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1.
Anal Biochem ; 660: 114929, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36270332

RESUMO

Detection and quantification of antibodies, especially immunoglobulin G (IgG), is a cornerstone of ELISAs, many diagnostics, and the development of antibody-based drugs. Current state-of-the-art immunoassay techniques for antibody detection require species-specific secondary antibodies and carefully-controlled bioconjugations. Poor conjugation efficiency degrades assay performance and increases the risk of clinical false positives due to non-specific binding. We developed a generic, highly-sensitive platform for IgG quantification by fusing the IgG-Fc binding Z domain of Staphylococcal Protein A with the ultrabright bioluminescence reporter Nanoluc-luciferase (Nluc). We demonstrated the application of this fusion protein in a sandwich IgG detection immunoassay using surface-bound antigens to capture target IgG and protein A-Nanoluc fusion as the detector. We optimized the platform's sensitivity by incorporating multiple repeats of the Z domain into the fusion protein constructs. Using rabbit and mouse anti-SARS-CoV-2 Nucleoprotein IgGs as model analytes, we performed ELISAs in two different formats, either with SARS-CoV-2 Nucleoprotein as the capture antigen or with polyclonal chicken IgY as the capture antibody. Using standard laboratory equipment, the platform enabled the quantitation of antibody analytes at concentrations as low as 10 pg/mL (67 fM).


Assuntos
COVID-19 , Imunoglobulina G , Camundongos , Coelhos , Animais , Proteína Estafilocócica A , SARS-CoV-2 , Anticorpos Antivirais , Imunoensaio/métodos , Nucleoproteínas , Sensibilidade e Especificidade
2.
Int J Mol Sci ; 24(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36674796

RESUMO

Staphylococcus aureus protein A (SpA) is an IgG Fc-binding virulence factor that is widely used in antibody purification and as a scaffold to develop affinity molecules. A cyclized SpA Z domain could offer exopeptidase resistance, reduced chromatographic ligand leaching after single-site endopeptidase cleavage, and enhanced IgG binding properties by preorganization, potentially reducing conformational entropy loss upon binding. In this work, a Z domain trimer (Z3) was cyclized using protein intein splicing. Interactions of cyclic and linear Z3 with human IgG1 were characterized by differential scanning fluorimetry (DSF), surface plasmon resonance (SPR), and isothermal titration calorimetry (ITC). DSF showed a 5 ℃ increase in IgG1 melting temperature when bound by each Z3 variant. SPR showed the dissociation constants of linear and cyclized Z3 with IgG1 to be 2.9 nM and 3.3 nM, respectively. ITC gave association enthalpies for linear and cyclic Z3 with IgG1 of -33.0 kcal/mol and -32.7 kcal/mol, and -T∆S of association 21.2 kcal/mol and 21.6 kcal/mol, respectively. The compact cyclic Z3 protein contains 2 functional binding sites and exhibits carboxypeptidase Y-resistance. The results suggest cyclization as a potential approach toward more stable SpA-based affinity ligands, and this analysis may advance our understanding of protein engineering for ligand and drug development.


Assuntos
Inteínas , Staphylococcus aureus , Humanos , Inteínas/genética , Ligantes , Termodinâmica , Imunoglobulina G , Calorimetria/métodos , Ligação Proteica
3.
Pharm Res ; 36(10): 144, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31392417

RESUMO

PURPOSE: Boron neutron capture therapy (BNCT) has the potential to become a viable cancer treatment modality, but its clinical translation requires sufficient tumor boron delivery while minimizing nonspecific accumulation. METHODS: Thermal sensitive liposomes (TSLs) were designed to have a stable drug payload at physiological temperatures but engineered to have high permeability under mild hyperthermia. RESULTS: We found that TSLs improved the tumor-specific delivery of boronophenylalanine (BPA) and boronated 2-nitroimidazole derivative B-381 in D54 glioma cells. Uniquely, the 2-nitroimidazole moiety extended the tumor retention of boron content compared to BPA. CONCLUSION: This is the first study to show the delivery of boronated compounds using TSLs for BNCT, and these results will provide the basis of future clinical trials using TSLs for BNCT.


Assuntos
Compostos de Boro/química , Terapia por Captura de Nêutron de Boro , Lipossomos/química , Animais , Antineoplásicos/química , Compostos de Boro/administração & dosagem , Compostos de Boro/farmacocinética , Linhagem Celular Tumoral , Neoplasias do Sistema Nervoso Central/metabolismo , Doxorrubicina/química , Liberação Controlada de Fármacos , Feminino , Glioma/metabolismo , Humanos , Hipertermia Induzida , Camundongos Nus , Nitroimidazóis/administração & dosagem , Nitroimidazóis/química , Tamanho da Partícula , Fenilalanina/administração & dosagem , Fenilalanina/análogos & derivados , Fenilalanina/química , Fosfolipídeos/química , Temperatura , Distribuição Tecidual
4.
Obes Surg ; 34(7): 2627-2633, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38837020

RESUMO

INTRODUCTION: Revisional bariatric surgery is associated with higher perioperative complications over primary procedures. Adjustable gastric bands (AGB) continue to be the most frequently converted bariatric configuration. This study examines trends in current clinical indication and safety profile of the most frequently pursued AGB conversions. MATERIALS AND METHODS: MBSAQIP data from 2020 to 2022 was retrospectively analyzed in a cohort study examining 30-day postoperative outcomes after AGB conversion to sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), or single anastomosis duodenoileostomy (SADI). Descriptive statistics were used, including multivariable and 2:1 nearest neighbor matching analysis. RESULTS: This study included 19,335 AGB conversions, of which most were to SG (n = 11,736) followed by RYGB (n = 7442) and SADI (n = 157). While a majority were completed for weight loss, there were differences in distribution of primary indication for each conversion cohort, such as higher proportion of RYGB conversion for gastroesophageal reflux disease (18.7%) compared to SG (7.92%) and SADI (5.10%). Multivariable analysis demonstrates conversion to RYGB has significantly higher odds of 30-day major complications (OR 1.75, p < 0.001), reoperation (OR 2.08; p = 0.001), readmission (OR 1.69; p = 0.001), and emergency department visits (OR 1.50; p = 0.001) over SG. These risks and odds of reintervention (OR 1.75; p < 0.001) remained significantly higher after conversion to RYGB versus SG on matched analysis. None of these risks is significantly different between conversions to SADI versus SG in either multivariable or matched analysis. CONCLUSIONS: Compared to AGB conversion to SG, single-stage conversion to RYGB had increased odds of perioperative complications while risks of conversion to SADI were not significantly different.


Assuntos
Gastrectomia , Derivação Gástrica , Obesidade Mórbida , Complicações Pós-Operatórias , Reoperação , Humanos , Derivação Gástrica/métodos , Derivação Gástrica/efeitos adversos , Feminino , Masculino , Estudos Retrospectivos , Gastrectomia/métodos , Obesidade Mórbida/cirurgia , Reoperação/estatística & dados numéricos , Adulto , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Gastroplastia/métodos , Gastroplastia/efeitos adversos , Redução de Peso , Anastomose Cirúrgica/métodos , Duodeno/cirurgia , Resultado do Tratamento
5.
BMJ Open Respir Res ; 11(1)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38749534

RESUMO

INTRODUCTION: Early enteral nutrition (EN) in critically ill adult patients is thought to improve mortality and morbidity; expert guidelines recommend early initiation of EN in critically ill adults. However, the ideal schedule and dose of EN remain understudied. STUDY OBJECTIVE: Our objective was to evaluate the relationship between achieving 70% of recommended EN within 2 days of intubation ('early goal EN') and clinical outcomes in mechanically ventilated medically critically ill adults. We hypothesised that early goal EN would be associated with reduced in-hospital death. METHODS: We conducted a retrospective cohort study of mechanically ventilated adult patients admitted to our medical intensive care unit during 2013-2019. We assessed the proportion of recommended total EN provided to the patient each day following intubation until extubation, death or 7 days whichever was shortest. Patients who received 70% or more of their recommended total daily EN within 2 days of intubation (ie, 'baseline period') were considered to have achieved 'early goal EN'; these patients were compared with patients who did not ('low EN'). The primary outcome was in-hospital death; secondary outcomes were successful extubation and discharge alive. RESULTS: 938 patients met eligibility criteria and survived the baseline period. During the 7-day postintubation period, 64% of all patients reached 70% of recommended daily calories; 33% of patients achieved early goal EN. In unadjusted and adjusted models, early goal EN versus low EN was associated with a lower incidence of in-hospital death (subdistribution HR (SHR) unadjusted=0.63, p=0.0003, SHR adjusted=0.73, p=0.02). Early goal EN was also associated with a higher incidence of successful extubation (SHR unadjusted=1.41, p<0.00001, SHR adjusted=1.27, p=0.002) and discharge alive (SHR unadjusted=1.54, p<0.00001, SHR adjusted=1.24, p=0.02). CONCLUSIONS: Early goal EN was associated with significant improvement in clinical metrics of decreased in-hospital death, increased extubation and increased hospital discharge alive.


Assuntos
Estado Terminal , Nutrição Enteral , Mortalidade Hospitalar , Respiração Artificial , Humanos , Estudos Retrospectivos , Estado Terminal/mortalidade , Estado Terminal/terapia , Masculino , Nutrição Enteral/métodos , Respiração Artificial/estatística & dados numéricos , Feminino , Pessoa de Meia-Idade , Idoso , Unidades de Terapia Intensiva , Fatores de Tempo
6.
Pract Lab Med ; 35: e00314, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37181647

RESUMO

Objective: Anti-Müllerian Hormone (AMH) is a quantitative marker for ovarian reserve and is used to predict response during ovarian stimulation. Streamlining testing to the clinic or even to the physician's office would reduce inconvenience, turnaround time, patient stress and potentially also the total cost of testing, allowing for more frequent monitoring. In this paper, AMH is used as a model biomarker to describe the rational development and optimization of sensitive, quantitative, clinic-based rapid diagnostic tests. Design and Methods: We developed a one-step lateral-flow europium (III) chelate-based fluorescent immunoassay (LFIA) for the detection of AMH on a portable fluorescent reader, optimizing the capture/detection antibodies, running buffer, and reporter conjugates. Results: A panel of commercial calibrators was used to develop a standard curve to determine the analytical sensitivity (LOD = 0.41 ng/ml) and the analytical range (0.41-15.6 ng/ml) of the LFIA. Commercial controls were then tested to perform an initial evaluation of the prototype performance and showed a high degree of precision (Control I CV 2.18%; Control II CV 3.61%) and accuracy (Control I recovery 126%; Control II recovery 103%). Conclusions: This initial evaluation suggests that, in future clinical testing, the AMH LFIA will likely have the capability of distinguishing women with low ovarian reserve (<1 ng/ml AMH) from women with normal (1-4 ng/ml AMH) ovarian reserve. Furthermore, the LFIA demonstrated a wide linear range, indicating the assay's applicability to the detection of other health conditions such as PCOS, which requires AMH measurement at higher concentrations (>6 ng/ml).

7.
Leukemia ; 35(8): 2346-2357, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33479469

RESUMO

T-cell-based immunotherapy, such as CAR-T cells and bispecific T-cell engagers (BiTEs), has shown promising clinical outcomes in many cancers; however, these therapies have significant limitations, such as poor pharmacokinetics and the ability to target only one antigen on the cancer cells. In multiclonal diseases, these therapies confer the development of antigen-less clones, causing tumor escape and relapse. In this study, we developed nanoparticle-based bispecific T-cell engagers (nanoBiTEs), which are liposomes decorated with anti-CD3 monoclonal antibodies (mAbs) targeting T cells, and mAbs targeting the cancer antigen. We also developed a nanoparticle that targets multiple cancer antigens by conjugating multiple mAbs against multiple cancer antigens for T-cell engagement (nanoMuTEs). NanoBiTEs and nanoMuTEs have a long half-life of about 60 h, which enables once-a-week administration instead of continuous infusion, while maintaining efficacy in vitro and in vivo. NanoMuTEs targeting multiple cancer antigens showed greater efficacy in myeloma cells in vitro and in vivo, compared to nanoBiTEs targeting only one cancer antigen. Unlike nanoBiTEs, treatment with nanoMuTEs did not cause downregulation (or loss) of a single antigen, and prevented the development of antigen-less tumor escape. Our nanoparticle-based immuno-engaging technology provides a solution for the major limitations of current immunotherapy technologies.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Antígenos de Neoplasias/imunologia , Imunoterapia/métodos , Mieloma Múltiplo/terapia , Nanopartículas/administração & dosagem , Linfócitos T/imunologia , Animais , Anticorpos Monoclonais/imunologia , Apoptose , Proliferação de Células , Feminino , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Nanopartículas/química , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Biosens Bioelectron ; 165: 112327, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32729475

RESUMO

Purification of therapeutic monoclonal antibodies usually involves a protein A affinity capture step. Because column breakthrough of antibody in complex, UV-absorbing culture fluid cannot be readily detected in real time, processes are designed so conservatively that column capacity is usually underutilized, wasting adsorbent and reducing productivity. We have developed a fluorescence-based monitoring technology which allows real-time mAb monitoring and used it to detect IgG in column breakthrough. The column effluent was continuously contacted with soluble fluorescein-labeled Fc-binding ligands to produce an immediately-detectable shift in both fluorescence polarization and intensity. To extend the upper limit of inlet flow rate, a 14:1 split-ratio flow splitter was tested with an inlet flow of 15 mL/min (0.9 L/h), producing a sampling stream at 1 mL/min while still enabling continuous detection functionality. We observed significant shifts in fluorescence intensity in CHO cell culture fluid spiked with human IgG, and detected 0.02-0.1 g/L human IgG in protein A column breakthrough at a flow velocity of 80 cm/h. The increase in fluorescence intensity upon 0.1% breakthrough of an 1 g/L feed was used to trigger column switching using Python-enabled two-way communication with the standard Unicorn OPC process control protocol. The technology allows rapid, continuous and reliable monitoring of IgG in a flowing process stream, without elaborate sample preparation.


Assuntos
Técnicas Biossensoriais , Proteína Estafilocócica A , Animais , Células CHO , Cromatografia de Afinidade , Cricetinae , Cricetulus , Humanos
9.
Cancers (Basel) ; 12(2)2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32012878

RESUMO

Multiple myeloma (MM) remains to be incurable despite recent therapeutic advances. CD47, an immune checkpoint known as the "don't eat me" signal, is highly expressed on the surface of various cancers, allowing cancer cells to send inhibitory signals to macrophages and impede phagocytosis and immune response. In this study, we hypothesized that blocking the "don't eat me" signaling using an anti-CD47 monoclonal antibody will induce killing of MM cells. We report that CD47 expression was directly correlated with stage of the disease, from normal to MGUS to MM. Moreover, MM cells had remarkably higher CD47 expression than other cell populations in the bone marrow. These findings indicate that CD47 is specifically expressed on MM and can be used as a potential therapeutic target. Further, blocking of CD47 using an anti-CD47 antibody induced immediate activation of macrophages, which resulted in induction of phagocytosis and killing of MM cells in the 3D-tissue engineered bone marrow model, as early as 4 hours. These results suggest that macrophage checkpoint immunotherapy by blocking the CD47 "don't eat me" signal is a novel and promising strategy for the treatment of MM, providing a basis for additional studies to validate these effects in vivo and in patients.

10.
Nat Commun ; 11(1): 6037, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33247158

RESUMO

Drug resistance and dose-limiting toxicities are significant barriers for treatment of multiple myeloma (MM). Bone marrow microenvironment (BMME) plays a major role in drug resistance in MM. Drug delivery with targeted nanoparticles have been shown to improve specificity and efficacy and reduce toxicity. We aim to improve treatments for MM by (1) using nanoparticle delivery to enhance efficacy and reduce toxicity; (2) targeting the tumor-associated endothelium for specific delivery of the cargo to the tumor area, and (3) synchronizing the delivery of chemotherapy (bortezomib; BTZ) and BMME-disrupting agents (ROCK inhibitor) to overcome BMME-induced drug resistance. We find that targeting the BMME with P-selectin glycoprotein ligand-1 (PSGL-1)-targeted BTZ and ROCK inhibitor-loaded liposomes is more effective than free drugs, non-targeted liposomes, and single-agent controls and reduces severe BTZ-associated side effects. These results support the use of PSGL-1-targeted multi-drug and even non-targeted liposomal BTZ formulations for the enhancement of patient outcome in MM.


Assuntos
Bortezomib/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Nanopartículas/química , Inibidores de Proteínas Quinases/uso terapêutico , Microambiente Tumoral , Quinases Associadas a rho/antagonistas & inibidores , Amidas/farmacologia , Amidas/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Bortezomib/farmacologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Progressão da Doença , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Lipossomos , Glicoproteínas de Membrana/metabolismo , Camundongos , Selectina-P/metabolismo , Ligação Proteica , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Piridinas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Carga Tumoral , Microambiente Tumoral/efeitos dos fármacos , Quinases Associadas a rho/metabolismo , Quinases da Família src/metabolismo
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