No description available.

No description available.

Poxviruses are renowned for encoding proteins that modulate virtually every aspect of the host immune system. One effective barrier against virus infection is apoptosis, a form of programmed cell death. Apoptosis is controlled at the mitochondria by pro- and anti-apoptotic members of the highly conserved Bcl-2 family of proteins, and two members in particular, Bak and Bax, are absolutely critical to the induction of cell death. Although poxviruses encode an array of effective inhibitors of apoptosis, only members of the Avipoxvirus genus, of which fowlpox virus is the prototypical member, encode proteins with obvious, albeit limited, sequence identity to cellular Bcl-2 proteins. Fowlpox virus, the prototypical avipoxvirus, encodes FPV039, a protein that possesses two of the four highly conserved Bcl-2 homology (BH) domains that characterise the Bcl-2 family. Here we demonstrate that, like cellular Bcl-2 proteins, FPV039 localised to the mitochondria where it prevented apoptosis induced by a variety of cytotoxic stimuli, including virus infection itself. FPV039 inhibited apoptosis induced by Bak and Bax through an interaction with Bak and activated Bax. FPV039 also interacted with a discrete subset of BH3-only proteins, the upstream activators of Bak and Bax, to prevent Bax activation in the first place. Additionally, we have characterised the function and mechanism of action of a novel deerpox virus protein, DPV022. Intriguingly, DPV022 lacks obvious homology to cellular Bcl-2 proteins but shares limited regions of amino acid identity with two other poxviral inhibitors of apoptosis, vaccinia virus F1L and myxoma virus M11L, which are themselves unrelated. Here we demonstrate that DPV022 localised to the mitochondria where it interacted directly with Bak and Bax to inhibit apoptosis, even in the absence all cellular anti-apoptotic Bcl-2 proteins. We have also embarked on a preliminary analysis of the apical events that initially trigger apoptosis during infection with vaccinia virus, the prototypical poxvirus. Accordingly, we demonstrate that the BH3-only protein Noxa contributed to the vaccinia virus-induced apoptotic response, possibly through an involvement with dsRNA. Together, this study represents a comprehensive analysis of the ways in which poxviruses manipulate the cellular Bcl-2 family of proteins, the arbiters of cell death. / Virology

No description available.

Pox viruses have been demonstrated in over 60 types of wild and exotic birds as well as domestic birds. Avipox viruses have been isolated and characterised from fowls, quails, canaries, parrots and lovebirds. This work describes the first isolation of a poxvirus from Jackass penguins (Spheniscus dermersus) and the characterisation of the virus as a separate species of penguinpox virus.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / This study described the first outbreak of avian fowlpox in Brazil in previously vaccinated turkeys and also established, in an attempt to help the Federal Inspection Service, a standard of condemnation for carcasses with lesions characteristic of fowlpox. The turkeys had crusted macroscopic lesions on their skin, suggestive of avian fowlpox in the head and neck and no additional clinical signs were observed. The mortality rates in the flock did not change. In the slaughterhouse, 30 carcasses were removed from the slaughter line to collect damaged skin fragments for its characterization and research of the virus. The samples were fixed in formalin, embedded in paraffin, cut into sections of 6 microns and stained with hematoxylin-eosin for viewing in microscope. The agent identification was performed by conventional PCR with subsequent sequencing of the gene fpv167. On histopathology were observed: hyperkeratosis, acanthosis and hydropic degeneration; the presence of eosinophilic intracytoplasmic inclusion corpuscles (Bollinger) was observed in keratinocytes in 46.6% of samples. The PCR reaction was positive in 83.3% of samples. Using both diagnostic techniques was determined that 93.3% of the samples were positive for fowlpox. In the phylogenetic study, the samples show 100% of identity to each other suggesting that the outbreak occurred by a single virus strain. The sequenced gene fragment did not allow differentiation between strains of virus that infect turkeys, chickens or vaccinal strain. The fowlpox virus is avian species specific, and there are no reports of its occurrence in mammals. According to the macroscopic and microscopic characteristics of the skin lesions is not justified total condemnation of turkey\'s carcasses affected by avian fowlpox, except in cases of cachexia, disgusting aspect and other specifications at Federal Inspection Service regulations. Studies including the sequencing of other genes are needed to better viral characterization and can assist in identifying origin of the etiologic agent responsible for the outbreak and its possible sources. / Esse estudo descreveu o primeiro surto de bouba aviária no Brasil em perus de corte previamente vacinados e também estabeleceu, na tentativa de auxiliar o Serviço de Inspeção Federal, um padrão de condenação para carcaças apresentando lesões características de bouba aviária. As aves apresentaram lesões cutâneas crostosas macroscópicas sugestivas de bouba aviária na região da cabeça e do pescoço e nenhum sinal clínico adicional foram observados. Os índices de mortalidade no lote não foram alterados. No frigorífico, 30 carcaças foram retiradas da linha de abate para coleta de fragmentos de pele lesionada para sua caracterização e pesquisa do vírus. As amostras foram fixadas em formol, embebidas em parafina, cortadas em secções de 6 μm e coradas pela técnica de hematoxilina-eosina para visualização em microscópio de luz clara. A identificação do agente foi realizada por meio da técnica de PCR convencional com posterior sequenciamento do gene fpv167. No exame histopatológico foram observados: hiperqueratose, acantose e degeneração hidrópica; a presença de corpúsculos de inclusão intracitoplasmáticos eosinofílicos (Bollinger) nos queratinócitos foi observada em 46,6% das amostras. A reação de PCR foi positiva para 83,3% das amostras. Com o uso das duas técnicas de diagnóstico foi possível determinar que 93,3% das amostras foram positivas para bouba aviária. No estudo filogenético realizado, as amostras apresentam 100% de identidade entre si sugerindo que o surto ocorreu por uma única estirpe de vírus. O fragmento do gene sequenciado não permitiu a diferenciação entre estirpes de vírus que infectam perus, vacinal ou de galinhas. O vírus da bouba aviária é espécie específica, e não existem relatos sobre sua ocorrência em mamíferos. De acordo com as características macroscópicas e microscópicas das lesões cutâneas, não se justifica a condenação total das carcaças das aves acometidas pelo vírus da bouba aviária, exceto nos casos de caquexia, aspecto repugnante e outros especificados nos regulamentos do SIF. Estudos incluindo o sequenciamento de outros genes são necessários para melhor caracterização viral e podem auxiliar na identificação da origem do agente etiológico responsável pelo surto e suas possíveis fontes. / Mestre em Ciências Veterinárias

The development of a safe and effective HIV vaccine remains challenging due to its high antigenic variability. Poxviruses are large, stable, and have a track record of use as human vaccine candidates. Recombinant fowlpox virus 9 (rFP9), a highly attenuated host range-restricted poxvirus strain, has been safely administered to humans with no ill effects, and is known to be immunogenic. This thesis describes the construction of complex rFP9 encoding various sequences of SIVmac239. The SIVmac239/macaque model is widely used for HIV vaccine development. The ultimate aim of this work was to combine the advantages of FP9 with those of live attenuated SIV to produce a safe yet hopefully effective model HIV vaccine candidate. Transfer plasmids for five different insertion sites within the FP9 genome were designed and constructed. Homologous recombination (HR) of adjacent FP9 sequences was employed to facilitate the integration of SIVmac239 sequences into the FP9 genome. Positive rFP9 were identified by blue colouration in presence of X-gal using a transient colour selection (TCS) technique, and the final markerless pure recombinants were confirmed by PCR. Expression of the target SIV proteins in the presence of T7 polymerase has been demonstrated by immunocytochemical (ICC) staining and Western blotting (WB) assays. Expression was also quantified by enzyme-linked immunosorbent assay (ELISA) in various cell lines at multiple time points. Five different unique rFP9 have been constructed through this project. All SIVmac239 open reading frames (ORFs) save nef have been integrated into the FP9 genome, and protein expression demonstrated where possible. Moreover, a single rFP9 vector expressing the defective SIVmac239 genome driven by T7 RNA polymerase has been successfully constructed and validated using a green fluorescent protein marker.rFP9 showed appropriate transgene expression in both avian and mammalian cells, although at different levels. The expression efficiency of rFP9 was finally compared to another attenuated poxvirus vector, modified vaccinia Ankara (MVA). Comparing the protein expression levels between rFP9 and rMVA was quite difficult because different poxvirus promoters (early/late in rFP9; intermediate in rMVA) were used to direct the transcription of the T7 RNA gene. Given this limitation, although generally higher levels of expression were seen with rFP9, this cannot be attributed to the FP9 with any certainty.