simplicifolia (BS-1). To further name the cytokine expressing cells immunoenzymatic double staining using DAB and New Fuchsin was performed. White matter lesions were classified according to histopathological criteria into acute, subacute and chronic. Canine distemper virus nucleoprotein antigen was demonstrated in nearly all plaques, except in older plaques where virus was not present within the plaque but adjacent to the lesion. IL-1 expression was observed to varying degrees in all types of lesions. Most often IL-1 was present in CD3 and BS-1 positive cells in the brain parenchyma in earlier plaques and comprising perivascular cuffs found in chronic plaques. IL-6 expression was present in all lesions, and followed a similar distribution pattern as IL-1. IL-12 displayed very often a granular extracellular pattern of immunoreactivity, especially in the brain parenchyma, and was found only in individual perivascular cells. TNF staining, predominantly found in astrocytes, was present in lesions of various types; however, staining appeared to be stronger in acute lesions and decreased in chronic plaques. In the latter, TNF seemed to be more prominent in areas adjacent to the plaques. Summarizing, in early non-demyelinating lesions without overt inflammation TNF seemed to be important, whereas in distemper lesions with inflammatory infiltrates IL-1 and to a lesser degree IL-6 were more prominent. These results imply that TNF may be involved in the pathogenesis of early demyelination in nervous distemper.

Animals↗

Increased expression of pro-inflammatory cytokines and lack of up-regulation of anti-inflammatory cytokines in early distemper CNS lesions.

To investigate the pathogenesis of early lesions in canine distemper virus (CDV) leukoencephalomyelitis, the expressions of pro- and anti-inflammatory cytokines such as interleukin (IL)-1beta, IL-2, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and transforming growth factor (TGF)-beta and the housekeeping genes beta-actin and GAPDH were studied using semi-quantitative RT-PCR. Relative cytokine values were related to the degree of CDV infection, MHC class II expression and infiltration of CD4-, CD8- and CD3epsilon-positive lymphocytes. Actin up-regulation, in contrast to GAPDH, was influenced by CDV infection and therefore could not be used as an internal standard to study cytokine expression. In early CDV infection of the cerebellum, either no detectable lesions or mild infiltration of CD8 positive cells or demyelination and up-regulation of MHC class II antigen were observed. IL-6, -8, -12 and TNF-alpha transcripts were found in 94%, 94%, 78% and 56% of distemper dogs, respectively, compared to 17%, 33%, 0% and 0% in controls, whereas IL-1beta, -2 and IFN-gamma were not detectable in any of the studied cerebella. Conversely, IL-10 and TGF-beta transcripts were present in 83% and 100% of the investigated cerebella of distemper dogs and controls. Relative RT-PCR results, expressed as %GAPDH, revealed a significant up-regulation of IL-6, -8, -12 and TNF-alpha mRNA in distemper dogs; whereas IL-10 and TGF-beta showed only a weak and not significantly increased expression following infection. Relative pro-inflammatory cytokine expression values were highest following CDV infection, indicating that the virus itself directly triggered the up-regulation of the pro-inflammatory cytokines. Succeeding changes, such as lymphocyte infiltration, MHC class II up-regulation and demyelination resulted only in a minor additional increase in cytokine expression, implying a secondary or by-stander mechanism of cytokine activation by these changes. Disease initiation and progression in early distemper leukoencephalomyelitis seemed to be due to a lacking or inappropriate response of the anti-inflammatory cytokines in the presence of a vigorous up-regulation of pro-inflammatory cytokines.

Animals↗

Dominating interleukin-10 mRNA expression induction in cerebrospinal fluid cells of dogs with natural canine distemper virus induced demyelinating and non-demyelinating CNS lesions.

Canine distemper virus (CDV) infection in dogs is commonly associated with demyelinating leukoencephalitis (DL). Although the mechanism of primary demyelination in distemper remains undetermined recent studies showed a direct virus-induced cytolysis in early non-inflammatory and immune-mediated mechanisms in inflammatory lesions. To further investigate the pathogenesis of this morbillivirus-induced demyelination the expression of a variety of cytokine mRNA species (interleukin (IL)-1beta, IL-2, IL-6, IL-10, IL-12, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, and interferon (IFN)-gamma in cerebrospinal fluid cells of 12 dogs with CDV encephalitis was investigated employing reverse transcription-polymerase chain reaction (RT-PCR) and these findings were correlated to the type of CNS lesions. Neuropathology revealed the whole spectrum of distemper DL lesions from acute to chronic alterations, however, most plaques lacked active demyelination. Three control animals were devoid of any cytokine expression, whereas in distemper animals IL-10 transcripts were found in nine dogs with acute and chronic lesions. IL-6, TNF, and TGF mRNA was found in six, four, and three animals, respectively. IL-12 and IFN-gamma, suggestive of a TH1-like dominated immune response, were detected only in one animal with chronic lesions. Summarized, TNF and IL-6, associated with disease exacerbation, and IL-10 and TGF, indicative of remission, were often observed simultaneously in distemper DL and could not be assigned to a specific disease stage. However IL-10 mRNA remained the most frequently detected cytokine indicating a stage of inactivity in most animals investigated.

Animals↗