The Experts below are selected from a list of 119646 Experts worldwide ranked by ideXlab platform
Wilfred A Jefferies - One of the best experts on this subject based on the ideXlab platform.
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towards the conservation of endangered avian species a recombinant west nile virus vaccine results in increased humoral and cellular immune responses in japanese quail coturnix japonica
PLOS ONE, 2013Co-Authors: Joanne A Young, Wilfred A JefferiesAbstract:West Nile Virus (WNV) arrived in North America in 1999 and is now endemic. Many families of birds, especially corvids, are highly susceptible to WNV and infection often results in fatality. Avian species susceptible to WNV infection also include endangered species, such as the Greater Sage-Grouse (Centrocercus uropbasianuts) and the Eastern Loggerhead Shrike (Lanius ludovicianus migrans). The virus has been shown to contribute towards the likelihood of their extinction. Although a clear and present threat, there exists no avian WNV vaccine available to combat this lethal menace. As a first step in establishing an avian model for testing candidate WNV vaccines, avian Antibody based reagents were assessed for cross-reactivity with Japanese quail (Coturnix japonica) T cell markers CD4 and CD8; the most reactive were found to be the anti-duck CD8 Antibody, clone Du-CD8-1, and the anti-chicken/turkey CD4 Antibody, clone CT4. These reagents were then used to assess vaccine performance as well as to establish T cell populations in quail, with a novel population of CD4/CD8 double positive T cells being identified in Japanese quail. Concurrently, non-replicating recombinant adenoviruses, expressing either the WNV envelope or NS3 ‘genes’ were constructed and assessed for effectiveness as avian vaccines. Japanese Quail were selected for testing the vaccines, as they provide an avian model that parallels the population diversity of bird species in the wild. Both the level of WNV specific antibodies and the number of T cells in vaccinated birds were increased compared to unvaccinated controls. The results indicate the vaccines to be effective in increasing both humoral and cellular immune responses. These recombinant vaccines therefore may find utility as tools to protect and maintain domestic and wild avian populations. Their implementation may also arrest the progression towards extinction of endangered avian species and reduce the viral reservoir that potentiates infection in humans.
Joanne A Young - One of the best experts on this subject based on the ideXlab platform.
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Towards the Conservation of Endangered Avian Species: A Recombinant West Nile Virus Vaccine Results in Increased Humoral and Cellular Immune Responses in Japanese Quail (Coturnix japonica)
2016Co-Authors: Joanne A Young, Wilfred JefferiesAbstract:West Nile Virus (WNV) arrived in North America in 1999 and is now endemic. Many families of birds, especially corvids, are highly susceptible to WNV and infection often results in fatality. Avian species susceptible to WNV infection also include endangered species, such as the Greater Sage-Grouse (Centrocercus uropbasianuts) and the Eastern Loggerhead Shrike (Lanius ludovicianus migrans). The virus has been shown to contribute towards the likelihood of their extinction. Although a clear and present threat, there exists no avian WNV vaccine available to combat this lethal menace. As a first step in establishing an avian model for testing candidate WNV vaccines, avian Antibody based reagents were assessed for cross-reactivity with Japanese quail (Coturnix japonica) T cell markers CD4 and CD8; the most reactive were found to be the anti-duck CD8 Antibody, clone Du-CD8-1, and the anti-chicken/turkey CD4 Antibody, clone CT4. These reagents were then used to assess vaccine performance as well as to establish T cell populations in quail, with a novel population of CD4/CD8 double positive T cells being identified in Japanese quail. Concurrently, non-replicating recombinant adenoviruses, expressing either the WNV envelope or NS3 ‘genes ’ were constructed and assessed for effectiveness as avian vaccines. Japanese Quail were selected for testing the vaccines, as they provide an avian model that parallels the population diversity of bird species in the wild. Both the level of WNV specific antibodies and the number of T cells in vaccinated birds were increased compared to unvaccinated controls. The results indicate the vaccines to be effective in increasing both humoral and cellula
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towards the conservation of endangered avian species a recombinant west nile virus vaccine results in increased humoral and cellular immune responses in japanese quail coturnix japonica
PLOS ONE, 2013Co-Authors: Joanne A Young, Wilfred A JefferiesAbstract:West Nile Virus (WNV) arrived in North America in 1999 and is now endemic. Many families of birds, especially corvids, are highly susceptible to WNV and infection often results in fatality. Avian species susceptible to WNV infection also include endangered species, such as the Greater Sage-Grouse (Centrocercus uropbasianuts) and the Eastern Loggerhead Shrike (Lanius ludovicianus migrans). The virus has been shown to contribute towards the likelihood of their extinction. Although a clear and present threat, there exists no avian WNV vaccine available to combat this lethal menace. As a first step in establishing an avian model for testing candidate WNV vaccines, avian Antibody based reagents were assessed for cross-reactivity with Japanese quail (Coturnix japonica) T cell markers CD4 and CD8; the most reactive were found to be the anti-duck CD8 Antibody, clone Du-CD8-1, and the anti-chicken/turkey CD4 Antibody, clone CT4. These reagents were then used to assess vaccine performance as well as to establish T cell populations in quail, with a novel population of CD4/CD8 double positive T cells being identified in Japanese quail. Concurrently, non-replicating recombinant adenoviruses, expressing either the WNV envelope or NS3 ‘genes’ were constructed and assessed for effectiveness as avian vaccines. Japanese Quail were selected for testing the vaccines, as they provide an avian model that parallels the population diversity of bird species in the wild. Both the level of WNV specific antibodies and the number of T cells in vaccinated birds were increased compared to unvaccinated controls. The results indicate the vaccines to be effective in increasing both humoral and cellular immune responses. These recombinant vaccines therefore may find utility as tools to protect and maintain domestic and wild avian populations. Their implementation may also arrest the progression towards extinction of endangered avian species and reduce the viral reservoir that potentiates infection in humans.
A Kirn - One of the best experts on this subject based on the ideXlab platform.
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primary cultures of endothelial cells from the human liver sinusoid are permissive for human immunodeficiency virus type 1
Proceedings of the National Academy of Sciences of the United States of America, 1992Co-Authors: Annemarie Steffan, Marieedith Lafon, Jeanlouis Gendrault, Christine Schweitzer, Catherine A Royer, Daniel Jaeck, Jeanpierre Arnaud, M P Schmitt, Annemarie Aubertin, A KirnAbstract:Human endothelial cells isolated from hepatic sinusoids were infected in vitro with human immunodeficiency virus type 1 (HIV-1). An early sign of infection occurring in the culture was the formation of multinucleated cells. By double-labeling immunofluorescence, 5-15% of the cells recognized as endothelial cells owing to the presence of von Willebrand factor were found to contain HIV p24 and gp120 antigens after 2 weeks. Reverse transcriptase activity was released into the medium, and different steps in the process of viral budding were observed by electron microscopy. The virus produced by the endothelial cells was found to be infectious for CEM cells, a human T-cell line. CD4 molecules are present at the surface of the endothelial cells, as demonstrated by immunogold-silver staining and backscattered electron imaging. Treatment with an anti-CD4 Antibody abolished productive infection of the sinusoidal endothelial cells. The possibility that endothelial cells of the liver sinusoid are infected in vivo with HIV remains to be clearly shown.
Michael Fung - One of the best experts on this subject based on the ideXlab platform.
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synergistic in vitro antiretroviral activity of a humanized monoclonal anti CD4 Antibody tnx 355 and enfuvirtide t 20
Antimicrobial Agents and Chemotherapy, 2006Co-Authors: Xingquan Zhang, Meredith J Sorensen, Michael Fung, Robert T SchooleyAbstract:Recently, antiretroviral agents directed at several steps involved in viral entry have been shown to reduce viral replication in vitro and in vivo. We have demonstrated a high level of in vitro synergistic antiretroviral activity for two entry inhibitors that are directed at sequential steps in the entry process.
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a humanized nondepleting anti CD4 Antibody that blocks virus entry inhibits virus replication in rhesus monkeys chronically infected with simian immunodeficiency virus
AIDS Research and Human Retroviruses, 2002Co-Authors: Keith A Reimann, Rajinder Khunkhun, Wenyu Lin, Wayne Gordon, Michael FungAbstract:Therapeutic approaches that interfere with viral entry hold promise in preventing or treating HIV infection. Hu5A8, a humanized monoclonal Antibody against CD4, was previously shown to inhibit HIV and SIV replication in vitro and was safely administered to rhesus monkeys without depleting CD4(+) T cells. This Antibody completely suppressed replication of six different SIVmac 251 primary isolates in vitro. Twice weekly administration of 3-mg/kg doses of hu5A8 for 2 to 4 weeks to SIV-infected rhesus monkeys resulted in sustained plasma Antibody levels of > or =20 microg/ml during treatment and 5- to 50-fold decreases in plasma viremia, although suppression of viral replication was transient. Two of three treated monkeys developed Antibody responses against the administered monoclonal Antibody. Loss of antiviral effect was not temporally associated with anti-hu5A8 Antibody responses or due to activation of CD4(+) T cells by hu5A8. However, SIV isolated after hu5A8 treatment was approximately 5-fold more resistant to suppression by hu5A8 than SIV isolates obtained from the same monkeys before treatment. The rapid development of resistance may have resulted from SIV variants that infect cells by a CD4-independent mechanism. These results support the overall concept of anti-CD4 monoclonal Antibody treatment to suppress AIDS virus replication in vivo while demonstrating important issues as to its clinical feasibility.
Steven M Wolinsky - One of the best experts on this subject based on the ideXlab platform.
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detection of CD4 t cells harboring human immunodeficiency virus type 1 dna by flow cytometry using simultaneous immunophenotyping and pcr driven in situ hybridization evidence of epitope masking of the CD4 cell surface molecule in vivo
Journal of Virology, 1995Co-Authors: Bruce K Patterson, Charles L Goolsby, Vida Hodara, Kenton L Lohman, Steven M WolinskyAbstract:Human immunodeficiency virus type 1 (HIV-1) infection of T cells and cells of the monocyte/macrophage lineage requires a specific interaction between the CD4 antigen expressed on the cell surface and the HIV-1 external envelope glycoprotein (gp120). To study the association between HIV-1 infection and modulation of cell surface expression of the CD4 molecule in vivo, we examined the CD4+ T cells harboring proviral DNA obtained from HIV-1-infected individuals who had received no antiretroviral therapy for at least 90 days. Simultaneous immunophenotyping of CD4 cell surface expression and PCR-driven in situ hybridization for HIV-1 DNA were used to resolve the CD4+ T cells into distinct populations predicted upon the presence or absence of proviral DNA. Among the HIV-1-infected study subjects, the percentage of CD4+ T cells harboring proviral DNA ranged from 17.3 to 55.5%, with a mean of 40.5%. Cell surface fluorescent staining with anti-CD4 Antibody directed against a non-gp120 binding site-related epitope (L120) or a conformation-dependent epitope of the gp120 binding site (Leu 3A) demonstrated either an equivalent or a 1.5- to 3-fold-lower cell surface staining intensity for the HIV-1 DNA-positive subpopulation relative to the HIV-1 DNA-negative subpopulation, respectively. These data suggest that masking or alteration of specific epitopes on the CD4 molecule occurs after viral infection.