Use of protein AG in an enzyme-linked immunosorbent assay for screening for antibodies against parapoxvirus in wild animals in Japan.
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Using protein AG in an enzyme-linked immunosorbent assay (ELISA), we tried to detect antibodies against parapoxvirus in 9 species of wild animals in Japan: the Japanese badger (Meles meles anakuma), Japanese black bear (Ursus thibetanus japonicus), Japanese deer (Cervus nippon centralis), Japanese monkey (Macaca fuscata), Japanese raccoon dog (Nyctereutes procyonoides viverrinus), Japanese serow (Capricornis crispus), Japanese wild boar (Sus scrofa leucomystax), masked palm civet (Paguma larvata), and nutria (Myocastor coypus). A total of 272 serum samples were collected over the period from 1984 to 1995 and were tested by the protein AG-ELISA, the agar gel immunodiffusion test, and an indirect immunofluorescence assay. The protein AG-ELISA was effective in a serological survey for parapoxvirus in wild animals, and antibodies were detected only in Japanese serows. A total of 24 of 66 (36.4%) Japanese serows reacted positively, and they were found in almost all prefectures in all years tested. These results suggest that epizootic cycles of parapoxvirus exist widely in Japanese serows and that they could be reservoirs for the virus in the field in Japan. Moreover, it is probable that they might carry the virus to domestic animals such as cattle, sheep, and goats. (+info)
Re-emergence of monkeypox in Africa: a review of the past six years.
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Human monkeypox was first identified in 1970 in the Democratic Republic of the Congo. Extensive studies of this zoonotic infection in the 1970s and 1980s indicated a largely sporadic disease with a minority of cases resulting from person-to-person transmission, rarely beyond two generations. In August 1996, an unusually large outbreak of human monkeypox was reported, and cases continued through 1997 with peak incidence in August 1996, March 1997 and August 1997. Preliminary results from the field investigations in 1997 suggest a new epidemiological pattern where a majority of secondary cases result from person-to-person transmission, and a clinically milder disease. But there is preliminary laboratory evidence of a simultaneous outbreak of varicella in the same geographic region which will undoubtedly modify these preliminary results. Since smallpox was eradicated and vaccinia vaccination terminated in this region, the population of susceptible individuals has grown. The use of vaccination to protect the population at risk, however, must take into account HIV prevalence and the risk of generalized vaccinia when using vaccinia vaccine in populations where HIV is known to be present. (+info)
Poxvirus-encoded serpins do not prevent cytolytic T cell-mediated recovery from primary infections.
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Previous observations that the highly conserved poxvirus-encoded serpins inhibit cytotoxic activities of alloreactive CTL via granule and/or Fas-mediated pathways was taken to indicate their involvement in immune evasion by poxviruses. We now show that interference with 51Cr release from target cells by ectromelia and cowpoxvirus is limited to alloreactive but not MHC-restricted CTL. The data are in support of the paramount importance of CTL and its effector molecule perforin in the recovery from primary ectromelia virus infection and question the role of serpins in the evasion of poxviruses from killing by CTL. Further analysis of poxvirus interference with target cell lysis by alloreactive CTL revealed that suppression primarily affects the Fas-mediated, and to a lesser extent, the granule exocytosis pathway. Serpin-2 is the main contributor to suppression for both killing pathways. In addition, inhibition of lysis was shown to be both target cell type- and MHC allotype-dependent. We hypothesize that differences in TCR affinities and/or state of activation between alloreactive and MHC-restricted CTL as well as the quality (origin) of target cells are responsible for the observed phenomenon. (+info)
An epidemic of parapoxvirus infection among cattle: isolation and antibody survey.
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A disease characterized by papules, nodules, vesicles and, rarely, pustules and ulcers on teats was seen among cattle on a farm in Chiba Prefecture, Japan. A virus was isolated by inoculation of fetal bovine lung cell cultures from a vesicle on a teat of an infected cow. The virus was subsequently passaged in fetal bovine lung and muscle cells in which it produced complete cytopathic changes. The virus was identified by physicochemical examinations and electromicroscopic observation as a parapoxvirus. A seroepidemiological survey was performed on antibody to the isolated virus by the agar gel immunodiffusion test. The isolated virus formed a precipitation line which cross reacted with other parapoxviruses isolated previously in Japan. The positive rate was more than 50% among cattle in the Kanto district. The positive rate increased with age. It was suggested that parapoxvirus infection might have already been prevalent among cattle in Japan. (+info)
Endosomal/lysosomal retention and degradation of major histocompatibility complex class I molecules is induced by myxoma virus.
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The highly immunosuppressive leporipoxvirus myxoma, previously was shown to promote the loss of cell surface class I major histocompatibility complex (MHC I) molecules. Here, we show that myxoma virus induces the loss of both cell surface and intracellular post-Golgi, beta(2)-microglobulin-associated MHC I. Myxoma-induced loss of these MHC I molecules is abrogated by vacuolar ATPase inhibitors, NH(4)Cl, and leupeptin. Furthermore, immunofluorescence microscopic studies reveal that in myxoma-infected cells, beta(2)-microglobulin-associated MHC I accumulates in Lamp-1(+) vesicular structures, suggesting that myxoma virus targets MHC I for degradation in late endosomes and/or lysosomes. These events are regulated by early gene product or products because they occur unabated in cells infected with myxoma virus in the presence of cytosine arabinoside, an inhibitor of DNA synthesis. Studies with baby green monkey kidney cells transfected with wild-type and tail-less forms of a mouse MHC I molecule, H-2L(d), indicate that the MHC I cytoplasmic tail is required for myxoma-induced localization in Lamp-1(+) organelles. Myxoma-induced endocytosis and degradation of MHC I may provide the virus with a means of dispensing with cell surface MHC I molecules that were loaded with peptides derived from viral proteins synthesized early in infection. (+info)
A review of virus infections of cataceans and the potential impact of morbilliviruses, poxviruses and papillomaviruses on host population dynamics.
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Viruses belonging to 9 families have been detected in cetaceans. We critically review the clinical features, pathology and epidemiology of the diseases they cause. Cetacean morbillivirus (family Paramyxoviridae) induces a serious disease with a high mortality rate and persists in several populations. It may have long-term effects on the dynamics of cetacean populations either as enzootic infection or recurrent epizootics. The latter presumably have the more profound impact due to removal of sexually mature individuals. Members of the family Poxviridae infect several species of odontocetes, resulting in ring and tattoo skin lesions. Although poxviruses apparently do not induce a high mortality, circumstancial evidence suggests they may be lethal in young animals lacking protective immunity, and thus may negatively affect net recruitment. Papillomaviruses (family Papovaviridae) cause genital warts in at least 3 species of cetaceans. In 10% of male Burmeister's porpoises Phocoena spinipinnis from Peru, lesions were sufficiently severe to at least hamper, if not impede, copulation. Members of the families Herpesviridae, Orthomyxoviridae and Rhabdoviridae were demonstrated in cetaceans suffering serious illnesses, but with the exception of a 'porpoise herpesvirus' their causative role is still tentative. Herpes-like viruses and caliciviruses (Caliciviridae) give rise to cutaneous diseases in Monodontidae and Delphinidae. Antibodies to several serotypes of caliciviruses were found in odontocetes and mysticetes. An unrecognized Hepadnaviridae was detected by serology in a captive Pacific white-sided dolphin Lagenorhynchus obliquidens with chronic persistent hepatitis. Adenoviruses (Adenoviridae) were isolated from the intestinal tracts of mysticeti and a beluga Delphinapterus leucas but were not associated with any pathologies. We discuss the potential impact of Paramyxoviridae, Poxviridae and Papovaviridae on the dynamics of several odontocete populations. (+info)
DNA vaccination with vaccinia virus L1R and A33R genes protects mice against a lethal poxvirus challenge.
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Previously we found that passive transfer of monoclonal antibodies (MAbs) specific to either the vaccinia virus (VACV) L1R or A33R gene product protected mice from challenge with VACV. The L1R-specific MAbs, which bind the intracellular mature virion (IMV), neutralized virus in cell culture, whereas the A33R-specific MAbs, which bind extracellular enveloped virions (EEV), did not. To investigate whether a protective response could be generated by vaccination with these genes, we constructed and evaluated DNA vaccines expressing the VACV L1R and/or A33R genes under control of a cytomegalovirus promoter. Mice were vaccinated with DNA-coated gold beads by using a gene gun and then challenged with VACV (strain WR) intraperitoneally. Mice vaccinated with L1R alone developed neutralizing antibodies and were partially protected. Mice vaccinated with a combination of both genes loaded on the same gold beads developed a robust anti-A33R response; however, no neutralizing antibody response was detected, and the mice were not protected. In contrast, when mice were vaccinated with L1R and A33R loaded on different gold beads, neutralizing (presumably anti-L1R) and anti-A33R antibody responses were detected, and protection was markedly improved. Our results indicated that vaccination with both L1R and A33R proteins, intended to evoke mechanistically distinct and complementary forms of protection, was more effective than vaccination with either protein by itself. (+info)
Detection of poxvirus in cattle associated with human cases in the State of Rio de Janeiro: preliminary report.
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This preliminary report describes human and cow cases of poxvirus that recently occurred in the State of Rio de Janeiro. The electron microscopic findings were consistent with parapoxviral and orthopoxviral infection. Orthopoxvirus strains were isolated from human and cow cases. Detailed viral characterization by means of genetical techniques is under investigation. Based on these informations, poxviral diseases should be also considered an emerging viral zoonosis that can affect human beings. (+info)