Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correl...Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correlate with the PD-L1 expression level;hence,accurate detection of PD-L1 expression can guide immunotherapy to achieve better therapeutic effects.Therefore,based on the high affinity antibody Nb109,a new site-specifically radiolabeled tracer,^(68)Ga-NODA-cysteine,aspartic acid,and valine(CDV)-Nb109,was designed and synthesized to accurately monitor PD-L1 expression.The tracer ^(68)Ga-NODA-CDV-Nb109 was obtained using a site-specific conjugation strategy with a radiochemical yield of about 95%and radiochemical purity of 97%.It showed high affinity for PD-L1 with a dissociation constant of 12.34±1.65 nM.Both the cell uptake assay and positron emission tomography(PET)imaging revealed higher tracer uptake in PD-L1-positive A375-hPD-L1 and U87 tumor cells than in PD-L1-negative A375 tumor cells.Meanwhile,dynamic PET imaging of a NCI-H1299 xenograft indicated that doxorubicin could upregulate PD-L1 expression,allowing timely interventional immunotherapy.In conclusion,this tracer could sensitively and dynamically monitor changes in PD-L1 expression levels in different cancers and help screen patients who can benefit from anti-PD-L1 immunotherapy.展开更多
It is well established that all camelids have unique antibodies circulating in their blood.Unlike antibodies from all other species,these special antibodies are devoid of light chains,and are composed of a heavy chain...It is well established that all camelids have unique antibodies circulating in their blood.Unlike antibodies from all other species,these special antibodies are devoid of light chains,and are composed of a heavy chain homodimer.These so-called heavy-chain antibodies(HCAbs)are expressed after a V-D-J rearrangement and require dedicated constant gamma genes. An immune response is raised in these HCAbs following a classical immunization protocol.These HCAbs are easily purified from serum,and their antigen-binding fragment interacts with parts of the target that are less antigenic to conventional antibodies.The antigen binding site of the dromedary HCAb comprises one single domain,referred to as VHH or nanobody(Nb),therefore,a strategy was designed to clone the Nb repertoire of an immunized dromedary and to select the Nb with specificity for our target antigens.The monoclonal Nb is produced well in bacteria,is very stable and highly soluble,and it binds the antigen with high affinity and specificity.Currently,the recombinant Nb has been developed successfully for research purposes, as a probe in biosensors,to diagnose infections,or to treat diseases such as cancer or trypanosomiasis.展开更多
Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a h...Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a have human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe- cifically recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked im- munosorbent assay demonstrated this antibody bound specifically to human amyloid-beta 42 tetramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc- cessfully constructed a human phage display library and screened a single-domain antibody that specifically recognized amyloid-beta 42 oligomers.展开更多
The aim of this work was to investigate the size-related magnetism for the single-domain Co Fe2O4 nano-particles synthesized using the hydrothermal method. The effects of the reaction temperature and the reaction time...The aim of this work was to investigate the size-related magnetism for the single-domain Co Fe2O4 nano-particles synthesized using the hydrothermal method. The effects of the reaction temperature and the reaction time on the lattice constants, particle morphologies, and the room-temperature magnetic properties were studied from the X-ray diffraction, the transmission electron microscope, and the vibrating-sample magnetometer. The experimental results show that the samples are composed of Co Fe2O4 nano-particles with an average crystallite size（D） smaller than 40 nm, and the magnetic properties of the samples can be manipulated in a wide range： the MS values vary from smaller than 50 emu/g to close to 80 emu/g, and the HC values are between about 200 Oe and 2000 Oe. Additionally, the relationship between HC and 1/D^3/2 satisfi es linearship, showing the characteristic of single-domain structure. These results indicate that the single-domain Co Fe2O4 nano-particles with size controlled between the superparamagnetic critical size and single-domain critical size can be easily prepared using this hydrothermal method.展开更多
In this study,we investigated the molecular recognition mechanisms of shark-derived single-domain antibodies(ssdAbs)targeting fluoroquinolones using an integrated approach that combines in silico homologous modeling,m...In this study,we investigated the molecular recognition mechanisms of shark-derived single-domain antibodies(ssdAbs)targeting fluoroquinolones using an integrated approach that combines in silico homologous modeling,molecular dynamics simulations,molecular docking,and alanine scanning mutagenesis.Three ssdAbs—2E6,1N9,and 1O17—specific to enrofloxacin,norfloxacin,and ofloxacin,respectively,were selected based on previous work.Through AlphaFold2 and GalaxyWEB,the protein structures of these ssdAbs were predicted and optimized,followed by molecular dynamics simulations to emulate realistic protein behavior in a solvent environment.Molecular docking,alanine scanning mutagenesis,and subsequent verifications identified 30N and 93W of 2E6;30N,89R,98Y,and 99D of 1N9;100W and 101R of 1O17,all located within the complementarity determining region 3 loop,as critical for antigen binding.These residues primarily interact with their targets through hydrogen bonds,salt bridges,π–πstackings,and cation–πinteractions.This study revealed,for the first time,the binding mechanism of ssdAbs to fluoroquinolones from a theoretical perspective,emphasizing the importance of aromatic and polar residues in recognizing characteristic epitopes,such as the carboxyl group at the C3 position and the 1-piperazinyl group at the C7 position.Our findings provide valuable insights for the rational design and enhancement of ssdAbs for detecting small molecule hazards in aquaculture.展开更多
Single-domain antibodies(sdAbs),initially identified in camelids or sharks and commonly referred to as nanobodies or VNARs,have emerged as a promising alternative to conventional therapeutic antibodies.These sdAbs hav...Single-domain antibodies(sdAbs),initially identified in camelids or sharks and commonly referred to as nanobodies or VNARs,have emerged as a promising alternative to conventional therapeutic antibodies.These sdAbs have many superior physicochemical and pharmacological properties,including small size,good solubility and thermostability,easier accessible epitopes,and strong tissue penetration.However,the inherent challenges associated with the animal origin of sdAbs limit their clinical use.In recent years,various innovative humanization technologies,including complementarity-determining region(CDR)grafting or complete engineering of fully human sdAbs,have been developed to mitigate potential immunogenicity issues and enhance their compatibility.This review provides a comprehensive exploration of sdAbs,emphasizing their distinctive features and the progress in humanization methodologies.In addition,we provide an overview of the recent progress in developing drugs and therapeutic strategies based on sdAbs and their potential in solid tumor treatment,such as sdAbedrug conjugates,multispecific sdAbs,sdAb-based delivery systems,and sdAb-based cell therapy.展开更多
Background Post-weaning diarrhea(PWD)in piglets,often caused by F4^(+)enterotoxigenic Escherichia coli(ETEC),poses significant challenges in pig production.Traditional solutions like antibiotics and zinc oxide face in...Background Post-weaning diarrhea(PWD)in piglets,often caused by F4^(+)enterotoxigenic Escherichia coli(ETEC),poses significant challenges in pig production.Traditional solutions like antibiotics and zinc oxide face increasing restrictions due to growing concerns over antibiotic resistance and environmental sustainability.This study investigates the application of bivalent heavy chain variable domain(V_(H)H)constructs(BL1.2 and BL2.2)targeting ETEC virulence factors,administered in feed to mitigate ETEC-induced PWD in weaned piglets.Results The supplementation of BL1.2 and BL2.2 in both mash and pelleted feed significantly reduced the diarrhea incidence and fecal shedding of F4^(+)ETEC in challenged piglets.Pelleted feed containing V_(H)H constructs helped to preserve gut barrier integrity by maintaining levels of the tight junction protein occludin in the small intestine.Additionally,the constructs maintained blood granulocyte counts at a similar level to the non-challenged control group,including neutrophils,and ameliorated the acute phase protein response after challenge.Notably,even at low feed intake immediately after weaning,V_(H)H constructs helped maintain piglet health by mitigating ETEC-induced inflammation and the resulting diarrhea.Conclusions Our findings demonstrated that using V_(H)H constructs as feed additives could serve as an effective strategy to help manage ETEC-associated PWD,by reducing F4^(+)ETEC gut colonization and supporting gut barrier function of weaned piglets.The high stability of these V_(H)H constructs supports their incorporation into industrial feed manufacturing processes,offering a more sustainable preventive strategy compared to traditional antimicrobial interventions,which could contribute to sustainable farming practices.展开更多
Type IV collagenase plays a pivotal role in invasion, metastasis and angiogenesis of tumor. Single domain antibodies are attractive as tumor-targeting vehicle because of their much smaller size com-pared with antibody...Type IV collagenase plays a pivotal role in invasion, metastasis and angiogenesis of tumor. Single domain antibodies are attractive as tumor-targeting vehicle because of their much smaller size com-pared with antibody molecules produced by conventional methods. Lidamycin (LDM) is a potent enediyne-containing antitumor antibiotic. In this study an engineered and energized fusion protein VL-LDP-AE composed of lidamycin and VL domain of mAb 3G11 directed against type IV collagenase was prepared using a novel two-step method. First a VL-LDP fusion protein was constructed by DNA recombination. Secondly VL-LDP-AE was obtained by molecular reconstitution. In MTT assay, VL-LDP-AE showed potent cytotoxicity to HT-1080 cells and KB cells with IC50 values of 8.55×10-12 and 1.70×10-11 mol/L, respectively. VL-LDP-AE showed antiangiogenic activity in chick chrorioallantoic membrane (CAM) assay and tube formation assay. In in vivo experiments, VL-LDP-AE was proved to be more effective than free LDM against the growth of subcutaneously transplanted hepatoma 22 in mice. Drugs were given intravenously on day 3 and 10 after tumor transplantation. Compared in terms of maximal tolerated doses, VL-LDP-AE at 0.25 mg/kg suppressed the tumor growth by 89.5%, LDM at 0.05 mg/kg by 69.9%, and mitomycin at 1 mg/kg by 35%. Having a molecular weight of 25.2 kDa, VL-LDP-AE was much smaller than other reported antibody-based drugs. The results suggested that VL-LDP-AE would be a promising candidate for tumor targeting therapy. And the 2-step approach could serve as a new technology platform for making a series of highly potent engineered antibody-based drugs for a variety of cancers.展开更多
The cure or functional cure of the"Berlin patient"and"London patient"indicates that infusion of HIV-resistant cells could be a viable treatment strategy.Very recently,we genetically linked a short-...The cure or functional cure of the"Berlin patient"and"London patient"indicates that infusion of HIV-resistant cells could be a viable treatment strategy.Very recently,we genetically linked a short-peptide fusion inhibitor with a glycosylphosphatidylinositol(GPI)attachment signal,rendering modified cells fully resistant to HIV infection.In this study,GPI-anchored m36.4,a single-domain antibody(nanobody)targeting the coreceptor-binding site of gp120,was constructed with a lentiviral vector.We verified that m36.4 was efficiently expressed on the plasma membrane of transduced TZM-bl cells and targeted lipid raft sites without affecting the expression of HIV receptors(CD4,CCR5,and CXCR4).Significantly,TZM-bl cells expressing GPI-m36.4 were highly resistant to infection with divergent HIV-1 subtypes and potently blocked HIV-1 envelope-mediated cell-cell fusion and cell-cell viral transmission.Furthermore,we showed that GPI-m36.4-modified human CEMss-CCR5 cells were nonpermissive to both CCR5-and CXCR4-tropic HIV-1 isolates and displayed a strong survival advantage over unmodified cells.It was found that GPI-m36.4 could also Impair HIV-1 Env processing and viral infectivity in transduced cells,underlying a multifaceted mechanism of antiviral action.In conclusion,our studies characterize m36.4 as a powerful nanobody that can generate HIV-resistant cells,offering a novel gene therapy approach that can be used alone or in combination.展开更多
Single-domain antibodies have the characteristics of small molecular weight,strong tissue penetration,and high affinity,and are widely used to construct molecular probes for disease diagnosis and treatment.This articl...Single-domain antibodies have the characteristics of small molecular weight,strong tissue penetration,and high affinity,and are widely used to construct molecular probes for disease diagnosis and treatment.This article reviews molecular imaging studies including positron emission tomography(PET),single-photon emission computed tomography/computed tomography(CT),PET/CT,and fluorescent imaging of molecular probes composed of single-domain antibodies against eight esophageal squamous cell carcinoma biological targets.These 8 targets are highly expressed on the membrane of esophageal squamous cell carcinoma cells and include epidermal growth factor receptor,human epidermal growth factor receptor 2,human epidermal growth factor receptor 3,hepatocyte growth factor receptor,vascular endothelial growth factor receptor 2,chemokine receptor 4,chemokine receptor 7,and carcinoembryonic antigen.The current problems and solutions are also discussed to provide a reference for future design of molecular imaging probes targeting esophageal squamous cell carcinoma.展开更多
It was reported a facile strategy to fabricate magnetite(Fe3O4)single-crystal particles with critical single-domain size by employing graphene oxide(GO)sheets as template.In this method,the small-sized Fe2 O3 nanopart...It was reported a facile strategy to fabricate magnetite(Fe3O4)single-crystal particles with critical single-domain size by employing graphene oxide(GO)sheets as template.In this method,the small-sized Fe2 O3 nanoparticles were first synthesized,and then low-temperature annealing under H2 would convert them into large-sized Fe3 O4 single-crystal particles.The synthetic particles with an average size of 100 nm exhibit high saturation magnetization(Ms)of 0.085 A·m^2·g^-1,which is very close to theoretical value,being among the highest values in ever reported for Fe3O4 made from chemical methods.On this basis,the small-sized Fe3 O4 particles(average size of 30 nm)were also fabricated by coating with Na2 CO3 shell.展开更多
Well-aligned and uniform Coo.sZno.2Fe204 nanofibers （NFs） are prepared by electrospinning via sol-gel and sub- sequent heat treatment. Each of the as-spun NFs has a diameter of about 300 nm and a smooth surface morp...Well-aligned and uniform Coo.sZno.2Fe204 nanofibers （NFs） are prepared by electrospinning via sol-gel and sub- sequent heat treatment. Each of the as-spun NFs has a diameter of about 300 nm and a smooth surface morphology. The scanning electron microscope （SEM） image shows that the diameter decreases to 70 nm after the Coo.sZno.2Fe204 NF has been annealed at 650℃ for 3 h. The structure and chemical of Co0.8Zn0.2Fe204 NF are investigated by X- ray diffraction （XRD） and energy dispersive X-ray spectroscopy （EDS）, respectively. Single phase cubic spinel structure, Coo.sZno.2Fe204 NF, is successfully obtained after having been calcined at 550 ~C in air for 3 h, and a reduced lattice constant of the Coo.8Zno.2Fe204 NF provides the evidence of effective Zn2＋ substitution. The magnetic measurements show that the substitution of Zn2＋ for Co2＋ , i.e., the introduction of non-magnetic Zn2＋ ions into A sites, can increase the saturation magnetization （Ms） and reduce the coercivity （He）. The obtained Hc results of different samples reveal that the critical single-domain size of the Co0.8Zn0.2Fe204 NF is approximately 44 nm. By doping Zn2＋ with different concentra- tions, the morphologies of Co1-xZnxFe2O4 （0 〈 x 〈 0.5） NFs do not show obvious changes. For magnetic properties, the Ms increases and Hc decreases monotonically, respectively.展开更多
The top-seeded infiltration and growth process (TSIG) is an important method to fabricate YBCO bulk superconductors. In this paper, single domain YBCO superconductors with different Gd2Ba4CuWOx (GdW2411) additions hav...The top-seeded infiltration and growth process (TSIG) is an important method to fabricate YBCO bulk superconductors. In this paper, single domain YBCO superconductors with different Gd2Ba4CuWOx (GdW2411) additions have been fabricated by TSIG process, the amount of GdW2411 added to Y2BaCuO5 (Y211) is in the range from 0wt% to 8 wt%, but there is no other additions to the liquid source. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 14 to 25 N with the increasing of GdW2411 addition from 0 to 4 wt%, and decreasing from 25 to 7 N with the increasing of GdW2411 addition from 4 to 8 wt%, the largest levitation force is obtained when the GdW2411 content is about 4 wt%. This is helpful for the fabrication of high quality YBCO bulk superconductors.展开更多
In order to improve the functional affinity of the humanized VH single domain antibody against human lung cancer, the genes coding the homogenous dimers dihu3D3Vn and tetramers tehu3D3VH were constructed by fusing the...In order to improve the functional affinity of the humanized VH single domain antibody against human lung cancer, the genes coding the homogenous dimers dihu3D3Vn and tetramers tehu3D3VH were constructed by fusing the SV5-Cys short peptide and p53 tetramefization structural domain gene to hu3D3VH gene via recombinant PCR technique, respectively. Then, the dihu3D3VH and tehu3D3VH genes were cloned to the prokaryotic expression vector pET-22b（ ＋ ） and expressed in E. coli BL21 （DE3）. The proteins expressed were purified through Ni^2＋ -affinity chromatographic column. Meanwhile, the hu3D3VH, dihu3D3VH and tehu3D3VH proteins were labeled with FTTC, and their reactivity with antigen and specificity were analyzed by immunofluorescence assay. As to their functional affinities, it was analyzed and compared by flow cytometry. The results indicated that these two genes were expressed as monomers and mainly as inclusion bodies. After purification and renaturation, there were about 50% of dimers and 70% of tetramer remaining in the protein solution. In addition, the dihu3D3VH and tehu3D3VH proteins still remained the reactivity with antigen and specificity of hu3D3VH protein, and their functional affinities were increased about 60% or 100% respectively, compared with those of hu3D3VH protein. It is evident that the functional affinity of hu3D3VH protein can be greatly improved by increasing its binding valency.展开更多
Immuno-positron emission tomography(immuno-PET)is an innovative medical imaging technique that combines antibodies(Abs)or other immune-targeting molecules with positron-emitting radionuclides.By targeting antigens tha...Immuno-positron emission tomography(immuno-PET)is an innovative medical imaging technique that combines antibodies(Abs)or other immune-targeting molecules with positron-emitting radionuclides.By targeting antigens that are highly expressed in hematologic malignancies,immuno-PET has transformed diagnostic capabilities and enables precise monitoring of therapeutic responses through highly sensitive and specific tumor cell detection.Additionally,it plays a critical role in advancing therapeutic approaches by seamlessly linking diagnostic imaging with personalized treatment strategies.Its non-invasive nature and ability to provide whole-body imaging offer significant advantages over traditional diagnostic methods,especially for detecting minimal residual disease and guiding adaptive therapeutic interventions.In Ab-based immuno-PET,positronemitting radionuclides must have a half-life sufficient for slower pharmacokinetics and blood clearance of Abs.Recent studies have highlighted the advantages of long-lived radionuclides,such as 89Zr,which exhibit low positron energy and enable high sensitivity and resolution,making them particularly effective for tumor visualization and characterization.This review explores the current applications,recent advancements,and potential of immuno-PET for hematologic malignancies,emphasizing its pivotal role in improving patient outcomes and advancing precision medicine.展开更多
In the past decade,ferroelectric materials have been intensively explored as promising photocatalysts.An intriguing ability of ferroelectrics is to directly sperate the photogenerated electrons and holes,which is beli...In the past decade,ferroelectric materials have been intensively explored as promising photocatalysts.An intriguing ability of ferroelectrics is to directly sperate the photogenerated electrons and holes,which is believed to arise from a spontaneous polarization.Understanding how polarization affects the photocatalytic performance is vital to design high-efficiency photocatalysts.In this work,we report a size effect of ferroelectric polarization on regulating the photocatalytic overall water splitting of SrTiO_(3)/PbTiO_(3)nanoplate heterostructures for the first time.This was realized hydrothermally by controlling the thickness and thus spontaneous polarization strength of single-crystal and single-domain PbTiO_(3)nanoplates,which served as the substrate for selective heteroepitaxial growth of SrTiO_(3).An enhancement of 22 times in the photocatalytic overall water splitting performance of the heterostructures has been achieved when the average thickness of the nanoplate increases from 30 to 107 nm.A combined experimental investigation revealed that the incompletely compensated depolarization filed is the dominated driving force for the photogenerated carrier separation within heterostructures,and its increase with the thickness of the nanoplates accounts for the enhancement of photocatalytic activity.Moreover,the concentration of oxygen vacancies for negative polarization compensation has been found to grow as the thickness of the nanoplates increases,which promotes oxygen evolution reaction and reduces the stoichiometric ratio of H_(2)/O_(2).These findings may provide the opportunity to design and develop high-efficiency ferroelectric photocatalysts.展开更多
I. INTRODUCTIONThe outstanding magnetic properties of Nd-Fe-B permanent alloy with very high coercive force and maximum magnetic energy product have attracted scientists’ attention greatly and extensive investigation...I. INTRODUCTIONThe outstanding magnetic properties of Nd-Fe-B permanent alloy with very high coercive force and maximum magnetic energy product have attracted scientists’ attention greatly and extensive investigation has been made on its structure and mag-展开更多
基金support from the National Natural Science Foundation of China(Grant No.:22076069)the Natural Science Foundation of Jiangsu Province(Grant No.:BK20201135)+1 种基金the Major Scientific Research Project of Jiangsu Commission of Health(Grant No.:ZDA2020007)the Science Technology and Development Project of Wuxi(Grant No.:Y20212013).
文摘Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correlate with the PD-L1 expression level;hence,accurate detection of PD-L1 expression can guide immunotherapy to achieve better therapeutic effects.Therefore,based on the high affinity antibody Nb109,a new site-specifically radiolabeled tracer,^(68)Ga-NODA-cysteine,aspartic acid,and valine(CDV)-Nb109,was designed and synthesized to accurately monitor PD-L1 expression.The tracer ^(68)Ga-NODA-CDV-Nb109 was obtained using a site-specific conjugation strategy with a radiochemical yield of about 95%and radiochemical purity of 97%.It showed high affinity for PD-L1 with a dissociation constant of 12.34±1.65 nM.Both the cell uptake assay and positron emission tomography(PET)imaging revealed higher tracer uptake in PD-L1-positive A375-hPD-L1 and U87 tumor cells than in PD-L1-negative A375 tumor cells.Meanwhile,dynamic PET imaging of a NCI-H1299 xenograft indicated that doxorubicin could upregulate PD-L1 expression,allowing timely interventional immunotherapy.In conclusion,this tracer could sensitively and dynamically monitor changes in PD-L1 expression levels in different cancers and help screen patients who can benefit from anti-PD-L1 immunotherapy.
文摘It is well established that all camelids have unique antibodies circulating in their blood.Unlike antibodies from all other species,these special antibodies are devoid of light chains,and are composed of a heavy chain homodimer.These so-called heavy-chain antibodies(HCAbs)are expressed after a V-D-J rearrangement and require dedicated constant gamma genes. An immune response is raised in these HCAbs following a classical immunization protocol.These HCAbs are easily purified from serum,and their antigen-binding fragment interacts with parts of the target that are less antigenic to conventional antibodies.The antigen binding site of the dromedary HCAb comprises one single domain,referred to as VHH or nanobody(Nb),therefore,a strategy was designed to clone the Nb repertoire of an immunized dromedary and to select the Nb with specificity for our target antigens.The monoclonal Nb is produced well in bacteria,is very stable and highly soluble,and it binds the antigen with high affinity and specificity.Currently,the recombinant Nb has been developed successfully for research purposes, as a probe in biosensors,to diagnose infections,or to treat diseases such as cancer or trypanosomiasis.
基金supported by the National Natural Science Foundation of China,No.30600099(FD)
文摘Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a have human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe- cifically recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked im- munosorbent assay demonstrated this antibody bound specifically to human amyloid-beta 42 tetramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc- cessfully constructed a human phage display library and screened a single-domain antibody that specifically recognized amyloid-beta 42 oligomers.
基金Funded by the National Natural Science Foundation of China(51172166)the PhD Programs Foundation of City College,Wuhan University of Science and Technology(2014CYBSKY003)
文摘The aim of this work was to investigate the size-related magnetism for the single-domain Co Fe2O4 nano-particles synthesized using the hydrothermal method. The effects of the reaction temperature and the reaction time on the lattice constants, particle morphologies, and the room-temperature magnetic properties were studied from the X-ray diffraction, the transmission electron microscope, and the vibrating-sample magnetometer. The experimental results show that the samples are composed of Co Fe2O4 nano-particles with an average crystallite size（D） smaller than 40 nm, and the magnetic properties of the samples can be manipulated in a wide range： the MS values vary from smaller than 50 emu/g to close to 80 emu/g, and the HC values are between about 200 Oe and 2000 Oe. Additionally, the relationship between HC and 1/D^3/2 satisfi es linearship, showing the characteristic of single-domain structure. These results indicate that the single-domain Co Fe2O4 nano-particles with size controlled between the superparamagnetic critical size and single-domain critical size can be easily prepared using this hydrothermal method.
基金supported by the National Natural Science Foundation of China[No.32072308]the Key Research and Development Program of Shandong Province[No.2023CXGC010709].
文摘In this study,we investigated the molecular recognition mechanisms of shark-derived single-domain antibodies(ssdAbs)targeting fluoroquinolones using an integrated approach that combines in silico homologous modeling,molecular dynamics simulations,molecular docking,and alanine scanning mutagenesis.Three ssdAbs—2E6,1N9,and 1O17—specific to enrofloxacin,norfloxacin,and ofloxacin,respectively,were selected based on previous work.Through AlphaFold2 and GalaxyWEB,the protein structures of these ssdAbs were predicted and optimized,followed by molecular dynamics simulations to emulate realistic protein behavior in a solvent environment.Molecular docking,alanine scanning mutagenesis,and subsequent verifications identified 30N and 93W of 2E6;30N,89R,98Y,and 99D of 1N9;100W and 101R of 1O17,all located within the complementarity determining region 3 loop,as critical for antigen binding.These residues primarily interact with their targets through hydrogen bonds,salt bridges,π–πstackings,and cation–πinteractions.This study revealed,for the first time,the binding mechanism of ssdAbs to fluoroquinolones from a theoretical perspective,emphasizing the importance of aromatic and polar residues in recognizing characteristic epitopes,such as the carboxyl group at the C3 position and the 1-piperazinyl group at the C7 position.Our findings provide valuable insights for the rational design and enhancement of ssdAbs for detecting small molecule hazards in aquaculture.
基金supported by grants from the National Key R&D Program of China(2019YFA0904400)National Natural Science Foundation of China(32270984)+1 种基金Science and Technology Commission of Shanghai Municipality(23XD1400800,China)Shanghai Municipal Health Commission(GWVI-11.2-YQ46,China).
文摘Single-domain antibodies(sdAbs),initially identified in camelids or sharks and commonly referred to as nanobodies or VNARs,have emerged as a promising alternative to conventional therapeutic antibodies.These sdAbs have many superior physicochemical and pharmacological properties,including small size,good solubility and thermostability,easier accessible epitopes,and strong tissue penetration.However,the inherent challenges associated with the animal origin of sdAbs limit their clinical use.In recent years,various innovative humanization technologies,including complementarity-determining region(CDR)grafting or complete engineering of fully human sdAbs,have been developed to mitigate potential immunogenicity issues and enhance their compatibility.This review provides a comprehensive exploration of sdAbs,emphasizing their distinctive features and the progress in humanization methodologies.In addition,we provide an overview of the recent progress in developing drugs and therapeutic strategies based on sdAbs and their potential in solid tumor treatment,such as sdAbedrug conjugates,multispecific sdAbs,sdAb-based delivery systems,and sdAb-based cell therapy.
基金financially supported by the Green Development and Demonstration Programme(GUDP)(case number 34009-19-1585)。
文摘Background Post-weaning diarrhea(PWD)in piglets,often caused by F4^(+)enterotoxigenic Escherichia coli(ETEC),poses significant challenges in pig production.Traditional solutions like antibiotics and zinc oxide face increasing restrictions due to growing concerns over antibiotic resistance and environmental sustainability.This study investigates the application of bivalent heavy chain variable domain(V_(H)H)constructs(BL1.2 and BL2.2)targeting ETEC virulence factors,administered in feed to mitigate ETEC-induced PWD in weaned piglets.Results The supplementation of BL1.2 and BL2.2 in both mash and pelleted feed significantly reduced the diarrhea incidence and fecal shedding of F4^(+)ETEC in challenged piglets.Pelleted feed containing V_(H)H constructs helped to preserve gut barrier integrity by maintaining levels of the tight junction protein occludin in the small intestine.Additionally,the constructs maintained blood granulocyte counts at a similar level to the non-challenged control group,including neutrophils,and ameliorated the acute phase protein response after challenge.Notably,even at low feed intake immediately after weaning,V_(H)H constructs helped maintain piglet health by mitigating ETEC-induced inflammation and the resulting diarrhea.Conclusions Our findings demonstrated that using V_(H)H constructs as feed additives could serve as an effective strategy to help manage ETEC-associated PWD,by reducing F4^(+)ETEC gut colonization and supporting gut barrier function of weaned piglets.The high stability of these V_(H)H constructs supports their incorporation into industrial feed manufacturing processes,offering a more sustainable preventive strategy compared to traditional antimicrobial interventions,which could contribute to sustainable farming practices.
基金Supported by the National High Technology Research and Development Program of China (863 Program)(Grant No. 2006AA02A255)
文摘Type IV collagenase plays a pivotal role in invasion, metastasis and angiogenesis of tumor. Single domain antibodies are attractive as tumor-targeting vehicle because of their much smaller size com-pared with antibody molecules produced by conventional methods. Lidamycin (LDM) is a potent enediyne-containing antitumor antibiotic. In this study an engineered and energized fusion protein VL-LDP-AE composed of lidamycin and VL domain of mAb 3G11 directed against type IV collagenase was prepared using a novel two-step method. First a VL-LDP fusion protein was constructed by DNA recombination. Secondly VL-LDP-AE was obtained by molecular reconstitution. In MTT assay, VL-LDP-AE showed potent cytotoxicity to HT-1080 cells and KB cells with IC50 values of 8.55×10-12 and 1.70×10-11 mol/L, respectively. VL-LDP-AE showed antiangiogenic activity in chick chrorioallantoic membrane (CAM) assay and tube formation assay. In in vivo experiments, VL-LDP-AE was proved to be more effective than free LDM against the growth of subcutaneously transplanted hepatoma 22 in mice. Drugs were given intravenously on day 3 and 10 after tumor transplantation. Compared in terms of maximal tolerated doses, VL-LDP-AE at 0.25 mg/kg suppressed the tumor growth by 89.5%, LDM at 0.05 mg/kg by 69.9%, and mitomycin at 1 mg/kg by 35%. Having a molecular weight of 25.2 kDa, VL-LDP-AE was much smaller than other reported antibody-based drugs. The results suggested that VL-LDP-AE would be a promising candidate for tumor targeting therapy. And the 2-step approach could serve as a new technology platform for making a series of highly potent engineered antibody-based drugs for a variety of cancers.
基金supported by grants from the CAMS Innovation Fund for Medical Sciences(2017-I2M-1-014)National Science and Technology Major Project of China(2018ZX10301103 and 2017ZX10202102-001-003)National Natural Science Foundation of China(81630061).
文摘The cure or functional cure of the"Berlin patient"and"London patient"indicates that infusion of HIV-resistant cells could be a viable treatment strategy.Very recently,we genetically linked a short-peptide fusion inhibitor with a glycosylphosphatidylinositol(GPI)attachment signal,rendering modified cells fully resistant to HIV infection.In this study,GPI-anchored m36.4,a single-domain antibody(nanobody)targeting the coreceptor-binding site of gp120,was constructed with a lentiviral vector.We verified that m36.4 was efficiently expressed on the plasma membrane of transduced TZM-bl cells and targeted lipid raft sites without affecting the expression of HIV receptors(CD4,CCR5,and CXCR4).Significantly,TZM-bl cells expressing GPI-m36.4 were highly resistant to infection with divergent HIV-1 subtypes and potently blocked HIV-1 envelope-mediated cell-cell fusion and cell-cell viral transmission.Furthermore,we showed that GPI-m36.4-modified human CEMss-CCR5 cells were nonpermissive to both CCR5-and CXCR4-tropic HIV-1 isolates and displayed a strong survival advantage over unmodified cells.It was found that GPI-m36.4 could also Impair HIV-1 Env processing and viral infectivity in transduced cells,underlying a multifaceted mechanism of antiviral action.In conclusion,our studies characterize m36.4 as a powerful nanobody that can generate HIV-resistant cells,offering a novel gene therapy approach that can be used alone or in combination.
基金supported,in part,by the National Key Research&Development Program of China(No.2018YFC0910600)the National Natural Science Foundation of China(Nos.81871397,81701853,81627807)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2019JQ-519,2019JQ-201,2019JQ-045)the Fundamental Research Funds for the Central Universities(No.JB191209).
文摘Single-domain antibodies have the characteristics of small molecular weight,strong tissue penetration,and high affinity,and are widely used to construct molecular probes for disease diagnosis and treatment.This article reviews molecular imaging studies including positron emission tomography(PET),single-photon emission computed tomography/computed tomography(CT),PET/CT,and fluorescent imaging of molecular probes composed of single-domain antibodies against eight esophageal squamous cell carcinoma biological targets.These 8 targets are highly expressed on the membrane of esophageal squamous cell carcinoma cells and include epidermal growth factor receptor,human epidermal growth factor receptor 2,human epidermal growth factor receptor 3,hepatocyte growth factor receptor,vascular endothelial growth factor receptor 2,chemokine receptor 4,chemokine receptor 7,and carcinoembryonic antigen.The current problems and solutions are also discussed to provide a reference for future design of molecular imaging probes targeting esophageal squamous cell carcinoma.
基金financially supported by the National Natural Science Foundation of China(No.51701109)
文摘It was reported a facile strategy to fabricate magnetite(Fe3O4)single-crystal particles with critical single-domain size by employing graphene oxide(GO)sheets as template.In this method,the small-sized Fe2 O3 nanoparticles were first synthesized,and then low-temperature annealing under H2 would convert them into large-sized Fe3 O4 single-crystal particles.The synthetic particles with an average size of 100 nm exhibit high saturation magnetization(Ms)of 0.085 A·m^2·g^-1,which is very close to theoretical value,being among the highest values in ever reported for Fe3O4 made from chemical methods.On this basis,the small-sized Fe3 O4 particles(average size of 30 nm)were also fabricated by coating with Na2 CO3 shell.
基金Project supported by the National Natural Science Foundation of China(Grant No.50873047)the Foundation of Gansu Education Department,China(Grant No.0603-02)
文摘Well-aligned and uniform Coo.sZno.2Fe204 nanofibers （NFs） are prepared by electrospinning via sol-gel and sub- sequent heat treatment. Each of the as-spun NFs has a diameter of about 300 nm and a smooth surface morphology. The scanning electron microscope （SEM） image shows that the diameter decreases to 70 nm after the Coo.sZno.2Fe204 NF has been annealed at 650℃ for 3 h. The structure and chemical of Co0.8Zn0.2Fe204 NF are investigated by X- ray diffraction （XRD） and energy dispersive X-ray spectroscopy （EDS）, respectively. Single phase cubic spinel structure, Coo.sZno.2Fe204 NF, is successfully obtained after having been calcined at 550 ~C in air for 3 h, and a reduced lattice constant of the Coo.8Zno.2Fe204 NF provides the evidence of effective Zn2＋ substitution. The magnetic measurements show that the substitution of Zn2＋ for Co2＋ , i.e., the introduction of non-magnetic Zn2＋ ions into A sites, can increase the saturation magnetization （Ms） and reduce the coercivity （He）. The obtained Hc results of different samples reveal that the critical single-domain size of the Co0.8Zn0.2Fe204 NF is approximately 44 nm. By doping Zn2＋ with different concentra- tions, the morphologies of Co1-xZnxFe2O4 （0 〈 x 〈 0.5） NFs do not show obvious changes. For magnetic properties, the Ms increases and Hc decreases monotonically, respectively.
基金National Natural Science Foundation of China (50872079)National High Technology Research and Development Program of China ("863"2007AA03Z241)Fundamental Research Funds for the Central Universities (GK200901017)
文摘The top-seeded infiltration and growth process (TSIG) is an important method to fabricate YBCO bulk superconductors. In this paper, single domain YBCO superconductors with different Gd2Ba4CuWOx (GdW2411) additions have been fabricated by TSIG process, the amount of GdW2411 added to Y2BaCuO5 (Y211) is in the range from 0wt% to 8 wt%, but there is no other additions to the liquid source. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 14 to 25 N with the increasing of GdW2411 addition from 0 to 4 wt%, and decreasing from 25 to 7 N with the increasing of GdW2411 addition from 4 to 8 wt%, the largest levitation force is obtained when the GdW2411 content is about 4 wt%. This is helpful for the fabrication of high quality YBCO bulk superconductors.
文摘In order to improve the functional affinity of the humanized VH single domain antibody against human lung cancer, the genes coding the homogenous dimers dihu3D3Vn and tetramers tehu3D3VH were constructed by fusing the SV5-Cys short peptide and p53 tetramefization structural domain gene to hu3D3VH gene via recombinant PCR technique, respectively. Then, the dihu3D3VH and tehu3D3VH genes were cloned to the prokaryotic expression vector pET-22b（ ＋ ） and expressed in E. coli BL21 （DE3）. The proteins expressed were purified through Ni^2＋ -affinity chromatographic column. Meanwhile, the hu3D3VH, dihu3D3VH and tehu3D3VH proteins were labeled with FTTC, and their reactivity with antigen and specificity were analyzed by immunofluorescence assay. As to their functional affinities, it was analyzed and compared by flow cytometry. The results indicated that these two genes were expressed as monomers and mainly as inclusion bodies. After purification and renaturation, there were about 50% of dimers and 70% of tetramer remaining in the protein solution. In addition, the dihu3D3VH and tehu3D3VH proteins still remained the reactivity with antigen and specificity of hu3D3VH protein, and their functional affinities were increased about 60% or 100% respectively, compared with those of hu3D3VH protein. It is evident that the functional affinity of hu3D3VH protein can be greatly improved by increasing its binding valency.
文摘Immuno-positron emission tomography(immuno-PET)is an innovative medical imaging technique that combines antibodies(Abs)or other immune-targeting molecules with positron-emitting radionuclides.By targeting antigens that are highly expressed in hematologic malignancies,immuno-PET has transformed diagnostic capabilities and enables precise monitoring of therapeutic responses through highly sensitive and specific tumor cell detection.Additionally,it plays a critical role in advancing therapeutic approaches by seamlessly linking diagnostic imaging with personalized treatment strategies.Its non-invasive nature and ability to provide whole-body imaging offer significant advantages over traditional diagnostic methods,especially for detecting minimal residual disease and guiding adaptive therapeutic interventions.In Ab-based immuno-PET,positronemitting radionuclides must have a half-life sufficient for slower pharmacokinetics and blood clearance of Abs.Recent studies have highlighted the advantages of long-lived radionuclides,such as 89Zr,which exhibit low positron energy and enable high sensitivity and resolution,making them particularly effective for tumor visualization and characterization.This review explores the current applications,recent advancements,and potential of immuno-PET for hematologic malignancies,emphasizing its pivotal role in improving patient outcomes and advancing precision medicine.
基金supported by the National Key R&D Program of China(No.2021YFA1500800)the National Natural Science Foundation of China(Nos.52425201,52272129,and 12125407)+2 种基金the Natural Science Foundation of Zhejiang Province,China(No.LR21E020004)the ShanxiZheda Institute of Advanced Materials and Chemical Engineering(No.2021SX-FR007)the Joint Funds of the National Natural Science Foundation of China(No.U21A2067).
文摘In the past decade,ferroelectric materials have been intensively explored as promising photocatalysts.An intriguing ability of ferroelectrics is to directly sperate the photogenerated electrons and holes,which is believed to arise from a spontaneous polarization.Understanding how polarization affects the photocatalytic performance is vital to design high-efficiency photocatalysts.In this work,we report a size effect of ferroelectric polarization on regulating the photocatalytic overall water splitting of SrTiO_(3)/PbTiO_(3)nanoplate heterostructures for the first time.This was realized hydrothermally by controlling the thickness and thus spontaneous polarization strength of single-crystal and single-domain PbTiO_(3)nanoplates,which served as the substrate for selective heteroepitaxial growth of SrTiO_(3).An enhancement of 22 times in the photocatalytic overall water splitting performance of the heterostructures has been achieved when the average thickness of the nanoplate increases from 30 to 107 nm.A combined experimental investigation revealed that the incompletely compensated depolarization filed is the dominated driving force for the photogenerated carrier separation within heterostructures,and its increase with the thickness of the nanoplates accounts for the enhancement of photocatalytic activity.Moreover,the concentration of oxygen vacancies for negative polarization compensation has been found to grow as the thickness of the nanoplates increases,which promotes oxygen evolution reaction and reduces the stoichiometric ratio of H_(2)/O_(2).These findings may provide the opportunity to design and develop high-efficiency ferroelectric photocatalysts.
文摘I. INTRODUCTIONThe outstanding magnetic properties of Nd-Fe-B permanent alloy with very high coercive force and maximum magnetic energy product have attracted scientists’ attention greatly and extensive investigation has been made on its structure and mag-
