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1.
J Neurosci ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830764

RESUMO

Human genetics and preclinical studies have identified key contributions of TREM2 to several neurodegenerative conditions, inspiring efforts to modulate TREM2 therapeutically. Here, we characterize the activities of three TREM2 agonist antibodies in multiple mixed-sex mouse models of Alzheimer's Disease (AD) pathology and remyelination. Receptor activation and downstream signaling are explored in vitro, and active dose ranges are determined in vivo based on pharmacodynamic responses from microglia. For mice bearing amyloid-ß (Aß) pathology (PS2APP) or combined Aß and tau pathology (TauPS2APP), chronic TREM2 agonist antibody treatment had limited impact on microglia engagement with pathology, overall pathology burden, or downstream neuronal damage. For mice with demyelinating injuries triggered acutely with lysolecithin, TREM2 agonist antibodies unexpectedly disrupted injury resolution. Likewise, TREM2 agonist antibodies limited myelin recovery for mice experiencing chronic demyelination from cuprizone. We highlight the contributions of dose timing and frequency across models. These results introduce important considerations for future TREM2-targeting approaches.Significance Statement Multiple TREM2 agonist antibodies are investigated in mouse models of Alzheimer's Disease and Multiple Sclerosis. Despite agonism in culture models and after acute dosing in mice, antibodies do not show benefit in overall AD pathology and worsen recovery after demyelination.

2.
Anal Chem ; 95(47): 17263-17272, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37956201

RESUMO

Intact protein mass spectrometry (MS) coupled with liquid chromatography was applied to characterize the pharmacokinetics and stability profiles of therapeutic proteins. However, limitations from chromatography, including throughput and carryover, result in challenges with handling large sample numbers. Here, we combined intact protein MS with multiple front-end separations, including affinity capture, SampleStream, and high-field asymmetric waveform ion mobility spectrometry (FAIMS), to perform high-throughput and specific mass measurements of a multivalent antibody with one antigen-binding fragment (Fab) fused to an immunoglobulin G1 (IgG1) antibody. Generic affinity capture ensures the retention of both intact species 1Fab-IgG1 and the tentative degradation product IgG1. Subsequently, the analytes were directly loaded into SampleStream, where each injection occurs within ∼30 s. By separating ions prior to MS detection, FAIMS further offered improvement in signal-overnoise by ∼30% for denatured protein MS via employing compensation voltages that were optimized for different antibody species. When enhanced FAIMS transmission of 1Fab-IgG1 was employed, a qualified assay was established for spiked-in serum samples between 0.1 and 25 µg/mL, resulting in ∼10% accuracy bias and precision coefficient of variation. Selective FAIMS transmission of IgG1 as the degradation surrogate product enabled more sensitive detection of clipped species for intact 1Fab-IgG1 at 5 µg/mL in serum, generating an assay to measure 1Fab-IgG1 truncation between 2.5 and 50% with accuracy and precision below 20% bias and coefficient of variation. Our results revealed that the SampleStream-FAIMS-MS platform affords high throughput, selectivity, and sensitivity for characterizing therapeutic antibodies from complex biomatrices qualitatively and quantitatively.


Assuntos
Imunoglobulina G , Espectrometria de Mobilidade Iônica , Espectrometria de Mobilidade Iônica/métodos , Espectrometria de Massas/métodos , Cromatografia Líquida , Íons/química
3.
Nat Biotechnol ; 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37857725

RESUMO

The broad application of precision cancer immunotherapies is limited by the number of validated neoepitopes that are common among patients or tumor types. To expand the known repertoire of shared neoantigen-human leukocyte antigen (HLA) complexes, we developed a high-throughput platform that coupled an in vitro peptide-HLA binding assay with engineered cellular models expressing individual HLA alleles in combination with a concatenated transgene harboring 47 common cancer neoantigens. From more than 24,000 possible neoepitope-HLA combinations, biochemical and computational assessment yielded 844 unique candidates, of which 86 were verified after immunoprecipitation mass spectrometry analyses of engineered, monoallelic cell lines. To evaluate the potential for immunogenicity, we identified T cell receptors that recognized select neoepitope-HLA pairs and elicited a response after introduction into human T cells. These cellular systems and our data on therapeutically relevant neoepitopes in their HLA contexts will aid researchers studying antigen processing as well as neoepitope targeting therapies.

4.
AAPS J ; 25(4): 64, 2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37353723

RESUMO

RO7449135, an anti-kallikrein (KLK)5/KLK7 bispecific antibody, is in development as a potential therapy against Netherton's syndrome (NS). In cynomolgus monkey studies, RO7449135 bound to KLK5 and KLK7, causing considerable accumulation of total KLKs, but with non-dose-proportional increase. To understand the complex PKPD, a population model with covariate analysis was developed accounting for target binding in skin and migration of bound targets from skin to blood. The covariate analysis suggested the animal batch as the categorical covariate impacting the different KLK5 synthesis rates between the repeat-dose study and single-dose study, and the dose as continuous covariate impacting the internalization rate of the binary and ternary complexes containing KLK7. To comprehend the mechanism underlying, we hypothesized that inhibition of KLK5 by RO7449135 prevented its cleavage of the pro-enzyme of KLK7 (pro-KLK7) and altered the proportion between pro-KLK7 and KLK7. Besides the pro-KLK7, RO7449135 can interact with other proteins like LEKTI through KLK7 connection in a dose-dependent manner. The different high-order complexes formed by RO7449135 interacting with pro-KLK7 or LEKTI-like proteins can be subject to faster internalization rate. Accounting for the dose and animal batch as covariates, the model-predicted free target suppression is well aligned with the visual target engagement check. The population PKPD model with covariate analysis provides the scientific input for the complex PKPD analysis, successfully predicts the target suppression in cynomolgus monkeys, and thereby can be used for the human dose projection of RO7449135.


Assuntos
Anticorpos Biespecíficos , Calicreínas , Pele , Animais , Macaca fascicularis , Pele/metabolismo , Anticorpos Biespecíficos/farmacocinética
5.
J Prim Care Community Health ; 14: 21501319231172900, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37199386

RESUMO

OBJECTIVES: Sexually transmitted infections (STIs) are an ongoing public health issue in adolescents. the Centers for Disease Control and Prevention and American Academy of Pediatrics have and continue to recommend STI screening in at-risk adolescents, however screening and testing continues to lag behind the need. We previously designed and implemented an electronic risk assessment tool to support STI testing in our pediatric emergency department. Pediatric primary care clinics may be better positioned for STI risk assessments, as they can offer greater privacy and confidentiality, a lower stress environment, and greater opportunity for longitudinal care. STI risk assessment and testing continues to be a challenge in this setting. The goal of this work was to evaluate the usability of our electronic tool to support adaptation and implementation in pediatric primary care practices. METHODS: We conducted qualitative interviews of pediatricians, clinic staff, and adolescents from 4 pediatric practices as part of a study whose goal is to ultimately implement STI screening in pediatric primary care. The goal of the interviews were (1) to understand contextual factors related to STI screening in primary care, which we have reported previously, and (2) to obtain feedback on our electronic platform, the questionnaire content, and their perspective on implementing it in primary care settings, which we report here. We received quantitative feedback using the System Usability Scale (SUS). The SUS is a validated, reliable tool to measure the usability of hardware, software, websites, and applications. SUS scores range from a score of 0 to 100, with a score of 68 or higher indicating above average usability. We additionally obtained qualitative feedback via interviews and used inductive analysis to identify common themes. RESULTS: We recruited 14 physicians, 9 clinic staff, and 12 adolescents. Participants rated the tool highly using the SUS, with a median score of 92.5 (threshold for average usability is 68) and an interquartile range of 82.5 to 100. Thematically, all participants perceived a need for such a screening program and indicated the format would encourage more honest responses on the topic adolescents. We used these results to modify the questionnaire prior to implementing it into participating practices. CONCLUSION: We demonstrated that our electronic STI risk assessment tool had a high level of usability and could be adapted for use in pediatric primary care.


Assuntos
Pediatria , Infecções Sexualmente Transmissíveis , Adolescente , Humanos , Criança , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/prevenção & controle , Instituições de Assistência Ambulatorial , Inquéritos e Questionários , Atenção Primária à Saúde
6.
Transl Vis Sci Technol ; 11(10): 27, 2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-36255358

RESUMO

Purpose: Diabetic macular edema (DME) is the leading cause of vision loss and blindness among working-age adults. Although current intravitreal anti-vascular endothelial growth factor (VEGF) therapies improve vision for many patients with DME, approximately half do not achieve the visual acuity required to drive. We therefore sought additional approaches to resolve edema and improve vision for these patients. Methods: We explored direct agonists of Tie2, a receptor known to stabilize vasculature and prevent leakage. We identified a multivalent PEG-Fab conjugate, Tie2.1-hexamer, that oligomerizes Tie2 and drives receptor activation and characterized its activities in vitro and in vivo. Results: Tie2.1-hexamer normalized and stabilized intercellular junctions of stressed endothelial cell monolayers in vitro, suppressed vascular leak in mice under conditions where anti-VEGF alone was ineffective, and demonstrated extended ocular exposure and robust pharmacodynamic responses in non-human primates. Conclusions: Tie2.1-hexamer directly activates the Tie2 pathway, reduces vascular leak, and is persistent within the vitreal humor. Translational Relevance: Our study presents a promising potential therapeutic for the treatment of DME.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Edema Macular , Camundongos , Animais , Edema Macular/tratamento farmacológico , Edema Macular/etiologia , Retinopatia Diabética/tratamento farmacológico , Fatores de Crescimento Endotelial/uso terapêutico , Acuidade Visual , Transtornos da Visão/complicações , Transtornos da Visão/tratamento farmacológico , Cegueira/complicações
7.
AAPS J ; 24(6): 100, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36127472

RESUMO

RO7297089, an anti-B-cell maturation antigen (BCMA)/CD16A bispecific tetravalent antibody, is being developed as a multiple myeloma (MM) therapeutic. This study characterized nonclinical pharmacokinetics (PK), pharmacodynamics (PD), soluble BCMA (sBCMA), and soluble CD16 (sCD16) changes following administration of RO7297089 to support clinical trials. Unbound and total RO7297089 concentrations were measured in cynomolgus monkeys. RO7297089 exhibited a bi-phasic systemic concentration-time profile, similar to a typical human immunoglobulin 1 antibody. Target engagement by RO7297089 led to a robust increase (~100-fold) in total systemic sBCMA levels and relatively mild increase (~2-fold) in total sCD16 levels. To describe the relationship of nonclinical PK/PD data, we developed a target-mediated drug disposition (TMDD) model that includes the systemic target engagement of membrane BCMA (mBCMA), sBCMA, membrane CD16 (mCD16), and sCD16. We then used this model to simulate the PK/PD relationship of RO7297089 in MM patients by translating relevant PK parameters and target levels, based on the literature and newly generated data such as baseline sCD16A levels. Our model suggested that the impact of TMDD on RO7297089 exposure may be more significant in MM patients due to significantly higher expression levels of both mBCMA and sBCMA compared to healthy cynomolgus monkeys. Based on model simulations, we propose more frequent dosing of RO7297089 compared to regular monthly frequency in the clinic at the beginning of treatment to ensure sustained target engagement. This study demonstrates a translational research strategy for collecting relevant nonclinical data, establishing a TMDD model, and using simulations from this model to inform clinical dose regimens.


Assuntos
Mieloma Múltiplo , Animais , Humanos , Imunoterapia , Macaca fascicularis , Mieloma Múltiplo/tratamento farmacológico
8.
Clin Pharmacol Ther ; 111(4): 826-834, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35064573

RESUMO

Delivery of biologics via cerebrospinal fluid (CSF) has demonstrated potential to access the tissues of the central nervous system (CNS) by circumventing the blood-brain barrier and blood-CSF barrier. Developing an effective CSF drug delivery strategy requires optimization of multiple parameters, including choice of CSF access point, delivery device technology, and delivery kinetics to achieve effective therapeutic concentrations in the target brain region, whereas also considering the biologic modality, mechanism of action, disease indication, and patient population. This review discusses key preclinical and clinical examples of CSF delivery for different biologic modalities (antibodies, nucleic acid-based therapeutics, and gene therapy) to the brain via CSF or CNS access routes (intracerebroventricular, intrathecal-cisterna magna, intrathecal-lumbar, intraparenchymal, and intranasal), including the use of novel device technologies. This review also discusses quantitative models of CSF flow that provide insight into the effect of fluid dynamics in CSF on drug delivery and CNS distribution. Such models can facilitate delivery device design and pharmacokinetic/pharmacodynamic translation from preclinical species to humans in order to optimize CSF drug delivery to brain regions of interest.


Assuntos
Produtos Biológicos , Encéfalo , Transporte Biológico/fisiologia , Barreira Hematoencefálica , Sistema Nervoso Central , Humanos
9.
Protein Sci ; 30(6): 1169-1183, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33840137

RESUMO

Despite the need to monitor the impact of Cancer Immunotherapy (CI)/Immuno-Oncology (IO) therapeutics on neoantigen-specific T-cell responses, very few clinical programs incorporate this aspect of immune monitoring due to the challenges in high-throughput (HTP) generation of Major Histocompatibility Complex Class I (MHCI) tetramers across a wide range of HLA alleles. This limitation was recently addressed through the development of MHCI complexes with peptides containing a nonnatural UV cleavable amino acid (conditional MHCI ligands) that enabled HTP peptide exchange upon UV exposure. Despite this advancement, the number of alleles with known conditional MHCI ligands is limited. We developed a novel workflow to enable identification and validation of conditional MHCI ligands across a range of HLA alleles. First, known peptide binders were screened via an enzyme-linked immunosorbent assay (ELISA) assay. Conditional MHCI ligands were designed using the highest-performing peptides and evaluated in the same ELISA assay. The top performers were then selected for scale-up production. Next-generation analytical techniques (LC/MS, SEC-MALS, and 2D LC/MS) were used to characterize the complex after refolding with the conditional MHCI ligands. Finally, we used 2D LC/MS to evaluate peptide exchange with these scaled-up conditional MHCI complexes after UV exposure with validated peptide binders. Successful peptide exchange was observed for all conditional MHCI ligands upon UV exposure, validating our screening approach. This approach has the potential to be broadly applied and enable HTP generation of MHCI monomers and tetramers across a wider range of HLA alleles, which could be critical to enabling the use of MHCI tetramers to monitor neoantigen-specific T-cells in the clinic.


Assuntos
Antígenos de Histocompatibilidade Classe I/química , Peptídeos/química , Humanos , Ligantes
10.
MAbs ; 13(1): 1862452, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33382956

RESUMO

Early success with brentuximab vedotin in treating classical Hodgkin lymphoma spurred an influx of at least 20 monomethyl auristatin E (MMAE) antibody-drug conjugates (ADCs) into clinical trials. While three MMAE-ADCs have been approved, most of these conjugates are no longer being investigated in clinical trials. Some auristatin conjugates show limited or no efficacy at tolerated doses, but even for drugs driving initial remissions, tumor regrowth and metastasis often rapidly occur. Here we describe the development of second-generation therapeutic ADCs targeting Lymphocyte antigen 6E (Ly6E) where the tubulin polymerization inhibitor MMAE (Compound 1) is replaced with DNA-damaging agents intended to drive increased durability of response. Comparison of a seco-cyclopropyl benzoindol-4-one (CBI)-dimer (compound 2) to MMAE showed increased potency, activity across more cell lines, and resistance to efflux by P-glycoprotein, a drug transporter commonly upregulated in tumors. Both anti-Ly6E-CBI and -MMAE conjugates drove single-dose efficacy in xenograft and patient-derived xenograft models, but seco-CBI-dimer conjugates showed reduced tumor outgrowth following multiple weeks of treatment, suggesting that they are less susceptible to developing resistance. In parallel, we explored approaches to optimize the targeting antibody. In contrast to immunization with recombinant Ly6E or Ly6E DNA, immunization with virus-like particles generated a high-affinity anti-Ly6E antibody. Conjugates to this antibody improve efficacy versus a previous clinical candidate both in vitro and in vivo with multiple cytotoxics. Conjugation of compound 2 to the second-generation antibody results in a substantially improved ADC with promising preclinical efficacy.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos de Superfície/imunologia , Antineoplásicos/imunologia , Imunoconjugados/imunologia , Oligopeptídeos/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Antineoplásicos Imunológicos/farmacocinética , Antineoplásicos Imunológicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Feminino , Proteínas Ligadas por GPI/imunologia , Células HEK293 , Humanos , Imunoconjugados/farmacocinética , Imunoconjugados/farmacologia , Camundongos SCID , Ratos Sprague-Dawley , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/imunologia
11.
Cell ; 182(2): 329-344.e19, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32589946

RESUMO

Cell surface receptors and their interactions play a central role in physiological and pathological signaling. Despite its clinical relevance, the immunoglobulin superfamily (IgSF) remains uncharacterized and underrepresented in databases. Here, we present a systematic extracellular protein map, the IgSF interactome. Using a high-throughput technology to interrogate most single transmembrane receptors for binding to 445 IgSF proteins, we identify over 500 interactions, 82% previously undocumented, and confirm more than 60 receptor-ligand pairs using orthogonal assays. Our study reveals a map of cell-type-specific interactions and the landscape of dysregulated receptor-ligand crosstalk in cancer, including selective loss of function for tumor-associated mutations. Furthermore, investigation of the IgSF interactome in a large cohort of cancer patients identifies interacting protein signatures associated with clinical outcome. The IgSF interactome represents an important resource to fuel biological discoveries and a framework for understanding the functional organization of the surfaceome during homeostasis and disease, ultimately informing therapeutic development.


Assuntos
Imunoglobulinas/metabolismo , Neoplasias/patologia , Mapas de Interação de Proteínas , Antígeno B7-H1/metabolismo , Antígeno Carcinoembrionário/metabolismo , Comunicação Celular , Análise por Conglomerados , Meios de Cultivo Condicionados/química , Células HEK293 , Humanos , Imunoglobulinas/química , Imunoglobulinas/genética , Ligantes , Mutação , Neoplasias/genética , Neoplasias/metabolismo , Ligação Proteica , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo
12.
J Neurosci ; 40(9): 1956-1974, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-31980586

RESUMO

TREM2 is an Alzheimer's disease (AD) risk gene expressed in microglia. To study the role of Trem2 in a mouse model of ß-amyloidosis, we compared PS2APP transgenic mice versus PS2APP mice lacking Trem2 (PS2APP;Trem2ko) at ages ranging from 4 to 22 months. Microgliosis was impaired in PS2APP;Trem2ko mice, with Trem2-deficient microglia showing compromised expression of proliferation/Wnt-related genes and marked accumulation of ApoE. Plaque abundance was elevated in PS2APP;Trem2ko females at 6-7 months; but by 12 or 19-22 months of age, it was notably diminished in female and male PS2APP;Trem2ko mice, respectively. Across all ages, plaque morphology was more diffuse in PS2APP;Trem2ko brains, and the Aß42:Aß40 ratio was elevated. The amount of soluble, fibrillar Aß oligomers also increased in PS2APP;Trem2ko hippocampi. Associated with these changes, axonal dystrophy was exacerbated from 6 to 7 months onward in PS2APP;Trem2ko mice, notwithstanding the reduced plaque load at later ages. PS2APP;Trem2ko mice also exhibited more dendritic spine loss around plaque and more neurofilament light chain in CSF. Thus, aggravated neuritic dystrophy is a more consistent outcome of Trem2 deficiency than amyloid plaque load, suggesting that the microglial packing of Aß into dense plaque is an important neuroprotective activity.SIGNIFICANCE STATEMENT Genetic studies indicate that TREM2 gene mutations confer increased Alzheimer's disease (AD) risk. We studied the effects of Trem2 deletion in the PS2APP mouse AD model, in which overproduction of Aß peptide leads to amyloid plaque formation and associated neuritic dystrophy. Interestingly, neuritic dystrophies were intensified in the brains of Trem2-deficient mice, despite these mice displaying reduced plaque accumulation at later ages (12-22 months). Microglial clustering around plaques was impaired, plaques were more diffuse, and the Aß42:Aß40 ratio and amount of soluble, fibrillar Aß oligomers were elevated in Trem2-deficient brains. These results suggest that the Trem2-dependent compaction of Aß into dense plaques is a protective microglial activity, limiting the exposure of neurons to toxic Aß species.


Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Axônios/patologia , Espinhas Dendríticas/patologia , Glicoproteínas de Membrana/genética , Fragmentos de Peptídeos/metabolismo , Placa Amiloide/genética , Receptores Imunológicos/genética , Fator Trefoil-1/metabolismo , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/patologia , Neuritos/patologia , Proteínas de Neurofilamentos/líquido cefalorraquidiano , Placa Amiloide/patologia
13.
Mol Cell Proteomics ; 18(11): 2310-2323, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31308249

RESUMO

Receptors expressed on the plasma membrane and their interacting partners critically regulate cellular communication during homeostasis and disease, and as such represent main therapeutic targets. Despite its importance for drug development, receptor-ligand proteomics has remained a daunting field, in part because of the challenges associated to the study of membrane-expressed proteins. Here, to enable sensitive detection of receptor-ligand interactions in high throughput, we implement a new platform, the Conditioned Media AlphaScreen, for interrogation of a library consisting of most single transmembrane human proteins. Using this method to study key immune receptors, we identify and further validate the interleukin receptor IL20RA as the first binding partner for the checkpoint inhibitor B7-H3. Further, KIR2DL5, a natural killer cell protein that had remained orphan, is uncovered as a functional binding partner for the poliovirus receptor (PVR). This interaction is characterized using orthogonal assays, which demonstrate that PVR specifically engages KIR2DL5 on natural killer cells leading to inhibition of cytotoxicity. Altogether, these results reveal unappreciated links between protein families that may importantly influence receptor-driven functions during disease. Applicable to any target of interest, this technology represents a versatile and powerful approach for elucidation of receptor-ligand interactomes, which is essential to understand basic aspects of the biology of the plasma membrane proteins and ultimately inform the development of novel therapeutic strategies.


Assuntos
Antígenos B7/metabolismo , Matriz Extracelular/metabolismo , Células Matadoras Naturais/metabolismo , Receptores de Interleucina/metabolismo , Receptores KIR2DL5/metabolismo , Receptores Virais/metabolismo , Comunicação Celular , Células HEK293 , Humanos , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Ligantes , Ligação Proteica , Mapas de Interação de Proteínas
14.
Br J Pharmacol ; 174(22): 4173-4185, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28859225

RESUMO

BACKGROUND AND PURPOSE: The potential for therapeutic antibody treatment of neurological diseases is limited by poor penetration across the blood-brain barrier. I.c.v. delivery is a promising route to the brain; however, it is unclear how efficiently antibodies delivered i.c.v. penetrate the cerebrospinal spinal fluid (CSF)-brain barrier and distribute throughout the brain parenchyma. EXPERIMENTAL APPROACH: We evaluated the pharmacokinetics and pharmacodynamics of an inhibitory monoclonal antibody against ß-secretase 1 (anti-BACE1) following continuous infusion into the left lateral ventricle of healthy adult cynomolgus monkeys. KEY RESULTS: Animals infused with anti-BACE1 i.c.v. showed a robust and sustained reduction (~70%) of CSF amyloid-ß (Aß) peptides. Antibody distribution was near uniform across the brain parenchyma, ranging from 20 to 40 nM, resulting in a ~50% reduction of Aß in the cortical parenchyma. In contrast, animals administered anti-BACE1 i.v. showed no significant change in CSF or cortical Aß levels and had a low (~0.6 nM) antibody concentration in the brain. CONCLUSION AND IMPLICATIONS: I.c.v. administration of anti-BACE1 resulted in enhanced BACE1 target engagement and inhibition, with a corresponding dramatic reduction in CNS Aß concentrations, due to enhanced brain exposure to antibody.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/farmacocinética , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/imunologia , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/líquido cefalorraquidiano , Ácido Aspártico Endopeptidases/imunologia , Encéfalo/metabolismo , Feminino , Infusões Intraventriculares , Macaca fascicularis
15.
Biotechnol Prog ; 33(6): 1579-1588, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28649725

RESUMO

Transient gene expression in mammalian cells is an efficient process for producing recombinant proteins for various research applications to support large molecule therapeutics development. For the first time, we report a high throughput small molecule (SM) screen to identify novel compounds that increase antibody titers after polyethylenimine (PEI) transient transfection of a HEK293 cell line. After screening 31,413 SMs in a 50 µL scaled-down process, we validated 164 SMs to improve yields by up to twofold. The titer increase mediated by the SMs varied for different antibodies. SM dose optimizations resulted in almost threefold higher titers. The top 2, structurally distinct SM hits, increased antibody titers more than twofold in a 1 mL production process. Averaged across three antibodies of different expression levels, the compounds enhanced transient productivity by ∼80%. Intriguingly, both compounds arrested cells in the G2/M cell cycle phase leading to a decrease in growth and nutrient consumption, while elevating titer, nuclear plasmid DNA (pDNA) copy numbers, and mRNA levels. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 3:1579-1588, 2017.


Assuntos
Formação de Anticorpos/genética , Ensaios de Triagem em Larga Escala , Imunoglobulina G/biossíntese , Proteínas Recombinantes/biossíntese , Animais , Anticorpos/genética , Anticorpos/imunologia , Formação de Anticorpos/imunologia , Células CHO , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Células HEK293 , Humanos , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Polietilenoimina/farmacologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Bibliotecas de Moléculas Pequenas/farmacologia , Transfecção
16.
Biotechnol Prog ; 33(2): 523-533, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28127892

RESUMO

While the most common causes of clonal instability are DNA copy number loss and silencing, toxicity of the expressed protein(s) may also induce clonal instability. Human DNase I (hDNase I) is used therapeutically for the treatment of cystic fibrosis (CF) and may have potential benefit for use in systemic lupus erythematosus (SLE). hDNase I is an endonuclease that catalyzes degradation of extracellular DNA and is inhibited by both salt and G-actin. Engineered versions of hDNase I, bearing multiple point mutations, which renders them Hyperactive, Salt- and Actin-Resistant (HSAR-hDNase I) have been developed previously. However, constitutive expression of HSAR-hDNase I enzymes has been very challenging and, despite considerable efforts and screening thousands of clones, no stable clone capable of constitutive expression had been obtained. Here, we developed a regulated expression system for stable expression of an HSAR-hDNase I in Chinese Hamster Ovary (CHO) cells. The HSAR-hDNase I clones were stable and, upon induction, expressed enzymatically functional protein. Our findings suggest that degradation of host's DNA mediated by HSAR-hDNase I during cell division is the likely cause of clonal instability observed in cells constitutively expressing this protein. Purified HSAR-hDNase I was both hyperactive and resistant to inhibition by salt and G-actin, resulting in an enzyme having ca. 10-fold greater specific activity and the potential to be a superior therapeutic agent to wild type (WT) hDNase I. Furthermore, the ability to regulate hDNase I expression has enabled process development improvements that achieve higher cell growth and product titers while maintaining product quality. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 32:523-533, 2017.


Assuntos
Actinas/química , Clonagem Molecular/métodos , Desoxirribonuclease I/química , Desoxirribonuclease I/metabolismo , Engenharia de Proteínas/métodos , Sais/química , Animais , Células CHO , Proliferação de Células/fisiologia , Cricetulus , Desoxirribonuclease I/genética , Ativação Enzimática , Estabilidade Enzimática , Humanos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
17.
Contraception ; 95(2): 161-166, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27642154

RESUMO

OBJECTIVES: Provider self-disclosure (PSD) - defined as providers making statements regarding personal information to patients - has not been well characterized in the context of contraceptive counseling. In this study, we describe the incidence, content and context of contraceptive PSD. STUDY DESIGN: This mixed methods analysis used data from the Provider-Patient Contraceptive Counseling study, for which 349 family planning patients were recruited from 2009 to 2012 from six clinics in the San Francisco Bay Area. Audio-recordings from their visits were analyzed for the presence or absence of PSD, and those visits with evidence of PSD were analyzed using qualitative methods. The associations of patient and provider demographics and patient satisfaction measures, obtained from survey data, with PSD were analyzed using bivariable and multivariable analyses. RESULTS: Thirty-seven percent of providers showed evidence of PSD during at least one visit, and PSD occurred in 9% of clinic visits. Fifty-four percent of PSD statements were about intrauterine devices. About half of PSD statements occurred prior to the final selection of the contraceptive method and appeared to influence the choice of method. In post-visit surveys, all patients who reported receiving PSD considered it to be appropriate, and patient-reported PSD was not statistically associated with measures of patient satisfaction. CONCLUSIONS: This study provides some support for the appropriateness of PSD during family planning encounters, at least as practiced during the sampled visits. Further research could explore whether this counseling strategy has an impact on patients' ability to identify the best contraceptive methods for them. IMPLICATIONS: In this study, PSD did not have a demonstrated negative effect on the provider-patient relationship. In almost half of visits, PSD appeared to influence patients' choice of a method; whether this influence is beneficial needs further research.


Assuntos
Anticoncepção , Aconselhamento/métodos , Revelação , Serviços de Planejamento Familiar/métodos , Relações Médico-Paciente , Adulto , Comportamento de Escolha , Comportamento Contraceptivo/psicologia , Etnicidade , Feminino , Humanos , Satisfação do Paciente , Papel do Médico , São Francisco , Inquéritos e Questionários
18.
Science ; 352(6281): 99-103, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27034374

RESUMO

Host responses against metazoan parasites or an array of environmental substances elicit type 2 immunity. Despite its protective function, type 2 immunity also drives allergic diseases. The mechanisms that regulate the magnitude of the type 2 response remain largely unknown. Here, we show that genetic ablation of a receptor tyrosine kinase encoded byTyro3in mice or the functional neutralization of its ortholog in human dendritic cells resulted in enhanced type 2 immunity. Furthermore, the TYRO3 agonist PROS1 was induced in T cells by the quintessential type 2 cytokine, interleukin-4. T cell-specificPros1knockouts phenocopied the loss ofTyro3 Thus, a PROS1-mediated feedback from adaptive immunity engages a rheostat, TYRO3, on innate immune cells to limit the intensity of type 2 responses.


Assuntos
Imunidade Adaptativa/genética , Asma/imunologia , Interações Hospedeiro-Parasita/imunologia , Imunidade Inata/genética , Receptores Proteína Tirosina Quinases/fisiologia , Animais , Asma/genética , Proteínas Sanguíneas/antagonistas & inibidores , Proteínas Sanguíneas/genética , Proteínas Sanguíneas/metabolismo , Células Dendríticas/imunologia , Modelos Animais de Doenças , Técnicas de Inativação de Genes , Interações Hospedeiro-Parasita/genética , Humanos , Interleucina-4/imunologia , Interleucina-4/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nippostrongylus/imunologia , Proteína S , Pyroglyphidae/imunologia , Receptores Proteína Tirosina Quinases/genética , Infecções por Strongylida/imunologia , Linfócitos T/imunologia
19.
Immunity ; 44(2): 246-58, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26872695

RESUMO

Exposure to a plethora of environmental challenges commonly triggers pathological type 2 cell-mediated inflammation. Here we report the pathological role of the Wnt antagonist Dickkopf-1 (Dkk-1) upon allergen challenge or non-healing parasitic infection. The increased circulating amounts of Dkk-1 polarized T cells to T helper 2 (Th2) cells, stimulating a marked simultaneous induction of the transcription factors c-Maf and Gata-3, mediated by the kinases p38 MAPK and SGK-1, resulting in Th2 cell cytokine production. Circulating Dkk-1 was primarily from platelets, and the increase of Dkk-1 resulted in formation of leukocyte-platelet aggregates (LPA) that facilitated leukocyte infiltration to the affected tissue. Functional inhibition of Dkk-1 impaired Th2 cell cytokine production and leukocyte infiltration, protecting mice from house dust mite (HDM)-induced asthma or Leishmania major infection. These results highlight that Dkk-1 from thrombocytes is an important regulator of leukocyte infiltration and polarization of immune responses in pathological type 2 cell-mediated inflammation.


Assuntos
Asma/imunologia , Plaquetas/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Leishmania major/imunologia , Leishmaniose Cutânea/imunologia , Células Th2/imunologia , Proteínas Wnt/antagonistas & inibidores , Animais , Antígenos de Dermatophagoides/imunologia , Antígenos de Protozoários/imunologia , Diferenciação Celular , Células Cultivadas , Citocinas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Inflamação/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Animais , Pyroglyphidae , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/metabolismo
20.
PLoS Pathog ; 10(4): e1004060, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24722349

RESUMO

Human cytomegalovirus (HCMV) is the most common cause of congenital virus infection. Congenital HCMV infection occurs in 0.2-1% of all births, and causes birth defects and developmental abnormalities, including sensorineural hearing loss and developmental delay. Several key studies have established the guinea pig as a tractable model for the study of congenital HCMV infection and have shown that polyclonal antibodies can be protective. In this study, we demonstrate that an anti-guinea pig CMV (GPCMV) glycoprotein H/glycoprotein L neutralizing monoclonal antibody protects against fetal infection and loss in the guinea pig. Furthermore, we have delineated the kinetics of GPCMV congenital infection, from maternal infection (salivary glands, seroconversion, placenta) to fetal infection (fetus and amniotic fluid). Our studies support the hypothesis that a neutralizing monoclonal antibody targeting an envelope GPCMV glycoprotein can protect the fetus from infection and may shed light on the therapeutic intervention of HCMV congenital infection in humans.


Assuntos
Anticorpos Monoclonais Murinos/farmacologia , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/tratamento farmacológico , Citomegalovirus/imunologia , Animais , Anticorpos Monoclonais Murinos/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/patologia , Modelos Animais de Doenças , Cobaias , Células HEK293 , Humanos
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