L'interferon-γ (IFNγ) est une cytokine immunomodulatrice puissante, également dotée d'une activité antivirale. Il possède deux ligands de haute affinité : un récepteur par lequel il transmet ses signaux et des polysaccharides complexes de la famille des héparanes sulfates (HS), tous deux situés à la surface cellulaire. In vivo, la liaison aux HS permet de concentrer localement la cytokine et de réguler son activité biologique par le biais d'une protection partielle du domaine C-terminal de la protéine. Ce domaine C-terminal, caractérisé par deux domaines basiques D1 et D2, est impliqué dans la reconnaissance du récepteur et des HS. Dans ce contexte, nos travaux se sont attachés à définir les aspects structuraux de l'interaction de l'IFNg, et plus précisément de son extrémité C-terminale, avec ses deux ligands. Pour cela, de divers mutants ponctuels, multiples et de délétion de l'IFNg ont été produites, purifiées et étudiées. Leur capacité à lier les HS et le récepteur de l'IFNg est déterminée par SPR puis leur influence sur l'activité antivirale de l'IFNg est déterminée. Les paramètres thermodynamiques de l'interaction IFNg:HS-oligosaccharides sont investigués. Par ailleurs, nous avons préparé une banque oligosaccharidique dérivée d'HS. Le criblage de cette banque, pour sa capacité à lier l'IFNγ, a permis de démontrer que l'IFNg reconnaissait des motifs de sulfatation particuliers. Finalement, nous avons tenté de cristallisé le complexe IFNg:HS-oligosaccharide, jusqu'à présent sans obtention de cristaux qui diffractent. Ces différentes approches visent à élucider le mécanisme de reconnaissance d'IFNg par des HS. Ceci afin de concevoir un mime de ce site d'interaction inhibant la signalisation de l'IFNg. Enfin, une compréhension plus détaillé de l'interaction de l'IFNg avec les HS et son récepteur reste à établir afin d'entièrement comprendre comment l'IFNg migre des HS vers l'IFNgR. / Interferon-γ (IFNγ) is a strong immunomodulating cytokine with some antiviral activity. It has two ligands for which it has high affinities: a receptor through which it transmits its signals, and complex polysaccharides of the heparan sulphate (HS) family. Both are situated on the cellular surface. In vivo, binding on the HS permits local concentration of the cytokine, and regulates its biological activity via a partial protection of the C-terminal region. This C-terminal region, characterised by two basic domains, D1 and D2, is implicated in the recognition of the receptor and the HS. In this context, we investigated the structural features for the interaction of IFNγ, and more specifically the importance of his C-terminus, with both of his cellular ligands. Therefore, we produced, purified and examined various mutants of IFNγ, including points, multiples and deletions mutants. There ability to bind to HS and the IFNγ receptor is examined by SPR and there influence on IFNγ's antiviral activity is determined. The thermodynamics complexation of IFNγ with the HS-oligosaccharides is examined. Moreover, we have prepared an oligosaccharidic library derived from HS. By screening this library for its capacity to bind IFNγ, we have demonstrated that the cytokine recognizes a particular sulphated pattern. Finely, we tried to crystallize the IFNγ:HS-oligosaccharide complex, without obtaining diffracting crystals yet. These studies contribute to clarify the mechanism of recognition of IFNγ by the HS. This would enable us to design a mimic of the interaction site for IFNγ on the HS, who inhibits inappropriate signaling of the cytokine. Finely, a detailed comprehension of the interaction of IFNγ with his receptor and with the HS needs to be established to fully understand how IFNγ migrates for the HS to its receptor.

abstract: The concept of vaccination dates back further than Edward Jenner's first vaccine using cowpox pustules to confer immunity against smallpox in 1796. Nevertheless, it was Jenner's success that gave vaccines their name and made vaccinia virus (VACV) of particular interest. More than 200 years later there is still the need to understand vaccination from vaccine design to prediction of vaccine efficacy using mathematical models. Post-exposure vaccination with VACV has been suggested to be effective if administered within four days of smallpox exposure although this has not been definitively studied in humans. The first and second chapters analyze post-exposure prophylaxis of VACV in an animal model using v50ΔB13RMγ, a recombinant VACV expressing murine interferon gamma (IFN-γ) also known as type II IFN. While untreated animals infected with wild type VACV die by 10 days post-infection (dpi), animals treated with v50ΔB13RMγ 1 dpi had decreased morbidity and 100% survival. Despite these differences, the viral load was similar in both groups suggesting that v50ΔB13RMγ acts as an immunoregulator rather than as an antiviral. One of the main characteristics of VACV is its resistance to type I IFN, an effect primarily mediated by the E3L protein, which has a Z-DNA binding domain and a double-stranded RNA (dsRNA) binding domain. In the third chapter a VACV that independently expresses both domains of E3L was engineered and compared to wild type in cells in culture. The dual expression virus was unable to replicate in the JC murine cell line where both domains are needed together for replication. Moreover, phosphorylation of the dsRNA dependent protein kinase (PKR) was observed at late times post-infection which indicates that both domains need to be linked together in order to block the IFN response. Because smallpox has already been eradicated, the utility of mathematical modeling as a tool for predicting disease spread and vaccine efficacy was explored in the last chapter using dengue as a disease model. Current modeling approaches were reviewed and the 2000-2001 dengue outbreak in a Peruvian region was analyzed. This last section highlights the importance of interdisciplinary collaboration and how it benefits research on infectious diseases. / Dissertation/Thesis / Ph.D. Molecular and Cellular Biology 2011

RNA:protein interactions are central in many cellular processes, including activation of innate immune responses against microbial infection. Their study is essential to better understand the diverse biological events that occur within cells. However, isolation of RNA:protein complexes is often laborious and requires specialized techniques. This thesis is concerned with attempts to develop an improved purification protocol to isolate specific RNA:protein complexes. Taking advantage of the specific interaction of the Pseudomonas aeruginosa PP7 protein with its cognate RNA binding site, termed the PP7 recognition sequence (PRS), the aim was to identify cellular proteins involved in activating cell-signalling pathways, including the interferon-induction cascade, following viral infection with stocks of parainfluenza virus 5 (PIV5) rich in copyback defective interfering (DI) particles. Copyback DI genomes are powerful inducers of IFN and, here, I show they also activate the induction of IL-6, IL-8 and TNFα; cytokines that also have antiviral properties. Following the successful cloning of the PRS into a copyback DI genome, we investigated conditions for optimal in vitro capture of DI-PRS:protein complexes by PP7 on Dynabeads. When tested, the protocol led to the successful capture of ILF3 and PKR, two dsRNA binding proteins induced by IFN. We further developed a tap-tagging system to minimize the presence of non-specifically bound proteins to Dynabeads that may interfere with future mass spectrometry analysis. To isolate DI-PRS RNA:protein complexes from infected cells, attempts were made to rescue replicating DI-PRS genomes in the context of wild type PIV5. Similarly, efforts were made to isolate influenza A virus RNPs that contained the PRS in the neuraminidase (NA) gene from infected cells using the PP7-based protocol developed. However, for reasons discussed, unfortunately RNA:proteins complexes were not successfully purified from infected cells in either case.

A capacidade dos vírus em inibir a resposta imune inata é uma condição que os permite manterem-se na natureza. O vírus parainfluenza 5 (PIV5), por exemplo, expressa a proteína V, a qual é descrita como uma inibidora da sinalização de interferon (IFN), assim antagonizando seu efeito antiviral. O objetivo deste trabalho foi estudar os efeitos do bloqueio do receptor de IFN-I no crescimento de herpesvírus bovino tipos 1 (BoHV-1) e 5 (BoHV-5) in vitro e elucidar as relações entre a replicação viral e a resposta de IFN-I pela célula infectada. Para isso, foi modificada uma linhagem celular de bovinos (CRIB) que expressa de forma permanente a proteína V do PIV5. Esta linhagem celular foi denominada CRIB/V. Foram, então, realizados ensaios de penetração, tamanhos de placas virais e curvas de crescimento usando as amostras de BoHV-1 e BoHV-5 em células CRIB e CRIB/V. A análise com BoHV-1 não mostrou diferenças significativas nas cinéticas de penetração e crescimento. Entretanto os tamanhos de placa foram maiores em CRIB/V do que em CRIB. Para o BoHV-5, a penetração foi um pouco mais rápida em CRIB/V. Mesmo que os títulos finais não tenham sido diferentes nas duas células, o BoHV-5 alcançou títulos mais altos em CRIB/V do que em CRIB em períodos iniciais da curva de crescimento em CRIB/V em comparação a CRIB. Além disso, a média do tamanho de placa para BoHV-5 foi maior em CRIB/V do que nas células CRIB. Diferentemente das observações com BoHV-1, nossos resultados sugerem que o bloqueio do receptor de IFN-I pela proteína V facilitou a penetração, liberação e disseminação célula-célula do BoHV-5 nas células bovinas, suprimindo uma resposta antiviral, pelo menos, durante os estágios iniciais da infecção. / The ability of viruses to inhibit innate immune responses dictates a possibility to maintain in nature. For instance, Parainfluenza virus 5 (PIV5) expresses the V protein, which is described to inhibit type I interferon (IFN-I) signaling , then, antagonizing its antiviral effects. The aim of this work was to study the effect of blocking the IFN-I receptor signaling by this V protein on the growth properties of bovine herpesviruses types 1 (BoHV-1) and 5 (BoHV-5) in vitro. A plasmid expressing the V protein of PIV5 was transfected into CRIB cells. We performed penetration kinetics, measured viral plaque sizes and determined one step growth curves using BoHV-1 and BoHV-5 strains in both CRIB and CRIB/V cells. The analysis on BoHV-1 showed no significant difference in penetration and growth kinetics. However the BoHV-5 viral plaques were bigger in CRIB/V than CRIB. The penetration of BoHV-5 in CRIB/V cells was slightly faster than in CRIB cells. Even though the final titers did not differ in both cells, BoHV-5 reached higher titers in CRIB/V than in CRIB at earlier time points of its growth. Moreover, the mean plaque size caused by BoHV-5 in CRIB/V cells was spectacularly bigger in CRIB/V than in CRIB cells. Unlike the observations with BoHV-1, our results suggest that blocking the signaling via the IFN-I receptor by the V protein facilitated penetration, release and cell-to-cell spread of BoHV-5 in bovine cells, counteracting an antiviral response, at least, during the early stages of infection.

Submitted by Pós graduação Farmácia (ppgfar@ufba.br) on 2017-05-25T21:14:29Z No. of bitstreams: 1 JONATAS.pdf: 3036944 bytes, checksum: 53597feb372d2d4e4ad40f7c3d90119a (MD5) / Approved for entry into archive by Patricia Barroso (pbarroso@ufba.br) on 2017-05-29T17:25:17Z (GMT) No. of bitstreams: 1 JONATAS.pdf: 3036944 bytes, checksum: 53597feb372d2d4e4ad40f7c3d90119a (MD5) / Made available in DSpace on 2017-05-29T17:25:17Z (GMT). No. of bitstreams: 1 JONATAS.pdf: 3036944 bytes, checksum: 53597feb372d2d4e4ad40f7c3d90119a (MD5) / FAPESB / CAPES / O vírus da hepatite C (HCV) é a principal causa de hepatite crônica, insuficiência hepática terminal, cirrose, carcinoma hepatocelular e transplante hepático nos países industrializados. A infecção crônica pelo HCV promove, também, uma complexa disfunção nos linfócitos B que leva à produção de autoanticorpos não órgãos específicos (NOSA) e crioglobulinas (CG). Os mecanismos envolvidos nessa disfunção não estão completamente elucidados e os significados desses marcadores na imunopatologia da doença e no resultado da terapia antiviral são contraditórios assim como o efeito da terapia na expressão de tais marcadores durante tratamento. Objetivos: Avaliar o efeito da terapia antiviral sobre a expressão de marcadores laboratoriais de autoimunidade na hepatite C crônica e os significados de tais marcadores no prognóstico da doença e no resultado do tratamento. Pacientes, Materiais e Métodos: Foram incluídos 29 pacientes, sem tratamento prévio para a hepatite C, 15 homens e 14 mulheres, que foram investigados para autoanticorpos e crioglobulinas antes e nas semanas 12 e 24 após início do tratamento com interferon-α (IFN-α) peguilado mais ribavirina. Anticorpos séricos antimúsculo liso (SMA) e antinúcleo (ANA) foram pesquisados por imunofluorescência indireta; os autoanticorpos tireoidianos, antitireoperoxidase (anti- TPO) e antitireoglobulina (anti-TG), por ensaio imunoenzimático (ELISA). As crioglobulinas foram investigadas por crioprecipitação em tubo e por difusão em gel, enquanto o fator reumatóide (FR) foi quantificado por nefelometria. Resultados: Dos 29 pacientes incluídos, 24 (82,8%) eram portadores do genótipo 1, cinco (17,2%) estavam infectados pelo genótipo 3 e 17/29 (58,6%) tinham carga viral (CV) alta (>600.000 cópias). Na histopatologia hepática, segundo a classificação METAVIR, 72,4% (21/29) possuíam atividade necroinflamatória leve a moderada (A1 ou A2) e 51,7% (15/29) estavam com fibrose avançada e cirrose (F3 ou F4). FR, SMA e CG foram os mais prevalentes biomarcadores autoimunes nos pacientes pré-tratamento, com taxas de 62,1% (18/29), 51,7% (15/29) e 46,4% (13/28), respectivamente. A terapia antiviral diminuiu a positividade de CG após a 12ª e na 24ª semana de tratamento, P = 0,026 e P = 0,013, respectivamente. Ambas, CG e SMA foram associadas com fibrose avançada, P = 0,003, P = 0,017, respectivamente. No entanto, nenhuma positividade de ANA ou FR foi associada com histopatologia hepática (atividade necroinflamatória ou fibrose), e nem tiveram influência na resposta ao tratamento. Conclusões: Nossos resultados sugerem que a terapia antiviral diminui a produção de crioglobulinas devido à eliminação do HCV. Adicionalmente, a presença de alguns marcadores autoimunes em portadores do HCV, está associado com gravidade da doença sem qualquer influência no resultado do tratamento. / The hepatitis C virus (HCV) is the main cause of chronic hepatitis, terminal hepatic failure, cirrhosis, hepatocellular carcinoma and hepatic transplantation in the industrialized countries. HCV chronic infection also promotes a complex dysfunction in B-lymphocytes that leads to the production of non-organspecific- autoantibodies (NOSA) and cryoglobulins (CG). The mechanisms involved in this dysfunction are not fully elucidated and the meanings of these markers in the immunopathology of the disease and in the antiviral therapy outcomes are controversial as well as the effect of therapy in the expression of these markers during treatment. Objectives: The aims of this work were evaluate the effect of antiviral therapy on the expression of these autoimmune biomarkers in chronic hepatitis C and their meaning in disease prognosis and treatment outcome. Patients, Material and Methods: Twenty-nine hepatitis C untreated patients were enrolled in this study, 15 men and 14 women, and investigated for autoantibodies and cryoglobulins before and at 12 and 24 week treatment with pegylated interferon-α (IFN-α) plus ribavirin. Serum smooth muscle (SMA) and antinuclear (ANA) antibodies were tested by indirect immunofluorescence and enzyme-linked immunosorbent assay was used to determine serum anti-thyroid peroxidase (anti-TPO) and antithyroglobulin (anti-TG) antibody levels. Cryoglobulins were investigated by cryoprecipitation using tube and gel-diffusion techniques and rheumatoid factor (RF) was determined by nephelometry. Results: Twenty-four out of 29 patients (82.8%) were infected with HCV genotype, whereas five (17.2%) were infected with HCV genotype 3. High HCV load above 600,000 copies was found in 17 out of 29 patients before treatment. Twenty-one individuals had mild or moderate liver necroinflammatory activity (A1 or A2) and 15 patients and advanced fibrosis (F3) or cirrhosis (F4). RF, SMA and CG were the most prevalent autoimmune biomarkers in untreated patients with prevalence of 62.1% (18/29), 51.7% (15/29) and 46.4% (13/28), respectively. Antiviral therapy decreased cryoglobulin positivity after 12 and 24 weeks of treatment (P = 0.026 and P = 0.013, respectively). Both cryoglobulin and smooth muscle antibodies were associated with advanced fibrosis (P = 0.003 and P = 0.017, respectively). Neither ANA nor RF positivity was associated with liver histopathology (necroinflammatory activity or fibrosis), and they did not have influence on treatment outcome. Conclusions: Our results suggest that antiviral therapy decreases cryoglobulin production due to HCV eradication. In addition, the presence of some autoimmune biomarkers in HCV patients is associated with disease severity without any influence on treatment outcome.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-Graduação em Farmácia. / Made available in DSpace on 2012-10-24T08:48:03Z (GMT). No. of bitstreams: 1 266301.pdf: 6149913 bytes, checksum: 7ed745bd6f863260173b13bbbedca0c2 (MD5) / O aumento significativo no número de portadores de hepatite viral C crônica é preocupante. A infecção interfere diretamente na vida dos pacientes, dos familiares, nos sistemas de saúde, na sociedade em geral e na economia. No Brasil, os medicamentos são fornecidos pelo SUS, por meio do componente de Medicamentos de Dispensação Excepcional da Assistência Farmacêutica. O tratamento baseia-se no uso do interferon alfa 2a ou 2b, nas formas convencional ou peguilado, associado a ribavirina. O objetivo principal deste tratamento é a erradicação do vírus, porém estudos comprovaram que a eficácia do tratamento é em torno de 50%. O tratamento tem um custo elevado aos sistemas de saúde, além de produzir uma série de efeitos colaterais que prejudicam a qualidade de vida dos pacientes em tratamento.Taxas significativas de pacientes abandonam ou tem seu tratamento suspenso pela intensidade dos efeitos colaterais. O presente trabalho faz uma análise do resultado do tratamento dos pacientes que receberam medicamentos pelo Componente de Dispensação Excepcional e/ou por ação judicial e que foram atendidos no Pólo de Aplicação e Monitoramento de Medicamentos Injetáveis do Hospital Nereu Ramos (PAMMI/HNR) em Florianópolis de 2005 a 2008. Foram revisados 188 prontuários de pacientes com diagnóstico de hepatite viral C crônica e que concluíram seus tratamentos com interferon peguilado alfa (2a ou 2b) e ribavirina entre os meses de maio de 2005 até março de 2008. Para realizar este estudo de caráter retrospectivo e exploratório, foi criado um instrumento de coleta dos dados dos prontuários dos pacientes. Os dados foram digitados duplamente no EPI-DATA e analisados no EPI-INFO. Para o cálculo da resposta viral sustentada (RVS) considerando as perdas de seguimento após a conclusão dos tratamentos, utilizou-se uma estimativa de probabilidades condicionais, e obtivemos uma taxa de 26%. Durante a análise exploratória dos dados, concluiu-se que o Estado não controla resultados dos tratamentos e que o serviço enfrenta dificuldades no acompanhamento, na documentação e, principalmente, no seguimento pós-tratamento. Julgamos necessário aumentar a taxa de RVS e proporcionar um tratamento seguro aos pacientes, sugerindo a implementação do acompanhamento farmacoterapêutico baseado no modelo americano Pharmacist´s WorK-up of drug Therapy (PWDT) no PAMMI/HNR. Dados prospectivos e preliminares desta implementação apontaram que aproximadamente dois terços dos pacientes que iniciaram seus tratamentos em março de 2008 e estão acompanhados até dezembro de 2008 obtiveram 75% de resposta viral precoce (RVP) e os problemas relacionados aos medicamentos foram resolvidos de forma mais ágil e efetiva através da equipe multidisciplinar ou de encaminhamentos aos serviços especializados.

AN ABSTRACT OF THE DISSERTATION OF Priya Londhe, for the Doctor of Philosophy degree in Biochemistry and Molecular Biology, presented on 30th July, 2013 at Southern Illinois University Carbondale. TITLE: UNRAVELING THE MOLECULAR MECHANISMS OF THE CLASS II TRANSACTIVATOR IN SKELETAL MUSCLE MAJOR PROFESSOR: Dr. Judy Davie The inflammatory cytokine, interferon gamma, IFN-gamma orchestrates a diverse array of fundamental physiological processes and exhibits complex effects on myogenesis. IFN-gamma also induces the class II transactivator, CIITA, which is a critical mediator of IFN-gamma mediated repression and activation. The aims in my dissertation are directed towards understanding the role of IFN-gamma and CIITA in muscle. Stimulation by IFN-gamma in skeletal muscle cells induces CIITA expression as well as MHC class II gene expression. We show that the IFN-gamma induced inhibition of myogenesis is mediated by CIITA, which specifically interacts with myogenin. CIITA acts by both, repressing the expression and inhibiting the activity of myogenin at different stages of myogenesis. The IFN-gamma mediated repression is reversible, with myogenesis proceeding normally upon removal of IFN-gamma. We also show that CIITA is indispensible for the inhibition of myogenesis. To gain a mechanistic insight into the IFN-gamma induced repression of myogenesis, we have discovered that IFN-gamma and CIITA inhibit myogenesis by modifying gene regulation in a muscle cell subject to inflammation. We show that CIITA first interacts with JARID2, a non catalytic subunit of PRC2 complex, which induces a paused RNAPII, phosphorylated at serine 5 and then interacts with the catalytic subunit EZH2, in a JARID2 dependent manner. Our data show that both CIITA and IFN-gamma block myogenesis by the induction and recruitment of the PRC2 complex, which is normally silenced in a differentiating muscle cell. One of my dissertation aims sheds light on the silencing of CIITA in Rhabdomyosarcoma. Silencing of CIITA prevents the expression of MHC Class I and II genes. We have found that IFN-gamma signaling is intact in these cells, but pSTAT1 and IRF1 do not bind to the CIITA PIV promoter. The CIITA promoter is not hypermethylated in RD (ERMS) cells, but shows a modestly enhanced methylation status in SJRH30 (ARMS) cells. We have also observed that histone acetylation, which normally increases on the CIITA PIV promoter following IFN-gamma treatment, is blocked in both types of RMS cells. Further, our studies also impart a novel role for IFN-gamma and CIITA in inhibiting the IGF induced activation of muscle specific genes. Our data show that IFN-gamma does not block the signaling cascade of IGF. However, blocking exogenous IFN-gamma restores IGF activation of muscle specific genes. My dissertation also reveals an important role for the FACT complex in the early steps of gene activation through its histone chaperone activities that serve to open chromatin structure and facilitate transcription promoting muscle differentiation. We show that myogenin interacts with the FACT complex and the recruitment of FACT complex to muscle specific genes is dependent on myogenin. The final aim in my dissertation highlights the distinct binding profiles of the MRFs and E proteins during proliferation and differentiation. Our sequential ChIP assays show that MYOD, MYOG, and MYF5 co-occupy promoters. Taken together, my dissertation provides a comprehensive understanding of the molecular mechanisms during myogenesis and reveals the deleterious effects of chronic inflammation in skeletal muscle.

xi, 38 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / A critical question for developmental biology is the mechanism by which cells make fate decisions. In the hematopoietic system, stem cells differentiate into several different cell types, but the mechanisms that affect this process are incompletely known. Understanding these mechanisms is important because abnormal regulation of hematopoiesis can result in disease. STAT1 protein plays crucial roles in mediating innate immunity by transducing interferon signals, but recent results have also related STAT1 to hematopoietic cell differentiation. Here we cloned a previously uncharacterized zebrafish co-ortholog of the human STAT1 gene we call stat1b and investigated the functions of two zebrafish Stat1 proteins in hematopoiesis. The advantage of the zebrafish model is that, due to a whole genome duplication (WGD), some human genes have two co-orthologs in zebrafish. During evolution, co-orthologs have retained or acquired similar, complimentary, or new functions. Both stat1a and stat1b encode all four characteristic domains of the human STAT1 protein. Phylogenetic and conserved synteny analyses showed that stat1b and stat1a arose as duplicates in the teleost genome duplication event, and these analyses clarified the historical origin of the entire vertebrate STAT gene family. RT-PCR demonstrated maternal expression of both stat1a and stat1b . Expression of stat1b, but not stat1a, was detected in hematopoietic domains of embryos by in situ hybridization. Morpholino knockdown of stat1b , but not stat1a, mRNA expression resulted in a decrease in expression of the myeloid cell marker genes spi and mpx and an increase in expression of the hematopoietic progenitor marker gene scl and the erythrocyte marker gene gatal. These results show that in zebrafish, Stat1b protein functions in the commitment of hematopoietic cells to a myeloid cell fate. / Committee in charge: William Cresko, Chairperson, Biology; John Postlethwait, Advisor, Biology; Judith Eisen, Member, Biology; Jan Spitsbergen, Member, Not from U of O; J. Andrew Berglund, Outside Member, Chemistry

Made available in DSpace on 2015-05-22T18:39:49Z (GMT). No. of bitstreams: 2 305.pdf: 1935364 bytes, checksum: 2eca10b97499a0f7c7ce1c84ace159a3 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2012 / Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, Brasil / O presente estudo teve por objetivo identificar os níveis de IL-10 e IFN-gama e sua influência sobre a carga viral e a contagem de linfócitos T CD4+ em gestantes com HIV. Foi realizada uma Revisão Sistemática da Literatura, utilizando 4 bases de dados encontrando-se, ao final desta revisão, apenas 3 artigos corelacionando a produção de citocinas com níveis de linfócitos e viremia, demonstrando-se a escassez de dados a cerca do tema. Realizou-se um estudo exploratório, tipo seccional, visando avaliar os níveis plasmáticos de IL-10 e IFN-gama correlacionando com os níveis de viremia e linfócitos T CD4+ em: gestantes HIV-positivas (G1); não-gestantes HIV-positivas (G2) e gestantes saudáveis (G3). Foram encontrados níveis medianos de IL-10 mais baixos no G1 comparados ao G2 e ao G3, com diferenças estatisticamente significativa (p < 0,0001) e entre G1 e G3 ((p < 0,001). Quanto ao IFN-gama , foram encontrados níveis mais altos no G1, com diferenças significantes entre G1 e G2 (p=0,0076) e G1 e G3 (p=0,0038). No G1, houve maiores médias da IL-10 após o uso de antirretrovirais com diferenças significativas antes e depois deste uso (p = 0,01577). No G1, houve uma tendência após do uso de ARVs, entre aquelas com pior imunidade (CD4 < 350), a ter mais altos níveis de IL-10 e as com melhor imunidade (CD4 = 350), ter IL-10 mais baixa, embora não significativo (p=0,3142 e p=0,2056, respectivamente). Quanto à situação virológica, antes e após dos ARV, gestantes com CV mais altas (= 1000 cópias/ml) tendiam a ter IL-10 mais altas, mas esta diferença foi significativa apenas após os ARV (p = 0,046). Foi encontrada ainda, entre as gestantes com HIV, uma correlação fracamente positiva dos níveis de IL-10 com viremia, levando a crer que esta citocina pode interferir realmente na replicação viral e na resposta imune ao HIV. Porém, faz-se necessário novos estudos para melhor esclarecimento desta possibilidade e melhor compreensão dos mecanismos imunológicos das interações entre o HIV a gestação

Made available in DSpace on 2015-05-27T13:34:59Z (GMT). No. of bitstreams: 2 305.pdf: 1935364 bytes, checksum: 2eca10b97499a0f7c7ce1c84ace159a3 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2012 / Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, Brasil / O presente estudo teve por objetivo identificar os níveis de IL-10 e IFN-gama e sua influência sobre a carga viral e a contagem de linfócitos T CD4+ em gestantes com HIV. Foi realizada uma Revisão Sistemática da Literatura, utilizando 4 bases de dados encontrando-se, ao final desta revisão, apenas 3 artigos corelacionando a produção de citocinas com níveis de linfócitos e viremia, demonstrando-se a escassez de dados a cerca do tema. Realizou-se um estudo exploratório, tipo seccional, visando avaliar os níveis plasmáticos de IL-10 e IFN-gama correlacionando com os níveis de viremia e linfócitos T CD4+ em: gestantes HIV-positivas (G1); não-gestantes HIV-positivas (G2) e gestantes saudáveis (G3). Foram encontrados níveis medianos de IL-10 mais baixos no G1 comparados ao G2 e ao G3, com diferenças estatisticamente significativa (p < 0,0001) e entre G1 e G3 ((p < 0,001). Quanto ao IFN-gama , foram encontrados níveis mais altos no G1, com diferenças significantes entre G1 e G2 (p=0,0076) e G1 e G3 (p=0,0038). No G1, houve maiores médias da IL-10 após o uso de antirretrovirais com diferenças significativas antes e depois deste uso (p = 0,01577). No G1, houve uma tendência após do uso de ARVs, entre aquelas com pior imunidade (CD4 < 350), a ter mais altos níveis de IL-10 e as com melhor imunidade (CD4 = 350), ter IL-10 mais baixa, embora não significativo (p=0,3142 e p=0,2056, respectivamente). Quanto à situação virológica, antes e após dos ARV, gestantes com CV mais altas (= 1000 cópias/ml) tendiam a ter IL-10 mais altas, mas esta diferença foi significativa apenas após os ARV (p = 0,046). Foi encontrada ainda, entre as gestantes com HIV, uma correlação fracamente positiva dos níveis de IL-10 com viremia, levando a crer que esta citocina pode interferir realmente na replicação viral e na resposta imune ao HIV. Porém, faz-se necessário novos estudos para melhor esclarecimento desta possibilidade e melhor compreensão dos mecanismos imunológicos das interações entre o HIV a gestação