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1.
Food Chem Toxicol ; 135: 110973, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31738983

RESUMO

The construction, expression and functional analysis of codon-optimized single-chain variable fragment (coscFv) against clenbuterol (CBL) prepared from the Escherichia coli system is described. First, the ionic concentration for coscFv expression was optimized through single-factor experiments. Then, the extraction conditions of inclusion bodies were optimized, and coscFv was affinity-purified. Finally, the functional analysis of coscFv was elucidated by indirect competitive enzyme-linked immunosorbent assay (icELISA) and molecular docking. After optimizing the ionic concentration, the yield of coscFv increased from 21.69% to 23.26%. The molecular weight of coscFv was determined to be approximately 27 kDa according to the SDS-PAGE and Western blot assay. The percentage of coscFv was as high as 43.9% after the inclusion bodies were extracted, washed, and dissolved. Functional analysis indicated that the coscFv recognized CBL, and the 50% inhibition average concentration of CBL (IC50) was 4.22 ± 0.01 (n = 3) ng/mL. The binding site between coscFv and CBL consisted of Asp33H, Met34H, Ser50H, Arg52H, Tyr57H, Leu59H, Asp99H, and Tyr93L. Our study confirms that coscFv can bind with CBL through the key amino acid residues and can be used to sensitively detect CBL.


Assuntos
Agonistas Adrenérgicos beta/imunologia , Clembuterol/imunologia , Anticorpos de Cadeia Única/imunologia , Agonistas Adrenérgicos beta/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Clembuterol/metabolismo , Clonagem Molecular/métodos , Ensaio de Imunoadsorção Enzimática , Escherichia coli/genética , Simulação de Acoplamento Molecular , Ligação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/metabolismo
2.
Infect Immun ; 88(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31740528

RESUMO

Influenza A virus (H1N1) is an acute, highly contagious respiratory virus. The use of lactic acid bacteria (LAB) to deliver mucosal vaccines against influenza virus infection is a research hot spot. In this study, two recombinant Lactobacillus plantarum strains expressing hemagglutinin (HA) alone or coexpressing aCD11c-HA to target HA protein to dendritic cells (DCs) by fusion to an anti-CD11c single-chain antibody (aCD11c) were constructed. The activation of bone marrow dendritic cells (BMDCs) by recombinant strains and the interaction of activated BMDCs and sorted CD4+ or CD8+ T cells were evaluated through flow cytometry in vitro, and cellular supernatants were assessed by using an enzyme-linked immunosorbent assay kit. The results demonstrated that, compared to the HA strain, the aCD11c-HA strain significantly increased the activation of BMDCs and increased the production of CD4+ gamma interferon-positive (IFN-γ+) T cells, CD8+ IFN-γ+ T cells, and IFN-γ in the cell culture supernatant in vitro Consistent with these results, the aCD11c-HA strain clearly increased the activation and maturation of DCs, the HA-specific responses of CD4+ IFN-γ+ T cells, CD8+ IFN-γ+ T cells, and CD8+ CD107a+ T cells, and the proliferation of T cells in the spleen, finally increasing the levels of specific antibodies and neutralizing antibodies in mice. In addition, the protection of immunized mice was observed after viral infection, as evidenced by improved weight loss, survival, and lung pathology. The adoptive transfer of CD8+ T cells from the aCD11c-HA mice to NOD/Lt-SCID mice resulted in a certain level of protection after influenza virus infection, highlighting the efficacy of the aCD11c targeting strategy.


Assuntos
Antígeno CD11c/imunologia , Células Dendríticas/imunologia , Imunidade Celular/imunologia , Lactobacillus plantarum/imunologia , Anticorpos de Cadeia Única/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Células Dendríticas/virologia , Feminino , Vírus da Influenza A Subtipo H1N1/imunologia , Interferon gama/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia
3.
Immunology ; 159(1): 96-108, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31596953

RESUMO

Among various solid tumours, gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. Expansion into the peritoneal cavity, which results from dissemination of diffuse cancer cells, is the main cause of mortality in gastric adenocarcinoma patients. Therefore, investigation of putative biomarkers involved in metastasis is prerequisite for GC management. In an effort to discover potential tumour markers associated with peritoneal metastasis of GC, a semi-synthetic human scFv library (Tomlinson I) was used to isolate novel antibody fragments recognizing MKN-45, a poorly differentiated diffuse gastric adenocarcinoma cell line. Four rounds of subtractive selection each consisting of extensive pre-absorption of phage library with NIH-3T3 murine embryonic fibroblasts and AGS (a well-differentiated intestinal gastric adenocarcinoma) cell line were carried out prior to positive selection on MKN-45 target cells. ELISA-based screening of 192 phage-displayed scFv clones indicated 21 high-affinity binders with specific staining of MKN-45 compared with AGS cells. Diversity analysis of the selected phage-scFvs resulted in five distinct sequences with multiple frequency. Further analysis by ELISA and flow cytometry verified three clones that specifically recognized MKN-45 cells. Liquid chromatography-mass spectrometry analysis of the scFv-immunoprecipitated proteins has led to identification of c-Met, HSP90 α and HSP90 ß as candidate biomarkers associated with diffuse GC. Immunohistochemistry revealed the capability of purified scFvs to differentiate diffuse and intestinal gastric adenocarcinoma. Taken together, the isolated MKN-45-specific scFv fragments and their cognate antigens would be beneficial in screening and management as well as targeting and therapy of the diffuse gastric adenocarcinoma.


Assuntos
Adenocarcinoma/imunologia , Biomarcadores Tumorais/análise , Bioprospecção/métodos , Técnicas de Visualização da Superfície Celular , Proteínas de Choque Térmico HSP90/análise , Proteínas Proto-Oncogênicas c-met/análise , Anticorpos de Cadeia Única/imunologia , Neoplasias Gástricas/imunologia , Adenocarcinoma/patologia , Animais , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Diagnóstico Diferencial , Humanos , Imuno-Histoquímica , Camundongos , Células NIH 3T3 , Valor Preditivo dos Testes , Anticorpos de Cadeia Única/genética , Neoplasias Gástricas/patologia , Espectrometria de Massas em Tandem
4.
Iran J Allergy Asthma Immunol ; 18(3): 289-299, 2019 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-31522436

RESUMO

Vascular endothelial growth factor receptor 2 (VEGFR-2) is known as one of the important antigens playing a vital role in angiogenesis. In this study, phage display technology (PDT) was used to produce a single-chain variable fragment (scFv) antibody against a region of the domain 3 in VEGFR-2 called kinase insert domain receptor 3 (KDR3). After designing the KDR3 peptide and biopanning, a colony was chosen for scFv antibody expression. Following expression and purification; western blotting, dot blotting and immunofluorescence (IF) were used to evaluate the antibody function. Surface plasmon resonance (SPR) was also employed to measure affinity of produced antibody. Once a colony was selected and transferred to the expression host, the scFv antibody was expressed in the expected range of 28 kDa. Using a designed chromatography column, antibody purification was found to be about 95%. In this study, a novel scFv with the capability of binding to KDR3 was isolated and purified and its intracellular function was investigated and verified.


Assuntos
Biblioteca de Peptídeos , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/isolamento & purificação , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/imunologia , Afinidade de Anticorpos/imunologia , Especificidade de Anticorpos , Cromatografia de Afinidade , Imunofluorescência , Células Endoteliais da Veia Umbilical Humana , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/farmacologia , Relação Estrutura-Atividade , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/química
5.
BMC Cancer ; 19(1): 882, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488104

RESUMO

BACKGROUND: Bispecific T-cell engaging antibodies (BiTES), comprising dual anti-CD3 and anti-tumor antigen scFv fragments, are important therapeutic agents for the treatment of cancer. The dual scFv construct for BiTES requires proper protein folding while their small molecular size leads to rapid kidney clearance. METHODS: An intact (150 kDa) anti-tumor antigen antibody to CEA was joined in high yield (ca. 30%) to intact (150 kDa) anti-murine and anti-human CD3 antibodies using hinge region specific Click chemistry to form dual-specific, bivalent BiTES (dbBiTES, 300 kDa). dbBiTEs were tested in vitro by EM, flow cytometry and cell cytoxicity and in vivo by PET tumor imaging and redirected T-cell therapy. RESULTS: The interlocked hinge regions are compatible with a structural model that fits the electron micrographs of 300 kDa particles. Compared to intact anti-CEA antibody, dbBiTES exhibit high in vitro cytotoxicity, high in vivo tumor targeting as demonstrated by PET imaging, and redirected dbBiTE coated T-cells (1 microgram/10 million cells) that kill CEA+ target cells in vivo in CEA transgenic mice. CONCLUSION: dbBiTE redirected T-cell therapy is a promising, efficient approach for targeting and killing cancer cells.


Assuntos
Anticorpos Biespecíficos/uso terapêutico , Antígeno Carcinoembrionário/imunologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Neoplasias do Colo/terapia , Imunoterapia/métodos , Linfócitos T/imunologia , Animais , Complexo CD3/imunologia , Antígeno Carcinoembrionário/genética , Linhagem Celular Tumoral , Neoplasias do Colo/diagnóstico por imagem , Citotoxicidade Imunológica , Humanos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Simulação de Dinâmica Molecular , Tomografia por Emissão de Pósitrons , Dobramento de Proteína , Anticorpos de Cadeia Única/imunologia , Transfecção , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Int J Mol Sci ; 20(17)2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31461846

RESUMO

Affinity maturation and rational design have a raised importance in the application of nanobody (VHH), and its unique structure guaranteed these processes quickly done in vitro. An anti-CD47 nanobody, Nb02, was screened via a synthetic phage display library with 278 nM of KD value. In this study, a new strategy based on homology modeling and Rational Mutation Hotspots Design Protocol (RMHDP) was presented for building a fast and efficient platform for nanobody affinity maturation. A three-dimensional analytical structural model of Nb02 was constructed and then docked with the antigen, the CD47 extracellular domain (CD47ext). Mutants with high binding affinity are predicted by the scoring of nanobody-antigen complexes based on molecular dynamics trajectories and simulation. Ultimately, an improved mutant with an 87.4-fold affinity (3.2 nM) and 7.36 °C higher thermal stability was obtained. These findings might contribute to computational affinity maturation of nanobodies via homology modeling using the recent advancements in computational power. The add-in of aromatic residues which formed aromatic-aromatic interaction plays a pivotal role in affinity and thermostability improvement. In a word, the methods used in this study might provide a reference for rapid and efficient in vitro affinity maturation of nanobodies.


Assuntos
Afinidade de Anticorpos , Antígeno CD47/química , Simulação de Acoplamento Molecular , Anticorpos de Cadeia Única/química , Sítios de Ligação de Anticorpos , Antígeno CD47/genética , Antígeno CD47/imunologia , Humanos , Mutação , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia
7.
Cancer Sci ; 110(9): 2722-2733, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31461572

RESUMO

Mesothelin (MSLN) shows increased expression in various cancer cells. For clinical application of antibodies as a positron emission tomography (PET) imaging reagent, a human shortened antibody is essential both for avoiding redundant immune responses and for providing rapid imaging. Therefore, we cloned a single-chain fragment of variable regions (scFv) from a human-derived gene sequence. This was achieved through the construction of a naïve phage library derived from human tonsil lymphocytes. Using a column with human recombinant MSLN, we carried out bio-panning of phage-variants by colony formation. We first obtained 120 clones that were subjected to selection in an ELISA using human recombinant MSLN as a solid phase antigen, and 15 phage clones of scFv with a different sequence were selected and investigated by flow cytometry (FCM). Then, six variants were selected and the individual scFv gene was synthesized in the VL and VH domains and expressed in Chinese hamster ovary cells. Mammalian cell-derived human-origin scFv clones were analyzed by FCM again, and one MSLN highly specific scFv clone was established. PET imaging by 89 Zr-labeled scFv was done in mice bearing xenografts with MSLN-expressing cancer cells, and tumor legions were successfully visualized. The scFv variant established in the present study may be potentially useful for cancer diagnosis by PET imaging.


Assuntos
Proteínas Ligadas por GPI/imunologia , Neoplasias/diagnóstico por imagem , Compostos Radiofarmacêuticos/imunologia , Anticorpos de Cadeia Única/imunologia , Animais , Células CHO , Linhagem Celular Tumoral , Clonagem Molecular , Cricetulus , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/isolamento & purificação , Proteínas Ligadas por GPI/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Imagem Molecular/métodos , Neoplasias/patologia , Biblioteca de Peptídeos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Radioisótopos , Compostos Radiofarmacêuticos/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Anticorpos de Cadeia Única/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto , Zircônio
8.
Nature ; 571(7764): 284-288, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31263273

RESUMO

Hedgehog signalling is fundamental to embryonic development and postnatal tissue regeneration1. Aberrant postnatal Hedgehog signalling leads to several malignancies, including basal cell carcinoma and paediatric medulloblastoma2. Hedgehog proteins bind to and inhibit the transmembrane cholesterol transporter Patched-1 (PTCH1), which permits activation of the seven-transmembrane transducer Smoothened (SMO) via a mechanism that is poorly understood. Here we report the crystal structure of active mouse SMO bound to both the agonist SAG21k and to an intracellular binding nanobody that stabilizes a physiologically relevant active state. Analogous to other G protein-coupled receptors, the activation of SMO is associated with subtle motions in the extracellular domain, and larger intracellular changes. In contrast to recent models3-5, a cholesterol molecule that is critical for SMO activation is bound deep within the seven-transmembrane pocket. We propose that the inactivation of PTCH1 by Hedgehog allows a transmembrane sterol to access this seven-transmembrane site (potentially through a hydrophobic tunnel), which drives the activation of SMO. These results-combined with signalling studies and molecular dynamics simulations-delineate the structural basis for PTCH1-SMO regulation, and suggest a strategy for overcoming clinical resistance to SMO inhibitors.


Assuntos
Membrana Celular/química , Proteínas Hedgehog/agonistas , Transdução de Sinais/efeitos dos fármacos , Receptor Smoothened/agonistas , Receptor Smoothened/metabolismo , Esteróis/farmacologia , Animais , Sítios de Ligação , Técnicas Biossensoriais , Domínio Catalítico/efeitos dos fármacos , Membrana Celular/metabolismo , Colesterol/química , Colesterol/metabolismo , Colesterol/farmacologia , Proteínas Hedgehog/metabolismo , Ligantes , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Receptor Patched-1/antagonistas & inibidores , Receptor Patched-1/metabolismo , Conformação Proteica , Estabilidade Proteica , Anticorpos de Cadeia Única/imunologia , Receptor Smoothened/antagonistas & inibidores , Receptor Smoothened/química , Esteróis/química , Esteróis/metabolismo , Proteínas de Xenopus/química
9.
Appl Microbiol Biotechnol ; 103(18): 7703-7717, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31359103

RESUMO

G protein-coupled receptors (GPCRs), also known as seven-transmembrane domain receptors, are among the most important targets against which many small molecule drugs have been developed. However, only two antibody drugs targeting GPCRs have been approved for clinical use although many antibody drugs against non-GPCR protein targets have been successfully developed for various disease indications. One of the challenges for developing anti-GPCR drugs is the high difficulty to perform affinity maturation due to their insolubility in aqueous solutions. To address this issue, CHO cell display libraries of single-chain variable fragments (scFvs) and full-length antibodies were maturated directly against vesicle probes prepared from CHO cells displaying the endothelin A receptor (ETaR) GPCR. The probe in the vesicle form ensures the physiological conformation and functional activity of the protein and avoids issues with membrane protein insolubility. The size of the vesicle had a clear effect on protein-ligand interaction; we used small-sized vesicles with low expression levels of GPCRs for the affinity maturation. Four rounds of affinity maturation combining vesicles as probes with the CHO cell display platform improved affinity by 13.58-fold for scFvs and 5.05-fold for full-length antibodies. We expect that this method will not only be used for the affinity maturation of antibodies against GPCRs but will also be used to mature antibodies for other types of proteins where the conformation/activity of which depends on the proper membrane environment.


Assuntos
Afinidade de Anticorpos , Receptor de Endotelina A/imunologia , Anticorpos de Cadeia Única/imunologia , Animais , Células CHO , Cricetulus , Ligantes , Conformação Molecular
10.
J Exp Clin Cancer Res ; 38(1): 326, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337429

RESUMO

BACKGROUND: Prostate cancer (PCa) is the second leading cause of cancer-related death in the Western population. The use in oncology of positron emission tomography/computed tomography (PET/CT) with emerging radiopharmaceuticals promises accurate staging of primary disease, restaging of recurrent disease and detection of metastatic lesions. Prostate-specific membrane antigen (PSMA) expression, directly related to androgen-independence, metastasis and progression, renders this tumour associate antigen a good target for the development of new radiopharmaceuticals for PET. Aim of this study was to demonstrate in a preclinical in vivo model (PSMA-positive versus PSMA-negative tumours) the targeting specificity and sensitivity of the anti-PSMA single-chain variable fragment (scFv) labelled with 124I. METHODS: The 124I-labeling conditions of the antibody fragment scFvD2B were optimized and assessed for purity and immunoreactivity. The specificity of 124I-scFvD2B was tested in mice bearing PSMA-positive and PSMA-negative tumours to assess both ex-vivo biodistribution and immune-PET. RESULTS: The uptake fraction of 124I-scFvD2B was very high on PSMA positive cells (range 75-91%) and highly specific and immuno-PET at the optimal time point, defined between 15 h and 24 h, provides a specific localization of lesions bearing the target antigen of interest (PSMA positive vs PSMA negative tumors %ID/g: p = 0.0198 and p = 0.0176 respectively) yielding a median target/background ratio around 30-40. CONCLUSIONS: Preclinical in vivo results of our immuno-PET reagent are highly promising. The target to background ratio is improved notably using PET compared to SPECT previously performed. These data suggest that, upon clinical confirmation of sensitivity and specificity, our anti-PSMA 124I-scFvD2B may be superior to other diagnostic modalities for PCa. The possibility to combine in patients our 124I-scFvD2B in multi-modal systems, such as PET/CT, PET/MR and PET/SPECT/CT, will provide quantitative 3D tomographic images improving the knowledge of cancer biology and treatment.


Assuntos
Antígenos de Superfície/imunologia , Glutamato Carboxipeptidase II/imunologia , Neoplasias da Próstata/diagnóstico , Compostos Radiofarmacêuticos/farmacologia , Anticorpos de Cadeia Única/imunologia , Animais , Antígenos de Superfície/farmacologia , Linhagem Celular Tumoral , Glutamato Carboxipeptidase II/farmacologia , Humanos , Imunoconjugados/imunologia , Imunoconjugados/farmacologia , Radioisótopos do Iodo/farmacologia , Masculino , Camundongos , Metástase Neoplásica , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , Compostos Radiofarmacêuticos/imunologia , Anticorpos de Cadeia Única/farmacologia , Distribuição Tecidual
11.
BMC Biotechnol ; 19(1): 38, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31238939

RESUMO

BACKGROUND: Anti-Tumor Necrosis Factor-alpha therapy has become clinically important for treating inflammatory bowel disease. However, the use of conventional immunotherapy requires a systemic exposure of patients and collateral side effects. Lactic acid bacteria have been shown to be effective as mucosal delivering system for cytokine and single domain antibodies, and it is amenable to clinical purposes. Therefore, lactic acid bacteria may function as vehicles for delivery of therapeutic antibodies molecules to the gastrointestinal tract restricting the pharmacological effect towards the gut. Here, we use the mucosal delivery of Lactococcus lactis carrying an anti-TNFα scFv expression plasmid on a DSS-induced colitis model in mice. RESULTS: Experimental colitis was induced with DSS administered in drinking water. L. lactis carrying the scFv expression vector was introduced by gavage. After four days of treatment, animals showed a significant improvement in histological score and disease activity index compared to those of untreated animals. Moreover, treated mice display IL-6, IL17A, IL1ß, IL10 and FOXP3 mRNA levels similar to health control mice. Therefore, morphological and molecular markers suggest amelioration of the experimentally induced colitis. CONCLUSION: These results provide evidence for the use of this alternative system for delivering therapeutic biopharmaceuticals in loco for treating inflammatory bowel disease, paving the way for a novel low-cost and site-specific biotechnological route for the treatment of inflammatory disorders.


Assuntos
Colite/terapia , Citocinas/metabolismo , Vetores Genéticos/administração & dosagem , Lactococcus lactis/imunologia , Administração Oral , Animais , Anticorpos/genética , Anticorpos/imunologia , Anticorpos/metabolismo , Colite/induzido quimicamente , Colite/imunologia , Citocinas/genética , Citocinas/imunologia , Sulfato de Dextrana , Modelos Animais de Doenças , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Células HEK293 , Humanos , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , Camundongos Endogâmicos C57BL , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/metabolismo , Fator de Necrose Tumoral alfa/imunologia
12.
Vet Immunol Immunopathol ; 212: 9-14, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213252

RESUMO

Targeting antigens to endocytic receptors on the surface of dendritic cells is a new strategy for increasing the adaptive immune response. The objective of the current study was the construction and bacterial expression of a recombinant antibody single-chain fragment variable (ScFv) directed against chicken DEC 205, an endocytic receptor, for use in the genetic fusion of antigens. In particular, we use as antigen the hemagglutinin-neuraminidase (HN) of Newcastle disease virus. Our results show that inoculation of chickens with HN genetically fused to the ScFv anti-DEC 205 induced an evidently higher immune response against HN, in contrast to inoculation with unconjugated HN. In addition, neutralizing antibodies against Newcastle disease virus were detected only in the serum from chickens immunized with HN fused to ScFv anti-DEC 205. Inoculated fused antigens to ScFv against endocytic receptor DEC 205 resulted in a greater antibody-specific anti-HN production compared with antigens applied alone. The results of this study show that the strategy described here has the potential to be used in the development of more effective vaccines against infectious diseases in chickens.


Assuntos
Antígenos CD/imunologia , Lectinas Tipo C/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Vírus da Doença de Newcastle/enzimologia , Doenças das Aves Domésticas/prevenção & controle , Receptores de Superfície Celular/imunologia , Anticorpos de Cadeia Única/biossíntese , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Galinhas/imunologia , Escherichia coli/genética , Hemaglutininas Virais/imunologia , Neuraminidase/imunologia , Doenças das Aves Domésticas/imunologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Anticorpos de Cadeia Única/imunologia , Vacinas Virais/imunologia
13.
Nat Commun ; 10(1): 2681, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31213606

RESUMO

Although chimeric antigen receptor (CAR) T cell therapies have demonstrated considerable success in treating hematologic malignancies, they have simultaneously been plagued by a cytokine release syndrome (CRS) that can harm or even kill the cancer patient. We describe a CAR T cell strategy in which CAR T cell activation and cancer cell killing can be sensitively regulated by adjusting the dose of a low molecular weight adapter that must bridge between the CAR T cell and cancer cell to initiate tumor eradication. By controlling the concentration and dosing schedule of adapter administration, we document two methods that can rapidly terminate (<3 h) a pre-existing CRS-like toxicity and two unrelated methods that can pre-emptively prevent a CRS-like toxicity that would have otherwise occurred. Because all four methods concurrently enhance CAR T cell potency, we conclude that proper use of bispecific adapters could potentially avoid a life-threatening CRS while enhancing CAR T cell tumoricidal activity.


Assuntos
Doenças do Sistema Imunitário/prevenção & controle , Imunoterapia Adotiva/efeitos adversos , Neoplasias/terapia , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Animais , Engenharia Celular/métodos , Linhagem Celular Tumoral , Citocinas/imunologia , Fluoresceína/metabolismo , Receptores de Folato com Âncoras de GPI/metabolismo , Ácido Fólico/metabolismo , Humanos , Doenças do Sistema Imunitário/etiologia , Imunoterapia Adotiva/métodos , Ativação Linfocitária/imunologia , Camundongos , Neoplasias/imunologia , Receptores de Antígenos Quiméricos/metabolismo , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/metabolismo , Síndrome , Linfócitos T/metabolismo , Linfócitos T/transplante , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Cancer Treat Rev ; 77: 35-43, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31207478

RESUMO

Immunotherapeutic strategies have revolutionised cancer therapy in recent years, bringing meaningful improvements in outcomes for patients with previously intractable conditions. These successes have, however, been largely limited to certain types of liquid tumours and a small subset of solid tumours that are known to be particularly immunogenic. Broadening these advances across the majority of tumour indications, which are characterised by an immune-excluded, immune-deserted or immune-suppressed ('cold') phenotype, will require alternative approaches that are able to specifically address this unique biological environment. Several newer therapeutic modalities, including adoptive cell therapy and T cell redirecting bispecific molecules, are considered to hold particular promise and are being investigated in early phase clinical trials across various solid tumour indications. ImmTAC molecules are a novel class of T cell redirecting bispecific biologics that exploit TCR-based targeting of tumour cells; providing potent and highly specific access to the vast landscape of intracellular targets. The first of these reagents to reach the clinic, tebentafusp (IMCgp100), has generated demonstrable clinical efficacy in an immunologically cold solid tumour with a high unmet need. Here, we highlight the key elements of the ImmTAC platform that make it ideally positioned to overcome the cold tumour microenvironment in an off-the-shelf format.


Assuntos
Imunoterapia/métodos , Neoplasias/imunologia , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Antígenos de Neoplasias/imunologia , Produtos Biológicos/administração & dosagem , Humanos , Imunoterapia Adotiva/métodos , Proteínas/imunologia , Anticorpos de Cadeia Única/imunologia , Antígeno gp100 de Melanoma/imunologia
15.
PLoS One ; 14(5): e0217793, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31150495

RESUMO

The success of the targeting of amyloid-ß (Aß) oligomers through immunotherapy in Alzheimer's disease (AD) mouse models has not been translated into the clinics. The use of single-chain variable fragments (scFvs) has been proposed to prevent the potential severe effects of full-length mAbs by precluding crystallizable fraction-mediated microglia activation. The efficacy of scFv-h3D6, a bapineuzumab-derived anti-Aß scFv, has been extensively proven. In this work, we compared scFv-h3D6-EL, an elongated variant of the scFv-h3D6, with its original version to assess whether its characteristic higher thermodynamic stability improved its pharmacokinetic parameters. Although scFv-h3D6-EL had a longer half-life than its original version, its absorption from the peritoneal cavity into the systemic compartment was lower than that of the original version. Moreover, we attempted to determine the mechanism underlying the protective effect of scFv-h3D6. We found that scFv-h3D6 showed compartmental distribution and more interestingly crossed the blood-brain barrier. In the brain, scFv-h3D6 was engulfed by glial cells or internalized by Aß peptide-containing neurons in the early phase post-injection, and was colocalized with the Aß peptide almost exclusively in glial cells in the late phase post-injection. Aß peptide levels in the brain decreased simultaneously with an increase in scFv-h3D6 levels. This observation in addition to the increased tumor necrosis factor-α levels in the late phase post-injection suggested that the engulfment of Aß peptide/scFv-h3D6 complex extruded from large neurons by phagocytic cells was the mechanism underlying Aß peptide withdrawal. The mechanism of action of scFv-h3D6 demonstrates the effectivity of Aß-immunotherapy and lays the background for other studies focused on the finding of a treatment for AD.


Assuntos
Doença de Alzheimer/imunologia , Peptídeos beta-Amiloides/imunologia , Fragmentos de Imunoglobulinas/imunologia , Anticorpos de Cadeia Única/imunologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/farmacocinética , Peptídeos beta-Amiloides/farmacologia , Animais , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacocinética , Modelos Animais de Doenças , Humanos , Fragmentos de Imunoglobulinas/farmacologia , Camundongos , Neurônios/metabolismo , Sinais Direcionadores de Proteínas/genética , Estabilidade Proteica , Anticorpos de Cadeia Única/farmacocinética , Anticorpos de Cadeia Única/farmacologia , Termodinâmica
16.
Virology ; 533: 145-154, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31170612

RESUMO

Foot-and-mouth disease virus (FMDV) exhibits a high degree of antigenic diversity among its serotypes, requiring several anti-FMDV antibodies for its laboratory diagnosis, which complicated the used techniques. To conquer this cumbersome, we developed a new panel of different single-chain fragment variable (scFv) for serotype-independent detection of FMDV. The recombinant VP2 capsid protein, as a relatively conserved protein among FMDV serotypes, was expressed in E. Coli, and injected in mice. Spleen's RNA was extracted for isolating the coding sequences of IgG variable domains that were assembled into repertoires of scFv. Phage library displaying scFv was constructed with ∼1.9 × 108 plaque forming units. Characterization of the library showed eight of unique scFvs, which were expressed as bacterial periplasmic proteins with apparent molecular weight of ∼27 kDa. Our data revealed the broad-spectrum binding affinity of the eight scFvs as both coating and tracing antibodies to FMDV serotypes A, O, and SAT 2.


Assuntos
Proteínas do Capsídeo/imunologia , Vírus da Febre Aftosa/isolamento & purificação , Febre Aftosa/virologia , Anticorpos de Cadeia Única/análise , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/análise , Anticorpos Antivirais/imunologia , Feminino , Febre Aftosa/diagnóstico , Vírus da Febre Aftosa/classificação , Vírus da Febre Aftosa/genética , Vírus da Febre Aftosa/imunologia , Humanos , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Biblioteca de Peptídeos , Sorogrupo , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia
17.
Appl Microbiol Biotechnol ; 103(15): 6071-6079, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31175428

RESUMO

Single-chain variable fragment (scFv) has great prospect in medical therapies and diagnostic applications due to its binding affinity and low immunogenicity. However, the application of scFv is limited by its heterologous expression facing challenges of insoluble aggregation. sfGFP has been developed as fusion tag to facilitate the solubility of fusion partner in Escherichia coli. We designed fusion protein of anti-influenza PB2 scFv at C-terminus of sfGFP and successfully obtained soluble expression of sfGFP-scFv-His in Escherichia coli. The expression level of sfGFP-scFv-His reached at 20 mg/L of bacterial culture when the culture was induced with 0.1 mM IPTG at 18 °C for 16 h. And 6 mg scFv-His was obtained from the cleavage of 10 mg pure sfGFP-scFv-His with TEV protease. In addition, we found that sfGFP-scFv-His was more stable than scFv-His in chicken serum, suggesting that sfGFP not only facilitated the solubility of scFv in Escherichia coli, but also promoted the stability of scFv. The immunologic activity of sfGFP-scFv-His was confirmed by Western blot and ELISA; the results showed that anti-PB2 sfGFP-scFv-His exhibited specific binding to PB2. Hemagglutination and comparative real-time RT-PCR analysis indicated that sfGFP-scFv-His and scFv-His inhibited the replication of H1N1 influenza virus in the infected A549 cells. These results further develop the application of scFv as an agent, such as anti-influenza. Furthermore, soluble expression of scFv using sfGFP as fusion partner provide a cost-effective preparation model for manufacturing scFv against pandemic disease.


Assuntos
Anticorpos Antivirais/metabolismo , Escherichia coli/metabolismo , Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Anticorpos de Cadeia Única/biossíntese , Células A549 , Anticorpos Antivirais/química , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Biotecnologia/métodos , Western Blotting , Ensaio de Imunoadsorção Enzimática , Escherichia coli/genética , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/imunologia , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/imunologia , Dobramento de Proteína , Estabilidade Proteica , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Cultura de Vírus , Replicação Viral/efeitos dos fármacos
18.
MAbs ; 11(6): 1175-1190, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31181988

RESUMO

We describe a bispecific dual-antagonist antibody against human B cell activating factor (BAFF) and interleukin 17A (IL-17). An anti-IL-17 single-chain variable fragment (scFv) derived from ixekizumab (Taltz®) was fused via a glycine-rich linker to anti-BAFF tabalumab. The IgG-scFv bound both BAFF and IL-17 simultaneously with identical stoichiometry as the parental mAbs. Stability studies of the initial IgG-scFv revealed chemical degradation and aggregation not observed in either parental antibody. The anti-IL-17 scFv showed a high melting temperature (Tm) by differential scanning calorimetry (73.1°C), but also concentration-dependent, initially reversible, protein self-association. To engineer scFv stability, three parallel approaches were taken: labile complementary-determining region (CDR) residues were replaced by stable, affinity-neutral amino acids, CDR charge distribution was balanced, and a H44-L100 interface disulfide bond was introduced. The Tm of the disulfide-stabilized scFv was largely unperturbed, yet it remained monodispersed at high protein concentration. Fluorescent dye binding titrations indicated reduced solvent exposure of hydrophobic residues and decreased proteolytic susceptibility was observed, both indicative of enhanced conformational stability. Superimposition of the H44-L100 scFv (PDB id: 6NOU) and ixekizumab antigen-binding fragment (PDB id: 6NOV) crystal structures revealed nearly identical orientation of the frameworks and CDR loops. The stabilized bispecific molecule LY3090106 (tibulizumab) potently antagonized both BAFF and IL-17 in cell-based and in vivo mouse models. In cynomolgus monkey, it suppressed B cell development and survival and remained functionally intact in circulation, with a prolonged half-life. In summary, we engineered a potent bispecific antibody targeting two key cytokines involved in human autoimmunity amenable to clinical development.


Assuntos
Anticorpos Biespecíficos , Doenças Autoimunes/tratamento farmacológico , Fator Ativador de Células B/antagonistas & inibidores , Interleucina-17/antagonistas & inibidores , Anticorpos de Cadeia Única , Animais , Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/farmacologia , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Fator Ativador de Células B/imunologia , Feminino , Células HEK293 , Células HT29 , Humanos , Interleucina-17/imunologia , Macaca fascicularis , Camundongos , Camundongos Transgênicos , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/farmacologia
19.
Cells ; 8(5)2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31108883

RESUMO

Cancer therapy has entered a new era, transitioning from unspecific chemotherapeutic agents to increasingly specific immune-based therapeutic strategies. Among these, chimeric antigen receptor (CAR) T cells have shown unparalleled therapeutic potential in treating refractory hematological malignancies. In contrast, solid tumors pose a much greater challenge to CAR T cell therapy, which has yet to be overcome. As this novel therapeutic modality matures, increasing effort is being invested to determine the optimal structure and properties of CARs to facilitate the transition from empirical testing to the rational design of CAR T cells. In this review, we highlight how individual CAR domains contribute to the success and failure of this promising treatment modality and provide an insight into the most notable advances in the field of CAR T cell engineering.


Assuntos
Engenharia Celular/métodos , Imunoterapia Adotiva/métodos , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Antígenos CD28/imunologia , Complexo CD3/imunologia , Antígenos CD8/imunologia , Edição de Genes , Humanos , Domínios Proteicos/imunologia , Anticorpos de Cadeia Única/imunologia , Transgenes , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia
20.
Talanta ; 201: 397-405, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122440

RESUMO

This article reports the identification, engineering and characterisation of recombinant single chain variable fragment (scFv) antibody against Zearalenone (ZEN), an oestrogenic mycotoxin, using phage display antibody technology. To increase the chance of obtaining clones that can bind to free toxin, the conjugated proteins of the target antigen, i.e. bovine serum albumin ZEN-BSA and ovalbumin ZEN-OVA, were switched during the biopanning. One phage-displayed scFv clone specific to free ZEN, designated yZEN2A8, could be isolated. The gene encoding the yZEN2A8 scFv was sub-cloned into the pET-21d (+) and pKP300 delta III vectors to generate the recombinant scFv and scFv-AP antibody formats, respectively. After ELISA optimisation by checkerboard titration, the sensitivities of the recombinant yZEN2A8 scFv antibody and scFv-AP fusion were improved approx. 2 and 60 folds, respectively. Competitive ELISA indicated that the median inhibition concentration (IC50) of recombinant yZEN2A8 scFv antibody and scFv-AP fusion after ELISA optimisation were 90 and 14 ng mL-1, with a limit of detection (LOD) of 20 and 2 ng mL-1, respectively. No cross-reactivity to other common mycotoxins was observed. Homology modelling illustrated specific binding of the recombinant antibody to ZEN and demonstrated the role of complementary determining regions (CDRs) of both the variable heavy and light chains in antibody-antigen interactions. Efficient application of scFv-AP for the detection of ZEN contamination in corns and wheat samples were investigated for the first time. The antibody in the form of scFv-AP can be used as a prototype for the development of a convenient reagent for the detection of ZEN contamination in various format, including biosensor-based.


Assuntos
Ração Animal/análise , Contaminação de Alimentos/análise , Proteínas Recombinantes de Fusão/imunologia , Anticorpos de Cadeia Única/imunologia , Zearalenona/análise , Fosfatase Alcalina/genética , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Técnicas de Visualização da Superfície Celular/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Escherichia coli/genética , Humanos , Simulação de Acoplamento Molecular , Biblioteca de Peptídeos , Ligação Proteica , Coelhos , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Anticorpos de Cadeia Única/biossíntese , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/metabolismo , Triticum/química , Zea mays/química , Zearalenona/imunologia , Zearalenona/metabolismo
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