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Search results for: IgG1

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#32271944   2020/04/09 To Up

Vimentin citrullinationprobedby a novel monoclonal antibody serves as a specific indicator for reactive astrocytes in neurodegeneration.

Vimentin citrullination, the calcium (Ca )-dependentpeptidylarginine deiminase (PAD)-mediated conversion of anarginine residue of vimentin to a citrulline residue,has emerged as a pathophysiological outcome ofautoimmune diseases and neurodegeneration. However, the roles, functions, and expression of citrullinated vimentinhave not yet been elucidated because available antibodies are limited.
Byungki Jang, Mo-Jong Kim, Yun-Jung Lee, Akihito Ishigami, Yong-Sun Kim, Eun-Kyoung Choi

2698 related Products with: Vimentin citrullinationprobedby a novel monoclonal antibody serves as a specific indicator for reactive astrocytes in neurodegeneration.

1 ml25 µg25 µg100 TESTS0.25 mg0.2 mg0.2 mg100ul4 Membranes/Box1mg4 Membranes/Box100ug

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#32270791   2020/04/09 To Up

A novel fluorescence method for the rapid and effective detection of Listeria monocytogenes using aptamer-conjugated magnetic nanoparticles and aggregation-induced emission dots.

Fluorescence-based assays are efficient tools for the detection of Listeria monocytogenes (L. monocytogenes). However, they are always restricted by the phenomenon of aggregation-caused quenching (ACQ). The emergence of aggregation-induced emission (AIE) materials perfectly overcomes this shortcoming. Through harnessing the AIE characteristic with magnetic enrichment, we propose an approach to achieve a promising detection method that combines an aptamer and antibody-based dual recognition units. Aptamer-coupled magnetic beads were used for the specific capture of L. monocytogenes. [email protected] NPs were facilely synthesized through encapsulating 1-(4-hydroxyphenyl)-1,2,2-triphenylethene (TPE-OH) in bovine serum albumin (BSA) microspheres, and possessed a bright fluorescence signal due to the aggregation of TPE-OH in BSA NPs. Rabbit immunoglobulin G (IgG) antibodies were labelled on the surface. In the detection system, the fluorescence intensity of the [email protected] NPs in the supernatant was monitored to avoid the signal interference resulting from the deposit after magnetic separation. Using our strategy, the range of detection for L. monocytogenes is 10-106 cfu mL-1, and the detection limit is as low as 10 cfu mL-1 with a good selectivity. Upon analysis of spiked samples, the recoveries ranged from 95.37% to 101.90% without any pre-enrichment.
Yuanyuan Guo, Chao Zhao, Yushen Liu, Heran Nie, Xiaoxiao Guo, Xiuling Song, Kun Xu, Juan Li, Juan Wang

2550 related Products with: A novel fluorescence method for the rapid and effective detection of Listeria monocytogenes using aptamer-conjugated magnetic nanoparticles and aggregation-induced emission dots.

400Tests1 kit25 mg200 100ug1000 tests1 ml10 mg100ul 5 G100ug

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#32269125   2020/04/08 To Up

Murine cross-reactive non-neutralizing polyclonal IgG1 antibodies induced by influenza vaccine inhibit the cross-protective effect of IgG2 against heterologous virus in mice.

Annual vaccination against influenza viruses is the most reliable and efficient way to prevent and control annual epidemics and protect from severe influenza disease. However, current split influenza vaccines are generally not effective against antigenically mismatched (heterologous) strains. To broaden the protective spectrum of influenza vaccines, adjuvants that can induce cross-reactive antibodies with cross-protection via Fc-mediated effector functions are urgently sought. Although IgG2 antibodies are generally more efficient than IgG1 antibodies in Fc-mediated effector functions, it is not yet clear which IgG isotypes show superior cross-protection against heterologous strains. It also remains unclear whether these IgG isotypes interfere with each other's protective effects. Here, we found that influenza split vaccine adjuvanted with aluminum salts, which predominantly induce cross-reactive IgG1, did not confer cross-protection against heterologous virus challenge in mice. In contrast, split vaccine adjuvanted with CpG oligodeoxynucleotides, which predominantly induce cross-reactive IgG2, showed cross-protection through the interaction of cross-reactive non-neutralizing IgG2 and alveolar macrophages, indicating the importance of cross-reactive non-neutralizing IgG2 for cross-protection. Furthermore, by using serum samples from immunized mice and isolated polyclonal antibodies, we show that vaccine-induced cross-reactive non-neutralizing IgG1 suppress the cross-protective effects of IgG2 by competitively inhibiting the binding of IgG2 to virus. Thus, we demonstrate the new concept that cross-reactive IgG1 may interfere with the potential for cross-protection of influenza vaccine. We propose that adjuvants that selectively induce virus-specific IgG2 in mice, such as CpG oligodeoxynucleotides, are optimal for heterologous protection. Current influenza vaccines are generally effective against highly similar virus strains by inducing neutralizing antibodies. However, these antibodies fail to neutralize antigenically mismatched (heterologous) strains and therefore provide limited protection against them. Efforts are being made to develop vaccines with cross-protective ability that would protect broadly against heterologous strains, because the mismatch between predicted and epidemic strains cannot always be avoided, resulting in low vaccine efficacy. Here we show that non-neutralizing IgG2 antibodies induced by an optimal adjuvant play a crucial role in cross-protection against heterologous virus challenge in mice. Furthermore, non-neutralizing polyclonal IgG1 suppressed the cross-protective effects of non-neutralizing polyclonal IgG2 by competitively blocking the binding of IgG2 to its antigen. These data shed new light on the importance of IgG isotypes and the selection of appropriate adjuvants for the development of universal influenza vaccines. Furthermore, our findings are applicable to the rational design of vaccines against other pathogens.
Meito Shibuya, Taiki Aoshi, Etushi Kuroda, Yasuo Yoshioka

2277 related Products with: Murine cross-reactive non-neutralizing polyclonal IgG1 antibodies induced by influenza vaccine inhibit the cross-protective effect of IgG2 against heterologous virus in mice.

100 500 1 mL100 200 100 1 mg1 mg100 1 mL1 mL100

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#32269096   2020/04/08 To Up

T Follicular Helper Cells Regulate Humoral Response for Host Protection against Intestinal Infection.

colonizes at the colon and causes mucosal inflammation in mice. Previous studies have revealed the importance of the innate and adaptive immune response for controlling infection. In the present study, we examined the role of T follicular helper (Tfh) cells in intestinal infection using mice with deficiency in T cells. Tfh cells were absolutely required at the late, but not the early, phase to control infection. Compared with control mice, we observed systemic pathogen dissemination and more severe colitis in Tfh-deficient mice. Furthermore, the susceptibility of Tfh-deficient mice correlated with an impaired serum IgG1 response to infection, and serum Abs from infected wild-type mice protected Tfh-deficient mice from infection. The transfer of wild-type Tfh cells also restored the levels of IgG1 and led to effective clearance of the pathogens in Tfh-deficient mice. Moreover, during infection, IL-21- and IL-4-producing Tfh cells were increased obviously in wild-type mice, correlating with IgG1 as the major isotype in germinal center B cells. Taken together, our work highlights the requirement and the function of Tfh cells in regulating humoral response for the host protection against infection.
Xue Bai, Xinxin Chi, Qin Qiao, Shan Xie, Siyuan Wan, Lu Ni, Pengzhi Wang, Wei Jin, Chen Dong

2957 related Products with: T Follicular Helper Cells Regulate Humoral Response for Host Protection against Intestinal Infection.

0.1ml (1mg/ml)0.2 mg25 µg0.2 mg100 TESTS250 ml0.1 mg1 LITRE0.1 mg0.1ml (1mg/ml)100 ml25 µg

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#32264568   2017/11/28 To Up

Redox-responsive hyperbranched poly(amido amine) and polymer dots as a vaccine delivery system for cancer immunotherapy.

In order to enhance the cellular immune response of vaccines, numerous vaccine delivery systems have been developed, especially cationic nanoparticle carriers. Cationic polymer dots (PDs) have been widely used for biomedical imaging and drug delivery due to their excellent photoluminescence, small size and abundant positive charge. In this study, polyethyleneimine (600 Da) (PEI)-modified redox-responsive hyperbranched poly(amido amine) (PAA-PEI) and partially carbonized PAA-PEI PDs were designed and prepared as vaccine carriers to deliver the model antigen protein ovalbumin (OVA). Then, OVA-specific immune responses induced by PAA-PEI/OVA and PDs/OVA nanoparticles were evaluated in vivo. The results suggest that the PAA-PEI/OVA and PDs/OVA nanoparticles enhanced OVA-specific immune responses when compared to OVA alone. Further, PDs/OVA nanoparticles induced more potent OVA-specific cellular immune responses, including higher levels of the OVA-specific IgG2a/IgG1 antibody ratio, splenocyte proliferation, IL-12 and IFN-γ cytokines, maturation of dendritic cells, effector memory CD4 T cells and CD8 T cells as well as cytotoxic T lymphocytes (CTLs) than PAA-PEI/OVA nanoparticles did. Moreover, subcutaneously injected PDs/OVA nanoparticles significantly inhibited tumor growth of the mice bearing E.G7-OVA tumor and extended mice survival. All the results show that immunization with PDs/OVA nanoparticles elicited more effective OVA-specific cellular immune responses. PDs could serve as promising vaccine delivery systems for cancer immunotherapy.
Meng Lv, Sha Li, Haijie Zhao, Kewei Wang, Qianqian Chen, Zhong Guo, Zonghua Liu, Wei Xue

1703 related Products with: Redox-responsive hyperbranched poly(amido amine) and polymer dots as a vaccine delivery system for cancer immunotherapy.

100ug100 tests100ug1,000 tests100 assays

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#32264100   2017/06/12 To Up

Anion-exchange reactions: facile and general access to sensitive photoelectrochemical platforms for biomarker immunosensing.

Affordable methodologies for detecting tumor markers at low concentrations are very important for early diagnosis. The two key requirements for designing ultrasensitive photoelectrochemical (PEC) immunosensors are highly active PEC platforms and amplified recognition events on the transducer surfaces. Herein we report the development of an effective and general strategy for the sensitive immunoassay of biomarkers using a novel PEC platform. In particular, in contrast to traditional photoanode materials prepared by introducing well-stabilized quantum dots onto an electrode, in this work CdSe nanocrystal (NC)-based PEC films were first formed directly on an ITO surface by an anion-exchange reaction and followed by coverage with organic stabilizers. The compacted CdSe film produces ultrahigh photocurrent signals under visible-light irradiation (λ = 470 nm). Using rabbit immunoglobulin G (RIgG) as a model biomarker, we showed that through biotin-avidin bridges, biotin-functionalized peroxidase (B-HRP) could be further assembled and could catalyze the conversion of its substrate, 4-chloro-1-naphthol (4-CN), to realize precipitation of nonconductive benzo-4-chlorohexadienone on the CdSe surface, thus resulting in blocking of the electron donors and absorption of the incident light. As the resulting photocurrent decrease was directly related to the target concentration, a sensitive PEC immunoassay could be constructed. The target RIgG was detected over a concentration range from 1.0 fg mL to 10 μg mL with an ultralow detection limit of 0.5 fg mL. This study presents a promising and general strategy for the development of highly sensitive PEC biosensors, which can be extended to the detection of other enzymes and biomolecules.
Kaili Niu, Yuzhen Li, Ruili Bai, Yongfang Qu, Yanyan Song

2595 related Products with: Anion-exchange reactions: facile and general access to sensitive photoelectrochemical platforms for biomarker immunosensing.

100ul100ul250 ml500 reactions1 LITRE100 reactions100 ml1000 tests1 mg.500 Reactions50 ug50 reactions

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#32263465   2016/07/27 To Up

Preparation of fluorescent Au-SiO core-shell nanoparticles and nanorods with tunable silica shell thickness and surface modification for immunotargeting.

Gold-silica (Au-SiO) core-shell nanoparticles (NPs) enable multifunctional properties for in vivo biomedical applications. However, scalable synthesis methods are lacking for the preparation of Au-SiO core-shell NPs less than 30 nm in overall diameter with a tunable silica shell less than 10 nm in thickness. Therefore, we prepared monodispersed Au-SiO core-shell NPs less than 30 nm in overall diameter with a uniform, tunable silica shell ∼1 to 14 nm in thickness using either citrate reduction followed by a modified Stöber method or oleylamine reduction followed by a reverse microemulsion method. Oleylamine reduction enabled up to 80-fold greater concentration yield compared to the citrate reduction method currently used for synthesizing Au core NPs. The formation of a tunable silica shell less than 10 nm in thickness was facilitated by controlling the molecular weight of the priming polymer (modified Stöber) or surfactant (reverse microemulsion) in addition to the concentration of the silane precursor, and was robust for encapsulating non-spherical morphologies such as Au nanorods. The reverse microemulsion method enabled several distinct advantages over the modified Stöber method, including greater control over the silica shell thickness, ∼16-fold greater yield in core-shell NP concentrations for scalable synthesis, and the ability to encapsulate controlled concentrations of a molecular payload (e.g., fluorophores with four different emission profiles) in the silica shell. Au-SiO core-shell NPs were also bioconjugated with immunoglobulin-G (IgG) as a model antibody to demonstrate immunotargeting. Bioactivity of Au-SiO-IgG core-shell NPs was confirmed by agglomeration in the presence of protein A. The presence and proper orientation of IgG on NP surfaces was verified by direct observation in electron microscopy after negative staining. Therefore, the methods in this study for preparing and modifying Au-SiO core-shell NPs provide a platform for engineering core-shell NPs with size-dependent functional properties for multispectral/multimodal imaging, drug delivery, and combined theranostics.
Prakash D Nallathamby, Juliane Hopf, Lisa E Irimata, Tracie L McGinnity, Ryan K Roeder

2163 related Products with: Preparation of fluorescent Au-SiO core-shell nanoparticles and nanorods with tunable silica shell thickness and surface modification for immunotargeting.

100ug1 mg100.00 ul1,000 tests50 ug 25 mg1000 tests100ug5mg10 mg 5 G

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#32263408   2016/05/31 To Up

Surface modification with E-cadherin fusion protein for mesenchymal stem cell culture.

To effectively expand human mesenchymal stem cells (hMSCs) in vitro without affecting their innate biological properties, a fusion protein (hE-cad-Fc) consisting of a human E-cadherin extracellular domain and an immunoglobulin G Fc region was fabricated and used as a biomimetic matrix for MSC culture surface modification. The results showed that cells cultured on hE-cad-Fc-modified polystyrene surfaces exhibited improved proliferation and paracrine functions compared with cells cultured on unmodified and collagen-modified polystyrene surfaces. Meanwhile, surfaces modified with hE-cad-Fc effectively inhibited cell apoptosis even under the serum deprivation conditions. Additionally, the hE-cad-Fc not only up-regulated the expression of β-catenin in MSCs and stimulated the cellular membrane complex of E-cadherin/β-catenin, but also effectively activated the intracellular signals such as EGFR, AKT and ERK phosphorylation. Therefore, hE-cad-Fc appeared to be a promising candidate for biological surface modification and stem cell culture.
Yan Zhang, Hongli Mao, Mengyuan Qian, Feifei Hu, Lei Cao, Ke Xu, Qizhi Shuai, Chao Gao, Ren Lang, Toshihiro Akaike, Jun Yang

2280 related Products with: Surface modification with E-cadherin fusion protein for mesenchymal stem cell culture.

1 kit(96 Wells)5 x 10A5 cells/vial24 wells24 wells24 wells100ug Lyophilized0.1 mg 5 lt1 kit(96 Wells)100tests2

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#32263357   2016/08/08 To Up

Guanidinylated cationic nanoparticles as robust protein antigen delivery systems and adjuvants for promoting antigen-specific immune responses in vivo.

Weak immunogenicity and transient humoral or cellular immune responses are the major limitations of modern protein vaccines. Using delivery adjuvants is a good strategy to promote their immune response in vivo. In this study, a type of guanidinylated and cationic nanoparticle adjuvant self-assembled by monomethoxy poly(ethylene glycol)-block-poly(2-(diisopropyl amino)ethyl methacrylate)-block-poly(2-(guanidyl)ethyl methacrylate) (mPEG-b-PDPA-b-PGEM, PEDG) copolymers was used as an antigen delivery carrier. PEDG nanoparticles could encapsulate the model antigen ovalbumin (OVA) by facile electrostatic absorption with a loading efficiency of approximately 200 μg of OVA per 1 mg of the polymer. Rapid OVA release within 4 hours in acidic lysosomal compartments of antigen-presenting cells was observed. PEDG nanoparticles could stimulate the maturation of mouse bone marrow-derived dendritic cells and enhance antigen uptake and presentation by 4 fold compared to free OVA. The nanoparticles also induced the activation of macrophages (RAW 264.7) to produce a high level of cytokines including TNF-α, IL-6 and IL-10. OVA-loaded PEDG nanoparticles efficiently induced a superior antigen cross-presentation effect in vitro and in vivo compared to free OVA vaccination. In vivo stimulation of mice using nanoparticle-formulated OVA robustly enhanced the antigen-specific CD8 T cell proliferation and the secretion of antigen-specific IgG, serum IgG2a/IgG1 antibodies and cytokines (IFN-γ, IL-2). The strategy of nanoparticle delivery prolonged the antigen duration at the injection site and enhanced its migration to draining lymph nodes as indicated by fluorescence tracking. In all, the novel guanidinylated nanoparticles could act as an effective adjuvant delivery system for protein antigens to elicit both potent antigen-specific cellular immune responses, including Th1-based adaptive immunity and CD8 T cell response, and humoral immune responses.
Pan Li, Gaona Shi, Xiuyuan Zhang, Huijuan Song, Chuangnian Zhang, Weiwei Wang, Chen Li, Bing Song, Chun Wang, Deling Kong

1669 related Products with: Guanidinylated cationic nanoparticles as robust protein antigen delivery systems and adjuvants for promoting antigen-specific immune responses in vivo.

100 1 mg1 mg0.2 mg50ul0.1ml (1mg/ml)0.05 mg0.1ml (1mg/ml)0.1ml100 µg1000 Units

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#32263337   2013/06/20 To Up

Platinum nanodendrite functionalized graphene nanosheets as a non-enzymatic label for electrochemical immunosensing.

An ultrasensitive immunosensing method was developed using platinum nanodendrite functionalized graphene nanosheets ([email protected]) as a non-enzymatic label for the electrochemical detection of human immunoglobulin G (HIgG). The [email protected] hybrid was prepared in situ by reducing KPtCl with ascorbic acid in an aqueous solution of reduced graphene oxide, and characterized by scanning electron microscopy, transmission electron microscopy and spectral techniques. The disposable immunosensor was constructed by coating a polyethylene glycol film on a screen-printed carbon working electrode and then immobilizing the capture antibody on the film. After binding with the antigen for further capture of the [email protected] labelled antibody, [email protected] was introduced as an electrochemical tag to produce a large electrocatalytic current towards the reduction of dissolved oxygen for signal amplification. Compared with the enzyme-based immunosensor, [email protected] as non-enzymatic tag exhibited many advantages. This method showed a good linearity in the concentration range of 1 pg mL to 10 ng mL, with a detection limit of 0.87 pg mL. [email protected] as non-enzymatic label provides a versatile method for constructing ultrasensitive immunosensors, and demonstrates proof-of-concept in immunosensing.
Qiunan Xu, Lisong Wang, Jianping Lei, Shengyuan Deng, Huangxian Ju

1044 related Products with: Platinum nanodendrite functionalized graphene nanosheets as a non-enzymatic label for electrochemical immunosensing.

100 Tests / Kit100Tests430 tests100 tests50 assays720/kit1,000 tests100 assays96 Tests

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