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1.
Cell ; 175(1): 171-185.e25, 2018 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-30146162

RESUMO

CKIα ablation induces p53 activation, and CKIα degradation underlies the therapeutic effect of lenalidomide in a pre-leukemia syndrome. Here we describe the development of CKIα inhibitors, which co-target the transcriptional kinases CDK7 and CDK9, thereby augmenting CKIα-induced p53 activation and its anti-leukemic activity. Oncogene-driving super-enhancers (SEs) are highly sensitive to CDK7/9 inhibition. We identified multiple newly gained SEs in primary mouse acute myeloid leukemia (AML) cells and demonstrate that the inhibitors abolish many SEs and preferentially suppress the transcription elongation of SE-driven oncogenes. We show that blocking CKIα together with CDK7 and/or CDK9 synergistically stabilize p53, deprive leukemia cells of survival and proliferation-maintaining SE-driven oncogenes, and induce apoptosis. Leukemia progenitors are selectively eliminated by the inhibitors, explaining their therapeutic efficacy with preserved hematopoiesis and leukemia cure potential; they eradicate leukemia in MLL-AF9 and Tet2-/-;Flt3ITD AML mouse models and in several patient-derived AML xenograft models, supporting their potential efficacy in curing human leukemia.


Assuntos
Caseína Quinase Ialfa/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Caseína Quinase Ialfa/fisiologia , Proliferação de Células/efeitos dos fármacos , Quinase 9 Dependente de Ciclina/antagonistas & inibidores , Quinase 9 Dependente de Ciclina/fisiologia , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/fisiologia , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Elementos Facilitadores Genéticos/genética , Hematopoese , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas , Proteína Supressora de Tumor p53/fisiologia , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Immunity ; 56(2): 406-419.e7, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36792574

RESUMO

Malaria transmission-blocking vaccines (TBVs) aim to induce antibodies that interrupt malaria parasite development in the mosquito, thereby blocking onward transmission, and provide a much-needed tool for malaria control and elimination. The parasite surface protein Pfs48/45 is a leading TBV candidate. Here, we isolated and characterized a panel of 81 human Pfs48/45-specific monoclonal antibodies (mAbs) from donors naturally exposed to Plasmodium parasites. Genetically diverse mAbs against each of the three domains (D1-D3) of Pfs48/45 were identified. The most potent mAbs targeted D1 and D3 and achieved >80% transmission-reducing activity in standard membrane-feeding assays, at 10 and 2 µg/mL, respectively. Co-crystal structures of D3 in complex with four different mAbs delineated two conserved protective epitopes. Altogether, these Pfs48/45-specific human mAbs provide important insight into protective and non-protective epitopes that can further our understanding of transmission and inform the design of refined malaria transmission-blocking vaccine candidates.


Assuntos
Culicidae , Vacinas Antimaláricas , Malária Falciparum , Malária , Animais , Humanos , Plasmodium falciparum , Culicidae/metabolismo , Proteínas de Protozoários , Anticorpos Monoclonais , Malária Falciparum/prevenção & controle , Anticorpos Antiprotozoários
3.
Immunity ; 56(2): 420-432.e7, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36792575

RESUMO

Pfs230 is essential for Plasmodium falciparum transmission to mosquitoes and is the protein targeted by the most advanced malaria-transmission-blocking vaccine candidate. Prior understanding of functional epitopes on Pfs230 is based on two monoclonal antibodies (mAbs) with moderate transmission-reducing activity (TRA), elicited from subunit immunization. Here, we screened the B cell repertoire of two naturally exposed individuals possessing serum TRA and identified five potent mAbs from sixteen Pfs230 domain-1-specific mAbs. Structures of three potent and three low-activity antibodies bound to Pfs230 domain 1 revealed four distinct epitopes. Highly potent mAbs from natural infection recognized a common conformational epitope that is highly conserved across P. falciparum field isolates, while antibodies with negligible TRA derived from natural infection or immunization recognized three distinct sites. Our study provides molecular blueprints describing P. falciparum TRA, informed by contrasting potent and non-functional epitopes elicited by natural exposure and vaccination.


Assuntos
Vacinas Antimaláricas , Malária Falciparum , Humanos , Animais , Plasmodium falciparum , Epitopos , Proteínas de Protozoários , Antígenos de Protozoários , Anticorpos Monoclonais , Anticorpos Antiprotozoários , Malária Falciparum/prevenção & controle
4.
Cell ; 168(5): 904-915.e10, 2017 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-28235200

RESUMO

Sexual reproduction is almost universal in eukaryotic life and involves the fusion of male and female haploid gametes into a diploid cell. The sperm-restricted single-pass transmembrane protein HAP2-GCS1 has been postulated to function in membrane merger. Its presence in the major eukaryotic taxa-animals, plants, and protists (including important human pathogens like Plasmodium)-suggests that many eukaryotic organisms share a common gamete fusion mechanism. Here, we report combined bioinformatic, biochemical, mutational, and X-ray crystallographic studies on the unicellular alga Chlamydomonas reinhardtii HAP2 that reveal homology to class II viral membrane fusion proteins. We further show that targeting the segment corresponding to the fusion loop by mutagenesis or by antibodies blocks gamete fusion. These results demonstrate that HAP2 is the gamete fusogen and suggest a mechanism of action akin to viral fusion, indicating a way to block Plasmodium transmission and highlighting the impact of virus-cell genetic exchanges on the evolution of eukaryotic life.


Assuntos
Chlamydomonas/metabolismo , Proteínas de Fusão de Membrana/química , Proteínas de Plantas/química , Plasmodium/metabolismo , Proteínas de Protozoários/química , Sequência de Aminoácidos , Evolução Biológica , Chlamydomonas/citologia , Cristalografia por Raios X , Células Germinativas/química , Células Germinativas/metabolismo , Proteínas de Fusão de Membrana/genética , Proteínas de Fusão de Membrana/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plasmodium/citologia , Domínios Proteicos , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
5.
Immunol Rev ; 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39285523

RESUMO

The prevalence of asthma, rhinitis, and food allergies has increased dramatically over the last few decades. This increase originally started in western countries, but is now also evident in many other regions of the world. Given the fact that the increase is so quick, the noted increase cannot be linked to a genetic effect, and many environmental factors have been identified that are associated with increased or reduced prevalence of allergies, like changing dietary habits, increased urbanization, pollution, exposure to microorganisms and LPS, and the farming environment and raw milk consumption. Although the key role of allergen-specific IgE in allergies is well known, the role of allergen-specific IgG and IgA antibodies is less well defined. This review will provide an overview of the functions of allergen-specific IgE in allergy, the role of allergen-specific antibodies (IgG (4) and IgA) in allergen immunotherapy (AIT), the possibility to use allergen-specific antibodies for treatment of ongoing allergies, and the potential role of allergen-specific antibodies in tolerance induction to allergens in a preventive setting. In the last, more speculative, section we will present novel hypotheses on the potential role of allergen-specific non-IgE antibodies in allergies by directing antigen presentation, Th2 development, and innate immune training.

6.
Proc Natl Acad Sci U S A ; 121(35): e2322418121, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39159377

RESUMO

The growing world population and increasing life expectancy are driving the need to improve the quality of blood transfusion, organ transplantation, and preservation. Here, to improve the ability of red blood cells (RBCs) for normothermic machine perfusion, a biocompatible blood silicification approach termed "shielding-augmenting RBC-in-nanoscale amorphous silica (SARNAS)" has been developed. The key to RBC surface engineering and structure augmentation is the precise control of the hydrolysis form of silicic acid to realize stabilization of RBC within conformal nanoscale silica-based exoskeletons. The formed silicified RBCs (Si-RBCs) maintain membrane/structural integrity, normal cellular functions (e.g., metabolism, oxygen-carrying capability), and enhance resistance to external stressors as well as tunable mechanical properties, resulting in nearly 100% RBC cryoprotection. In vivo experiments confirm their excellent biocompatibility. By shielding RBC surface antigens, the Si-RBCs provide universal blood compatibility, the ability for allogeneic mechanical perfusion, and more importantly, the possibility for cross-species transfusion. Being simple, reliable, and easily scalable, the SARNAS strategy holds great promise to revolutionize the use of engineered blood for future clinical applications.


Assuntos
Materiais Biocompatíveis , Eritrócitos , Dióxido de Silício , Eritrócitos/metabolismo , Dióxido de Silício/química , Materiais Biocompatíveis/química , Animais , Humanos , Perfusão/métodos , Preservação de Sangue/métodos , Transfusão de Sangue/métodos , Camundongos
7.
EMBO Rep ; 25(2): 506-523, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38225355

RESUMO

Transient receptor potential vanilloid (TRPV) channels play a critical role in calcium homeostasis, pain sensation, immunological response, and cancer progression. TRPV channels are blocked by ruthenium red (RR), a universal pore blocker for a wide array of cation channels. Here we use cryo-electron microscopy to reveal the molecular details of RR block in TRPV2 and TRPV5, members of the two TRPV subfamilies. In TRPV2 activated by 2-aminoethoxydiphenyl borate, RR is tightly coordinated in the open selectivity filter, blocking ion flow and preventing channel inactivation. In TRPV5 activated by phosphatidylinositol 4,5-bisphosphate, RR blocks the selectivity filter and closes the lower gate through an interaction with polar residues in the pore vestibule. Together, our results provide a detailed understanding of TRPV subfamily pore block, the dynamic nature of the selectivity filter and allosteric communication between the selectivity filter and lower gate.


Assuntos
Antineoplásicos , Canais de Potencial de Receptor Transitório , Canais de Cátion TRPV/genética , Rutênio Vermelho/farmacologia , Microscopia Crioeletrônica , Cálcio/metabolismo
8.
J Biol Chem ; 300(4): 107155, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38479597

RESUMO

Despite significant advances in the development of therapeutic interventions targeting autoimmune diseases and chronic inflammatory conditions, lack of effective treatment still poses a high unmet need. Modulating chronically activated T cells through the blockade of the Kv1.3 potassium channel is a promising therapeutic approach; however, developing selective Kv1.3 inhibitors is still an arduous task. Phage display-based high throughput peptide library screening is a rapid and robust approach to develop promising drug candidates; however, it requires solid-phase immobilization of target proteins with their binding site preserved. Historically, the KcsA bacterial channel chimera harboring only the turret region of the human Kv1.3 channel was used for screening campaigns. Nevertheless, literature data suggest that binding to this type of chimera does not correlate well with blocking potency on the native Kv1.3 channels. Therefore, we designed and successfully produced advanced KcsA-Kv1.3, KcsA-Kv1.1, and KcsA-Kv1.2 chimeric proteins in which both the turret and part of the filter regions of the human Kv1.x channels were transferred. These T+F (turret-filter) chimeras showed superior peptide ligand-binding predictivity compared to their T-only versions in novel phage ELISA assays. Phage ELISA binding and competition results supported with electrophysiological data confirmed that the filter region of KcsA-Kv1.x is essential for establishing adequate relative affinity order among selected peptide toxins (Vm24 toxin, Hongotoxin-1, Kaliotoxin-1, Maurotoxin, Stichodactyla toxin) and consequently obtaining more reliable selectivity data. These new findings provide a better screening tool for future drug development efforts and offer insight into the target-ligand interactions of these therapeutically relevant ion channels.


Assuntos
Canal de Potássio Kv1.3 , Bloqueadores dos Canais de Potássio , Proteínas Recombinantes de Fusão , Animais , Humanos , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/antagonistas & inibidores , Sítios de Ligação , Canal de Potássio Kv1.3/metabolismo , Canal de Potássio Kv1.3/antagonistas & inibidores , Canal de Potássio Kv1.3/genética , Canal de Potássio Kv1.3/química , Ligantes , Biblioteca de Peptídeos , Bloqueadores dos Canais de Potássio/química , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio/metabolismo , Canais de Potássio/química , Canais de Potássio/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Linhagem Celular
9.
Proc Natl Acad Sci U S A ; 119(15): e2120003119, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35377795

RESUMO

Lymphatic filariasis is a vector-borne neglected tropical disease prioritized for global elimination. The filarial nematodes that cause the disease host a symbiotic bacterium, Wolbachia, which has been targeted using antibiotics, leading to cessation of parasite embryogenesis, waning of circulating larvae (microfilariae [mf]), and gradual cure of adult infection. One of the benefits of the anti-Wolbachia mode of action is that it avoids the rapid killing of mf, which can drive inflammatory adverse events. However, mf depleted of Wolbachia persist for several months in circulation, and thus patients treated with antibiotics are assumed to remain at risk for transmitting infections. Here, we show that Wolbachia-depleted mf rapidly lose the capacity to develop in the mosquito vector through a defect in exsheathment and inability to migrate through the gut wall. Transcriptomic and Western blotting analyses demonstrate that chitinase, an enzyme essential for mf exsheathment, is down-regulated in Wolbachia-depleted mf and correlates with their inability to exsheath and escape the mosquito midgut. Supplementation of in vitro cultures of Wolbachia-depleted mf with chitinase enzymes restores their ability to exsheath to a similar level to that observed in untreated mf. Our findings elucidate a mechanism of rapid transmission-blocking activity of filariasis after depletion of Wolbachia and adds to the broad range of biological processes of filarial nematodes that are dependent on Wolbachia symbiosis.


Assuntos
Antibacterianos , Quitinases , Filariose Linfática , Microfilárias , Wolbachia , Animais , Antibacterianos/farmacologia , Quitinases/genética , Filariose Linfática/transmissão , Humanos , Microfilárias/enzimologia , Microfilárias/crescimento & desenvolvimento , Microfilárias/microbiologia , Mosquitos Vetores/parasitologia , Wolbachia/efeitos dos fármacos , Wolbachia/genética
10.
Proc Natl Acad Sci U S A ; 119(30): e2119048119, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35858411

RESUMO

The major challenges in pancreatic ductal adenocarcinoma (PDAC) management are local or distant metastasis and limited targeted therapeutics to prevent it. To identify a druggable target in tumor secretome and to explore its therapeutic intervention, we performed a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis of tumors obtained from a patient-derived xenograft model of PDAC. Galectin-3 binding protein (Gal-3BP) is identified as a highly secreted protein, and its overexpression is further validated in multiple PDAC tumors and primary cells. Knockdown and exogenous treatment of Gal-3BP showed that it is required for PDAC cell proliferation, migration, and invasion. Mechanistically, we revealed that Gal-3BP enhances galectin-3-mediated epidermal growth factor receptor signaling, leading to increased cMyc and epithelial-mesenchymal transition. To explore the clinical impact of these findings, two antibody clones were developed, and they profoundly abrogated the metastasis of PDAC cells in vivo. Altogether, our data demonstrate that Gal-3BP is an important therapeutic target in PDAC, and we propose its blockade by antibody as a therapeutic option for suppressing PDAC metastasis.


Assuntos
Antígenos de Neoplasias , Antineoplásicos Imunológicos , Biomarcadores Tumorais , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antineoplásicos Imunológicos/imunologia , Antineoplásicos Imunológicos/uso terapêutico , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/imunologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/secundário , Carcinoma Ductal Pancreático/terapia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Cromatografia Líquida , Transição Epitelial-Mesenquimal , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Proteômica , Secretoma , Espectrometria de Massas em Tandem , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Nano Lett ; 24(34): 10642-10649, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39158134

RESUMO

CO poisoning in Pt-based anode catalysts significantly hampers the proton exchange membrane fuel cell (PEMFC) performance. Despite great advances in CO-tolerant catalysts, their effectiveness is often limited to fundamental three-electrode systems, which is inadequate for practical PEMFC applications. Herein, we present a straightforward thermal oxidation strategy for constructing a Ru oxide blocking layer on commercial PtRu/C through a one-step Ru-segregation-and-oxidation process. The resulting 0.7 nm thick Ru oxide layer effectively inhibits CO adsorption while maintaining hydrogen oxidation activity. PtRu@RuO2/C demonstrates exceptional CO tolerance, enduring 1% CO in rotating disk electrode tests, an ∼10-fold improvement compared to that of PtRu/C. Crucially, it retains high HOR activity and CO tolerance in PEMFC, with negligible polarization curve loss in the presence of 100 ppm CO. Notably, 85% HOR activity is retained after a 4 h stability test. This enhancement contributes to the Ru oxide layer decelerating CO adsorption kinetics, rather than promoting CO oxidation via the classic bifunctional mechanism.

12.
J Infect Dis ; 229(2): 567-575, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-37943633

RESUMO

BACKGROUND: Human immunity triggered by natural malaria infections impedes parasite transmission from humans to mosquitoes, leading to interest in transmission-blocking vaccines. However, immunity characteristics, especially strain specificity, remain largely unexplored. We investigated naturally acquired transmission-blocking immunity (TBI) against Plasmodium vivax, a major malaria parasite. METHODS: Using the direct membrane-feeding assay, we assessed TBI in plasma samples and examined the role of antibodies by removing immunoglobulins through protein G/L adsorption before mosquito feeding. Strain specificity was evaluated by conducting a direct membrane-feeding assay with plasma exchange. RESULTS: Blood samples from 47 patients with P vivax were evaluated, with 37 plasma samples successfully infecting mosquitoes. Among these, 26 showed inhibition before immunoglobulin depletion. Despite substantial immunoglobulin removal, 4 samples still exhibited notable inhibition, while 22 had reduced blocking activity. Testing against heterologous strains revealed some plasma samples with broad TBI and others with strain-specific TBI. CONCLUSIONS: Our findings indicate that naturally acquired TBI is mainly mediated by antibodies, with possible contributions from other serum factors. The transmission-blocking activity of plasma samples varied by the tested parasite strain, suggesting single polymorphic or multiple targets for naturally acquired TBI. These observations improve understanding of immunity against P vivax and hold implications for transmission-blocking vaccine development.


Assuntos
Anopheles , Malária Vivax , Malária , Animais , Humanos , Plasmodium vivax , Tailândia/epidemiologia , Malária Vivax/parasitologia , Imunidade Adaptativa , Anopheles/parasitologia , Anticorpos Antiprotozoários , Antígenos de Protozoários
13.
J Infect Dis ; 229(6): 1894-1903, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38408353

RESUMO

BACKGROUND: Plasmodium falciparum and Plasmodium vivax account for >90% global malaria burden. Transmission intervention strategies encompassing transmission-blocking vaccines (TBV) and drugs represent ideal public health tools to eliminate malaria at the population level. The availability of mature P. falciparum gametocytes through in vitro culture has facilitated development of a standard membrane feeding assay to assess efficacy of transmission interventions against P. falciparum. The lack of in vitro culture for P. vivax has significantly hampered similar progress on P. vivax and limited studies have been possible using blood from infected patients in endemic areas. The ethical and logistical limitations of on-time access to blood from patients have impeded the development of P. vivax TBVs. METHODS: Transgenic murine malaria parasites (Plasmodium berghei) expressing TBV candidates offer a promising alternative for evaluation of P. vivax TBVs through in vivo studies in mice, and ex vivo membrane feeding assay (MFA). RESULTS: We describe the development of transmission-competent transgenic TgPbvs25 parasites and optimization of parameters to establish an ex vivo MFA to evaluate P. vivax TBV based on Pvs25 antigen. CONCLUSIONS: The MFA is expected to expedite Pvs25-based TBV development without dependence on blood from P. vivax-infected patients in endemic areas for evaluation.


Assuntos
Vacinas Antimaláricas , Malária Vivax , Plasmodium berghei , Plasmodium vivax , Animais , Vacinas Antimaláricas/imunologia , Vacinas Antimaláricas/genética , Plasmodium vivax/genética , Plasmodium vivax/imunologia , Malária Vivax/transmissão , Malária Vivax/prevenção & controle , Malária Vivax/parasitologia , Plasmodium berghei/genética , Plasmodium berghei/imunologia , Camundongos , Antígenos de Protozoários/imunologia , Antígenos de Protozoários/genética , Humanos , Feminino , Antígenos de Superfície
14.
Infect Immun ; 92(3): e0037423, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38289124

RESUMO

Gamete surface protein P48/45 has been shown to be important for male gamete fertility and a strong candidate for the development of a malaria transmission-blocking vaccine (TBV). However, TBV development for Plasmodium vivax homolog Pvs48/45 has been slow because of a number of challenges: availability of conformationally suitable recombinant protein; the lack of an in vivo challenge model; and the inability to produce P. vivax gametocytes in culture to test transmission-blocking activity of antibodies. To support ongoing efforts to develop Pvs48/45 as a potential vaccine candidate, we initiated efforts to develop much needed reagents to move the field forward. We generated monoclonal antibodies (mAbs) directed against Pvs48/45 and characterized putative functional domains in Pvs48/45 using recombinant fragments corresponding to domains D1-D3 and their biological functionality through ex vivo direct membrane feeding assays (DMFAs) using P. vivax parasites from patients in a field setting in Brazil. While some mAbs partially blocked oocyst development in the DMFA, one mAb caused a significant enhancement of the infectivity of gametocytes in the mosquitoes. Individual mAbs exhibiting blocking and enhancing activities recognized non-overlapping epitopes in Pvs48/45. Further characterization of precise epitopes recognized by transmission-reducing and -enhancing antibodies will be crucial to design an effective immunogen with optimum transmission-reducing potential.


Assuntos
Vacinas Antimaláricas , Malária Vivax , Animais , Humanos , Masculino , Plasmodium vivax , Anticorpos Monoclonais , Proteínas de Membrana , Antígenos de Protozoários/genética , Epitopos , Células Germinativas , Anticorpos Antiprotozoários
15.
Int J Cancer ; 154(7): 1285-1297, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38180065

RESUMO

CD25, also known as the interleukin-2 receptor α chain (IL-2Rα), is highly expressed on regulatory T cells (Tregs), but relatively lower on effector T cells (Teffs). This makes it a potential target for Treg depletion, which can be used in tumor immunotherapy. However, marketed anti-CD25 antibodies (Basiliximab and Daclizumab) were originally developed as immunosuppressive drugs to prevent graft rejection, because these antibodies can block IL-2 binding to CD25 on Teffs, which in turn destroys the function of Teffs. Recent studies have shown that non-IL-2-blocking anti-CD25 antibodies have displayed exciting antitumor effects. Here, we screened out a non-IL-2-blocking anti-CD25 monoclonal antibody (mAb) 7B7 by hybridoma technology, and confirmed its antitumor activity via depleting Tregs in a CD25 humanized mouse model. Subsequently, we verified that the humanized 7B7, named as h7B7-15S, has comparable activities to 7B7, and that its Treg depletion is further increased when combined with anti-CTLA-4, leading to enhanced remodeling of the tumor immune microenvironment. Moreover, our findings reveal that the Fab form of h7B7-15S has the ability to deplete Tregs, independent of the Fc region. Taken together, our studies expand the application of anti-CD25 in tumor immunotherapy and provide insight into the underlying mechanism.


Assuntos
Anticorpos Monoclonais , Neoplasias , Camundongos , Animais , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Imunossupressores , Linfócitos T Reguladores , Microambiente Tumoral
16.
Biochem Biophys Res Commun ; 733: 150599, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39208643

RESUMO

TBVs are suggested to inhibit parasite transmission from humans to Anopheles mosquitoes. For the transmission of Plasmodium parasite, a variety of factors are included in gametes fusion phase. In this step, conserved male-specific generative cell specific 1 antigen is necessary for fusion of cytoplasmic membranes of micro- and macro-gametocytes and zygot formation. The partial blocking activities of elicited antibodies against either the HAP2-GCS1 domain or the cd loop of this antigen have been recorded to hinder the transmission of Plasmodium species in Anopheles mid-gut. Thus, the objective of the present study was to investigate if the cd loop-fusion can enhance the quantity and quality of humoral and cellular immune responses against Plasmodium falciparum GCS1 in comparison to non-fusion antigen (without cd loop), in the adjuvanted and non-adjuvanted mouse groups. The immunogenicity of two constructs of P. falciparum generative cell specific 1 antigen, a fusion protein composed of cd loop and HAP2-GCS1 domain (cd-HAP) and another recombinant PfGCS1 containing solo HAP2-GCS1 domain (HAP2) were assessed to impede Plasmodium gametocytes integration before zygote formation. The antibodies profiling, titer, and avidity of induced antibodies were measured by the immunized mice sera, and the released cytokines (IL-5, TNF, and INF-γ) were analyzed in the supernatants of stimulated splenocytes. Furthermore, the inhibitory potency of the elicited antibodies against HAP2 and cd-HAP was measured during oocyst development by Standard Membrane Feeding Assay (SMFA). The comparative results in the present study showed the higher titer of IgG antibodies and IgG2a subclass, avidity, and transmission-reducing activity (TRA = 72.5 %) when mice were immunized by cd-HAP rather than HAP2. Moreover, our findings confirmed intensified Th1-directed immune responses in group 4 received cd-HAP/Poly(I:C). These findings declared the potential ability of cd loop fusion (cd-HAP) to upsurge humoral and cellular immune responses. However, the immune responses may switch to stronger Th1-type using alternative formulations. Explicitly, the cd-HAP-based vaccine may enhance the overall efficiency of immune responses and present a promising implementation in aiming malaria transmission.

17.
Biostatistics ; 24(3): 743-759, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35579386

RESUMO

Understanding associations between injury severity and postacute care recovery for patients with traumatic brain injury (TBI) is crucial to improving care. Estimating these associations requires information on patients' injury, demographics, and healthcare utilization, which are dispersed across multiple data sets. Because of privacy regulations, unique identifiers are not available to link records across these data sets. Record linkage methods identify records that represent the same patient across data sets in the absence of unique identifiers. With a large number of records, these methods may result in many false links. Health providers are a natural grouping scheme for patients, because only records that receive care from the same provider can represent the same patient. In some cases, providers are defined within each data set, but they are not uniquely identified across data sets. We propose a Bayesian record linkage procedure that simultaneously links providers and patients. The procedure improves the accuracy of the estimated links compared to current methods. We use this procedure to merge a trauma registry with Medicare claims to estimate the association between TBI patients' injury severity and postacute care recovery.


Assuntos
Lesões Encefálicas Traumáticas , Cuidados Semi-Intensivos , Idoso , Humanos , Estados Unidos , Medicare , Teorema de Bayes , Sistema de Registros , Lesões Encefálicas Traumáticas/terapia
18.
BMC Med ; 22(1): 170, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38649867

RESUMO

BACKGROUND: The stalling global progress in malaria control highlights the need for novel tools for malaria elimination, including transmission-blocking vaccines. Transmission-blocking vaccines aim to induce human antibodies that block parasite development in the mosquito and mosquitoes becoming infectious. The Pfs48/45 protein is a leading Plasmodium falciparum transmission-blocking vaccine candidate. The R0.6C fusion protein, consisting of Pfs48/45 domain 3 (6C) and the N-terminal region of P. falciparum glutamate-rich protein (R0), has previously been produced in Lactococcus lactis and elicited functional antibodies in rodents. Here, we assess the safety and transmission-reducing efficacy of R0.6C adsorbed to aluminium hydroxide with and without Matrix-M™ adjuvant in humans. METHODS: In this first-in-human, open-label clinical trial, malaria-naïve adults, aged 18-55 years, were recruited at the Radboudumc in Nijmegen, the Netherlands. Participants received four intramuscular vaccinations on days 0, 28, 56 and 168 with either 30 µg or 100 µg of R0.6C and were randomised for the allocation of one of the two different adjuvant combinations: aluminium hydroxide alone, or aluminium hydroxide combined with Matrix-M1™ adjuvant. Adverse events were recorded from inclusion until 84 days after the fourth vaccination. Anti-R0.6C and anti-6C IgG titres were measured by enzyme-linked immunosorbent assay. Transmission-reducing activity of participants' serum and purified vaccine-specific immunoglobulin G was assessed by standard membrane feeding assays using laboratory-reared Anopheles stephensi mosquitoes and cultured P. falciparum gametocytes. RESULTS: Thirty-one participants completed four vaccinations and were included in the analysis. Administration of all doses was safe and well-tolerated, with one related grade 3 adverse event (transient fever) and no serious adverse events occurring. Anti-R0.6C and anti-6C IgG titres were similar between the 30 and 100 µg R0.6C arms, but higher in Matrix-M1™ arms. Neat participant sera did not induce significant transmission-reducing activity in mosquito feeding experiments, but concentrated vaccine-specific IgGs purified from sera collected two weeks after the fourth vaccination achieved up to 99% transmission-reducing activity. CONCLUSIONS: R0.6C/aluminium hydroxide with or without Matrix-M1™ is safe, immunogenic and induces functional Pfs48/45-specific transmission-blocking antibodies, albeit at insufficient serum concentrations to result in transmission reduction by neat serum. Future work should focus on identifying alternative vaccine formulations or regimens that enhance functional antibody responses. TRIAL REGISTRATION: The trial is registered with ClinicalTrials.gov under identifier NCT04862416.


Assuntos
Vacinas Antimaláricas , Malária Falciparum , Glicoproteínas de Membrana , Plasmodium falciparum , Proteínas de Protozoários , Adolescente , Adulto , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Adjuvantes Imunológicos/administração & dosagem , Hidróxido de Alumínio/administração & dosagem , Anticorpos Antiprotozoários , Vacinas Antimaláricas/imunologia , Vacinas Antimaláricas/administração & dosagem , Malária Falciparum/prevenção & controle , Malária Falciparum/transmissão , Malária Falciparum/imunologia , Países Baixos , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia
19.
Small ; : e2400707, 2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39183516

RESUMO

Graphene oxide (GO) has been attracting intensive attention as a flexible barrier film, however, provides no barrier for proton transfer due to its out-of-plane proton conductivity (10-6 S cm-1) based on nanoscale defects with oxygen functional groups. In this study, it is reported that a pore-free GO (Pf-GO) membrane with controlled oxygen functional groups exhibits unexpected proton blocking behavior (10-11 S cm-1). Proton permeation tests conducted in aqueous solution demonstrate that proton permeation is below the detection limit, and lithium metal foils coated with the Pf-GO show higher chemical stability to water than those coated with previously reported GO. The Pf-GO has periodic honeycomb atomic structure, which is found to impart the Pf-GO membrane with novel performance characteristics distinct from those of conventional GO.

20.
Small ; 20(28): e2312085, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38342594

RESUMO

Developing high-performance lignin anti-corrosive waterborne epoxy (WEP) coatings is conducive to the advancement of environmentally friendly coatings and the value-added utilization of lignin. In this work, a functionalized biomass waterborne epoxy composite coating is prepared using quaternized sodium lignosulfonate (QLS) as a functional nanofiller for mild carbon steel protection. The results showed that QLS has excellent dispersion and interface compatibility within WEP, and its abundant phenolic hydroxyl, sulfonate, quaternary ammonium groups, and nanoparticle structure endowed the coating with excellent corrosion inhibition and superior barrier properties. The corrosion inhibition efficiency of 100 mg L-1 QLS in carbon steel immersed in a 3.5 wt% NaCl solution reached 95.76%. Furthermore, the coating maintained an impedance modulus of 2.29 × 106 Ω cm2 (|Z|0.01 Hz) after being immersed for 51 days in the high-salt system. In addition, QLS imparted UV-blocking properties and thermal-oxygen aging resistance to the coating, as evidenced by a |Z|0.01 Hz of 1.04 × 107 Ω cm2 after seven days of UV aging while still maintaining a similar magnitude as before aging. The green lignin/WEP functional coatings effectively withstand the challenging outdoor environment characterized by high salt concentration and intense UV radiation, thereby demonstrating promising prospects for application in metal protection.

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