The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform

P.a. Van Rijn - One of the best experts on this subject based on the ideXlab platform.

  • An experimental multivalent Bovine Virus Diarrhea Virus E2 subunit vaccine and two experimental conventionally inactivated vaccines induce partial fetal protection in sheep.
    Vaccine, 1999
    Co-Authors: C.j.m. Bruschke, J.t. Van Oirschot, P.a. Van Rijn
    Abstract:

    The primary aim of a Bovine Virus Diarrhea Virus (BVDV) vaccine is to prevent transplacental transmission of Virus. We studied the efficacy of two experimental conventionally inactivated vaccines, based on BVDV strain Singer and containing a different antigen amount, against three antigenically different BVDV strains in a vaccination-challenge experiment in sheep. We also studied the efficacy of an experimental multivalent E2 subunit vaccine against four antigenically different BVDV strains. The vaccine contained the glycoproteins E2 of BVDV strains that belong to antigenic groups IA, IB and II. All three vaccines induced neutralizing antibodies against all challenge strains. Only the conventional vaccine that contained the highest antigen amount induced complete protection against homologous challenge. Neither of the conventional vaccines provided complete protection against heterologous challenge. The multivalent subunit vaccine induced partial protection against the homologous challenge strains. However, the immune response did inhibit Virus replication in ewes, as shown by the results of the Virus titrations.

  • A subunit vaccine based on glycoprotein E2 of Bovine Virus Diarrhea Virus induces fetal protection in sheep against homologous challenge.
    Vaccine, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, J.t. Van Oirschot, P.a. Van Rijn
    Abstract:

    The primary aim of a Bovine Virus Diarrhea Virus (BVDV) vaccine is to prevent transplacental transmission of Virus. E2 genes of three BVDV strains, belonging to antigenic groups IA, IB and II, were expressed in insect cells. Three groups of 12 ewes were immunized twice with one of the E2 proteins. A fourth group served as a control. The ewes were served and the pregnant ewes of each vaccination group were allotted to three different challenge groups. Seven weeks after the second vaccination the ewes were challenged intranasally with one of the three BVDV strains. Three weeks later the fetuses were removed and fetal organs were collected for Virus isolation. At the day of challenge all vaccinated ewes had neutralizing antibodies against the homologous BVDV strains. One E2 subunit vaccine prevented fetal infection after homologous challenge.

  • Glycoprotein Erns of pestiViruses induces apoptosis in lymphocytes of several species.
    Journal of virology, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, Marcel Hulst, J.t. Van Oirschot
    Abstract:

    Classical swine fever Virus and Bovine Virus Diarrhea Virus are members of the genus pestiVirus, which belongs to the family of the Flaviviridae. Recently, envelope glycoprotein Erns was identified as an RNase. RNases can express different biological actions. They have been shown to be neurotoxic, antihelminthic, and immunosuppressive. We studied the immunosuppressive properties of Erns in vitro. The glycoprotein totally inhibited concanavalin A-induced proliferation of porcine, Bovine, ovine, and human lymphocytes. We then studied the direct cytotoxic effects of Erns on lymphocytes and epithelial cells in protein synthesis assays. Erns strongly inhibited the protein synthesis of lymphocytes of different species, without cell membrane damage. This suggested an apoptotic process, and indeed apoptosis of lymphocytes was detected after incubation with Erns. PestiVirus infections are characterized by leukopenia and immunosuppression. Our results suggest that Erns plays an important role in the pathogenesis of pestiViruses.

  • Antigenically different pestiVirus strains induce congenital infection in sheep: a model for Bovine Virus Diarrhea Virus vaccine efficacy studies.
    Veterinary microbiology, 1996
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, J.t. Van Oirschot
    Abstract:

    To study the efficacy and safety of Bovine Virus Diarrhea Virus (BVDV) vaccines there is need for a valid challenge model. We investigated whether sheep can be used in such a challenge model. We intranasally inoculated six groups (A-F) of seronegative sheep at day 49 of gestation with either of five antigenically different BVDV strains and one border disease Virus strain. A seventh group (G) was housed for 10 days with a persistently infected calf and an eighth group (H) served as control. From each group half of the sheep were killed at 2 weeks, and half at 4 weeks after infection. For Virus isolation five organs were collected from the sheep and seven from the fetuses. All sheep of groups A and H remained seronegative in the ELISA and in the serum neutralization test. At 2 and 4 weeks after infection Virus was isolated from almost all fetal organs in six groups. In group A and in the control group no Virus was isolated from the fetal organs. The Virus distribution patterns in fetuses from sheep housed with the persistently infected calf or intranasally inoculated with the same strain were similar. We concluded that (i) antigenically different BVDV strains can induce congentital infection in sheep and that (ii) the consequences of a contact infection were similar to those after intranasal infection. In a second experiment we infected two groups of seronegative sheep with one of the strains used in the first experiment, before mating. A control group was left uninfected. The sheep were served and all sheep were challenged with antigenically homologous or heterologous BVDV at day 49 of pregnancy. Three weeks after challenge, sheep were killed and the procedure as in the first experiment was followed. None of the fetuses of the infected sheep were Virus positive whereas all fetuses of the control sheep were Virus positive. Hence, the immune response after BVDV infection protects fetuses against homologous and heterologous infection during pregnancy. Sheep may therefore be used in vaccination-challenge experiments to evaluate BVDV vaccine efficacy in preventing congenital infection.

J.t. Van Oirschot - One of the best experts on this subject based on the ideXlab platform.

  • An experimental multivalent Bovine Virus Diarrhea Virus E2 subunit vaccine and two experimental conventionally inactivated vaccines induce partial fetal protection in sheep.
    Vaccine, 1999
    Co-Authors: C.j.m. Bruschke, J.t. Van Oirschot, P.a. Van Rijn
    Abstract:

    The primary aim of a Bovine Virus Diarrhea Virus (BVDV) vaccine is to prevent transplacental transmission of Virus. We studied the efficacy of two experimental conventionally inactivated vaccines, based on BVDV strain Singer and containing a different antigen amount, against three antigenically different BVDV strains in a vaccination-challenge experiment in sheep. We also studied the efficacy of an experimental multivalent E2 subunit vaccine against four antigenically different BVDV strains. The vaccine contained the glycoproteins E2 of BVDV strains that belong to antigenic groups IA, IB and II. All three vaccines induced neutralizing antibodies against all challenge strains. Only the conventional vaccine that contained the highest antigen amount induced complete protection against homologous challenge. Neither of the conventional vaccines provided complete protection against heterologous challenge. The multivalent subunit vaccine induced partial protection against the homologous challenge strains. However, the immune response did inhibit Virus replication in ewes, as shown by the results of the Virus titrations.

  • A subunit vaccine based on glycoprotein E2 of Bovine Virus Diarrhea Virus induces fetal protection in sheep against homologous challenge.
    Vaccine, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, J.t. Van Oirschot, P.a. Van Rijn
    Abstract:

    The primary aim of a Bovine Virus Diarrhea Virus (BVDV) vaccine is to prevent transplacental transmission of Virus. E2 genes of three BVDV strains, belonging to antigenic groups IA, IB and II, were expressed in insect cells. Three groups of 12 ewes were immunized twice with one of the E2 proteins. A fourth group served as a control. The ewes were served and the pregnant ewes of each vaccination group were allotted to three different challenge groups. Seven weeks after the second vaccination the ewes were challenged intranasally with one of the three BVDV strains. Three weeks later the fetuses were removed and fetal organs were collected for Virus isolation. At the day of challenge all vaccinated ewes had neutralizing antibodies against the homologous BVDV strains. One E2 subunit vaccine prevented fetal infection after homologous challenge.

  • Glycoprotein Erns of pestiViruses induces apoptosis in lymphocytes of several species.
    Journal of virology, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, Marcel Hulst, J.t. Van Oirschot
    Abstract:

    Classical swine fever Virus and Bovine Virus Diarrhea Virus are members of the genus pestiVirus, which belongs to the family of the Flaviviridae. Recently, envelope glycoprotein Erns was identified as an RNase. RNases can express different biological actions. They have been shown to be neurotoxic, antihelminthic, and immunosuppressive. We studied the immunosuppressive properties of Erns in vitro. The glycoprotein totally inhibited concanavalin A-induced proliferation of porcine, Bovine, ovine, and human lymphocytes. We then studied the direct cytotoxic effects of Erns on lymphocytes and epithelial cells in protein synthesis assays. Erns strongly inhibited the protein synthesis of lymphocytes of different species, without cell membrane damage. This suggested an apoptotic process, and indeed apoptosis of lymphocytes was detected after incubation with Erns. PestiVirus infections are characterized by leukopenia and immunosuppression. Our results suggest that Erns plays an important role in the pathogenesis of pestiViruses.

  • Antigenically different pestiVirus strains induce congenital infection in sheep: a model for Bovine Virus Diarrhea Virus vaccine efficacy studies.
    Veterinary microbiology, 1996
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, J.t. Van Oirschot
    Abstract:

    To study the efficacy and safety of Bovine Virus Diarrhea Virus (BVDV) vaccines there is need for a valid challenge model. We investigated whether sheep can be used in such a challenge model. We intranasally inoculated six groups (A-F) of seronegative sheep at day 49 of gestation with either of five antigenically different BVDV strains and one border disease Virus strain. A seventh group (G) was housed for 10 days with a persistently infected calf and an eighth group (H) served as control. From each group half of the sheep were killed at 2 weeks, and half at 4 weeks after infection. For Virus isolation five organs were collected from the sheep and seven from the fetuses. All sheep of groups A and H remained seronegative in the ELISA and in the serum neutralization test. At 2 and 4 weeks after infection Virus was isolated from almost all fetal organs in six groups. In group A and in the control group no Virus was isolated from the fetal organs. The Virus distribution patterns in fetuses from sheep housed with the persistently infected calf or intranasally inoculated with the same strain were similar. We concluded that (i) antigenically different BVDV strains can induce congentital infection in sheep and that (ii) the consequences of a contact infection were similar to those after intranasal infection. In a second experiment we infected two groups of seronegative sheep with one of the strains used in the first experiment, before mating. A control group was left uninfected. The sheep were served and all sheep were challenged with antigenically homologous or heterologous BVDV at day 49 of pregnancy. Three weeks after challenge, sheep were killed and the procedure as in the first experiment was followed. None of the fetuses of the infected sheep were Virus positive whereas all fetuses of the control sheep were Virus positive. Hence, the immune response after BVDV infection protects fetuses against homologous and heterologous infection during pregnancy. Sheep may therefore be used in vaccination-challenge experiments to evaluate BVDV vaccine efficacy in preventing congenital infection.

C.j.m. Bruschke - One of the best experts on this subject based on the ideXlab platform.

  • An experimental multivalent Bovine Virus Diarrhea Virus E2 subunit vaccine and two experimental conventionally inactivated vaccines induce partial fetal protection in sheep.
    Vaccine, 1999
    Co-Authors: C.j.m. Bruschke, J.t. Van Oirschot, P.a. Van Rijn
    Abstract:

    The primary aim of a Bovine Virus Diarrhea Virus (BVDV) vaccine is to prevent transplacental transmission of Virus. We studied the efficacy of two experimental conventionally inactivated vaccines, based on BVDV strain Singer and containing a different antigen amount, against three antigenically different BVDV strains in a vaccination-challenge experiment in sheep. We also studied the efficacy of an experimental multivalent E2 subunit vaccine against four antigenically different BVDV strains. The vaccine contained the glycoproteins E2 of BVDV strains that belong to antigenic groups IA, IB and II. All three vaccines induced neutralizing antibodies against all challenge strains. Only the conventional vaccine that contained the highest antigen amount induced complete protection against homologous challenge. Neither of the conventional vaccines provided complete protection against heterologous challenge. The multivalent subunit vaccine induced partial protection against the homologous challenge strains. However, the immune response did inhibit Virus replication in ewes, as shown by the results of the Virus titrations.

  • A subunit vaccine based on glycoprotein E2 of Bovine Virus Diarrhea Virus induces fetal protection in sheep against homologous challenge.
    Vaccine, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, J.t. Van Oirschot, P.a. Van Rijn
    Abstract:

    The primary aim of a Bovine Virus Diarrhea Virus (BVDV) vaccine is to prevent transplacental transmission of Virus. E2 genes of three BVDV strains, belonging to antigenic groups IA, IB and II, were expressed in insect cells. Three groups of 12 ewes were immunized twice with one of the E2 proteins. A fourth group served as a control. The ewes were served and the pregnant ewes of each vaccination group were allotted to three different challenge groups. Seven weeks after the second vaccination the ewes were challenged intranasally with one of the three BVDV strains. Three weeks later the fetuses were removed and fetal organs were collected for Virus isolation. At the day of challenge all vaccinated ewes had neutralizing antibodies against the homologous BVDV strains. One E2 subunit vaccine prevented fetal infection after homologous challenge.

  • Glycoprotein Erns of pestiViruses induces apoptosis in lymphocytes of several species.
    Journal of virology, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, Marcel Hulst, J.t. Van Oirschot
    Abstract:

    Classical swine fever Virus and Bovine Virus Diarrhea Virus are members of the genus pestiVirus, which belongs to the family of the Flaviviridae. Recently, envelope glycoprotein Erns was identified as an RNase. RNases can express different biological actions. They have been shown to be neurotoxic, antihelminthic, and immunosuppressive. We studied the immunosuppressive properties of Erns in vitro. The glycoprotein totally inhibited concanavalin A-induced proliferation of porcine, Bovine, ovine, and human lymphocytes. We then studied the direct cytotoxic effects of Erns on lymphocytes and epithelial cells in protein synthesis assays. Erns strongly inhibited the protein synthesis of lymphocytes of different species, without cell membrane damage. This suggested an apoptotic process, and indeed apoptosis of lymphocytes was detected after incubation with Erns. PestiVirus infections are characterized by leukopenia and immunosuppression. Our results suggest that Erns plays an important role in the pathogenesis of pestiViruses.

  • Antigenically different pestiVirus strains induce congenital infection in sheep: a model for Bovine Virus Diarrhea Virus vaccine efficacy studies.
    Veterinary microbiology, 1996
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, J.t. Van Oirschot
    Abstract:

    To study the efficacy and safety of Bovine Virus Diarrhea Virus (BVDV) vaccines there is need for a valid challenge model. We investigated whether sheep can be used in such a challenge model. We intranasally inoculated six groups (A-F) of seronegative sheep at day 49 of gestation with either of five antigenically different BVDV strains and one border disease Virus strain. A seventh group (G) was housed for 10 days with a persistently infected calf and an eighth group (H) served as control. From each group half of the sheep were killed at 2 weeks, and half at 4 weeks after infection. For Virus isolation five organs were collected from the sheep and seven from the fetuses. All sheep of groups A and H remained seronegative in the ELISA and in the serum neutralization test. At 2 and 4 weeks after infection Virus was isolated from almost all fetal organs in six groups. In group A and in the control group no Virus was isolated from the fetal organs. The Virus distribution patterns in fetuses from sheep housed with the persistently infected calf or intranasally inoculated with the same strain were similar. We concluded that (i) antigenically different BVDV strains can induce congentital infection in sheep and that (ii) the consequences of a contact infection were similar to those after intranasal infection. In a second experiment we infected two groups of seronegative sheep with one of the strains used in the first experiment, before mating. A control group was left uninfected. The sheep were served and all sheep were challenged with antigenically homologous or heterologous BVDV at day 49 of pregnancy. Three weeks after challenge, sheep were killed and the procedure as in the first experiment was followed. None of the fetuses of the infected sheep were Virus positive whereas all fetuses of the control sheep were Virus positive. Hence, the immune response after BVDV infection protects fetuses against homologous and heterologous infection during pregnancy. Sheep may therefore be used in vaccination-challenge experiments to evaluate BVDV vaccine efficacy in preventing congenital infection.

J. F. Pohlenz - One of the best experts on this subject based on the ideXlab platform.

  • Organ and tissue distribution of the antigen of thecytopathogenic Bovine Virus Diarrhea Virus in theearly and advanced phase of experimentalmucosal disease
    Archives of Virology, 1997
    Co-Authors: E. M. Liebler-tenorio, I. Greiser-wilke, J. F. Pohlenz
    Abstract:

    To study the development of lesions in mucosal disease, the spread of cytopathogenic (cp) Bovine Virus Diarrhea Virus (BVDV) to different organs was examined in relation to the time post inoculation (pi). Mucosal disease was induced in 15 persistently viremic cattle from two herds by intranasal inoculation with antigenically similar cp BVDV strain. This strain reacted with one additional monoclonal antibody when compared to the corresponding herd-specific non cytopathogenic (ncp) isolate. Twelve cattle were euthanized at days 3, 5, 7, 9 and 13 pi in the early phase before they developed clinical signs of mucosal disease, three in the advanced phase when they were moribund and three served as controls. Antigen of the cp BVDV strains was selectively detected in tissue sections by immunohistochemistry. In the early phase, varying amounts cp BVDV were present most consistently in tonsils, lymph nodes, Peyer’s patches and lymphoid nodules in the large intestine. In the lymphoid tissues, first a few cells in single lymphoid follicles, then groups of lymphoid follicles contained antigen. In intestinal epithelium, cp BVDV antigen was found focally in the early phase of mucosal disease. Its diffuse distribution in the late phase corresponded with clinical signs of Diarrhea.

  • Organ and tissue distribution of the antigen of the cytopathogenic Bovine Virus Diarrhea Virus in the early and advanced phase of experimental mucosal disease.
    Archives of virology, 1997
    Co-Authors: E. M. Liebler-tenorio, Irene Greiser-wilke, J. F. Pohlenz
    Abstract:

    To study the development of lesions in mucosal disease, the spread of cytopathogenic (cp) Bovine Virus Diarrhea Virus (BVDV) to different organs was examined in relation to the time post inoculation (pi). Mucosal disease was induced in 15 persistently viremic cattle from two herds by intranasal inoculation with antigenically similar cp BVDV strain. This strain reacted with one additional monoclonal antibody when compared to the corresponding herd-specific non cytopathogenic (ncp) isolate. Twelve cattle were euthanized at days 3, 5, 7, 9 and 13 pi in the early phase before they developed clinical signs of mucosal disease, three in the advanced phase when they were moribund and three served as controls. Antigen of the cp BVDV strains was selectively detected in tissue sections by immunohistochemistry. In the early phase, varying amounts cp BVDV were present most consistently in tonsils, lymph nodes, Peyer's patches and lymphoid nodules in the large intestine. In the lymphoid tissues, first a few cells in single lymphoid follicles, then groups of lymphoid follicles contained antigen. In intestinal epithelium, cp BVDV antigen was found focally in the early phase of mucosal disease. Its diffuse distribution in the late phase corresponded with clinical signs of Diarrhea.

R. J. M. Moormann - One of the best experts on this subject based on the ideXlab platform.

  • A subunit vaccine based on glycoprotein E2 of Bovine Virus Diarrhea Virus induces fetal protection in sheep against homologous challenge.
    Vaccine, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, J.t. Van Oirschot, P.a. Van Rijn
    Abstract:

    The primary aim of a Bovine Virus Diarrhea Virus (BVDV) vaccine is to prevent transplacental transmission of Virus. E2 genes of three BVDV strains, belonging to antigenic groups IA, IB and II, were expressed in insect cells. Three groups of 12 ewes were immunized twice with one of the E2 proteins. A fourth group served as a control. The ewes were served and the pregnant ewes of each vaccination group were allotted to three different challenge groups. Seven weeks after the second vaccination the ewes were challenged intranasally with one of the three BVDV strains. Three weeks later the fetuses were removed and fetal organs were collected for Virus isolation. At the day of challenge all vaccinated ewes had neutralizing antibodies against the homologous BVDV strains. One E2 subunit vaccine prevented fetal infection after homologous challenge.

  • Glycoprotein Erns of pestiViruses induces apoptosis in lymphocytes of several species.
    Journal of virology, 1997
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, Marcel Hulst, J.t. Van Oirschot
    Abstract:

    Classical swine fever Virus and Bovine Virus Diarrhea Virus are members of the genus pestiVirus, which belongs to the family of the Flaviviridae. Recently, envelope glycoprotein Erns was identified as an RNase. RNases can express different biological actions. They have been shown to be neurotoxic, antihelminthic, and immunosuppressive. We studied the immunosuppressive properties of Erns in vitro. The glycoprotein totally inhibited concanavalin A-induced proliferation of porcine, Bovine, ovine, and human lymphocytes. We then studied the direct cytotoxic effects of Erns on lymphocytes and epithelial cells in protein synthesis assays. Erns strongly inhibited the protein synthesis of lymphocytes of different species, without cell membrane damage. This suggested an apoptotic process, and indeed apoptosis of lymphocytes was detected after incubation with Erns. PestiVirus infections are characterized by leukopenia and immunosuppression. Our results suggest that Erns plays an important role in the pathogenesis of pestiViruses.

  • Antigenically different pestiVirus strains induce congenital infection in sheep: a model for Bovine Virus Diarrhea Virus vaccine efficacy studies.
    Veterinary microbiology, 1996
    Co-Authors: C.j.m. Bruschke, R. J. M. Moormann, P.a. Van Rijn, J.t. Van Oirschot
    Abstract:

    To study the efficacy and safety of Bovine Virus Diarrhea Virus (BVDV) vaccines there is need for a valid challenge model. We investigated whether sheep can be used in such a challenge model. We intranasally inoculated six groups (A-F) of seronegative sheep at day 49 of gestation with either of five antigenically different BVDV strains and one border disease Virus strain. A seventh group (G) was housed for 10 days with a persistently infected calf and an eighth group (H) served as control. From each group half of the sheep were killed at 2 weeks, and half at 4 weeks after infection. For Virus isolation five organs were collected from the sheep and seven from the fetuses. All sheep of groups A and H remained seronegative in the ELISA and in the serum neutralization test. At 2 and 4 weeks after infection Virus was isolated from almost all fetal organs in six groups. In group A and in the control group no Virus was isolated from the fetal organs. The Virus distribution patterns in fetuses from sheep housed with the persistently infected calf or intranasally inoculated with the same strain were similar. We concluded that (i) antigenically different BVDV strains can induce congentital infection in sheep and that (ii) the consequences of a contact infection were similar to those after intranasal infection. In a second experiment we infected two groups of seronegative sheep with one of the strains used in the first experiment, before mating. A control group was left uninfected. The sheep were served and all sheep were challenged with antigenically homologous or heterologous BVDV at day 49 of pregnancy. Three weeks after challenge, sheep were killed and the procedure as in the first experiment was followed. None of the fetuses of the infected sheep were Virus positive whereas all fetuses of the control sheep were Virus positive. Hence, the immune response after BVDV infection protects fetuses against homologous and heterologous infection during pregnancy. Sheep may therefore be used in vaccination-challenge experiments to evaluate BVDV vaccine efficacy in preventing congenital infection.