Assuntos
Infecções por Birnaviridae/veterinária , Vírus da Varíola dos Canários/imunologia , Vírus da Doença Infecciosa da Bursa/genética , Doenças das Aves Domésticas/imunologia , Proteínas Estruturais Virais/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/genética , Antígenos Virais/imunologia , Infecções por Birnaviridae/imunologia , Infecções por Birnaviridae/prevenção & controle , Bolsa de Fabricius/diagnóstico por imagem , Bolsa de Fabricius/patologia , Vírus da Varíola dos Canários/genética , Vírus da Varíola dos Canários/metabolismo , Galinhas , Vetores Genéticos , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas Estruturais Virais/biossíntese , Proteínas Estruturais Virais/genética , Vacinas Virais/administração & dosagem , Vacinas Virais/genéticaRESUMO
We previously delineated a highly conserved immunosuppressive (IS) domain within murine and primate retroviral envelope proteins that is critical for virus propagation in vivo. The envelope-mediated immunosuppression was assessed by the ability of the proteins, when expressed by allogeneic tumor cells normally rejected by engrafted mice, to allow these cells to escape, at least transiently, immune rejection. Using this approach, we identified key residues whose mutation (i) specifically abolishes immunosuppressive activity without affecting the "mechanical" function of the envelope protein and (ii) significantly enhances humoral and cellular immune responses elicited against the virus. The objective of this work was to study the immunosuppressive activity of the envelope protein (p15E) of feline leukemia virus (FeLV) and evaluate the effect of its abolition on the efficacy of a vaccine against FeLV. Here we demonstrate that the FeLV envelope protein is immunosuppressive in vivo and that this immunosuppressive activity can be "switched off" by targeted mutation of a specific amino acid. As a result of the introduction of the mutated envelope sequence into a previously well characterized canarypox virus-vectored vaccine (ALVAC-FeLV), the frequency of vaccine-induced FeLV-specific gamma interferon (IFN-γ)-producing cells was increased, whereas conversely, the frequency of vaccine-induced FeLV-specific interleukin-10 (IL-10)-producing cells was reduced. This shift in the IFN-γ/IL-10 response was associated with a higher efficacy of ALVAC-FeLV against FeLV infection. This study demonstrates that FeLV p15E is immunosuppressive in vivo, that the immunosuppressive domain of p15E can modulate the FeLV-specific immune response, and that the efficacy of FeLV vaccines can be enhanced by inhibiting the immunosuppressive activity of the IS domain through an appropriate mutation.
Assuntos
Vírus da Varíola dos Canários/genética , Produtos do Gene env/química , Produtos do Gene env/imunologia , Imunossupressores/química , Vírus da Leucemia Felina/genética , Leucemia Felina/imunologia , Mutação de Sentido Incorreto , Proteínas Oncogênicas de Retroviridae/genética , Vacinas Virais/genética , Animais , Vírus da Varíola dos Canários/metabolismo , Gatos , Feminino , Produtos do Gene env/administração & dosagem , Produtos do Gene env/genética , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Imunossupressores/administração & dosagem , Imunossupressores/imunologia , Interferons/genética , Interferons/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Vírus da Leucemia Felina/química , Vírus da Leucemia Felina/imunologia , Leucemia Felina/prevenção & controle , Leucemia Felina/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Estrutura Terciária de Proteína , Proteínas Oncogênicas de Retroviridae/administração & dosagem , Proteínas Oncogênicas de Retroviridae/química , Proteínas Oncogênicas de Retroviridae/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/química , Vacinas Virais/imunologiaAssuntos
Vacinas contra a AIDS/imunologia , Infecções por HIV/prevenção & controle , HIV/imunologia , Anticorpos Neutralizantes/análise , Anticorpos Neutralizantes/imunologia , Vírus da Varíola dos Canários/imunologia , Vírus da Varíola dos Canários/metabolismo , Ensaios Clínicos como Assunto , HIV/patogenicidade , Anticorpos Anti-HIV/análise , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Imunidade Celular , Imunização Secundária , Tailândia/epidemiologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologiaRESUMO
Human immunodeficiency virus type 1 (HIV-1) canarypox vaccines are safe but poorly immunogenic. CD40 ligand (CD40L), a member of the tumor necrosis factor superfamily (TNFSF), is a pivotal costimulatory molecule for immune responses. To explore whether CD40L can be used as an adjuvant for HIV-1 canarypox vaccine, we constructed recombinant canarypox viruses expressing CD40L. Co-immunization of mice with CD40L expressing canarypox and the canarypox vaccine expressing HIV-1 proteins, vCP1452, augmented HIV-1 specific cytotoxic T lymphocyte (CTL) responses in terms of frequency, polyfunctionality and interleukin (IL)-7 receptor alpha chain (IL-7Ralpha, CD127) expression. In addition, CD40L expressed from canarypox virus could significantly augment CD4+ T cell responses against HIV-1 in mice. CD40L expressed from canarypox virus matured human monocyte-derived dendritic cells (MDDCs) in a tumor necrosis factor-alpha (TNF-alpha) independent manner, which underwent less apoptosis, and could expand ex vivo Epstein-Barr virus (EBV)-specific CTL responses from healthy human individuals and ex vivo HIV-1-specific CTL responses from HIV-1-infected individuals in the presence or absence of CD4+ T cells. Taken together, our results suggest that CD40L incorporation into poxvirus vectors could be used as a strategy to enhance their immunogenicity.
Assuntos
Ligante de CD40/metabolismo , Ligante de CD40/farmacologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Vírus da Varíola dos Canários/metabolismo , Infecções por HIV/imunologia , Vacinas Virais/metabolismo , Vacinas contra a AIDS/química , Vacinas contra a AIDS/imunologia , Adjuvantes Imunológicos , Animais , Apoptose/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Vírus da Varíola dos Canários/imunologia , Células Dendríticas/efeitos dos fármacos , Feminino , Infecções por HIV/genética , HIV-1/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB CRESUMO
We describe the development and preliminary characterization of a recombinant canarypox virus vectored vaccine for protective immunization of ruminants against bluetongue virus (BTV) infection. Sheep (n=6) immunized with recombinant canarypox virus vector (BTV-CP) co-expressing synthetic genes encoding the two outer capsid proteins (VP2 and VP5) of BTV serotype 17 (BTV-17) developed high titers (40-160) of virus-specific neutralizing antibodies and were resistant to challenge with a field strain of BTV-17. In contrast, sheep (n=5) immunized with a commercial recombinant canarypox virus vector expressing the E and preM genes of West Nile virus were seronegative to BTV and developed pyrexia, lymphopenia, and extended, high-titered viremias following challenge exposure to the field strain of BTV-17. These data confirm that the BTV-CP vaccine may be useful for the protective immunization of ruminants against bluetongue, and it may avoid the problems inherent to live-attenuated (LA) BTV vaccines.
Assuntos
Vírus Bluetongue/metabolismo , Bluetongue/prevenção & controle , Vírus da Varíola dos Canários/metabolismo , Proteínas do Capsídeo/imunologia , Vacinas Virais/imunologia , Animais , Vírus Bluetongue/imunologia , Vírus da Varíola dos Canários/genética , Proteínas do Capsídeo/metabolismo , Feminino , Regulação Viral da Expressão Gênica , Masculino , Ovinos , Fatores de TempoRESUMO
We tested the canarypox virus vector ALVAC and the genetically attenuated vaccinia virus vector NYVAC as vehicles for achieving local immunomodulation in domestic animals bearing spontaneous tumours. Following intratumoral administration of ALVAC-, or NYVAC-luciferase in dogs with melanoma, it was demonstrated that viral recombinants remained localized along the needle track, with no virus detectable in the periphery of the tumour. Given these distribution characteristics and their well-documented safety profile, ALVAC- or NYVAC-based recombinants expressing feline or human IL2, respectively, were administered to domestic cats, in order to prevent the recurrence of spontaneous fibrosarcomas. In the absence of immunotherapy, tumour recurrence was observed in 61% of animals within a 12-month follow-up period after treatment with surgery and iridium-based radiotherapy. In contrast, only 39 and 28% of cats receiving either NYVAC-human IL2 or ALVAC-feline IL2, respectively, exhibited tumour recurrences. Based on such results, and in the context of ongoing clinical studies conducted in humans, we discuss the utilization of ALVAC- or NYVAC-based recombinants as viable therapeutic modalities for local immunotherapy or therapeutic vaccination against cancer, both in humans and companion animals.