Made available in DSpace on 2015-03-26T13:47:16Z (GMT). No. of bitstreams: 1 texto completo.pdf: 926741 bytes, checksum: 18d302c22a4907755b01b95cb9c1ea36 (MD5) Previous issue date: 2013-06-04 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The diseases associated with PCV2 (PCVAD) require various factors to occur, however, the virus infection is critical to the development of any one of the syndromes. The present study aimed to determine differences in serologic and viremic profiles for PCV2 in the swine breed Piau and a commercial line (Landrace x Large White x Pietrain) at a subclinically infected farm by the virus studied. The experiment was conducted at the Genetic Improvement Pig Farm (GMS), Federal University of Viçosa (UFV), in which it isn´t carried out vaccination against PCV2. This study conducted a cross-sectional sample of sows (> 2 parity), pigs for 1-3 weeks, 3-8 weeks and 8-22 weeks of age. The serum samples were used to measure the level of total antibodies by ELISA and quantitation of viremia by real time PCR. The results showed that, at the age of 3-8 weeks, the Piau breed piglets seroconverted earlier than the commercial line piglets and the Piau breed sows showed lower levels of total antibodies in relation to the commercial line. There were no differences in viremia between the different stages of production within each genetic group or between groups. This work provides evidence that the breed Piau has a different humoral immune response than the commercial line studied when facing a natural PCV2 subclinical infection. The results of this study reinforce the importance of the conservation of native breeds that have not been used for development of high productivity commercial lines. / As doenças associadas ao PCV2 (PCVAD) necessitam de vários fatores para ocorrer, no entanto, a infecção pelo vírus é fundamental para o desenvolvimento de qualquer uma das síndromes. O presente estudo teve como objetivo verificar diferenças nos perfis sorológicos e virêmicos para o PCV2 entre suínos da raça Piau e de uma linhagem comercial (Landrace x Large White x Pietrain) em uma granja subclinicamente infectada pelo vírus estudado. O experimento foi realizado na Granja de Melhoramento Genético (GMS) da Universidade Federal de Viçosa (UFV), na qual não é realizada a vacinação contra o PCV2. O presente estudo realizou uma amostragem transversal em porcas (>2º parto), suínos de 1-3 semanas, 3-8 semanas e 8-22 semanas de idade. As amostras de soro obtidas foram utilizadas para mensuração dos níveis de anticorpos totais por ELISA indireto e quantificação da viremia por PCR em tempo real. Os resultados demonstraram que, na idade de 3-8 semanas, os leitões da raça Piau soroconverteram mais precocemente em relação aos leitões da linhagem comercial e as porcas da raça Piau apresentaram menores níveis de anticorpos totais em relação às da linhagem comercial. Não houve diferença na viremia entre as diferentes fases de produção dentro de cada grupo genético ou entre os grupos. Este trabalho fornece indícios de que a raça Piau apresenta uma resposta imune humoral diferente da desenvolvida pela linhagem comercial estudada diante de uma infecção subclínica natural pelo PCV2. Os resultados obtidos neste estudo reforçam a importância da conservação das raças nativas que não foram utilizadas para formação de linhagens de alta produtividade.

Albert Font Haro ABSTRACT Modulation of plasmacytoid dendritic cell function: role of immunoreceptors TIM-3 and BDCA-2 Plasmacytoid dendritic cells (pDCs) are key players in the antiviral response as well as in linking innate and adaptive immune response. They express endosomal toll-like receptors 7 and 9, which can detect ssRNA and unmethylated CpG DNA, respectively. Due to the constitutive expression of the transcription factor IRF7, pDCs are able to rapidly produce massive quantities of type I (α, β, ω) and type III (1, 2, 3, 4) interferons (IFN-I and IFN-III) as well as pro- inflammatory cytokines such as IL-1, IL-6 and TNF-α. After maturation, they also function as antigen-presenting cells. Despite intense research, the mechanisms of IFN and pro-inflammatory cytokines production and regulation are still poorly understood. Using the pDC cell line GEN2.2 and also primary human pDCs, we shed light on the role of kinases MEK and SYK in IFN-I production and regulation. We found that SYK is not only involved in the regulatory receptor (RR)-mediated BCR-like pathway that represents the negative regulation of IFN-I and IFN-III secretion but also in the positive TLR7/9-mediated signal transduction pathway that leads to IFN-I production, representing the immunogenic function. We also found that MEK plays a...