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1.
Nature ; 617(7961): 548-554, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37100905

RESUMO

Changes in patterns of activity within the medial prefrontal cortex enable rodents, non-human primates and humans to update their behaviour to adapt to changes in the environment-for example, during cognitive tasks1-5. Parvalbumin-expressing inhibitory neurons in the medial prefrontal cortex are important for learning new strategies during a rule-shift task6-8, but the circuit interactions that switch prefrontal network dynamics from maintaining to updating task-related patterns of activity remain unknown. Here we describe a mechanism that links parvalbumin-expressing neurons, a new callosal inhibitory connection, and changes in task representations. Whereas nonspecifically inhibiting all callosal projections does not prevent mice from learning rule shifts or disrupt the evolution of activity patterns, selectively inhibiting only callosal projections of parvalbumin-expressing neurons impairs rule-shift learning, desynchronizes the gamma-frequency activity that is necessary for learning8 and suppresses the reorganization of prefrontal activity patterns that normally accompanies rule-shift learning. This dissociation reveals how callosal parvalbumin-expressing projections switch the operating mode of prefrontal circuits from maintenance to updating by transmitting gamma synchrony and gating the ability of other callosal inputs to maintain previously established neural representations. Thus, callosal projections originating from parvalbumin-expressing neurons represent a key circuit locus for understanding and correcting the deficits in behavioural flexibility and gamma synchrony that have been implicated in schizophrenia and related conditions9,10.


Assuntos
Aprendizagem , Inibição Neural , Vias Neurais , Neurônios , Parvalbuminas , Córtex Pré-Frontal , Animais , Camundongos , Aprendizagem/fisiologia , Neurônios/metabolismo , Parvalbuminas/metabolismo , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/fisiologia , Esquizofrenia/fisiopatologia , Corpo Caloso/citologia , Corpo Caloso/fisiologia , Inibição Neural/fisiologia
2.
Clin Exp Immunol ; 206(1): 68-81, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34146397

RESUMO

Adoptive immunotherapy using Epstein-Barr Virus (EBV)-specific T cells is a potentially curative treatment for patients with EBV-related malignancies where other clinical options have proved ineffective. We describe improved good manufacturing practice (GMP)-compliant culture and analysis processes for conventional lymphoblastoid cell line (LCL)-driven EBV-specific T cell manufacture, and describe an improved phenotyping approach for analysing T cell products. We optimized the current LCL-mediated clinical manufacture of EBV-specific T cells to establish an improved process using xenoprotein-free GMP-compliant reagents throughout, and compared resulting products with our previous banked T cell clinical therapy. We assessed effects of changes to LCL:T cell ratio in T cell expansion, and developed a robust flow cytometric marker panel covering T cell memory, activation, differentiation and intracellular cytokine release to characterize T cells more effectively. These data were analysed using a t-stochastic neighbour embedding (t-SNE) algorithm. The optimized GMP-compliant process resulted in reduced cell processing time and improved retention and expansion of central memory T cells. Multi-parameter flow cytometry determined the optimal protocol for LCL stimulation and expansion of T cells and demonstrated that cytokine profiling using interleukin (IL)-2, tumour necrosis factor (TNF)-α and interferon (IFN)-γ was able to determine the differentiation status of T cells throughout culture and in the final product. We show that fully GMP-compliant closed-process culture of LCL-mediated EBV-specific T cells is feasible, and profiling of T cells through cytokine expression gives improved characterization of start material, in-process culture conditions and final product. Visualization of the complex multi-parameter flow cytometric data can be simplified using t-SNE analysis.


Assuntos
Técnicas de Cultura de Células , Infecções por Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4 , Imunoterapia Adotiva , Células T de Memória/imunologia , Citocinas/imunologia , Infecções por Vírus Epstein-Barr/terapia , Citometria de Fluxo , Humanos , Células T de Memória/transplante
3.
Cytotherapy ; 23(8): 730-739, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33593688

RESUMO

BACKGROUND AIMS: Cell-based therapies (CBTs) provide opportunities to treat rare and high-burden diseases. Manufacturing development of these innovative products is said to be complex and costly. However, little research is available providing insight into resource use and cost drivers. Therefore, this study aimed to assess the feasibility of estimating the cost of manufacturing development of two cell-based therapy case studies using a CBT cost framework specifically designed for small-scale cell-based therapies. METHODS: A retrospective costing study was conducted in which the cost of developing an adoptive immunotherapy of Epstein-Barr virus-specific cytotoxic T lymphocytes (CTLs) and a pluripotent stem cell (PSC) master cell bank was estimated. Manufacturing development was defined as products advancing from technology readiness level 3 to 6. The study was conducted in a Scottish facility. Development steps were recreated via developer focus groups. Data were collected from facility administrative and financial records and developer interviews. RESULTS: Application of the manufacturing cost framework to retrospectively estimate the manufacturing design cost of two case studies in one Scottish facility appeared feasible. Manufacturing development cost was estimated at £1,201,016 for CTLs and £494,456 for PSCs. Most costs were accrued in the facility domain (56% and 51%), followed by personnel (20% and 32%), materials (19% and 15%) and equipment (4% and 2%). CONCLUSIONS: Based on this study, it seems feasible to retrospectively estimate resources consumed in manufacturing development of cell-based therapies. This fosters inclusion of cost in the formulation and dissemination of best practices to facilitate early and sustainable patient access and inform future cost-conscious manufacturing design decisions.


Assuntos
Infecções por Vírus Epstein-Barr , Terapia Baseada em Transplante de Células e Tecidos , Estudos de Viabilidade , Herpesvirus Humano 4 , Humanos , Estudos Retrospectivos
4.
Stem Cells ; 37(9): 1130-1135, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31021472

RESUMO

This report summarizes the recent activity of the International Stem Cell Banking Initiative held at Harvard Stem Cell Institute, Boston, MA, USA, on June 18, 2017. In this meeting, we aimed to find consensus on ongoing issues of quality control (QC), safety, and efficacy of human pluripotent stem cell banks and their derivative cell therapy products for the global harmonization. In particular, assays for the QC testing such as pluripotency assays test and general QC testing criteria were intensively discussed. Moreover, the recent activities of global stem cell banking centers and the regulatory bodies were briefly summarized to provide an overview on global developments and issues. Stem Cells 2019;37:1130-1135.


Assuntos
Células-Tronco Pluripotentes/citologia , Células-Tronco/citologia , Bancos de Tecidos/normas , Boston , Terapia Baseada em Transplante de Células e Tecidos/métodos , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Cooperação Internacional , Controle de Qualidade
5.
Cytotherapy ; 22(12): 762-771, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32828673

RESUMO

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) isolated from various tissues are under investigation as cellular therapeutics in a wide range of diseases. It is appreciated that the basic biological functions of MSCs vary depending on tissue source. However, in-depth comparative analyses between MSCs isolated from different tissue sources under Good Manufacturing Practice (GMP) conditions are lacking. Human clinical-grade low-purity islet (LPI) fractions are generated as a byproduct of islet isolation for transplantation. MSC isolates were derived from LPI fractions with the aim of performing a systematic, standardized comparative analysis of these cells with clinically relevant bone marrow-derived MSCs (BM MSCs). METHODS: MSC isolates were derived from LPI fractions and expanded in platelet lysate-supplemented medium or in commercially available xenogeneic-free medium. Doubling rate, phenotype, differentiation potential, gene expression, protein production and immunomodulatory capacity of LPIs were compared with those of BM MSCs. RESULTS: MSCs can be readily derived in vitro from non-transplanted fractions resulting from islet cell processing (i.e., LPI MSCs). LPI MSCs grow stably in serum-free or platelet lysate-supplemented media and demonstrate in vitro self-renewal, as measured by colony-forming unit assay. LPI MSCs express patterns of chemokines and pro-regenerative factors similar to those of BM MSCs and, importantly, are equally able to attract immune cells in vitro and in vivo and suppress T-cell proliferation in vitro. Additionally, LPI MSCs can be expanded to therapeutically relevant doses at low passage under GMP conditions. CONCLUSIONS: LPI MSCs represent an alternative source of GMP MSCs with functions comparable to BM MSCs.


Assuntos
Células da Medula Óssea/citologia , Técnicas de Cultura de Células/métodos , Imunidade , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/imunologia , Neovascularização Fisiológica , Pâncreas/citologia , Biomarcadores/metabolismo , Diferenciação Celular , Proliferação de Células , Forma Celular , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Humanos , Imunomodulação , Interferon gama/metabolismo , Medicina Regenerativa , Linfócitos T/citologia
6.
Cytotherapy ; 22(7): 388-397, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32414635

RESUMO

BACKGROUND AIMS: Recent technical and clinical advances with cell-based therapies (CBTs) hold great promise in the treatment of patients with rare diseases and those with high unmet medical need. Currently the majority of CBTs are developed and manufactured in specialized academic facilities. Due to small scale, unique characteristics and specific supply chain, CBT manufacturing is considered costly compared to more conventional medicinal products. As a result, biomedical researchers and clinicians are increasingly faced with cost considerations in CBT development. The objective of this research was to develop a costing framework and methodology for academic and other small-scale facilities that manufacture cell-based therapies. METHODS: We conducted an international multi-center costing study in four facilities in Europe using eight CBTs as case studies. This study includes costs from cell or tissue procurement to release of final product for clinical use. First, via interviews with research scientists, clinicians, biomedical scientists, pharmacists and technicians, we designed a high-level costing framework. Next, we developed a more detailed uniform methodology to allocate cost items. Costs were divided into steps (tissue procurement, manufacturing and fill-finish). The steps were each subdivided into cost categories (materials, equipment, personnel and facility), and each category was broken down into facility running (fixed) costs and operational (variable) costs. The methodology was tested via the case studies and validated in developer interviews. Costs are expressed in 2018 euros (€). RESULTS: The framework and methodology were applicable across facilities and proved sensitive to differences in product and facility characteristics. Case study cost estimates ranged between €23 033 and €190 799 Euros per batch, with batch yield varying between 1 and 88 doses. The cost estimations revealed hidden costs to developers and provided insights into cost drivers to help design manufacturing best practices. CONCLUSIONS: This framework and methodology provide step-by-step guidance to estimate manufacturing costs specifically for cell-based therapies manufactured in academic and other small-scale enterprises. The framework and methodology can be used to inform and plan cost-conscious strategies for CBTs.


Assuntos
Academias e Institutos , Terapia Baseada em Transplante de Células e Tecidos/economia , Custos e Análise de Custo , Comércio , Europa (Continente) , Instalações de Saúde , Humanos
7.
Stem Cells ; 36(10): 1552-1566, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30004605

RESUMO

Although autologous induced pluripotent stem cells (iPSCs) can potentially be useful for treating patients without immune rejection, in reality it will be extremely expensive and labor-intensive to make iPSCs to realize personalized medicine. An alternative approach is to make use of human leukocyte antigen (HLA) haplotype homozygous donors to provide HLA matched iPSC products to significant numbers of patients. To establish a haplobank of iPSCs, we repurposed the cord blood bank by screening ∼4,200 high resolution HLA typed cord blood samples, and selected those homozygous for the 10 most frequent HLA-A,-B,-DRB1 haplotypes in the Korean population. Following the generation of 10 iPSC lines, we conducted a comprehensive characterization, including morphology, expression of pluripotent markers and cell surface antigens, three-germ layer formation, vector clearance, mycoplasma/microbiological/viral contamination, endotoxin, and short tandem repeat (STR) assays. Various genomic analyses using microarray and comparative genomic hybridization (aCGH)-based single nucleotide polymorphism (SNP) and copy number variation (CNV) were also conducted. These 10 HLA-homozygous iPSC lines match 41.07% of the Korean population. Comparative analysis of HLA population data shows that they are also of use in other Asian populations, such as Japan, with some limited utility in ethnically diverse populations, such as the UK. Taken together, the generation of the 10 most frequent Korean HLA-homozygous iPSC lines serves as a useful pointer for the development of optimal methods for iPSC generation and quality control and indicates the benefits and limitations of collaborative HLA driven selection of donors for future stocking of worldwide iPSC haplobanks. Stem Cells 2018;36:1552-1566.


Assuntos
Armazenamento de Sangue/métodos , Instabilidade Genômica/genética , Antígenos HLA/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Haplótipos , Antígenos de Histocompatibilidade Classe II , Humanos
8.
Cytotherapy ; 19(9): 1113-1124, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28673774

RESUMO

BACKGROUND AIMS: Autologous macrophage therapy represents a potentially significant therapeutic advance for the treatment of severe progressive liver cirrhosis. Administration of macrophages has been shown to reduce inflammation and drive fibrotic scar breakdown and tissue repair in relevant models. This therapeutic approach is being assessed for safety and feasibility in a first-in-human trial (MAcrophages Therapy for liver CirrHosis [MATCH] trial). METHODS: We outline the development and validation phases of GMP production. This includes use of the CliniMACS Prodigy cell sorting system to isolate CD14+ cells; optimizing macrophage culture conditions, assessing cellular identity, product purity, functional capability and determining the stability of the final cell product. RESULTS: The GMP-compliant macrophage products have a high level of purity and viability, and have a consistent phenotypic profile, expressing high levels of mature macrophage markers 25F9 and CD206 and low levels of CCR2. The macrophages demonstrate effective phagocytic capacity, are constitutively oriented to an anti-inflammatory profile and remain responsive to cytokine and TLR stimulation. The process validation shows that the cell product in excipient is remarkably robust, consistently passing the viability and phenotypic release criteria up to 48 hours after harvest. CONCLUSIONS: This is the first report of validation of a large-scale, fully Good Manufacturing Practice-compliant, autologous macrophage cell therapy product for the potential treatment of cirrhosis. Phenotypic and functional assays confirm that these cells remain functionally viable for up to 48 h, allowing significant flexibility in administration to patients.


Assuntos
Técnicas de Cultura de Células/métodos , Cirrose Hepática/terapia , Macrófagos/citologia , Fagocitose/fisiologia , Biomarcadores/metabolismo , Técnicas de Cultura de Células/normas , Separação Celular/métodos , Separação Celular/normas , Transplante de Células/métodos , Citocinas/farmacologia , Feminino , Humanos , Lectinas Tipo C/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Receptor de Manose , Lectinas de Ligação a Manose/metabolismo , Monócitos/citologia , Receptores CCR2/metabolismo , Receptores de Superfície Celular/metabolismo
9.
Transfusion ; 55(9): 2123-33, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26032915

RESUMO

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) is a transmissible spongiform encephalopathy affecting humans, acquired initially through infection with bovine spongiform encephalopathy (BSE). A small number of vCJD cases have been acquired through the transfusion of blood from asymptomatic donors who subsequently developed vCJD. Filter devices that selectively bind the infectious agent associated with prion disease have been developed for removal of infection from blood. This study independently assessed one such filter, the P-CAPT filter, for efficacy in removing infectivity associated with the BSE agent in sheep blood. The sheep BSE model has previously been used to evaluate the distribution of infectivity in clinically relevant blood components. This is the first study to assess the ability of the P-CAPT filter to remove endogenous infectivity associated with blood components prepared from a large animal model. STUDY DESIGN AND METHODS: Paired units of leukoreduced red blood cells (LR-RBCs) were prepared from donors at the clinical stage of infection and confirmed as having BSE. One cohort of recipients was transfused with LR-RBCs alone, whereas a parallel cohort received LR and P-CAPT-filtered RBCs (LR-RBCs-P-CAPT). RESULTS: Of 14 recipients, two have been confirmed as having BSE. These sheep had received LR-RBCs and LR-RBCs-P-CAPT from the same donor. CONCLUSIONS: The results indicate that, after leukoreduction and P-CAPT filtration, there can still be sufficient residual infectivity in sheep RBCs to transmit infection when transfused into a susceptible recipient.


Assuntos
Eritrócitos , Hemofiltração/instrumentação , Hemofiltração/métodos , Doenças Priônicas/sangue , Príons , Animais , Bovinos , Humanos , Doenças Priônicas/prevenção & controle , Príons/sangue , Príons/isolamento & purificação , Ovinos
10.
Br J Haematol ; 167(3): 402-10, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25066775

RESUMO

Epstein-Barr virus (EBV) is associated with several malignancies, including post-transplant lymphoproliferative disorder (PTLD). Conventional treatments for PTLD are often successful, but risk organ rejection and cause significant side effects. EBV-specific cytotoxic T lymphocytes (CTLs) generated in vitro from peripheral blood lymphocytes provide an alternative treatment modality with few side effects, but autologous CTLs are difficult to use in clinical practice. Here we report the establishment and operation of a bank of EBV-specific CTLs derived from 25 blood donors with human leucocyte antigen (HLA) types found at high frequency in European populations. Since licensure, there have been enquiries about 37 patients, who shared a median of three class I and two class II HLA types with these donors. Cells have been infused into ten patients with lymphoproliferative disease, eight of whom achieved complete remission. Neither patient with refractory disease was matched for HLA class II. Both cases of EBV-associated non-haematopoietic sarcoma receiving cells failed to achieve complete remission. Thirteen patients died before any cells could be issued, emphasizing that the bank should be contacted before patients become pre-terminal. Thus, this third party donor-derived EBV-specific CTL cell bank can supply most patients with appropriately matched cells and most recipients have good outcomes.


Assuntos
Infecções por Vírus Epstein-Barr/terapia , Herpesvirus Humano 4/imunologia , Imunoterapia Adotiva , Transtornos Linfoproliferativos/terapia , Linfócitos T Citotóxicos/imunologia , Bancos de Tecidos/organização & administração , Adolescente , Aloenxertos , Neoplasias do Sistema Nervoso Central/terapia , Neoplasias do Sistema Nervoso Central/virologia , Pré-Escolar , Infecções por Vírus Epstein-Barr/imunologia , Feminino , Antígenos HLA/análise , Teste de Histocompatibilidade , Humanos , Lactente , Leiomiossarcoma/terapia , Leiomiossarcoma/virologia , Licenciamento , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/virologia , Transtornos Linfoproliferativos/etiologia , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/virologia , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Complicações Pós-Operatórias/imunologia , Complicações Pós-Operatórias/terapia , Complicações Pós-Operatórias/virologia , Indução de Remissão , Sarcoma/terapia , Sarcoma/virologia , Especificidade do Receptor de Antígeno de Linfócitos T , Linfócitos T Citotóxicos/transplante , Bancos de Tecidos/normas , Resultado do Tratamento , Adulto Jovem
11.
Stem Cells ; 31(2): 338-48, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23165527

RESUMO

A decade of research has sought to identify circulating endothelial progenitor cells (EPC) in order to harness their potential for cardiovascular regeneration. Endothelial outgrowth cells (EOC) most closely fulfil the criteria for an EPC, but their origin remains obscure. Our aim was to identify the source and precursor of EOC and to assess their regenerative potential compared to mature endothelial cells. EOC are readily isolated from umbilical cord blood (6/6 donors) and peripheral blood mononuclear cells (4/6 donors) but not from bone marrow (0/6) or peripheral blood following mobilization with granulocyte-colony stimulating factor (0/6 donors). Enrichment and depletion of blood mononuclear cells demonstrated that EOC are confined to the CD34(+)CD133(-)CD146(+) cell fraction. EOC derived from blood mononuclear cells are indistinguishable from mature human umbilical vein endothelial cells (HUVEC) by morphology, surface antigen expression, immunohistochemistry, real-time polymerase chain reaction, proliferation, and functional assessments. In a subcutaneous sponge model of angiogenesis, both EOC and HUVEC contribute to de novo blood vessel formation giving rise to a similar number of vessels (7.0 ± 2.7 vs. 6.6 ± 3.7 vessels, respectively, n = 9). Bone marrow-derived outgrowth cells isolated under the same conditions expressed mesenchymal markers rather than endothelial cell markers and did not contribute to blood vessels in vivo. In this article, we confirm that EOC arise from CD34(+)CD133(-)CD146(+) mononuclear cells and are similar, if not identical, to mature endothelial cells. Our findings suggest that EOC do not arise from bone marrow and challenge the concept of a bone marrow-derived circulating precursor for endothelial cells.


Assuntos
Células Endoteliais/citologia , Sangue Fetal/citologia , Leucócitos Mononucleares/citologia , Pele/irrigação sanguínea , Antígenos CD/genética , Biomarcadores/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Linhagem da Célula , Células Cultivadas , Células Endoteliais/metabolismo , Sangue Fetal/metabolismo , Expressão Gênica , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Imunofenotipagem , Leucócitos Mononucleares/metabolismo , Neovascularização Fisiológica , Pele/citologia , Técnicas de Cultura de Tecidos
12.
Front Immunol ; 15: 1412211, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39011042

RESUMO

Adoptive immunotherapy with Epstein-Barr virus (EBV)-specific T cells is an effective treatment for relapsed or refractory EBV-induced post-transplant lymphoproliferative disorders (PTLD) with overall survival rates of up to 69%. EBV-specific T cells have been conventionally made by repeated stimulation with EBV-transformed lymphoblastoid cell lines (LCL), which act as antigen-presenting cells. However, this process is expensive, takes many months, and has practical risks associated with live virus. We have developed a peptide-based, virus-free, serum-free closed system to manufacture a bank of virus-specific T cells (VST) for clinical use. We compared these with standard LCL-derived VST using comprehensive characterization and potency assays to determine differences that might influence clinical benefits. Multi-parameter flow cytometry revealed that peptide-derived VST had an expanded central memory population and less exhaustion marker expression than LCL-derived VST. A quantitative HLA-matched allogeneic cytotoxicity assay demonstrated similar specific killing of EBV-infected targets, though peptide-derived EBV T cells had a significantly higher expression of antiviral cytokines and degranulation markers after antigen recall. High-throughput T cell receptor-beta (TCRß) sequencing demonstrated oligoclonal repertoires, with more matches to known EBV-binding complementary determining region 3 (CDR3) sequences in peptide-derived EBV T cells. Peptide-derived products showed broader and enhanced specificities to EBV nuclear antigens (EBNAs) in both CD8 and CD4 compartments, which may improve the targeting of highly expressed latency antigens in PTLD. Importantly, peptide-based isolation and expansion allows rapid manufacture and significantly increased product yield over conventional LCL-based approaches.


Assuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Imunoterapia Adotiva , Peptídeos , Humanos , Herpesvirus Humano 4/imunologia , Imunoterapia Adotiva/métodos , Peptídeos/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/terapia , Linhagem Celular Transformada , Ativação Linfocitária/imunologia , Linfócitos T/imunologia
13.
Neuroepidemiology ; 39(1): 1-18, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22777385

RESUMO

BACKGROUND: Evidence of risk of Creutzfeldt-Jakob disease (CJD) associated with medical procedures, including surgery and blood transfusion, is limited by susceptibility to bias in epidemiological studies. METHODS: Sensitivity to bias was explored using a central-birth-cohort model using data from 18 case-control studies obtained after a review of 494 reports on medical procedures and risk of CJD, systematic for the period January 1, 1989 to December 31, 2011. RESULTS: The validity of the findings in these studies may have been undermined by: recall; control selection; exposure assessment in life-time periods of different duration, out of time-at-risk of effect, or asymmetry in case/control data; and confounding by concomitant blood transfusion at the time of surgery. For sporadic CJD (sCJD), a history of surgery or blood transfusion was associated with risk in some, but not all, recent studies at a ≥10 year lag time, when controls were longitudinally sampled. Space-time aggregation of surgical events was not seen. Surgery at early clinical onset might be overrepresented among cases. Neither surgical history nor blood transfusion unlabelled for donor status, dental treatments or endoscopic examinations were linked to variant CJD (vCJD). CONCLUSIONS: These results indicate the need for further research. Common challenges within these studies include access to and content of past medical/dental treatment records for diseases with long incubation periods.


Assuntos
Transfusão de Sangue/estatística & dados numéricos , Síndrome de Creutzfeldt-Jakob/epidemiologia , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Viés , Estudos de Casos e Controles , Síndrome de Creutzfeldt-Jakob/transmissão , Humanos , Fatores de Risco
14.
J Pathol ; 223(5): 635-45, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21341268

RESUMO

Susceptibility to prion infection involves interplay between the prion strain and host genetics, but expression of the host-encoded cellular prion protein is a known prerequisite. Here we consider human embryonic stem cell (hESC) susceptibility by characterizing the genetics and expression of the normal cellular prion protein and by examining their response to acute prion exposure. Seven hESC lines were tested for their prion protein gene codon 129 genotype and this was found to broadly reflect that of the normal population. hESCs expressed prion protein mRNA, but only low levels of prion protein accumulated in self-renewing populations. Following undirected differentiation, up-regulation of prion protein expression occurred in each of the major embryonic lineages. Self-renewing populations of hESCs were challenged with infectious human and animal prions. The exposed cells rapidly and extensively took up this material, but when the infectious source was removed the level and extent of intracellular disease-associated prion protein fell rapidly. In the absence of a sufficiently sensitive test for prions to screen therapeutic cells, and given the continued use of poorly characterized human and animal bioproducts during hESC derivation and cultivation, the finding that hESCs rapidly take up and process abnormal prion protein is provocative and merits further investigation.


Assuntos
Células-Tronco Embrionárias/metabolismo , Príons/biossíntese , Animais , Bovinos , Diferenciação Celular/fisiologia , Células Cultivadas , Síndrome de Creutzfeldt-Jakob/metabolismo , Síndrome de Creutzfeldt-Jakob/transmissão , Encefalopatia Espongiforme Bovina/metabolismo , Encefalopatia Espongiforme Bovina/transmissão , Humanos , Polimorfismo Genético , Proteínas Priônicas , Príons/genética , Príons/patogenicidade , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Regulação para Cima/fisiologia
15.
BMJ Open ; 11(11): e053190, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34750149

RESUMO

INTRODUCTION: Liver cirrhosis is a growing global healthcare challenge. Cirrhosis is characterised by severe liver fibrosis, organ dysfunction and complications related to portal hypertension. There are no licensed antifibrotic or proregenerative medicines and liver transplantation is a scarce resource. Hepatic macrophages can promote both liver fibrogenesis and fibrosis regression. The safety and feasibility of peripheral infusion of ex vivo matured autologous monocyte-derived macrophages in patients with compensated cirrhosis has been demonstrated. METHODS AND ANALYSIS: The efficacy of autologous macrophage therapy, compared with standard medical care, will be investigated in a cohort of adult patients with compensated cirrhosis in a multicentre, open-label, parallel-group, phase 2, randomised controlled trial. The primary outcome is the change in Model for End-Stage Liver Disease score at 90 days. The trial will provide the first high-quality examination of the efficacy of autologous macrophage therapy in improving liver function, non-invasive fibrosis markers and other clinical outcomes in patients with compensated cirrhosis. ETHICS AND DISSEMINATION: The trial will be conducted according to the ethical principles of the Declaration of Helsinki 2013 and has been approved by Scotland A Research Ethics Committee (reference 15/SS/0121), National Health Service Lothian Research and Development department and the Medicine and Health Care Regulatory Agency-UK. Final results will be presented in peer-reviewed journals and at relevant conferences. TRIAL REGISTRATION NUMBERS: ISRCTN10368050 and EudraCT; reference 2015-000963-15.


Assuntos
Doença Hepática Terminal , Ensaios Clínicos Fase II como Assunto , Humanos , Cirrose Hepática/terapia , Macrófagos , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Pesquisa , Índice de Gravidade de Doença , Medicina Estatal , Resultado do Tratamento
17.
Mol Immunol ; 46(4): 551-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18950864

RESUMO

Ficolins and one collectin, mannan-binding lectin (MBL), are the only factors known to activate the lectin pathway (LP) of complement. There is considerable circumstantial evidence that MBL insufficiency can increase susceptibility to various infections and influence the course of several non-infectious diseases complicated by infections. Much less information is available concerning l-ficolin. We report the results of a prospective study to investigate any association between either MBL deficiency or l-ficolin deficiency with prematurity, low birthweight or perinatal infections in a large cohort of Polish neonates, representing an ethnically homogenous population (n=1832). Cord blood samples were analysed to determine mbl-2 gene variants, MBL concentrations and MBL-MASP-2 complex activities (MBL-dependent lectin pathway activity) as well as l-ficolin levels. Median concentrations of l-ficolin and MBL were 2500 and 1124 ng/ml, respectively, while median LP activity was 272 mU/ml. After genotyping, 60.6% of babies were mbl-2 A/A, 35.4% were A/O and 4% were O/O genotypes. We found relative l-ficolin deficiency to be associated with prematurity, low birthweight and infections. l-Ficolin concentration correlated with gestational age and with birthweight, independently of gestational age. Preterm deliveries (<38 weeks) occurred more frequently among neonates with low LP activity but not with those having low serum MBL levels. Similarly, no association of serum MBL deficiency with low birthweight was found, but there was a correlation between LP activity and birthweight. Genotypes conferring very low serum MBL concentrations were associated with perinatal infections, and high-MBL-conferring genotypes were associated with prematurity. Our findings suggest that l-ficolin participates in host defence during the perinatal period and constitute the first evidence that relative l-ficolin deficiency may contribute to the adverse consequences of prematurity. Some similar trends were found with facets of MBL deficiency, but the observed relationships were weaker and less consistent.


Assuntos
Recém-Nascido de Baixo Peso/imunologia , Recém-Nascido Prematuro/imunologia , Lectinas/sangue , Lectinas/genética , Lectina de Ligação a Manose/sangue , Lectina de Ligação a Manose/genética , Bactérias/imunologia , Infecções Bacterianas/genética , Infecções Bacterianas/imunologia , Infecções Bacterianas/microbiologia , Estudos de Coortes , Proteínas do Sistema Complemento/imunologia , Proteínas do Sistema Complemento/metabolismo , Feminino , Frequência do Gene/genética , Frequência do Gene/imunologia , Predisposição Genética para Doença , Genótipo , Humanos , Recém-Nascido de Baixo Peso/sangue , Recém-Nascido , Recém-Nascido Prematuro/sangue , Lectinas/deficiência , Lectinas/imunologia , Masculino , Lectina de Ligação a Manose/deficiência , Lectina de Ligação a Manose/imunologia , Serina Proteases Associadas a Proteína de Ligação a Manose/análise , Polônia , Estudos Prospectivos , Ficolinas
18.
Stem Cell Res ; 49: 102035, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33221677

RESUMO

The development of induced pluripotent stem cells (iPSCs) by Shinya Yamanaka and colleagues in 2006 has led to a potential new paradigm in cellular therapeutics, including the possibility of producing patient-specific, disease-specific and immune matched allogeneic cell therapies. One can envisage two routes to immunologically compatible iPSC therapies: using genetic modification to generate a 'universal donor' with reduced expression of Human Leukocyte Antigens (HLA) and other immunological targets or developing a haplobank containing iPSC lines specifically selected to provide HLA matched products to large portions of the population. HLA matched lines can be stored in a designated physical or virtual global bank termed a 'haplobank'. The process of 'iPSC haplobanking' refers to the banking of iPSC cell lines, selected to be homozygous for different HLA haplotypes, from which therapeutic products can be derived and matched immunologically to patient populations. By matching iPSC and derived products to a patient's HLA class I and II molecules, one would hope to significantly reduce the risk of immune rejection and the use of immunosuppressive medication. Immunosuppressive drugs are used in several conditions (including autoimmune disease and in transplantation procedures) to reduce rejection of infused cells, or transplanted tissue and organs, due to major and minor histocompatibility differences between donor and recipient. Such regimens can lead to immune compromise and pathological consequences such as opportunistic infections or malignancies due to decreased cancer immune surveillance. In this article, we will discuss what is practically involved if one is developing and executing an iPSC haplobanking strategy.


Assuntos
Células-Tronco Pluripotentes Induzidas , Bancos de Tecidos , Linhagem Celular , Antígenos HLA/genética , Haplótipos , Humanos , Doadores de Tecidos
19.
Stem Cell Res ; 49: 102036, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33212350

RESUMO

The Global Alliance for iPSC Therapies (GAiT) is a new initiative to support the implementation and clinical application of therapies derived from pluripotent stem cells to the benefit of patients globally. GAiT's mission is to serve as a central, international resource for those organisations developing therapies from clinical-grade induced pluripotent stem cells, and to support the expansion of this nascent field. With the support of its international partners, GAiT already has an early position on manufacturing, regulatory and quality standards. This article details GAiT's development, its mission and structure, as well as how, and by whom, it is funded. The article ends with brief overview of current and upcoming activities.


Assuntos
Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes , Marcha , Humanos
20.
Cell Rep ; 31(2): 107495, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32294447

RESUMO

Tbr1 is a high-confidence autism spectrum disorder (ASD) gene encoding a transcription factor with distinct pre- and postnatal functions. Postnatally, Tbr1 conditional knockout (CKO) mutants and constitutive heterozygotes have immature dendritic spines and reduced synaptic density. Tbr1 regulates expression of several genes that underlie synaptic defects, including a kinesin (Kif1a) and a WNT-signaling ligand (Wnt7b). Furthermore, Tbr1 mutant corticothalamic neurons have reduced thalamic axonal arborization. LiCl and a GSK3ß inhibitor, two WNT-signaling agonists, robustly rescue the dendritic spines and the synaptic and axonal defects, suggesting that this could have relevance for therapeutic approaches in some forms of ASD.


Assuntos
Espinhas Dendríticas/metabolismo , Proteínas com Domínio T/metabolismo , Via de Sinalização Wnt/fisiologia , Animais , Transtorno do Espectro Autista/genética , Proteínas de Ligação a DNA/metabolismo , Espinhas Dendríticas/fisiologia , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurogênese/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Sinapses/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/fisiologia , Tálamo/metabolismo , Via de Sinalização Wnt/genética
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