RESUMO
Coronavirus disease 2019 (Covid-19) is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) which is responsible for a global pandemic that started in late 2019 in Wuhan, China. To prevent the worldwide spread of this highly pathogenic virus, development of an effective and safe vaccine is urgently needed. The SARS-CoV-2 and SARS-CoV share a high degree of genetic and pathologic identity and share safety and immune-enhancement concerns regarding vaccine development. Prior animal studies with first generation (whole virus-based) preparations of SARS-CoV vaccines (inactivated and attenuated vaccine modalities) indicated the possibility of increased infectivity or eosinophilic infiltration by immunization. Therefore, development of second and third generation safer vaccines (by using modern vaccine platforms) is actively sought for this viral infection. The spike (S) protein of SARS-CoVs is the main determinant of cell entry and tropism and is responsible for facilitating zoonosis into humans and sustained person-to-person transmission. Furthermore, 'S' protein contains multiple neutralizing epitopes that play an essential role in the induction of neutralizing antibodies (nAbs) and protective immunity. Moreover, T-cell responses against the SARS-CoV-2 'S' protein have also been characterized that correlate to the IgG and IgA antibody titres in Covid-19 patients. Thus, S protein is an obvious candidate antigen for inclusion into vaccine platforms against SARS-CoV-2 viral infection. This manuscript reviews different characteristics of S protein, its potency and 'state of the art' of the vaccine development strategies and platforms using this antigen, for construction of a safe and effective SARS-CoV-2 vaccine.
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Anticorpos Antivirais/biossíntese , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Genoma Viral/imunologia , Pandemias , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/biossíntese , Ensaios Clínicos como Assunto , Vetores Genéticos/química , Vetores Genéticos/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Esquemas de Imunização , Imunogenicidade da Vacina , Segurança do Paciente , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Vacinas Atenuadas , Vacinas de DNA , Vacinas de Subunidades AntigênicasRESUMO
By the age of 5 years, virtually all children have been infected by group A rotavirus (RVA), which is responsible for around half million mortality annually prior to vaccination. Relatively high rate of the morbidity and mortality highlights the necessity of applying preventive procedures particularly in developing countries. Two live attenuated RVA vaccines (Rotarix and RotaTeq) are licensed and now being used in many countries worldwide. Although these vaccines are shown to reduce the mortality up to 50%, several key questions yet remained to answer. Indeed, the licensed RV vaccines were found to be less effective in countries of sub-Saharan Africa and Southeast Asia. Therefore, developing next generation RVA vaccines is warranted. VP6 is highly abundant and conserved protein that forms the middle layer of RV particles and was shown to be both antigenic and immunogenic. Although it does not induce neutralizing antibodies, different VP6 preparations were found to induce homologous and cross-reactive immune responses with partial protection from RVA replication. Although the molecular mechanisms are not fully elucidated, VP6-based RVA vaccine candidates are worthy of further consideration. This review aims to focus on different aspects of VP6 protein and its potentiality for an alternative RV vaccine against RV disease.
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Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/imunologia , Rotavirus/imunologia , África Subsaariana , Antígenos Virais/isolamento & purificação , Sudeste Asiático , Proteínas do Capsídeo/isolamento & purificação , Proteção Cruzada , Países em Desenvolvimento , Humanos , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/isolamento & purificaçãoRESUMO
Cancer therapy using oncolytic viruses is an emerging area, in which viruses are engineered to selectively propagate in tumor tissues without affecting healthy cells. Because of the advantages that adenoviruses (Ads) have over other viruses, they are more considered. To achieve tumor selectivity, two main modifications on Ads genome have been applied: small deletions and insertion of tissue- or tumor-specific promoters. Despite oncolytic adenoviruses ability in tumor cell lysis and immune responses stimulation, to further increase their antitumor effects, genomic modifications have been carried out including insertion of checkpoint inhibitors and antigenic or immunostimulatory molecules into the adenovirus genome and combination with dendritic cells and chemotherapeutic agents. This study reviews oncolytic adenoviruses structures, their antitumor efficacy in combination with other therapeutic strategies, and finally challenges around this treatment approach.
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Adenoviridae/patogenicidade , Neoplasias/terapia , Terapia Viral Oncolítica , Vírus Oncolíticos/patogenicidade , Adenoviridae/genética , Adenoviridae/crescimento & desenvolvimento , Adenoviridae/imunologia , Animais , Antineoplásicos Imunológicos/uso terapêutico , Quimioterapia Adjuvante , Células Dendríticas/imunologia , Células Dendríticas/transplante , Terapia Genética , Humanos , Imunoterapia Adotiva , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/virologia , Terapia Viral Oncolítica/efeitos adversos , Vírus Oncolíticos/genética , Vírus Oncolíticos/crescimento & desenvolvimento , Vírus Oncolíticos/imunologia , Replicação ViralRESUMO
The association of Merkel cell polyomavirus (MCPyV) with Merkel cell carcinoma (MCC) in immunocompromised individuals has been revealed in a number of surveys. The study of MCPyV specific antibody titers and viral loads in such patients has a great attraction for research groups interested in viral reactivation. In this cross-sectional study to evaluate MCPyV antibody titer, DNA prevalence and viral load in peripheral blood mononuclear cells (PBMCs), we examined 205 HIV-1 infected patients and 100 un-infected controls. The HIV-1 infected patients divided into two groups (HIV/AIDS and non-AIDS) according to their CD4 status. Total IgG antibody titer against MCPyV was analyzed by virus like particle (VLP)-based enzyme linked immunosorbent assay (ELISA). Presence of MCPyV-DNA in subject's PBMCs was examined by quantitative real-time PCR assay. Levels of anti-MCPyV IgG in HIV/AIDS patients were significantly higher than those in non-AIDS HIV-infected and control subjects (p value = <0.001). The prevalence rate of MCPyV-DNA in PBMCs of HIV/AIDS, non-AIDS HIV-infected and un-infected controls were 17%, 16%, and 14% respectively. The MCPyV viral load among the groups ranged between 0.15 to 2.9 copies/103cells (median, 1.9 copies/103cells), with no significant difference between the studied populations (p value = 0.3).
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Síndrome da Imunodeficiência Adquirida/sangue , Síndrome da Imunodeficiência Adquirida/patologia , Anticorpos Antivirais/sangue , Carcinoma de Célula de Merkel/sangue , Imunoglobulina G/sangue , Poliomavírus das Células de Merkel/imunologia , Síndrome da Imunodeficiência Adquirida/imunologia , Adulto , Anticorpos Antivirais/imunologia , Carcinoma de Célula de Merkel/imunologia , Carcinoma de Célula de Merkel/patologia , Carcinoma de Célula de Merkel/virologia , Estudos Transversais , Progressão da Doença , Feminino , HIV-1/genética , HIV-1/imunologia , HIV-1/fisiologia , Humanos , Imunoglobulina G/imunologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/virologia , Masculino , Poliomavírus das Células de Merkel/genética , Poliomavírus das Células de Merkel/fisiologia , Carga Viral , Adulto JovemRESUMO
METHODS: This case-control study, was performed on 136 blood samples based on 81 patients with chronic HCV genotypes 1 and 3 including 64 SVR positive and 17 negative and 55 healthy individual controls. DNA was isolated from the samples and the frequency of the polymorphism was analyzed using a PCR-RFLP method. Finally, the products were detected on 3.5% agarose gel electrophoresis. RESULTS: The analysis of the data for C/T polymorphism indicated that the CC genotype was found in 19 of 64 patients who achieved SVR, while the TT genotype was detected in 3 patients and SVR was achieved in 2. Finally, heterozygous CT was identified in 53 patients and 10 patients were resistant to treatment. CONCLUSIONS: The results did not support any significant effects of TT or CT genotypes on susceptibility to HCV infection (p = 0.935, OR = 1.031, CI = 0.464 - 2.026). Moreover, there was no significant correlation between SVR to PEG-IFN combined by ribavirin therapy in patients with genotype CC (p = 0.601, OR = 0.736, CI = 0.234 - 2.319).
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Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Interleucinas/genética , Polimorfismo de Nucleotídeo Único , Ribavirina/uso terapêutico , Antivirais/farmacologia , Estudos de Casos e Controles , Quimioterapia Combinada , Genótipo , Hepacivirus , Humanos , Interferon-alfa , Irã (Geográfico) , Proteínas Recombinantes , Ribavirina/farmacologiaRESUMO
BACKGROUND: The current standard treatment for hepatitis C is a combination of pegylated interferon alpha and ribavirin (peg-IFNα/RBV). Recent studies have shown that single nucleotide polymorphisms (SNPs) near the interleukin 28B (IL28B) gene coding for IFN-λ3 were associated with the antiviral treatment response. Therefore, in this study, we determined the distribution of the rs8099917 (T/G) polymorphism with sustained virological response (SVR) to chronic hepatitis C virus infection among Iranian patients. METHODS: This cross-sectional study was performed on 150 blood samples based on 93 patients with chronic HCV genotypes 1 and 3 including 71 SVR positive, 22 negative, and 57 healthy individual controls. DNA was extracted from the samples and the frequency of the polymorphism was analyzed the using PCR-RFLP method. Finally, the products were detected on 3.5% agarose gel electrophoresis. RESULTS: The analysis of the data for G/T polymorphism showed that the GG genotype was identified in 6 patients of 71 who achieved SVR, while the GT heterozygous was found in 33 patients and SVR was achieved in 19. Finally, the TT was detected in 53 patients and 7 patients were resistant to treatment. CONCLUSIONS: The results showed significant effects of G allele carriers on susceptibility to HCV infection com-pared to the other allele (T) in our studied population (p = 0.013, OR = 2.23, 95% CI = 1.18-4.21), but we did not find a significant correlation for SVR to therapy in patients with genotype TT (p = 0.055, OR = 0.48, 95% CI = 0.23-1.01). However, further studies with more samples are necessary.
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Hepatite C Crônica/genética , Interleucinas/genética , Polimorfismo de Nucleotídeo Único , Adulto , Estudos Transversais , Feminino , Genótipo , Hepatite C Crônica/virologia , Humanos , Interferons , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Hepatitis C virus (HCV) genome contains an overlapping reading frame which results in alternative core protein (ARFP). Baculovirus expression system was used as a powerful eukaryotic vector system to express core+1/F protein for the first time. This recombinant core+1/F protein was used to assess the anti-core+1 antibody in anti-HCV drug resistant and sustained virologic response (SVR) patients. METHODS: The core+1 coding sequence from HCV genotype 1 was designed and synthesized in pUC57 vector. It was subcloned into baculovirus donor plasmid pFastBacTM HTA and transposed into baculovirus shuttle vector (bacmid) to transfect Sf9 cells. Recombinant core+1 protein was purified using Ni-NTA agarose under native condition and verified using SDS-PAGE electrophoresis and Western blotting. An enzyme-linked immunosorbent assay (ELISA) was developed using this purified protein to assess anti-core+1 antibody in 28 anti-HCV drug resistant patients and in 34 patients with sustained virologic response (SVR) in comparison with 31 healthy volunteers used as the negative control. RESULTS: Expression of HCV core+1 protein in Sf9 cells was confirmed by using SDS-PAGE and Western blotting. Antibody titer against core+1 protein in anti-HCV drug resistant patients was significantly higher than that in both the healthy volunteers and SVR patients (p < 0.0001). CONCLUSIONS: HCV core+1 protein was expressed successfully in a baculovirus expression system in high yield in order to develop an ELISA to assess the anti-core+1 antibody. Further studies are needed to reveal the potential application of core+1 protein in anti-HCV treatment prognosis.
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Baculoviridae/genética , Anticorpos Anti-Hepatite C/sangue , Hepatite C/tratamento farmacológico , Proteínas do Core Viral/genética , Adulto , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/imunologia , Proteínas do Core Viral/imunologiaRESUMO
CONTEXT: Administration of sildenafil citrate (SC) is considered as a strategy in the treatment of pulmonary hypertension. OBJECTIVE: This study reports production of the inhalable microparticles containing SC-loaded poly(lactide-co-glycolic acid)-nanoparticles. METHODS: SC-nanoparticles were prepared by the double emulsion solvent evaporation method. Next, free SC and SC-loaded nanoparticles were spray dried in the presence of appropriate excipients (lactose, maltose and trehalose). Physicochemical properties and aerodynamic behavior of prepared powders were evaluated. In addition, drug accumulation from selected formulations in the rat lung tissue was compared with oral and IV administration. RESULTS: Size and fine particle fraction of selected nanocomposites and free SC microparticles were 7 and 4.5 µm, and 60.2% and 68.2%, respectively. Following oral and IV administration, the drug was not detectable in the lung after 4 and 6 h, respectively, but in SC-loaded nanoparticles, the drug was detectable in the lung even after 12 h of inhalation. Respirable particles containing free SC provided high concentration at first that was detectable up to 6 after insufflation. CONCLUSION: In vivo study demonstrated that pulmonary administration of sildenafil and sildenafil nanoparticles produced longer half-life and higher concentration of the drug in the lung tissue as compared to oral and IV administration. So, these formulations could be more effective than oral and IV administration of this drug.
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Pulmão/metabolismo , Nanocompostos/administração & dosagem , Nanopartículas/administração & dosagem , Citrato de Sildenafila/administração & dosagem , Citrato de Sildenafila/farmacocinética , Administração por Inalação , Animais , Química Farmacêutica/métodos , Portadores de Fármacos/química , Emulsões/administração & dosagem , Emulsões/química , Emulsões/farmacocinética , Excipientes/química , Masculino , Nanocompostos/química , Nanopartículas/química , Tamanho da Partícula , Poliglactina 910/química , Pós/administração & dosagem , Pós/química , Pós/farmacocinética , Ratos , Ratos Sprague-Dawley , Citrato de Sildenafila/químicaRESUMO
Amphiphilic peptides hold great potential as drug delivery systems. A popular peptide design approach has been to place amino acids in the peptide sequence based on their known properties. On the other hand, the directed discovery approach aims to screen a sequence space for a desired property. However, screening amphiphilic peptides for desirable drug delivery properties is not possible without a quantity that is predictive of these properties. We studied the predictive power of critical aggregation concentration (CAC) values on the drug delivery performance of a series of amphiphilic peptides with different hydrophobic tails and close CAC values. The CAC values were predicted by our previously developed model and doxorubicin was used as a model hydrophobic drug. All peptides showed close drug loading, entrapment efficiency, and release profile. They also formed similar spherical particles by assembling in reverse ß-sheet arrangements regardless of drug presence. Moreover, the assembled particles were able to accumulate doxorubicin inside ordinary as well as drug-resistant breast cancer cells and enhance its toxicity up to 39 and 17 folds, respectively. It can be concluded that similar drug delivery properties displayed by the peptides can be attributed to their similar hydrophilic-lipophilic balance as reflected in their close CAC values.
Assuntos
Doxorrubicina , Sistemas de Liberação de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Peptídeos , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Doxorrubicina/farmacocinética , Humanos , Peptídeos/química , Sistemas de Liberação de Medicamentos/métodos , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Linhagem Celular Tumoral , Agregados Proteicos , Células MCF-7 , Tensoativos/químicaRESUMO
Background: The E6 oncoprotein of HPV plays a crucial role in promoting cell proliferation and inhibiting apoptosis, leading to tumor growth. Non-viral vectors such as nona-arginine (R9) peptides have shown to be potential as carriers for therapeutic molecules. This study aimed to investigate the efficacy of nona-arginine in delivering E6 shRNA and suppressing the E6 gene of HeLa cells in vitro. Methods: HeLa cells carrying E6 gene were treated with a complex of nona-arginine and E6 shRNA. The complex was evaluated using gel retardation assay and FESEM microscopy. The optimal N/P ratio for R9 peptide to transfect HeLa cells with luciferase gene was determined. Relative real-time PCR was used to evaluate the efficiency of mRNA suppression efficiency for E6 shRNA, while the effect of E6 shRNA on cell viability was measured using an MTT assay. Results: The results indicated that R9 efficiently binds to shRNA and effectively transfects E6 shRNA complexes at N/P ratios greater than 30. Transfection with R9 and PEI complexes resulted in a significant toxicity compared to the scrambled plasmid, indicating selective toxicity for HeLa cells. Real-time PCR confirmed the reduction of E6 mRNA expression levels in the cells transfected with anti-E6 shRNA. Conclusion: The study suggests that R9 is a promising non-viral gene carrier for transfecting E6 shRNA in vitro, with significant transfection efficiency and minimal toxicity.
Assuntos
Proteínas Oncogênicas Virais , Neoplasias do Colo do Útero , Humanos , Feminino , RNA Interferente Pequeno/genética , Células HeLa , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Proteínas Repressoras/metabolismo , Apoptose/genética , RNA Mensageiro/genética , Arginina/farmacologia , Arginina/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Transfecção , Linhagem Celular TumoralRESUMO
BACKGROUND: Along with research on development of more efficient gene delivery systems, it is necessary to search on stabilization processes to extend their active life span. Chitosan is a nontoxic, biocompatible and available gene delivery carrier. The aim of this study was to assess the ability of this polymer to preserve transfection efficiency during spray-drying and a modified freeze-drying process in the presence of commonly used excipients. METHODS: Molecular weight of chitosan was reduced by a chemical reaction and achieved low molecular weight chitosan (LMWC) was complexed with pDNA. Obtained nanocomplex suspensions were diluted by solutions of lactose and leucine, and these formulations were spray dried or freeze dried using a modified technique. Size, polydispersity index, zeta potential, intensity of supercoiled DNA band on gel electrophoresis, and transfection efficiency of reconstituted nanocomplexes were compared with freshly prepared ones. RESULTS AND CONCLUSION: Size distribution profiles of both freeze dried, and 13 out of 16 spray-dried nanocomplexes remained identical to freshly prepared ones. LMWC protected up to 100% of supercoiled structure of pDNA in both processes, although DNA degradation was higher in spray-drying of the nanocomplexes prepared with low N/P ratios. Both techniques preserved transfection efficiency similarly even in lower N/P ratios, where supercoiled DNA content of spray dried formulations was lower than freeze-dried ones. Leucine did not show a significant effect on properties of the processed nanocomplexes. It can be concluded that LMWC can protect DNA structure and transfection efficiency in both processes even in the presence of leucine.
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BACKGROUND: The purpose of the study. Along with research on development of more efficient gene delivery systems, it is necessary to search on stabilization processes to extend their active life span. Chitosan is a nontoxic, biocompatible and available gene delivery carrier. The aim of this study was to assess the ability of this polymer to preserve transfection efficiency during spray-drying and a modified freeze-drying process in the presence of commonly used excipients. METHOD: Molecular weight of chitosan was reduced by a chemical reaction and achieved low molecular weight chitosan (LMWC) was complexed with pDNA. Obtained nanocomplex suspensions were diluted by solutions of lactose and leucine, and these formulations were spray dried or freeze dried using a modified technique. Size, polydispersity index, zeta potential, intensity of supercoiled DNA band on gel electrophoresis, and transfection efficiency of reconstituted nanocomplexes were compared with freshly prepared ones. RESULTS AND MAJOR CONCLUSION: Size distribution profiles of both freeze dried, and 13 out of 16 spray-dried nanocomplexes remained identical to freshly prepared ones. LMWC protected up to 100% of supercoiled structure of pDNA in both processes, although DNA degradation was higher in spray-drying of the nanocomplexes prepared with low N/P ratios. Both techniques preserved transfection efficiency similarly even in lower N/P ratios, where supercoiled DNA content of spray dried formulations was lower than freeze-dried ones. Leucine did not show a significant effect on properties of the processed nanocomplexes. It can be concluded that LMWC can protect DNA structure and transfection efficiency in both processes even in the presence of leucine.
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BACKGROUND: This study evaluated the potential of chitosan based polymeric micelles as a nanocarrier system for pulmonary delivery of itraconazole (ITRA). METHODS: Hydrophobically modified chitosan were synthesized by conjugation of stearic acid to the hydrophilic depolymerized chitosan. FTIR and 1HNMR were used to prove the chemical structure and physical properties of the depolymerized and the stearic acid grafted chitosan. ITRA was entrapped into the micelles and physicochemical properties of the micelles were investigated. Fluorescence spectroscopy, dynamic laser light scattering and transmission electron microscopy were used to characterize the physicochemical properties of the prepared micelles. The in vitro pulmonary profile of polymeric micelles was studied by an air-jet nebulizer connected to a twin stage impinger. RESULTS: The polymeric micelles prepared in this study could entrap up to 43.2±2.27 µg of ITRA per milliliter. All micelles showed mean diameter between 120-200 nm. The critical micelle concentration of the stearic acid grafted chitosan was found to be 1.58×10-2 mg/ml. The nebulization efficiency was up to 89% and the fine particle fraction (FPF) varied from 38% to 47%. The micelles had enough stability to remain encapsulation of the drug during nebulization process. CONCLUSIONS: In vitro data showed that stearic acid grafted chitosan based polymeric micelles has a potential to be used as nanocarriers for delivery of itraconazole through inhalation.
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For adenoviruses (Ads) to be optimally effective in cancer theranostics, they need to be retargeted toward target cells and lose their natural tropism. Typically, this is accomplished by either engineering fiber proteins and/or employing bispecific adapters, capable of bonding Ad fibers and tumor antigen receptors. This study aimed to present a simple and versatile method for generating Ad-based bionanoparticles specific to target cells, using the SpyTag-SpyCatcher system. The SpyTag peptide was inserted into the HI loop of fiber-knob protein, which could act as a covalent anchoring site for a targeting moiety fused to a truncated SpyCatcher (SpyCatcherΔ) pair. After confirming the presence and functionality of SpyTag on the Ad type-5 (Ad5) fiber knob, an adapter molecule, comprising of SpyCatcherΔ fused to an anti-vascular endothelial growth factor receptor 2 (VEGFR2) nanobody, was recombinantly expressed in Escherichia coli and purified before conjugation to fiber-modified Ad5 (fmAd5). After evaluating fmAd5 detargeting from its primary coxsackie and adenovirus receptor (CAR), the nanobody-decorated fmAd5 could be efficiently retargeted to VEGFR2-expressing 293/KDR and human umbilical vein endothelial (HUVEC) cell lines. In conclusion, a plug-and-play platform was described in this study for detargeting and retargeting Ad5 through the SpyTag-SpyCatcher system, which could be potentially applied to generate tailored bionanoparticles for a broad range of specific targets; therefore, it can be introduced as a promising approach in cancer nanotheranostics.
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Self-assembling amphiphilic peptides have recently received special attention in medicine. Nonetheless, testing the myriad of combinations generated from at least 20 coded and several hundreds of noncoded amino acids to obtain candidate sequences for each application, if possible, is time-consuming and expensive. Therefore, rapid and accurate approaches are needed to select candidates from countless combinations. In the current study, we examined three conventional descriptor sets along with a novel descriptor set derived from the simulated aggregation propensity of di- and tripeptides to model the critical aggregation concentration (CAC) of amphiphilic peptides. In contrast to the conventional descriptors, the radial kernel model derived from the novel descriptor set accurately predicted the critical aggregation concentration of the test set with a residual standard error of 0.10. The importance of aromatic side chains, as well as neighboring amino acids in the self-assembly, was emphasized by analysis of the influential descriptors. The addition of very long peptides (70-100 residues) to the data set decreased the model accuracy and changed the influential descriptors. The developed model can be used to predict the CAC of self-assembling amphiphilic peptides and also to derive rules to apply in designing novel amphiphilic peptides with desired properties.
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Cancer/tumor cells infected with the "avian paramyxovirus Newcastle Disease Virus (TC-NDV)" express the viral hemagglutinin-neuraminidase (HN) on the cell surface that is used as both the danger signal and anchor for bi/tri-specific antibodies (bs/tsAbs).We constructed a bs-Ab (HN-Fc-CD16) that bindsto HN and natural killer (NK)-CD16 receptor (FcgRIII)and a ts-Ab (HN-Fc-IL15-CD16) harbouring NK-activating cytokine "IL-15" within the bs-Ab.In silicoand computational predictions indicated proper exposure of both Abs in bs/tsAbs.Properbinding of thebi/tsAbstoHN on surface of TC-NDVandCD16+-cells was demonstrated by flow cytometry.The bi/tsAbstriggeredspecificcytotoxicity of NK cells againstTC-NDVand elicited substantial IFN-γproduction by activated NK cells(higher for ts-Ab) that sound promising for cancer immunotherapy purposes.
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Anticorpos Biespecíficos/biossíntese , Anticorpos Biespecíficos/farmacologia , Antineoplásicos Imunológicos/farmacologia , Proteína HN/imunologia , Neoplasias/terapia , Vírus da Doença de Newcastle/imunologia , Receptores de IgG/imunologia , Anticorpos Biespecíficos/química , Anticorpos Biespecíficos/imunologia , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/imunologia , Sítios de Ligação , Testes Imunológicos de Citotoxicidade , Células HEK293 , Células HeLa , Humanos , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoterapia/métodos , Interferon gama/metabolismo , Células Matadoras Naturais/imunologia , Ligantes , Modelos Moleculares , Neoplasias/imunologiaRESUMO
The nanostructured complexes can result in enhanced vaccine efficacy by facilitating the distribution and uptake of antigens by antigen-presenting cells (APCs), thereby stimulating immune responses. Here, we hypothesized that either directly coating of nanoadjuvants including aluminum phosphate (AlPO4) and adenovirus (Ad) with a modified HPV16 E7 MHC-I specific epitope, RAHYNIVTF49-57, or mixing the CpG oligodeoxynucleotide (CpG-ODN) with the cationic epitope to form nanocomlexes, and their combinational therapy would enhance their anti-tumor effects in a TC-1 mouse model. The positively-charged HPV16 E7 epitope was attracted to the oppositely-charged adjuvants by electrostatic interaction to generate epitope/adjuvant nanocomplexes. We showed that coating the nanosized adjuvants with the cationic epitope increased the particles' surface charge without significant change in their size. We then tested the cellular immunogenicity and therapeutic efficacy of nanocomplexes by measuring IL-10 and IFN-γ production, the expression of CD107a as a marker of CTL response, and tumor growth inhibition. The nanocomplexes were administered either in homologous or heterologous prime-boost regimens, and heterologous immunizations including Ad/Pep-CpG/Pep, CpG/Pep-Ad/Pep, Ad/Pep-Alum/Pep, and Alum/Pep-Ad/Pep induced significantly higher levels of IL-10, IFN-γ, and CD107a-expressing CD8 T cells compared with homologous administrations. Furthermore, the tumor growth was significantly suppressed in mice receiving nanostructured complexes in the heterologous immunizations. Our study highlights the potential of the heterologous prime-boost administration of the epitope-coated nanostructures as an effective immunization strategy.
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Epitopos/imunologia , Adjuvantes Imunológicos/farmacologia , Compostos de Alúmen , Animais , Antígenos , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/imunologia , Modelos Animais de Doenças , Imunização , Camundongos , Neoplasias , Oligodesoxirribonucleotídeos , Proteínas E7 de Papillomavirus , Linfócitos T Citotóxicos/imunologia , Vacinação , Eficácia de VacinasRESUMO
BACKGROUND: : Immunotherapy of cancer by bispecific antibodies (bsAb) is an attractive approach for retargeting immune effector cells including natural killer (NK) cells to the tumor if the proper expression and purification of the bsAb for such applications could be addressed. Herein, we describe E. coli expression of a recombinant bsAb (bsHN-CD16) recognizing NK-CD16 and hemagglutinin neuraminidase (HN) of Newcastle Disease Virus (NDV). This bsAb might be efficient for ex vivo stimulation of NK cells via coupling to HN on the surface of the NDV-infected tumor cells. METHODS: A bsAb-encoding pcDNA3.1 vector (anti-HN scFv-Fc-anti-CD16 scFv) was used as a template, and the scFv segments (after enzymatic digestion and cutting of the Fc part) were rejoined to construct the Fc-deprived bsAb (anti-HN scFv-anti-CD16 scFv; bsHN-CD16). The constructed bsHN-CD16 was inserted into the HindIII and BamHI site of the T7 promoter-based pET28a plasmid. Following restriction analyses and DNA sequencing to confirm the cloning steps, bsHN-CD16 encoding pET28a was transformed into the E. coli (Rosetta DE3 strain), induced for protein expression by IPTG, and the protein was purified under native condition by Ni/NTA column using imidazole. RESULTS: Analyses by SDS-PAGE and Western Blotting using Rabbit anti-human whole IgG-HRP conjugate, confirmed the expression and purification of the bsAb with the expected full size of 55 kDa and yields around 8% of the total protein. CONCLUSION: Results showed efficient production of the bsAb in E. coli for future large-scale purification.
RESUMO
Streptokinase (SK), a plasminogen activator (PA) that converts inactive plasminogen (Pg) to plasmin (Pm), is a protein secreted by groups A, C, and G streptococci (GAS, GCS, and GGS, respectively), with high sequence divergence and functional heterogeneity. While roles of some residual changes in altered SK functionality are shown, the underlying structural mechanisms are less known. Herein, using computational approaches, we analyzed the conformational basis for the increased activity of SK from a GGS (SKG132) isolate with four natural residual substitutions (Ile33Phe, Arg45Gln, Asn228Lys, Phe287Ile) compared to the standard GCS (SKC). Using the crystal structure of SK.Pm catalytic complex as main template SKC.µPm catalytic complex was modeled through homology modeling process and validated by several online validation servers. Subsequently, SKG132.µPm structure was constructed by altering the corresponding residual substitutions. Results of three independent MD simulations showed increased RMSF values for SKG132.µPm, indicating the enhanced structural flexibility compared to SKC.µPm, specially in 170 and 250 loops and three regions: R1 (149-161), R2 (182-215) and R3 (224-229). In parallel, the average number of Hydrogen bonds in 170 loop, R2 and R3 (especially for Asn228Lys) of SKG132 compared to that of the SKC was decreased. Accordingly, residue interaction networks (RINs) analyses indicated that Asn228Lys might induce more level of structural flexibility by generation of free Lys256, while Phe287Ile and Ile33Phe enhanced the stabilization of the SKG132.µPm catalytic complex. These results denoted the potential role of the optimal dynamic state and stabilized catalytic complex for increased PA potencies of SK as a thrombolytic drug.
Assuntos
Biocatálise , Simulação por Computador , Fibrinolisina/metabolismo , Mutação/genética , Streptococcus/enzimologia , Estreptoquinase/genética , Aminoácidos/metabolismo , Ligação de Hidrogênio , Modelos Moleculares , Estabilidade Proteica , Reprodutibilidade dos TestesRESUMO
Due to the limitations and safety issues of the two currently approved live attenuated rotavirus (RV) vaccines "RotaTeq and Rotarix," studies on nonreplicating sources of RV vaccines and search for proper RV antigens are actively carried out. The adjuvant activity of NSP4 and highly immunogenic properties of RV VP6 protein prompted us to consider the construction of a NSP4112-175-VP6 fusion protein and to assess the anti-VP6 IgG, IgA, and IgG subclass responses induced by Escherichia coli-derived NSP4-VP6 fusion protein compared to that of VP6 protein with/without formulation in Montanide ISA 50V2 (M50) in BALB/c mice. Results indicated to the proper expression of the fused NSP4-VP6 and VP6 proteins in E. coli. Intraperitoneal immunization by M50 formulated NSP4-VP6 fusion protein (M5+NSP4-VP6) induced the highest titration of VP6-specific IgG and IgA responses compared to the other groups. Indeed, the presence of NSP4 resulted to the induction of stronger humoral immune responses against the fused protein compared to that elicited by administration of VP6 protein alone (with/without M50 formulation), implying the adjuvant properties of NSP4 for the fused protein. Moreover, the "M50+NSP4-VP6" formulation induced higher serum IgG2a titers than IgG1 and increased Interferon-γ levels, despite unchanged interleukin-4 amounts compared to other groups, indicating Th1-oriented responses with a possible role of NSP4. In conclusion, this study further highlights the potentiality of NSP4-VP6 fusion protein as an efficient and cost-effective immunogen in the field of RV vaccine development.