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1.
J Cell Mol Med ; 24(23): 14026-14038, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33140521

RESUMO

Systemic Sclerosis (SSc) is a rare fibrotic autoimmune disorder for which no curative treatments currently exist. Metabolic remodelling has recently been implicated in other autoimmune diseases; however, its potential role in SSc has received little attention. Here, we aimed to determine whether changes to glycolysis and glutaminolysis are important features of skin fibrosis. TGF-ß1, the quintessential pro-fibrotic stimulus, was used to activate fibrotic pathways in NHDFs in vitro. Dermal fibroblasts derived from lesions of SSc patients were also used for in vitro experiments. Parameters of glycolytic function were assessed using by measuring extracellular acidification in response to glycolytic activators/inhibitors, whilst markers of fibrosis were measured by Western blotting following the use of the glycolysis inhibitors 2-dg and 3PO and the glutaminolysis inhibitor G968. Succinate was also measured after TGF-ß1 stimulation. Itaconate was added to SSc fibroblasts and collagen examined. TGF-ß1 up-regulates glycolysis in dermal fibroblasts, and inhibition of glycolysis attenuates its pro-fibrotic effects. Furthermore, inhibition of glutamine metabolism also reverses TGF-ß1-induced fibrosis, whilst glutaminase expression is up-regulated in dermal fibroblasts derived from SSc patient skin lesions, suggesting that enhanced glutamine metabolism is another aspect of the pro-fibrotic metabolic phenotype in skin fibrosis. TGF-ß1 was also able to enhance succinate production, with increased succinate shown to be associated with increased collagen expression. Incubation of SSc cells with itaconate, an important metabolite, reduced collagen expression. TGF-ß1 activation of glycolysis is a key feature of the fibrotic phenotype induced by TGF-B1 in skin cells, whilst increased glutaminolysis is also evident in SSc fibroblasts.


Assuntos
Reprogramação Celular , Metabolismo Energético , Glutamina/metabolismo , Miofibroblastos/metabolismo , Escleroderma Sistêmico/etiologia , Escleroderma Sistêmico/metabolismo , Biomarcadores , Células Cultivadas , Colágeno/metabolismo , Metabolismo Energético/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibrose , Glicólise/efeitos dos fármacos , Humanos , Modelos Biológicos , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Escleroderma Sistêmico/patologia , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/farmacologia
2.
Rheumatology (Oxford) ; 58(3): 527-535, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30462328

RESUMO

OBJECTIVE: SSc is an autoimmune connective tissue disease that results in skin fibrosis and currently has no effective treatment. Epigenetic modifications have been described and these may be key in initiating and driving fibroblast activation. Among these epigenetic modifications methylation may be of central importance. The aim of this study was to examine the role of methyl cap binding protein-2 (MeCP2) in SSc fibrosis. METHODS: We used healthy and SSc dermal fibroblasts to examine the role of MeCP2, using both small interfering RNA silencing and lentiviral overexpression to determine its effects. We also examined the expression of MeCP2 in SSc fibroblasts by immunoblotting. miRNA132 was quantified by Taqman real time PCR. RESULTS: We demonstrated that TGF-ß1 induced the expression of MeCP2 in normal cells, and showed that SSc fibroblasts expressed high levels of MeCP2 under basal conditions. MeCP2 positively regulated the expression of extracellular matrix through epigenetic repression of the Wnt antagonist sFRP-1, leading to enhanced Wnt signalling. This mediated fibrosis through glycolysis, as the glycolysis inhibitor 2-deoxyglucose diminished the Wnt-mediated collagen expression. MiR132 expression was reduced in SSc fibroblasts. CONCLUSION: The results suggest that an epigenetic loop exists mediating fibrosis. Targeting of MeCP2, as a key epigenetic regulator, may be a promising therapeutic approach, as would targeting the metabolic reprogramming that occurs through aerobic glycolysis.


Assuntos
Fibroblastos/metabolismo , Proteína 2 de Ligação a Metil-CpG/metabolismo , Escleroderma Sistêmico/metabolismo , Pele/metabolismo , Epigênese Genética , Matriz Extracelular/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Células HEK293 , Humanos , Proteína 2 de Ligação a Metil-CpG/genética , RNA Interferente Pequeno , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/patologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Pele/efeitos dos fármacos , Pele/patologia , Fator de Crescimento Transformador beta1/farmacologia
3.
Cell Physiol Biochem ; 45(2): 783-794, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29414811

RESUMO

BACKGROUND/AIMS: The Trabecular meshwork (TM) is the tissue responsible for outflow resistance and therefore intraocular pressure. TM cells contain a contractile apparatus that is composed of actin stress fibres which run parallel to the axis of the cell and are responsible for facilitating contraction. Cross-Linked Actin Networks (CLANs) are polygonal arrangements of actin that form a geodesic network found predominantly in TM cells both in situ and in vitro. The aim of this work is to determine the functional significance of CLANs in TM cells and to assess the effect of mechanical stretch stimulation on the induction (or not) of CLANs. METHODS: We used collagen gel contraction models to demonstrate functional impairment of cells when induced to express CLANs in situ. Cyclic mechanical stretch was used to stimulate cells and measure CLANs Results: CLANs inhibited contraction and cyclic mechanical stretch induced CLANs. Furthermore, we also demonstrated that using shape alone we could predict the appearance of CLANs using a simple light microscopy technique. CONCLUSION: Taken together we have now shown, for the first time, a functional deficit In TM cells with CLANs Furthermore that shape alone can predict the appearance of CLAN containing cells. CLANs can now be linked to a functional effect and may underlie the appearance of CLANs with the pathology of primary open angle glaucoma (POAG).


Assuntos
Citoesqueleto de Actina/fisiologia , Actinas/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo I/química , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Dexametasona/farmacologia , Ensaio de Imunoadsorção Enzimática , Peróxido de Hidrogênio/análise , Interleucina-6/análise , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Microscopia Confocal , Estresse Fisiológico , Imagem com Lapso de Tempo , Malha Trabecular/citologia , Malha Trabecular/metabolismo , Malha Trabecular/patologia , Fator de Crescimento Transformador beta2/análise
4.
Curr Rheumatol Rep ; 19(1): 2, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28116578

RESUMO

PURPOSE OF REVIEW: Systemic sclerosis (SSc) is a heterogeneous autoimmune disease which has defined three hallmarks: Small vessel vasculopathy, production of autoantibodies and fibroblast dysfunction. The exact aetiology of the disease remains unknown, due to the complex nature of the cellular signalling pathways involved. However, there is strong and consistent evidence that the innate system, in particular toll-like receptor signalling, is contributing to the progression and perhaps onset of systemic sclerosis. In light of this evidence, this review examines the role of innate immunity in systemic sclerosis and where appropriate suggests avenues for therapeutic modulation in SSc. RECENT FINDINGS: Multiple lines of evidence suggest that Toll-like receptors (TLRs) are dysregulated and emerging evidence suggests that many endogenous ligands are also elevated in the disease leading to 'sterile inflammation' and ultimately the induction of fibrosis. Currently, no effective therapy exists and exploiting the innate immune system perturbation may be one possible avenue. Innate immune dysregulation is key in SSc pathogenesis and may represent a novel target.


Assuntos
Escleroderma Sistêmico/imunologia , Proteínas do Sistema Complemento/imunologia , Humanos , Imunidade Inata , Inflamassomos/imunologia , Macrófagos/imunologia , Mastócitos/imunologia , Monócitos/imunologia , Receptores Toll-Like/imunologia
5.
Int J Mol Sci ; 17(9)2016 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-27618032

RESUMO

Hepatic damage can be caused by an array of factors which, if sustained, can lead to hepatic fibrosis.[...].


Assuntos
Fibrose , MicroRNAs/genética , Humanos , Cirrose Hepática
6.
Stroke ; 44(2): 462-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23299497

RESUMO

BACKGROUND AND PURPOSE: The Barthel Index (BI) is a 10-item measure of activities of daily living which is frequently used in clinical practice and as a trial outcome measure in stroke. We sought to describe the reliability (interobserver variability) of standard BI in stroke cohorts using systematic review and meta-analysis of published studies. METHODS: Two assessors independently searched various multidisciplinary electronic databases from inception to April 2012 inclusive. Inclusion criteria comprised: original research, human stroke participants, and inter-rater reliability data on equivalent methods of BI administration. Manuscripts were reviewed against prespecified inclusion criteria. Primary outcome for meta-analysis was reliability, measured by weighted κ (κw). RESULTS: From 20 210 titles, 306 abstracts were reviewed, 12 studies met inclusion criteria, and 10 were included in meta-analysis (n=543 participants; range of participants in studies, 7-21). There was substantial clinical heterogeneity with respect to method of BI application; population studied and assessors. Two papers were graded high quality. Overall interobserver reliability of standard administration of the BI was excellent (κw, 0.93; 95% confidence interval, 0.90-0.96 random effects modeling). CONCLUSIONS: The BI has excellent inter-rater reliability for standard administration after stroke. However, included studies were modest in size, with clinical heterogeneity and variable methodological quality. Despite these limitations, standard BI seems an appropriate outcome measure for stroke trials and practice.


Assuntos
Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Sobreviventes , Atividades Cotidianas , Humanos , Variações Dependentes do Observador , Reprodutibilidade dos Testes
7.
Retrovirology ; 9: 56, 2012 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-22799593

RESUMO

BACKGROUND: Current data suggest that an efficacious human immunodeficiency virus type 1 (HIV-1) vaccine should elicit both adaptive humoral and cell mediated immune responses. Such a vaccine will also need to protect against infection from a range of heterologous viral variants. Here we have developed a simian-human immunodeficiency virus (SHIV) based model in cynomolgus macaques to investigate the breadth of protection conferred by HIV-1W61D recombinant gp120 vaccination against SHIVsbg and SHIVSF33 challenge, and to identify correlates of protection. RESULTS: High titres of anti-envelope antibodies were detected in all vaccinees. The antibodies reacted with both the homologous HIV-1W61D and heterologous HIV-1IIIB envelope rgp120 which has an identical sequence to the SHIVsbg challenge virus. Significant titres of virus neutralising antibodies were detected against SHIVW61D expressing an envelope homologous with the vaccine, but only limited cross neutralisation against SHIVsbg, SHIV-4 and SHIVSF33 was observed. Protection against SHIVsbg infection was observed in vaccinated animals but none was observed against SHIVSF33 challenge. Transfer of immune sera from vaccinated macaques to naive recipients did not confer protection against SHIVsbg challenge. In a follow-up study, T cell proliferative responses detected after immunisation with the same vaccine against a single peptide present in the second conserved region 2 of HIV-1 W61D and HIV-1 IIIB gp120, but not SF33 gp120. CONCLUSIONS: Following extended vaccination with a HIV-1 rgp120 vaccine, protection was observed against heterologous virus challenge with SHIVsbg, but not SHIVSF33. Protection did not correlate with serological responses generated by vaccination, but might be associated with T cell proliferative responses against an epitope in the second constant region of HIV-1 gp120. Broader protection may be obtained with recombinant HIV-1 envelope based vaccines formulated with adjuvants that generate proliferative T cell responses in addition to broadly neutralising antibodies.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/terapia , HIV-1/imunologia , Vacinas contra a AIDS/administração & dosagem , Animais , Proliferação de Células , Modelos Animais de Doenças , Seguimentos , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/administração & dosagem , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/genética , HIV-1/patogenicidade , Soros Imunes/administração & dosagem , Soros Imunes/imunologia , Imunização , Macaca fascicularis , Testes de Neutralização , RNA Viral/análise , RNA Viral/genética , Vírus da Imunodeficiência Símia/imunologia , Linfócitos T/imunologia , Linfócitos T/virologia , Fatores de Tempo , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Carga Viral
8.
Front Cell Dev Biol ; 9: 681061, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34150776

RESUMO

OBJECTIVE: Systemic Sclerosis is an autoimmune connective tissue disease which results in fibrosis of the skin and lungs. The disease is characterized by activation of myofibroblasts but what governs this is unknown. Gremlin-1 is a BMP antagonist that is developmentally regulated and we sought to investigate its role in Systemic Sclerosis. METHODS: Dermal fibroblasts were transfected with Grem1pcDNA3.1 expression vectors or empty vectors. Various markers of myofibroblasts were measured at the mRNA and protein levels. Scratch wound assays were also performed. Media Transfer experiments were performed to evaluate cytokine like effects. Various inhibitors of TGF-ß signaling and MAPK signaling were used post-transfection. siRNA to Gremlin-1 in SSc dermal fibroblasts were performed to evaluate the role of Gremlin-1. Different cytokines were incubated with fibroblasts and Gremlin-1 measured. Bleomycin was used as model of fibrosis and immunohistochemistry performed. RESULTS: Overexpression of Gremlin-1 was achieved in primary dermal fibroblasts and lead to activation of quiescent cells to myofibroblasts indicated by collagen and α-Smooth muscle actin. Overexpression also led to functional effects. This was associated with increased TGF-ß1 levels and SBE luciferase activity but not increased Thrombospondin-1 expression. Inhibition of Gremlin-1 overexpression cells with antibodies to TGF-ß1 but not isotype controls led to reduced collagen and various TGF-ß pathway chemical inhibitors also led to reduced collagen levels. In SSc cells siRNA mediated reduction of Gremlin-1 reduced collagen expression and CTGF gene and protein levels in these cells. IL-13 did not lead to elevated Gremlin-1 expression nor did IL-11. Gremlin-1 was elevated in an animal model of fibrosis compared to NaCl-treated mice. CONCLUSION: Gremlin-1 is a key regulator of myofibroblast transition leading to enhanced ECM deposition. Strategies that block Gremlin-1 maybe a possible therapeutic target in fibrotic diseases such as SSc.

9.
Front Nutr ; 7: 575146, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33251241

RESUMO

Great importance is being given to the impact our food supply chain and consumers' food habits are having on the environment, human health, and animal welfare. One of the latest developments aiming at positively changing the food ecosystem is represented by cultured meat. This form of cellular agriculture has the objective to generate slaughter-free meat products starting from the cultivation of few cells harvested from the animal tissue of interest. As a consequence, a large number of cells has to be generated at a reasonable cost. Just to give an idea of the scale, there were billions of cells just in a bite of the first cultured-meat burger. Thus, one of the major challenges faced by the scientists involved in this new ambitious and fascinating field, is how to efficiently scale-up cell manufacture. Considering the great potential presented by cultured meat, audiences from different backgrounds are very interested in this topic and eager to be informed of the challenges and possible solutions in this area. In light of this, we will provide an overview of the main existing bioprocessing technologies used to scale-up adherent cells at a small and large scale. Thus, giving a brief technical description of these bioprocesses, with the main associated advantages and disadvantages. Moreover, we will introduce an alternative solution we believe has the potential to revolutionize the way adherent cells are grown, helping cultured meat become a reality.

10.
Echo Res Pract ; 7(1): G43-G49, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32190342

RESUMO

This article sets out a summary of standards for departmental accreditation set by the British Society of Echocardiography (BSE) Departmental Accreditation Committee. Full accreditation standards are available at www.bsecho.org. The BSE were the first national organisation to establish a quality standards framework for departments that support the practice of individual echocardiographers. This is an updated version which recognises that, not only should all echocardiographers be individually accredited as competent to practice, but that departments also need to be well organised and have the facilities, equipment and processes to ensure the services they deliver are of an appropriate clinical standard. In combination with individual accreditation, departmental accreditation lays down standards to help ensure safe and effective patient care. These standards supersede the 2012 BSE Departmental Accreditation Standards. Standards are set to cover all potential areas of practice, including transthoracic (level 2) echocardiography, transoesophageal echocardiography, stress echocardiography, training, and emergency (level 1) echocardiography. The emergency echocardiography standard is a new addition to departmental accreditation and has been developed with input from the Intensive Care Society.

11.
Echo Res Pract ; 5(4): G25-G33, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30400064

RESUMO

Background Quality assurance (QA) of echocardiographic studies is vital to ensure that clinicians can act on findings of high quality to deliver excellent patient care. To date, there is a paucity of published guidance on how to perform this QA. The British Society of Echocardiography (BSE) has previously produced an Echocardiography Quality Framework (EQF) to assist departments with their QA processes. This article expands on the EQF with a structured yet versatile approach on how to analyse echocardiographic departments to ensure high-quality standards are met. In addition, a process is detailed for departments that are seeking to demonstrate to external bodies adherence to a robust QA process. Methods The EQF consists of four domains. These include assessment of Echo Quality (including study acquisition and report generation); Reproducibility & Consistency (including analysis of individual variability when compared to the group and focused clinical audit), Education & Training (for all providers and service users) and Customer & Staff Satisfaction (of both service users and patients/their carers). Examples of what could be done in each of these areas are presented. Furthermore, evidence of participation in each domain is categorised against a red, amber or green rating: with an amber or green rating signifying that a quantifiable level of engagement in that aspect of QA has been achieved. Conclusion The proposed EQF is a powerful tool that focuses the limited time available for departmental QA on areas of practice where a change in patient experience or outcome is most likely to occur.

12.
J Invest Dermatol ; 137(5): 1003-1004, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28411831

RESUMO

Systemic sclerosis is an autoimmune disease characterized by T-cell infiltration in the skin that leads to fibrosis, which can be life-limiting. Although T cells are important, it is not known which types mediate the fibrosis. The work presented by Li et al shows that memory CD8+ cytotoxic T cells mediate fibrosis via the secretion of IL-13. IL-13 is profibrotic, and it is released in a higher amount in patients with systemic sclerosis. This suggests that targeting IL-13 may be therapeutically beneficial.


Assuntos
Interleucina-13 , Escleroderma Sistêmico/imunologia , Fibrose , Humanos , Pele/imunologia
13.
Immunotargets Ther ; 5: 69-80, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27579291

RESUMO

Autoinflammatory diseases are defined as the loss of self-tolerance in which an inflammatory response to self-antigens occurs, which are a significant global burden. Toll-like receptors are key pattern recognition receptors, which integrate signals leading to the activation of transcription factors and ultimately proinflammatory cytokines. Recently, it has become apparent that these are at the nexus of autoinflammatory diseases making them viable and attractive drug targets. The aim of this review was to evaluate the role of innate immunity in autoinflammatory conditions alongside the role of negative regulation while suggesting possible therapeutic targets.

14.
J Affect Disord ; 87(1): 83-9, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15967233

RESUMO

BACKGROUND: The personality dimensions of harm avoidance (HA) and self-directedness (SD), as measured by the Temperament and Character Inventory (TCI), have been widely associated with depression and there is preliminary evidence that they may represent trait markers for depression. However, many studies in this area are limited by the use of heterogeneous samples of depressed patients and by the confounding effect of depressed mood during personality testing. The current study compares TCI personality dimension scores in a group of euthymic young adults with recurrent early-onset major depressive disorder (RE-MDD) to well-matched euthymic controls. METHODS: Fifty-two young adults with a past history of RE-MDD were recruited from consecutive referrals to a psychiatric clinic at a university health service. Eighty nine controls were also recruited. Euthymia was established in patients by a score of less than 9 on the Hamilton Rating Scale for Depression (HRSD) and in controls by a Becks Depression Inventory (BDI) score of less than 10. All participants completed the TCI-125. RESULTS: Patients and controls were well matched in terms of sociodemographic profile. Euthymic RE-MDD patients scored significantly higher than controls on the temperament dimension of harm avoidance (HA; mean score 14.5 versus 7.8, p<0.0001) and significantly lower than controls on the character dimension of self-directedness (SD; mean score 14.1 versus 19.9, p<0.0001). Covariance analysis suggested that both HA and SD contributed independently to the familial risk of depression. LIMITATIONS: Subjects and controls all came from relatively affluent social backgrounds-these findings may not generalise to more socioeconomically diverse populations. The possibility of a 'scarring effect' of depressive episodes on self-reported personality dimension scores cannot be excluded. CONCLUSIONS: High HA and low SD represent trait markers for liability to recurrent major depressive disorder in young adults. Further research is needed to replicate these findings and to assess the contribution that the experience of depressive episodes makes to self-reported personality dimension scores.


Assuntos
Transtorno Depressivo Maior/psicologia , Personalidade , Autoimagem , Adulto , Idade de Início , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Transtornos da Personalidade/psicologia , Inventário de Personalidade , Recidiva
15.
16.
Front Neuroenergetics ; 2: 131, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21031160

RESUMO

Microglia are immune cells within the central nervous system. In brain-developing tumors, gliomas are able to silence the defense and immune functions of microglia, a phenomenon which strongly contributes to tumor progression and treatment resistance. Being activated and highly motile, microglia infiltrate tumors and secrete macrophagic chemoattractant factors. Thereafter, the tumor cells shut down their immune properties and stimulate the microglia to release tumor growth-promoting factors. The result of such modulation is that a kind of symbiosis occurs between microglia and tumor cells, in favor of tumor growth. However, little is known about microglial phenotype and metabolic modifications in a tumoral environment. Co-cultures were performed using CHME5 microglia cells grown on collagen beads or on coverslips and placed on monolayer of C6 cells, limiting cell/cell contacts. Phagocytic behavior and expression of macrophagic and cytoskeleton markers were monitored. Respiratory properties and energetic metabolism were also studied with regard to the activated phenotype of microglia. In co-cultures, transitory modifications of microglial morphology and metabolism were observed linked to a concomitant transitory increase of phagocytic properties. Therefore, after 1 h of co-culture, microglia were activated but when longer in contact with tumor cells, phagocytic properties appear silenced. Like the behavior of the phenotype, microglial respiration showed a transitory readjustment although the mitochondria maintained their perinuclear relocation. Nevertheless, the energetic metabolism of the microglia was altered, suggesting a new energetic steady state. The results clearly indicate that like the depressed immune properties, the macrophagic and metabolic status of the microglia is quickly driven by the glioma environment, despite short initial phagocytic activation. Such findings question the possible contribution of diffusible tumor factors to the microglial metabolism.

17.
J Gen Virol ; 89(Pt 9): 2240-2251, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18753233

RESUMO

Vaccination with live attenuated simian immunodeficiency virus (SIVmacC8) confers potent, reproducible protection against homologous wild-type virus challenge (SIVmacJ5). The ability of SIVmacC8 to confer resistance to superinfection with an uncloned ex vivo derivative of SIVmac251 (SIVmac32H/L28) was investigated. In naïve, Mauritian-derived cynomolgus macaques (Macaca fascicularis), SIVmac32H/L28 replicated to high peak titres (>10(8) SIV RNA copies ml(-1)), persisted at high levels and induced distinctive pathology in lymphoid tissues. In cynomolgus macaques vaccinated with SIVmacC8, no evidence of detectable superinfection was observed in 3/8 vaccinates following challenge 3 or 20 weeks later with SIVmac32H/L28. Analyses after SIVmac32H/L28 challenge revealed a significant reduction in viral RNA (P<0.001) and DNA levels between 20 week vaccinates and challenge controls. Amongst 3 week vaccinates, less potent protection was observed. However, analysis of env from breakthrough virus indicated >99% sequence similarity with the vaccine virus. Highly sensitive PCR assays that distinguish vaccine and challenge virus stocks demonstrated restimulation of replication of the vaccine virus SIVmacC8 in the face of potent protection against a vigorous, homologous challenge virus. Vaccine-induced antiviral neutralizing antibodies and anti-Nef CD8+ cytotoxic T cell responses did not correlate with the outcome of the challenge. Defining the mechanism of vaccine protection will need to account for the effective control of a genetically closely related challenge virus whilst remaining unable to suppress replication of the pre-existing vaccine virus. The role of innate and intrinsic anti-retroviral immunity in the protection conferred by live attenuated SIV vaccines warrants careful study.


Assuntos
Vacinas contra a SAIDS/farmacologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Vírus da Imunodeficiência Símia/fisiologia , Superinfecção/prevenção & controle , Animais , Sequência de Bases , DNA Viral/sangue , DNA Viral/genética , Produtos do Gene env/genética , Produtos do Gene env/imunologia , Imunidade Celular , Macaca fascicularis , RNA Viral/sangue , RNA Viral/genética , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/patogenicidade , Superinfecção/imunologia , Superinfecção/virologia , Vacinas Atenuadas/farmacologia , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/imunologia , Replicação Viral
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