Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nat Immunol ; 12(1): 45-53, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21151101

RESUMO

Cytotoxic T lymphocytes (CTLs) recognize peptides presented by HLA class I molecules on the cell surface. The C terminus of these CTL epitopes is considered to be produced by the proteasome. Here we demonstrate that the cytosolic endopeptidases nardilysin and thimet oligopeptidase (TOP) complemented proteasome activity. Nardilysin and TOP were required, either together or alone, for the generation of a tumor-specific CTL epitope from PRAME, an immunodominant CTL epitope from Epstein-Barr virus protein EBNA3C, and a clinically important epitope from the melanoma protein MART-1. TOP functioned as C-terminal trimming peptidase in antigen processing, and nardilysin contributed to both the C-terminal and N-terminal generation of CTL epitopes. By broadening the antigenic peptide repertoire, nardilysin and TOP strengthen the immune defense against intracellular pathogens and cancer.


Assuntos
Antígenos de Neoplasias/metabolismo , Epitopos de Linfócito T/metabolismo , Metaloendopeptidases/metabolismo , Linfócitos T Citotóxicos/metabolismo , Apresentação de Antígeno/genética , Antígenos de Neoplasias/química , Antígenos de Neoplasias/imunologia , Citotoxicidade Imunológica/genética , Epitopos de Linfócito T/química , Epitopos de Linfócito T/imunologia , Antígeno HLA-A3/metabolismo , Humanos , Células K562 , Metaloendopeptidases/genética , Metaloendopeptidases/imunologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , RNA Interferente Pequeno/genética , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/patologia , Transgenes/genética
2.
Cell ; 133(7): 1202-13, 2008 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-18585354

RESUMO

The multimeric membrane-tethering complexes TRAPPI and TRAPPII share seven subunits, of which four (Bet3p, Bet5p, Trs23p, and Trs31p) are minimally needed to activate the Rab GTPase Ypt1p in an event preceding membrane fusion. Here, we present the structure of a heteropentameric TRAPPI assembly complexed with Ypt1p. We propose that TRAPPI facilitates nucleotide exchange primarily by stabilizing the nucleotide-binding pocket of Ypt1p in an open, solvent-accessible form. Bet3p, Bet5p, and Trs23p interact directly with Ypt1p to stabilize this form, while the C terminus of Bet3p invades the pocket to participate in its remodeling. The Trs31p subunit does not interact directly with the GTPase but allosterically regulates the TRAPPI interface with Ypt1p. Our findings imply that TRAPPII activates Ypt1p by an identical mechanism. This view of a multimeric membrane-tethering assembly complexed with a Rab provides a framework for understanding events preceding membrane fusion at the molecular level.


Assuntos
Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Retículo Endoplasmático/metabolismo , Ativação Enzimática , Complexo de Golgi/metabolismo , Fatores de Troca do Nucleotídeo Guanina/química , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Modelos Moleculares , Mapeamento de Interação de Proteínas , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética , Proteínas rab de Ligação ao GTP/química
3.
BMC Med Educ ; 23(1): 256, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37069564

RESUMO

BACKGROUND: Practical skill assessment is an important part of the learning process to confirm competencies in acquired medical knowledge. OBJECTIVE: This study aimed to compare the assessments of endotracheal intubation skills using the HybridLab® methodology between students and teacher in terms of interobserver reliability. METHODS: Reliability analysis was performed with observational data (data are reported according to STROBE guidelines). The study was conducted in two countries, the Lithuanian University of Health Science (LUHS) and Pennsylvania State University (PSU) in the US, between 1 January and 30 June 2020. A total of 92 students (60 from LUHS and 32 from PSU) were trained in endotracheal intubation using an algorithm-driven hybrid learning method. At the end of the training session, the participants had to complete the evaluation scenario, which was assessed by one of the students and evaluated remotely by a single teacher. The student assessment of the endotracheal intubation procedure was compared with the teacher's assessment using correlation and estimation of the intraclass correlation coefficient. RESULTS: Overall, the medians of the student and teacher assessments were both 100% (0%). Spearman's correlation coefficient between the student and teacher assessments was 0.879 (p = 0.001). The intraclass correlation coefficient used for interobserver variations between the students and teacher was 0.883 (95% confidence interval from 0.824 to 0.923). CONCLUSIONS: The algorithm-driven hybrid learning method allows students to reliably assess endotracheal intubation skills to a level comparable with that of the teacher's evaluation. This learning method has the potential to be a cost-effective and efficient way to provide high-quality education while also saving human resources.


Assuntos
Aprendizagem , Estudantes , Humanos , Reprodutibilidade dos Testes , Avaliação Educacional , Intubação Intratraqueal
4.
BMC Anesthesiol ; 22(1): 42, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35135495

RESUMO

BACKGROUND: Simulation-based training is a clinical skill learning method that can replicate real-life situations in an interactive manner. In our study, we compared a novel hybrid learning method with conventional simulation learning in the teaching of endotracheal intubation. METHODS: One hundred medical students and residents were randomly divided into two groups and were taught endotracheal intubation. The first group of subjects (control group) studied in the conventional way via lectures and classic simulation-based training sessions. The second group (experimental group) used the hybrid learning method where the teaching process consisted of distance learning and small group peer-to-peer simulation training sessions with remote supervision by the instructors. After the teaching process, endotracheal intubation (ETI) procedures were performed on real patients under the supervision of an anesthesiologist in an operating theater. Each step of the procedure was evaluated by a standardized assessment form (checklist) for both groups. RESULTS: Thirty-four subjects constituted the control group and 43 were in the experimental group. The hybrid group (88%) showed significantly better ETI performance in the operating theater compared with the control group (52%). Further, all hybrid group subjects (100%) followed the correct sequence of actions, while in the control group only 32% followed proper sequencing. CONCLUSIONS: We conclude that our novel algorithm-driven hybrid simulation learning method improves acquisition of endotracheal intubation with a high degree of acceptability and satisfaction by the learners' as compared with classic simulation-based training.


Assuntos
Anestesiologia/educação , Competência Clínica/estatística & dados numéricos , Simulação por Computador/estatística & dados numéricos , Intubação Intratraqueal/métodos , Treinamento por Simulação/métodos , Estudantes de Medicina/estatística & dados numéricos , Adulto , Algoritmos , Avaliação Educacional/métodos , Avaliação Educacional/estatística & dados numéricos , Feminino , Humanos , Internato e Residência , Masculino , Adulto Jovem
5.
Proc Natl Acad Sci U S A ; 114(14): E2826-E2835, 2017 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-28325868

RESUMO

Insulin-degrading enzyme (IDE) hydrolyzes bioactive peptides, including insulin, amylin, and the amyloid ß peptides. Polyanions activate IDE toward some substrates, yet an endogenous polyanion activator has not yet been identified. Here we report that inositol phosphates (InsPs) and phosphatdidylinositol phosphates (PtdInsPs) serve as activators of IDE. InsPs and PtdInsPs interact with the polyanion-binding site located on an inner chamber wall of the enzyme. InsPs activate IDE by up to ∼95-fold, affecting primarily Vmax The extent of activation and binding affinity correlate with the number of phosphate groups on the inositol ring, with phosphate positional effects observed. IDE binds PtdInsPs from solution, immobilized on membranes, or presented in liposomes. Interaction with PtdInsPs, likely PtdIns(3)P, plays a role in localizing IDE to endosomes, where the enzyme reportedly encounters physiological substrates. Thus, InsPs and PtdInsPs can serve as endogenous modulators of IDE activity, as well as regulators of its intracellular spatial distribution.


Assuntos
Endossomos/metabolismo , Fosfatos de Inositol/metabolismo , Insulisina/metabolismo , Fosfatidilinositóis/metabolismo , Androstadienos/farmacologia , Animais , Sítios de Ligação , Células COS , Chlorocebus aethiops , Endossomos/efeitos dos fármacos , Ativação Enzimática , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Insulisina/química , Insulisina/genética , Lipossomos/química , Lipossomos/metabolismo , Mutação , Wortmanina
6.
Adv Neonatal Care ; 20(2): 176-179, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31764212

RESUMO

BACKGROUND: Chest tube placement is an important skill for providers and bedside nurses caring for critically ill infants, allowing for the evacuation of pleural fluid and pneumothoraces. No realistic simulation models are commercially available for trainees to practice and learn this skill on infants. PURPOSE: Our objective was to develop an inexpensive and reproducible model for percutaneous pleural pigtail placement for pleural fluid removal via the Seldinger technique. METHODS: The model was developed using hardware material and a discarded infant resuscitation manikin. The rib cage was constructed using electrical cable wires. Discarded and expired 250-mL bags of intravenous fluids were placed inside the chest cavity to simulate pleural fluid. Shelf liner was wrapped around the chest and abdomen of the infant model to simulate the skin layer. Pediatric critical care faculty performed the procedure on the final model and scored it for realism and utility for teaching. Without including the discarded manikin and fluid bags, the cost of the materials for the model was less than $20. RESULTS: Eight pediatric critical care faculty tested the pleural pigtail placement model. All faculty agreed the model provides a realistic simulated reproduction of placing a pleural pigtail, felt the model was simple to use, and indicated they would use it as a teaching tool in the future. IMPLICATIONS FOR PRACTICE: An effective model for pleural pigtail placement can be inexpensively constructed using discarded bags of intravenous fluid and easy-to-find hardware materials. IMPLICATIONS FOR RESEARCH: Future studies are needed to assess whether this model helps providers and nurses develop and maintain the clinical skills for successful percutaneous pleural pigtail catheter placement.Video Abstract available at https://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?videoId=35&autoPlay=true.


Assuntos
Tubos Torácicos , Enfermagem de Cuidados Críticos/educação , Drenagem/instrumentação , Drenagem/métodos , Recursos Humanos de Enfermagem Hospitalar/educação , Derrame Pleural , Treinamento por Simulação/métodos , Adulto , Feminino , Humanos , Lactente , Masculino , Manequins , Pessoa de Meia-Idade
7.
Gut ; 68(6): 1052-1064, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30121627

RESUMO

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is a disease of unmet medical need. While immunotherapy with chimeric antigen receptor T (CAR-T) cells has shown much promise in haematological malignancies, their efficacy for solid tumours is challenged by the lack of tumour-specific antigens required to avoid on-target, off-tumour effects. Switchable CAR-T cells whereby activity of the CAR-T cell is controlled by dosage of a tumour antigen-specific recombinant Fab-based 'switch' to afford a fully tunable response may overcome this translational barrier. DESIGN: In this present study, we have used conventional and switchable CAR-T cells to target the antigen HER2, which is upregulated on tumour cells, but also present at low levels on normal human tissue. We used patient-derived xenograft models derived from patients with stage IV PDAC that mimic the most aggressive features of PDAC, including severe liver and lung metastases. RESULTS: Switchable CAR-T cells followed by administration of the switch directed against human epidermal growth factor receptor 2 (HER2)-induced complete remission in difficult-to-treat, patient-derived advanced pancreatic tumour models. Switchable HER2 CAR-T cells were as effective as conventional HER2 CAR-T cells in vivo testing a range of different CAR-T cell doses. CONCLUSION: These results suggest that a switchable CAR-T system is efficacious against aggressive and disseminated tumours derived from patients with advanced PDAC while affording the potential safety of a control switch.


Assuntos
Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/terapia , Imunoterapia Adotiva/métodos , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Animais , Antígenos de Neoplasias/genética , Biópsia por Agulha , Carcinoma Ductal Pancreático/imunologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Imunoterapia/métodos , Invasividade Neoplásica/patologia , Metástase Neoplásica , Estadiamento de Neoplasias , Neoplasias Pancreáticas/imunologia , Receptor ErbB-2/genética , Estatísticas não Paramétricas , Resultado do Tratamento , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
8.
Paediatr Anaesth ; 29(7): 753-759, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31034728

RESUMO

BACKGROUND: Resident education in pediatric anesthesiology is challenging. Traditional curricula for anesthesiology residency programs have included a combination of didactic lectures and mentored clinical service, which can be variable. Limited pediatric medical knowledge, technical inexperience, and heightened resident anxiety further challenge patient care. We developed a pediatric anesthesia simulation-based curriculum to address crises related to hypoxemia and dysrhythmia management in the operating room as an adjunct to traditional didactic and clinical experiences. AIMS: The primary objective of this trial was to evaluate the impact of a simulation curriculum designed for anesthesiology residents on their performance during the management of crises in the pediatric operating room. A secondary objective was to compare the retention of learned knowledge by assessment at the eight-week time point during the rotation. METHODS: In this prospective, observational trial 30 residents were randomized to receive simulation-based education on four perioperative crises (Laryngospasm, Bronchospasm, Supraventricular Tachycardia (SVT), and Bradycardia) during the first week (Group A) or fifth week (Group B) of an eight-week rotation. Assessment sessions that included two scenarios (Laryngospasm, SVT) were performed in the first week, fifth week, and the eighth week of their rotation for all residents. The residents were assessed in real time and by video review using a 7-point checklist generated by a modified Delphi technique of senior pediatric anesthesiology faculty. RESULTS: Residents in Group A showed improvement between the first week and fifth week assessment as well as between first week and eighth week assessments without decrement between the fifth week and eighth week assessments for both the laryngospasm and SVT scenarios. Residents in Group B showed improvement between the first week and eighth week assessments for both scenarios and between the fifth week and eighth week assessment for the SVT scenario. CONCLUSION: This adjunctive simulation-based curriculum enhanced the learner's management of laryngospasm and SVT management and is a reasonable addition to didactic and clinical curricula for anesthesiology residents.


Assuntos
Anestesiologia/educação , Currículo , Educação de Pós-Graduação em Medicina/métodos , Emergências , Unidades de Terapia Intensiva Pediátrica , Criança , Pré-Escolar , Competência Clínica , Feminino , Humanos , Masculino , Salas Cirúrgicas , Estudos Prospectivos , Distribuição Aleatória
9.
Proc Natl Acad Sci U S A ; 113(4): E459-68, 2016 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-26759369

RESUMO

Chimeric antigen receptor T (CAR-T) cell therapy has produced impressive results in clinical trials for B-cell malignancies. However, safety concerns related to the inability to control CAR-T cells once infused into the patient remain a significant challenge. Here we report the engineering of recombinant antibody-based bifunctional switches that consist of a tumor antigen-specific Fab molecule engrafted with a peptide neo-epitope, which is bound exclusively by a peptide-specific switchable CAR-T cell (sCAR-T). The switch redirects the activity of the bio-orthogonal sCAR-T cells through the selective formation of immunological synapses, in which the sCAR-T cell, switch, and target cell interact in a structurally defined and temporally controlled manner. Optimized switches specific for CD19 controlled the activity, tissue-homing, cytokine release, and phenotype of sCAR-T cells in a dose-titratable manner in a Nalm-6 xenograft rodent model of B-cell leukemia. The sCAR-T-cell dosing regimen could be tuned to provide efficacy comparable to the corresponding conventional CART-19, but with lower cytokine levels, thereby offering a method of mitigating cytokine release syndrome in clinical translation. Furthermore, we demonstrate that this methodology is readily adaptable to targeting CD20 on cancer cells using the same sCAR-T cell, suggesting that this approach may be broadly applicable to heterogeneous and resistant tumor populations, as well as other liquid and solid tumor antigens.


Assuntos
Antígenos CD19/imunologia , Antígenos de Neoplasias/imunologia , Imunoterapia Adotiva/métodos , Leucemia de Células B/terapia , Receptores de Antígenos de Linfócitos T/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T , Subpopulações de Linfócitos T/imunologia , Animais , Azidas , Linfócitos B/imunologia , Linfócitos B/patologia , Fatores de Transcrição de Zíper de Leucina Básica/imunologia , Linhagem Celular Tumoral , Citocinas/metabolismo , Citotoxicidade Imunológica , Relação Dose-Resposta Imunológica , Feminino , Genes Reporter , Vetores Genéticos , Humanos , Imunoterapia Adotiva/efeitos adversos , Ativação Linfocitária , Linfopenia/etiologia , Linfopenia/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Fenilalanina/análogos & derivados , Engenharia de Proteínas/métodos , Receptores de Antígenos de Linfócitos T/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas de Saccharomyces cerevisiae/imunologia , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Relação Estrutura-Atividade , Subpopulações de Linfócitos T/transplante , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Proc Natl Acad Sci U S A ; 113(4): E450-8, 2016 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-26759368

RESUMO

The adoptive transfer of autologous T cells engineered to express a chimeric antigen receptor (CAR) has emerged as a promising cancer therapy. Despite impressive clinical efficacy, the general application of current CAR-T--cell therapy is limited by serious treatment-related toxicities. One approach to improve the safety of CAR-T cells involves making their activation and proliferation dependent upon adaptor molecules that mediate formation of the immunological synapse between the target cancer cell and T-cell. Here, we describe the design and synthesis of structurally defined semisynthetic adaptors we refer to as "switch" molecules, in which anti-CD19 and anti-CD22 antibody fragments are site-specifically modified with FITC using genetically encoded noncanonical amino acids. This approach allows the precise control over the geometry and stoichiometry of complex formation between CD19- or CD22-expressing cancer cells and a "universal" anti-FITC-directed CAR-T cell. Optimization of this CAR-switch combination results in potent, dose-dependent in vivo antitumor activity in xenograft models. The advantage of being able to titrate CAR-T-cell in vivo activity was further evidenced by reduced in vivo toxicity and the elimination of persistent B-cell aplasia in immune-competent mice. The ability to control CAR-T cell and cancer cell interactions using intermediate switch molecules may expand the scope of engineered T-cell therapy to solid tumors, as well as indications beyond cancer therapy.


Assuntos
Antígenos CD19/imunologia , Antígenos de Neoplasias/imunologia , Imunoterapia Adotiva/métodos , Leucemia de Células B/terapia , Engenharia de Proteínas/métodos , Receptores de Antígenos de Linfócitos T/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T , Linfócitos T/imunologia , Animais , Azidas , Linfócitos B/imunologia , Linfócitos B/patologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Feminino , Fluoresceína-5-Isotiocianato , Vetores Genéticos , Humanos , Imunoterapia Adotiva/efeitos adversos , Lentivirus/genética , Ativação Linfocitária , Linfopenia/etiologia , Linfopenia/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Modelos Moleculares , Fenilalanina/análogos & derivados , Conformação Proteica , Receptores de Antígenos de Linfócitos T/genética , Proteínas Recombinantes de Fusão/imunologia , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Linfócitos T/transplante , Transdução Genética , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Mol Ther ; 24(12): 2078-2089, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27731313

RESUMO

Phosphodiesterase 4 (PDE4) inhibitors are approved for the treatment of some moderate to severe inflammatory conditions. However, dose-limiting side effects in the central nervous system and gastrointestinal tract, including nausea, emesis, headache, and diarrhea, have impeded the broader therapeutic application of PDE4 inhibitors. We sought to exploit the wealth of validation surrounding PDE4 inhibition by improving the therapeutic index through generation of an antibody-drug conjugate (ADC) that selectively targets immune cells through the CD11a antigen. The resulting ADC consisted of a human αCD11a antibody (based on efalizumab clone hu1124) conjugated to an analog of the highly potent PDE4 inhibitor GSK256066. Both the human αCD11a ADC and a mouse surrogate αCD11a ADC (based on the M17 clone) rapidly internalized into immune cells and suppressed lipololysaccharide (LPS)-induced TNFα secretion in primary human monocytes and mouse peritoneal cells, respectively. In a carrageenan-induced air pouch inflammation mouse model, treatment with the ADC significantly reduced inflammatory cytokine production in the air pouch exudate. Overall, these results provide compelling evidence for the feasibility of delivering drugs with anti-inflammatory activity selectively to the immune compartment via CD11a and the development of tissue-targeted PDE4 inhibitors as a promising therapeutic modality for treating inflammatory diseases.


Assuntos
Aminoquinolinas/metabolismo , Antígenos CD11/metabolismo , Imunoconjugados/administração & dosagem , Inflamação/imunologia , Inibidores da Fosfodiesterase 4/metabolismo , Sulfonas/metabolismo , Animais , Células Cultivadas , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imunoconjugados/farmacologia , Lipopolissacarídeos/efeitos adversos , Camundongos , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Peritônio/efeitos dos fármacos , Peritônio/imunologia , Fator de Necrose Tumoral alfa/metabolismo
12.
Int J Mol Sci ; 18(11)2017 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-29077054

RESUMO

The treatment of patients with acute myeloid leukemia (AML) with targeted immunotherapy is challenged by the heterogeneity of the disease and a lack of tumor-exclusive antigens. Conventional immunotherapy targets for AML such as CD33 and CD123 have been proposed as targets for chimeric antigen receptor (CAR)-engineered T-cells (CAR-T-cells), a therapy that has been highly successful in the treatment of B-cell leukemia and lymphoma. However, CD33 and CD123 are present on hematopoietic stem cells, and targeting with CAR-T-cells has the potential to elicit long-term myelosuppression. C-type lectin-like molecule-1 (CLL1 or CLEC12A) is a myeloid lineage antigen that is expressed by malignant cells in more than 90% of AML patients. CLL1 is not expressed by healthy Hematopoietic Stem Cells (HSCs), and is therefore a promising target for CAR-T-cell therapy. Here, we describe the development and optimization of an anti-CLL1 CAR-T-cell with potent activity on both AML cell lines and primary patient-derived AML blasts in vitro while sparing healthy HSCs. Furthermore, in a disseminated mouse xenograft model using the CLL1-positive HL60 cell line, these CAR-T-cells completely eradicated tumor, thus supporting CLL1 as a promising target for CAR-T-cells to treat AML while limiting myelosuppressive toxicity.


Assuntos
Lectinas Tipo C/antagonistas & inibidores , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores Mitogênicos/antagonistas & inibidores , Proteínas Recombinantes de Fusão , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Antígenos de Neoplasias/imunologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Modelos Animais de Doenças , Feminino , Humanos , Imunoterapia Adotiva/métodos , Lectinas Tipo C/imunologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Camundongos , Receptores de Antígenos de Linfócitos T/genética , Receptores Mitogênicos/imunologia , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Paediatr Anaesth ; 26(5): 481-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26948074

RESUMO

BACKGROUND: Pediatric anesthesiologists must manage crises in neonates and children with timely responses and limited margin for error. Teaching the range of relevant skills during a 12-month fellowship is challenging. An experiential simulation-based curriculum can augment acquisition of knowledge and skills. OBJECTIVES: To develop a simulation-based boot camp (BC) for novice pediatric anesthesiology fellows and assess learner perceptions of BC activities. We hypothesize that BC is feasible, not too basic, and well received by fellows. METHODS: Skills stations, team-based in situ simulations, and group discussions of complex cases were designed. Stations were evaluated by anonymous survey; fellows rated usefulness in improving knowledge, self-confidence, technical skill, and clinical performance using a Likert scale (1 strongly disagree to 5 strongly agree). They were also asked if stations were too basic or too short. Median and interquartile range (IQR) data were calculated and noted as median (IQR). RESULTS: Fellows reported the difficult airway station and simulated scenarios improved knowledge, self-confidence, technical skill, and clinical performance. They disagreed that stations were too basic or too short with exception of the difficult airway session, which was too short [4 (4-3)]. Fellows believed the central line station improved knowledge [4 (4-3)], technical skills [4 (4-4)], self-confidence [4 (4-3)], and clinical performance [4 (4-3)]; scores trended toward neutral likely because the station was perceived as too basic [3.5 (4-3)]. An interactive session on epinephrine and intraosseous lines was valued. Complicated case discussion was of educational value [4 (5-4)], the varied opinions of faculty were helpful [4 (5-4)], and the session was neither too basic [2 (2-2)] nor too short [2 (2-2)]. CONCLUSION: A simulation-based BC for pediatric anesthesiology fellows was feasible, perceived to improve confidence, knowledge, technical skills, and clinical performance, and was not too basic.


Assuntos
Anestesiologia/educação , Internato e Residência/métodos , Simulação de Paciente , Pediatria/educação , Manuseio das Vias Aéreas , Criança , Pré-Escolar , Competência Clínica , Currículo , Educação de Pós-Graduação em Medicina , Epinefrina/uso terapêutico , Docentes , Estudos de Viabilidade , Humanos , Lactente , Recém-Nascido , Intubação Intratraqueal , Vasoconstritores/uso terapêutico
14.
Angew Chem Int Ed Engl ; 55(26): 7520-4, 2016 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-27145250

RESUMO

Chimeric antigen receptor T (CAR-T) cells have demonstrated promising results against hematological malignancies, but have encountered significant challenges in translation to solid tumors. To overcome these hurdles, we have developed a switchable CAR-T cell platform in which the activity of the engineered cell is controlled by dosage of an antibody-based switch. Herein, we apply this approach to Her2-expressing breast cancers by engineering switch molecules through site-specific incorporation of FITC or grafting of a peptide neo-epitope (PNE) into the anti-Her2 antibody trastuzumab (clone 4D5). We demonstrate that both switch formats can be readily optimized to redirect CAR-T cells (specific for the corresponding FITC or PNE) to Her2-expressing tumor cells, and afford dose-titratable activation of CAR-T cells ex vivo and complete clearance of the tumor in rodent xenograft models. This strategy may facilitate the application of immunotherapy to solid tumors by affording comparable efficacy with improved safety owing to switch-based control of the CAR-T response.


Assuntos
Neoplasias da Mama/terapia , Genes de Troca , Imunoterapia , Receptores de Antígenos de Linfócitos T , Animais , Relação Dose-Resposta a Droga , Feminino , Genes de Troca/genética , Xenoenxertos , Humanos , Camundongos , Receptor ErbB-2/efeitos dos fármacos , Receptor ErbB-2/metabolismo
15.
J Biol Chem ; 289(51): 35605-19, 2014 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-25378390

RESUMO

Neuropeptidases specialize in the hydrolysis of the small bioactive peptides that play a variety of signaling roles in the nervous and endocrine systems. One neuropeptidase, neurolysin, helps control the levels of the dopaminergic circuit modulator neurotensin and is a member of a fold group that includes the antihypertensive target angiotensin converting enzyme. We report the discovery of a potent inhibitor that, unexpectedly, binds away from the enzyme catalytic site. The location of the bound inhibitor suggests it disrupts activity by preventing a hinge-like motion associated with substrate binding and catalysis. In support of this model, the inhibition kinetics are mixed, with both noncompetitive and competitive components, and fluorescence polarization shows directly that the inhibitor reverses a substrate-associated conformational change. This new type of inhibition may have widespread utility in targeting neuropeptidases.


Assuntos
Regulação Alostérica , Inibidores Enzimáticos/química , Metaloendopeptidases/química , Estrutura Terciária de Proteína , Sítio Alostérico , Animais , Sítios de Ligação/genética , Biocatálise/efeitos dos fármacos , Domínio Catalítico , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Polarização de Fluorescência , Cinética , Metaloendopeptidases/genética , Metaloendopeptidases/metabolismo , Modelos Químicos , Modelos Moleculares , Estrutura Molecular , Mutação de Sentido Incorreto , Ligação Proteica , Ratos , Especificidade por Substrato
16.
J Am Chem Soc ; 137(16): 5288-91, 2015 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-25826669

RESUMO

The development of immunotherapies for multiple myeloma is critical to provide new treatment strategies to combat drug resistance. We report a bispecific antibody against B cell maturation antigen (BiFab-BCMA), which potently and specifically redirects T cells to lyse malignant multiple myeloma cells. BiFab-BCMA lysed target BCMA-positive cell lines up to 20-fold more potently than a CS1-targeting bispecific antibody (BiFab-CS1) developed in an analogous fashion. Further, BiFab-BCMA robustly activated T cells in vitro and mediated rapid tumor regression in an orthotopic xenograft model of multiple myeloma. The in vitro and in vivo activities of BiFab-BCMA are comparable to those of anti-BCMA chimeric antigen receptor T cell therapy (CAR-T-BCMA), for which two clinical trials have recently been initiated. A BCMA-targeted bispecific antibody presents a promising treatment option for multiple myeloma.


Assuntos
Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/uso terapêutico , Antígeno de Maturação de Linfócitos B/imunologia , Mieloma Múltiplo/terapia , Animais , Linhagem Celular Tumoral , Humanos , Imunoterapia , Camundongos SCID , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/patologia , Linfócitos T/imunologia , Linfócitos T/patologia
17.
J Autoimmun ; 60: 59-73, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25975491

RESUMO

Rheumatoid arthritis (RA) remains a debilitating autoimmune condition as many patients are refractory to existing conventional and biologic therapies, and hence successful development of novel treatments remains a critical requirement. Towards this, we now describe a synthetic drug-like small molecule analogue, SMA-12b, of an immunomodulatory parasitic worm product, ES-62, which acts both prophylactically and therapeutically against collagen-induced arthritis (CIA) in mice. Mechanistic analysis revealed that SMA-12b modifies the expression of a number of inflammatory response genes, particularly those associated with the inflammasome in mouse bone marrow-derived macrophages and indeed IL-1ß was the most down-regulated gene. Consistent with this, IL-1ß was significantly reduced in the joints of mice with CIA treated with SMA-12b. SMA-12b also increased the expression of a number of genes associated with anti-oxidant responses that are controlled by the transcription factor NRF2 and critically, was unable to inhibit expression of IL-1ß by macrophages derived from the bone marrow of NRF2(-/-) mice. Collectively, these data suggest that SMA-12b could provide the basis of an entirely novel approach to fulfilling the urgent need for new treatments for RA.


Assuntos
Anti-Inflamatórios/farmacologia , Artrite Experimental/tratamento farmacológico , Proteínas de Helminto/farmacologia , Interleucina-1beta/biossíntese , Fator 2 Relacionado a NF-E2/genética , Acanthocheilonema/metabolismo , Animais , Artrite Experimental/prevenção & controle , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/prevenção & controle , Colágeno , Gerbillinae , Inflamassomos/imunologia , Inflamação/tratamento farmacológico , Inflamação/imunologia , Articulações/imunologia , Articulações/patologia , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/imunologia
18.
Exp Eye Res ; 138: 134-44, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26142956

RESUMO

Amyloid-beta (Aß) is a group of aggregation-prone, 38- to 43-amino acid peptides generated in the eye and other organs. Numerous studies suggest that the excessive build-up of low-molecular-weight soluble oligomers of Aß plays a role in the progression of Alzheimer's disease and other brain degenerative diseases. Recent studies raise the hypothesis that excessive Aß levels may contribute also to certain retinal degenerative diseases. These findings, together with evidence that a major portion of Aß is released as monomer into the extracellular space, raise the possibility that a technology enabling the enzymatic break-down of monomeric Aß in the living eye under physiological conditions could prove useful for research on ocular Aß physiology and, perhaps ultimately, for therapeutic applications. Neprilysin (NEP), an endopeptidase known to cleave Aß monomer into inactive products, is a membrane-associated protein. However, sNEP, a recombinant form of the NEP catalytic domain, is soluble in aqueous medium. With the aim of determining the Aß-cleaving activity of exogenous sNEP in the microenvironment of the intact eye, we analyzed the effect of intra-vitreally delivered sNEP on ocular Aß levels in mice that exhibit readily measurable, aqueous buffer-extractable Aß40 and Aß42, two principal forms of Aß. Anesthetized 10-month wild-type (C57BL/6J) and 2-3-month 5XFAD transgenic mice received intra-vitreal injections of sNEP (0.004-10 µg) in one eye and were sacrificed at defined post-treatment times (30 min - 12 weeks). Eye tissues (combined lens, vitreous, retina, RPE and choroid) were homogenized in phosphate-buffered saline, and analyzed for Aß40 and Aß42 (ELISA) and for total protein (Bradford assay). The fellow, untreated eye of each mouse served as control, and concentrations of Aß (pmol/g protein) in the treated eye were normalized to that of the untreated control eye. In C57BL/6J mice, as measured at 2 h after sNEP treatment, increasing amounts of injected sNEP yielded progressively greater reductions of Aß40, ranging from 12% ± 3% (mean ± SEM; n = 3) with 4 ng sNEP to 85% ± 13% (n = 5) with 10 µg sNEP. At 4 ng sNEP the average Aß40 reduction reached >70% by 24 h following treatment and remained near this level for about 8 weeks. In 5XFAD mice, 10 µg sNEP produced an Aß40 decrease of 99% ± 1% (n = 4) and a substantial although smaller decrease in Aß42 (42% ± 36%; n = 4) within 24 h. Electroretinograms (ERGs) were recorded from eyes of C57BL/6J and 5XFAD mice at 9 days following treatment with 4 ng or 10 µg sNEP, conditions that on average led, respectively, to an 82% and 91% Aß40 reduction in C57BL/6J eyes, an 87% and 92% Aß40 reduction in 5XFAD eyes, and a 23% and 52% Aß42 reduction in 5XFAD eyes. In all cases, sNEP-treated eyes exhibited robust ERG responses, consistent with a general tolerance of the posterior eye tissues to the investigated conditions of sNEP treatment. The sNEP-mediated decrease of ocular Aß levels reported here represents a possible approach for determining effects of Aß reduction in normally functioning eyes and in models of retinal degenerative disease.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Corioide/metabolismo , Cristalino/metabolismo , Neprilisina/farmacologia , Retina/metabolismo , Corpo Vítreo/metabolismo , Idoso , Idoso de 80 Anos ou mais , Animais , Modelos Animais de Doenças , Eletrorretinografia , Ensaio de Imunoadsorção Enzimática , Humanos , Injeções Intravítreas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Doadores de Tecidos
20.
Exp Parasitol ; 158: 18-22, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25836375

RESUMO

ES-62 is the major secreted protein of the rodent filarial nematode Acanthocheilonema viteae. The molecule contains covalently attached phosphorylcholine (PC) residues, which confer anti-inflammatory properties on ES-62, underpinning the idea that drugs based on this active moiety may have therapeutic potential in human diseases associated with aberrant inflammation. Here we demonstrate that two synthetic small molecule analogues (SMAs) of ES-62 termed SMA 11a and SMA 12b are protective in the oxazolone-induced acute allergic contact dermatitis mouse model of skin inflammation, as measured by a significant reduction in ear inflammation following their administration before oxazolone sensitisation and before oxazolone challenge. Furthermore, it was found that when tested, 12b was effective at reducing ear swelling even when first administered before challenge. Histological analysis of the ears showed elevated cellular infiltration and collagen deposition in oxazolone-treated mice both of which were reduced by treatment with the two SMAs. Likewise, the oxazolone-induced increase in IFNγ mRNA in the ears was reduced but no effect on other cytokines investigated was observed. Finally, no influence on the mast cell populations in the ear was observed.


Assuntos
Acanthocheilonema/imunologia , Dermatite Alérgica de Contato/imunologia , Proteínas de Helminto/imunologia , Otite Externa/prevenção & controle , Adjuvantes Imunológicos/toxicidade , Animais , Dermatite Alérgica de Contato/parasitologia , Dermatite Alérgica de Contato/prevenção & controle , Modelos Animais de Doenças , Proteínas de Helminto/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Otite Externa/induzido quimicamente , Otite Externa/patologia , Oxazolona/toxicidade , Reação em Cadeia da Polimerase em Tempo Real
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa