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1.
Isr Med Assoc J ; 21(7): 444-448, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31507118

RESUMO

BACKGROUND: Although cross-reactions between Epstein-Barr virus (EBV) and human systemic lupus erythematosus (SLE) autoantigens occur, a complete analysis of the potential EBV peptide cross-reactome has not been performed. OBJECTIVES: To analyze the whole EBV proteome searching for peptides common to SLE-related proteins and endowed with an immunological potential. METHODS: Fifty-one SLE-related proteins were analyzed for hexapeptide sharing with EBV proteome using publicly available databases. RESULTS: An extremely high number of hexapeptides are shared between 34 human SLE autoantigens and EBV proteins. The peptide sharing mostly occurs with complement components C4 and Interleukin-10 (IL-10). CONCLUSIONS: This study thoroughly describes the EBV vs. SLE autoantigens peptide overlap and powerfully supports cross-reactivity as a major mechanism in EBV-associated SLE etiopathogenesis.


Assuntos
Autoantígenos/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Peptídeos/imunologia , Proteoma , Complemento C4/imunologia , Reações Cruzadas/imunologia , Bases de Dados Factuais , Herpesvirus Humano 4/imunologia , Humanos , Interleucina-10/imunologia
2.
Biophys Chem ; 253: 106213, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31276987

RESUMO

The interaction event between programmed death receptor-1 (PD-1) and its ligand (PD-L1) functions as an essential immune checkpoint against cytotoxic T effector cell activation. Previously, a number of small-molecule inhibitors and antibody drugs have been successfully developed to block the PD1/PDL1 signaling axis for breast cancer immunotherapy. Here, we attempt to directly disrupt the formation of PD-1/PD-L1 complex by using a self-inhibitory peptide (SIP) strategy. In the procedure, the complex crystal structure is examined systematically with energetic analysis and alanine scanning. Two double-stranded segments I and II in PD-L1 active finger are identified as hotspot regions; they directly interact with the amphipathic pocket of PD-1 to form the complex system. The segments are derived from PD-L1 to define two SIP peptides, namely, DS-I and DS-II, which are thought to have capability of rebinding at the complex interface, thus disrupting PD-1/PD-L1 interaction as a new immune checkpoint blockade. A further analysis reveals that the free linear DS-I and DS-II peptides are highly flexible without protein context support, which would incur a large entropy penalty (unfavorable indirect readout effect) when rebinding to PD-1. Next, intramolecular cyclization is applied to constraining the intrinsically disordered conformation of free DS-II peptide into native ordered double-stranded configuration, which can be substantiated by molecular dynamics simulation and circular dichroism spectroscopy. Several cyclized counterparts of linear DS-II peptide are designed and their affinities to PD-1 are determined using fluorescence polarization assays. As might be expected, three designed cyclic peptides DS-II[c111-127], ΔDS-II[c111-127] and ΔDS-II[c110-128] exhibit considerably increased potency (Kd = 28.0 ±â€¯4.2, 17.5 ±â€¯3.1 and 11.6 ±â€¯2.3 µM, respectively) relative to linear DS-II peptide (Kd = 109 ±â€¯15 µM).


Assuntos
Antígeno B7-H1/imunologia , Neoplasias da Mama/terapia , Imunoterapia , Peptídeos/imunologia , Receptor de Morte Celular Programada 1/imunologia , Antígeno B7-H1/química , Neoplasias da Mama/imunologia , Dicroísmo Circular , Ciclização , Feminino , Humanos , Simulação de Dinâmica Molecular , Peptídeos/síntese química , Peptídeos/química , Receptor de Morte Celular Programada 1/química , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , Linfócitos T Citotóxicos/imunologia
3.
BMC Bioinformatics ; 20(1): 387, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296178

RESUMO

BACKGROUND: Bioinformatics methods are helpful to identify new molecules for diagnostic or therapeutic applications. For example, the use of peptides capable of mimicking binding sites has several benefits in replacing a protein which is difficult to produce, or toxic. Using peptides is less expensive. Peptides are easier to manipulate, and can be used as drugs. Continuous epitopes predicted by bioinformatics tools are commonly used and these sequential epitopes are used as is in further experiments. Numerous discontinuous epitope predictors have been developed but only two bioinformatics tools have been proposed so far to predict peptide sequences: Superficial and PEPOP 2.0. PEPOP 2.0 can generate series of peptide sequences that can replace continuous or discontinuous epitopes in their interaction with their cognate antibody. RESULTS: We have developed an improved version of PEPOP (PEPOP 2.0) dedicated to answer to experimentalists' need for a tool able to handle proteins and to turn them into peptides. The PEPOP 2.0 web site has been reorganized by peptide prediction category and is therefore better formulated to experimental designs. Since the first version of PEPOP, 32 new methods of peptide design were developed. In total, PEPOP 2.0 proposes 35 methods in which 34 deal specifically with discontinuous epitopes, the most represented epitope type in nature. CONCLUSION: Through the presentation of its user-friendly, well-structured new web site conceived in close proximity to experimentalists, we report original methods that show how PEPOP 2.0 can assist biologists in dealing with discontinuous epitopes.


Assuntos
Biologia Computacional/métodos , Epitopos/metabolismo , Software , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Epitopos/química , Soros Imunes , Internet , Camundongos , Peptídeos/sangue , Peptídeos/química , Peptídeos/imunologia , Domínios Proteicos , Proteínas/química
4.
Microb Pathog ; 135: 103614, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31255726

RESUMO

Helicobacter pylori is an important etiological factor involved in chronic gastritis, peptic ulcer, and gastric cancer. There are currently no optimal preventive or therapeutic interventions for H. pylori infection. H. pylori survives in the stomach by sensing and adapting to the highly acidic environment by using the two-component signal transduction system that contains the most widely known gastric acid receptor, ArsRS (which is composed of ArsS and ArsR). This study aimed to identify peptides that antagonize the acid-sensing domain of H. pylori ArsS. These peptides could be used to block the acid-sensing signal and thereby hinder H. pylori adaption to acidic environments to prevent its survival. Using proSite, the functional domains (including the N-terminal acid-sensing domain) of H. pylori J99 ArsS were predicted. The purified recombinant ArsS N-terminal acid-sensing protein (P-ArsS-A) was used as the target in a panning protocol in which peptides from the Ph.D.-7 Phage Display Peptide Library that could bind to P-ArsS-A were identified. As a result, eight phage clones that could specifically bind to P-ArsS-A were obtained and five amino acid sequences were identified, including P03 (MMSYPKH) and P06 (LTPMPNW). An in vitro minimum inhibitory concentration (MIC) evaluation showed that P03 and P06 significantly inhibited the growth of H. pylori J99. The MIC of P03 was 8 µM, and the MIC of P06 was >16 µM, indicating that P03 is a stronger inhibitor compared to P06. This was confirmed by colony counting on blood agar plates after P03 and P06 administration. Using homology modeling and molecular docking analysis, it was shown that P03 and P06 could bind to the ArsS N-terminal domain, and there were four shared binding sites: TYR25, ASN39, ARG73, and GLU74. Additionally, one hydrogen bond was found between P03 and ArsS, which is more cohesive than other forms of bonding (van der Waals force, other non-covalent bonds).


Assuntos
Proteínas de Bactérias/metabolismo , Bacteriófagos/fisiologia , Helicobacter pylori/metabolismo , Biblioteca de Peptídeos , Peptídeos/isolamento & purificação , Ácidos , Proteínas de Bactérias/genética , Sítios de Ligação , Regulação Bacteriana da Expressão Gênica , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Peptídeos/imunologia , Proteínas Recombinantes , Transdução de Sinais/fisiologia
5.
Comp Immunol Microbiol Infect Dis ; 65: 137-143, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31300103

RESUMO

HisAK70 candidates have successfully been tested in cutaneous (CL) and visceral leishmaniosis (VL) mouse models. Here, we analyse different biomarkers in dog trials after a heterologous immunization strategy with a HisAK70 candidate (plasmid DNA plus adoptive transfer of peripheral blood-derived dendritic cells (DCs) pulsed with the same pathoantigen and CpG ODN as an adjuvant) to explore the antileishmanial activity in an ex vivo canine co-culture system in the presence of Leishmania infantum parasites. In the canine model, the heterologous HisAK70 vaccine could decrease the infection index in the DC-T cell co-culture system by up to 54% after 30 days and reach almost 67% after 100 days post-immunization, respectively, compared to those obtained in the control group of dogs. The observed security and potential to fight ex vivo L. infantum infection highlight a HisAK70 heterologous immunization strategy as a promising alternative to evaluate its effectiveness against canine VL.


Assuntos
Leishmania infantum/imunologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Visceral/veterinária , Vacinas de DNA/imunologia , Adjuvantes Imunológicos , Transferência Adotiva , Animais , Antígenos de Protozoários/imunologia , Biomarcadores/sangue , Técnicas de Cocultura , Células Dendríticas/imunologia , Modelos Animais de Doenças , Cães , Feminino , Leishmaniose Visceral/prevenção & controle , Masculino , Peptídeos/genética , Peptídeos/imunologia , Plasmídeos/genética , Plasmídeos/imunologia , Linfócitos T/imunologia , Células Th1/imunologia
6.
Comp Immunol Microbiol Infect Dis ; 65: 238-245, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31300121

RESUMO

Japanese encephalitis virus (JEV) and West Nile virus (WNV) are two major mosquito borne flaviviruses belonging to same serocomplex. JEV is transmitted by Culex mosquitoes and the reservoir host for the virus is pigs and/or water birds. WNV is also transmitted by Culex mosquitoes and reservoir host in this case is birds. It can also be transmitted through contact with other infected animals, their blood, or other tissues. The envelope protein of these viruses is the major source of epitopes and provides protective immunity. Bioinformatics tools were used to identify conserved epitopes in the envelope protein of these viruses. A conserved peptide "TPVGRLVTVNPFV" present in both the viruses containing predicted T and B cell epitopes was found. The model of one of the predicted epitope was generated and upon docking it bound in the groove of HLA-A0201 Class I MHC molecule. Further, it was amenable to proteasomal cleavage enhancing its chances of processing by cytosolic pathway. The peptide was found to be non toxic, non allergenic and stable in mammalian cells based on database search. The population coverage was pan world and nearly 70% identity of the peptide was found in the Zika virus envelope protein. The peptide was located in the domain III of envelope protein which is the exposed domain therefore B cell receptors may recognize this peptide easily. The conserved peptide containing T and B cell epitopes can have future application for designing epitope based vaccines for both JEV and WNV.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Mapeamento de Epitopos , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Proteínas do Envelope Viral/imunologia , Vírus do Nilo Ocidental , Biologia Computacional , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Simulação de Acoplamento Molecular , Peptídeos/imunologia , Ligação Proteica , Proteínas do Envelope Viral/genética , Vacinas Virais/imunologia
7.
Cancer Immunol Immunother ; 68(8): 1245-1261, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31222486

RESUMO

The efficacy of cancer immunotherapy, including treatment with immune-checkpoint inhibitors, often is limited by ineffective presentation of antigenic peptides that elicit T-cell-mediated anti-tumor cytotoxic responses. Manipulation of antigen presentation pathways is an emerging approach for enhancing the immunogenicity of tumors in immunotherapy settings. ER aminopeptidase 1 (ERAP1) is an intracellular enzyme that trims peptides as part of the system that generates peptides for binding to MHC class I molecules (MHC-I). We hypothesized that pharmacological inhibition of ERAP1 in cells could regulate the cellular immunopeptidome. To test this hypothesis, we treated A375 melanoma cells with a recently developed potent ERAP1 inhibitor and analyzed the presented MHC-I peptide repertoire by isolating MHC-I, eluting bound peptides, and identifying them using capillary chromatography and tandem mass spectrometry (LC-MS/MS). Although the inhibitor did not reduce cell-surface MHC-I expression, it induced qualitative and quantitative changes in the presented peptidomes. Specifically, inhibitor treatment altered presentation of about half of the total 3204 identified peptides, including about one third of the peptides predicted to bind tightly to MHC-I. Inhibitor treatment altered the length distribution of eluted peptides without change in the basic binding motifs. Surprisingly, inhibitor treatment enhanced the average predicted MHC-I binding affinity, by reducing presentation of sub-optimal long peptides and increasing presentation of many high-affinity 9-12mers, suggesting that baseline ERAP1 activity in this cell line is destructive for many potential epitopes. Our results suggest that chemical inhibition of ERAP1 may be a viable approach for manipulating the immunopeptidome of cancer.


Assuntos
Aminopeptidases/metabolismo , Antígenos de Neoplasias/metabolismo , Antineoplásicos/farmacologia , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/metabolismo , Imunoterapia/métodos , Melanoma/tratamento farmacológico , Antígenos de Histocompatibilidade Menor/metabolismo , Peptídeos/metabolismo , Inibidores de Proteases/farmacologia , Linfócitos T Citotóxicos/imunologia , Aminopeptidases/antagonistas & inibidores , Apresentação do Antígeno , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imunogenicidade da Vacina , Ativação Linfocitária , Terapia de Alvo Molecular , Peptídeos/genética , Peptídeos/imunologia , Ligação Proteica
8.
Mol Immunol ; 112: 274-282, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31226552

RESUMO

The viral peptides presentation by major histocompatibility complex class I (MHC I) molecules play a pivotal role in T-cell recognition and the subsequent virus clearance. This process is delicately adjusted by the variant residues of MHC I, especially the residues in the peptide binding groove (PBG). In a series of MHC I molecules, a salt bridge is formed above the N-terminus of the peptides. However, the potential impact of the salt bridge on peptide binding and T-cell receptor (TCR) recognition of MHC I, as well as the corresponding molecular basis, are still largely unknown. Herein, we determined the structures of HLA-B*4001 and H-2Kd in which two different types of salt bridges (Arg62-Glu163 or Arg66-Glu163) across the PBG were observed. Although the two salt bridges led to different conformation shifts of both the MHC I α helix and the peptides, binding of the peptides with the salt bridge residues was relatively conserved. Furthermore, through a series of in vitro and in vivo investigations, we found that MHC I mutations that disrupt the salt bridge alleviate peptide binding and can weaken the TCR recognition of MHC I-peptide complexes. Our study may provide key references for understanding MHC I-restricted peptide recognition by T-cells.


Assuntos
Apresentação do Antígeno/imunologia , Genes MHC Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Peptídeos/imunologia , Ligação Proteica/imunologia , Linfócitos T/imunologia , Animais , Sítios de Ligação/imunologia , Feminino , Antígenos HLA-B/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Conformação Proteica , Receptores de Antígenos de Linfócitos T/imunologia
9.
Cancer Sci ; 110(8): 2386-2395, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31206934

RESUMO

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer by providing new options in addition to existing therapies. However, peptide vaccination therapies still represent an attractive approach, because of the antigen specificity. We identified survivin 2B peptide (SVN-2B), a 9-mer antigenic peptide encoded by survivin, and an SVN-2B peptide vaccine-based phase II randomized clinical trial targeting unresectable and refractory pancreatic carcinoma was undertaken. The SVN-2B peptide vaccine did not have any statistically significant clinical benefits in that study. Therefore, we undertook an autopsy study to analyze the immune status of the pancreatic cancer lesions at the histological level. Autopsies were carried out in 13 patients who had died of pancreatic cancer, including 7 who had received SVN-2B peptide vaccination and 6 who had not, as negative controls. The expression of immune-related molecules was analyzed by immunohistochemical staining. Cytotoxic T lymphocytes were analyzed by tetramer staining and enzyme-linked immunospot assay. Histological analysis revealed dense infiltration of CD8+ T cells in some lesions in patients who had received the SVN-2B peptide vaccine. A high rate of programmed cell death ligand 1 expression in cancer cells was observed in these cases, indicating that CTLs were induced by SVN-2B peptide vaccination and had infiltrated the lesions. The lack of a significant antitumor effect was most likely attributable to the expression of immune checkpoint molecules. These findings suggest that the combination of a tumor-specific peptide vaccine and an ICI might be a promising approach to the treatment of pancreatic carcinoma in the future.


Assuntos
Vacinas Anticâncer/imunologia , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/terapia , Peptídeos/imunologia , Survivina/imunologia , Adulto , Idoso , Antígenos de Neoplasias/imunologia , Autopsia/métodos , Linfócitos T CD8-Positivos/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linfócitos T Citotóxicos/imunologia , Vacinação/métodos
10.
Virol J ; 16(1): 75, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159841

RESUMO

Porcine parvovirus (PPV) is a DNA virus that causes reproductive failure in gilts and sows, resulting in embryonic and fetal losses worldwide. Epitope mapping of PPV is important for developing new vaccines. In this study, we used spot synthesis analysis for epitope mapping of the capsid proteins of PPV (NADL-2 strain) and correlated the findings with predictive data from immunoinformatics. The virus was exposed to three conditions prior to inoculation in pigs: native (untreated), high hydrostatic pressure (350 MPa for 1 h) at room temperature and high hydrostatic pressure (350 MPa for 1 h) at - 18 °C, and was compared with a commercial vaccine produced using inactivated PPV. The screening of serum samples detected 44 positive spots corresponding to 20 antigenic sites. Each type of inoculated antigen elicited a distinct epitope set. In silico prediction located linear and discontinuous epitopes in B cells that coincided with several epitopes detected in spot synthesis of sera from pigs that received different preparations of inoculum. The conditions tested elicited antibodies against the VP1/VP2 antigen that differed in relation to the response time and the profile of structurally available regions that were recognized.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Epitopos/imunologia , Parvovirus Suíno/imunologia , Animais , Antígenos Virais/química , Mapeamento de Epitopos , Epitopos/química , Masculino , Testes de Neutralização , Peptídeos/genética , Peptídeos/imunologia , Suínos
11.
Oncology ; 97(3): 135-148, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31216557

RESUMO

BACKGROUND: We have developed a Wilms' tumor 1 (WT1)-targeting dendritic cell (DC)-based cancer vaccine combined with standard chemotherapy for patients with advanced pancreatic ductal adenocarcinoma (PDA). METHODS: We evaluated predictive markers of overall survival (OS) in PDA patients treated with multiple major histocompatibility complex class I/II-restricted, WT1 peptide-pulsed DC vaccinations (DC/WT1-I/II) in combination with chemotherapy. Throughout the entire period of immunochemotherapy, the plasma levels of soluble factors derived from granulocytes of 7 eligible PDA patients were examined. Moreover, systemic inflammatory response markers (neutrophil-to-lymphocyte ratio [NLR], monocyte-to-lymphocyte ratio [MLR], and granulocyte-to-lymphocyte ratio [GLR]) were assessed. In addition, cytoplasmic WT1 expression in PDA cells was examined. RESULTS: Compared to the 4 non-super-responders (OS <1 year), the remaining 3 super-responders (OS ≥1 year) showed significantly decreased low plasma matrix metalloproteinase-9 levels throughout long-term therapy. The NLR, MLR, and GLR after 5 DC/WT1-I/II vaccinations and 3 cycles of gemcitabine were significantly lower in the super-responders than in the non-super-responders. Furthermore, the cytoplasmic WT1 expression in the PDA cells of super-responders was relatively weak compared to that in the PDA cells of non-super-responders. CONCLUSIONS: Prolonged low levels of a granulocyte-related systemic inflammatory response after the early period of therapy and low cytoplasmic WT1 expression in PDA cells may be markers predictive of OS in PDA patients receiving WT1-targeting immunochemotherapy.


Assuntos
Biomarcadores Tumorais , Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Imunoterapia , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/mortalidade , Proteínas WT1/imunologia , Biomarcadores , Vacinas Anticâncer/administração & dosagem , Terapia Combinada , Células Dendríticas/metabolismo , Epitopos/imunologia , Feminino , Humanos , Imunofenotipagem , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/terapia , Peptídeos/imunologia , Peroxidase/metabolismo , Prognóstico , Fator de Crescimento Transformador beta1/metabolismo , Resultado do Tratamento , Vacinação , Proteínas WT1/genética
12.
Fish Shellfish Immunol ; 92: 322-330, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31200071

RESUMO

The development of vaccines employing conserved protein antigens, for instance ribosomal protein P0, has as disadvantage the high degree of identity between pathogen and host proteins due to possible induction of tolerance or auto antibodies in the host organism. To overcome this drawback, peptide-based vaccines have been designed with a proved high efficacy. The use of defined peptides as antigens has the problem that they are generally poor immunogenic unless coupled to a carrier protein. Several studies have established the potential for promiscuous T cell epitopes incorporated into chimeric peptides to enhance the immunogenicity in mammals. On the contrary, studies about the role of these epitopes on teleost immune system are scarce. Therefore, the main objective of our present study was to evaluate the potential of promiscuous T cell epitopes to boost specific IgM immune response in teleost fish against a peptide antigen. With this aim, we used a peptide of 35 amino acids from the ribosomal P0 protein of Lepeophtheirus salmonis, an important parasite in salmon aquaculture. We fused this peptide to the C-terminal of T cell epitopes from tetanus toxin and measles virus and produced the chimeric protein in Escherichia coli. Following vaccination, IgM antibody production was monitored in different immunization schemes in Tilapia, African catfish and Atlantic salmon. The results demonstrated for first time that the addition of T cell epitopes at the N-terminal of a target peptide increased IgM specific response in different teleost species, revealing the potential of this approach to develop peptide-based vaccines for aquaculture. The results are also of great importance in the context of vaccine development against sea lice using ribosomal protein P0 as antigen taking into account the key role of P0 in protein synthesis and other essential physiological processes.


Assuntos
Copépodes/imunologia , Ectoparasitoses/veterinária , Epitopos de Linfócito T/imunologia , Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Imunoglobulina M/imunologia , Animais , Proteínas de Artrópodes/imunologia , Peixes-Gato/imunologia , Ciclídeos/imunologia , Ectoparasitoses/imunologia , Peptídeos/imunologia , Proteínas Ribossômicas/imunologia , Salmo salar/imunologia , Vacinas de Subunidades/imunologia
13.
Nat Commun ; 10(1): 2730, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227691

RESUMO

Recently our groups discovered lugdunin, a new cyclic peptide antibiotic that inhibits Staphylococcus aureus epithelial colonization in humans and rodents. In this work, we analyzed its immuno-modulatory and antimicrobial potential as a single agent or in combination with other microbiota- or host-derived factors. We show that pretreatment of primary human keratinocytes or mouse skin with lugdunin in combination with microbiota-derived factors results in a significant reduction of S. aureus colonization. Moreover, lugdunin increases expression and release of LL-37 and CXCL8/MIP-2 in human keratinocytes and mouse skin, and results in the recruitment of monocytes and neutrophils in vivo, both by a TLR/MyD88-dependent mechanism. Interestingly, S. aureus elimination by lugdunin is additionally achieved by synergistic antimicrobial activity with LL-37 and dermcidin-derived peptides. In summary, our results indicate that lugdunin provides multi-level protection against S. aureus and may thus become a promising treatment option for S. aureus skin infections in the future.


Assuntos
Antibacterianos/farmacologia , Imunidade Inata/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Tiazolidinas/farmacologia , Animais , Antibacterianos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/imunologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/imunologia , Queratinócitos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microbiota/efeitos dos fármacos , Microbiota/imunologia , Peptídeos/imunologia , Peptídeos Cíclicos/uso terapêutico , Cultura Primária de Células , Pele/efeitos dos fármacos , Pele/imunologia , Pele/microbiologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Tiazolidinas/uso terapêutico
14.
Nat Commun ; 10(1): 2150, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31089130

RESUMO

Peptide-major histocompatibility complex class II (pMHCII)-based nanomedicines displaying tissue-specific autoantigenic epitopes can blunt specific autoimmune conditions by re-programming cognate antigen-experienced CD4+ T-cells into disease-suppressing T-regulatory type 1 (TR1) cells. Here, we show that single pMHCII-based nanomedicines displaying epitopes from mitochondrial, endoplasmic reticulum or cytoplasmic antigens associated with primary biliary cholangitis (PBC) or autoimmune hepatitis (AIH) can broadly blunt PBC, AIH and Primary Sclerosing Cholangitis in various murine models in an organ- rather than disease-specific manner, without suppressing general or local immunity against infection or metastatic tumors. Therapeutic activity is associated with cognate TR1 cell formation and expansion, TR1 cell recruitment to the liver and draining lymph nodes, local B-regulatory cell formation and profound suppression of the pro-inflammatory capacity of liver and liver-proximal myeloid dendritic cells and Kupffer cells. Thus, autoreactivity against liver-enriched autoantigens in liver autoimmunity is not disease-specific and can be harnessed to treat various liver autoimmune diseases broadly.


Assuntos
Doenças Autoimunes/tratamento farmacológico , Antígenos de Histocompatibilidade Classe II/imunologia , Hepatopatias/tratamento farmacológico , Nanopartículas/administração & dosagem , Peptídeos/administração & dosagem , Idoso , Animais , Autoantígenos/imunologia , Doenças Autoimunes/imunologia , Linhagem Celular , Modelos Animais de Doenças , Epitopos/imunologia , Feminino , Antígenos de Histocompatibilidade Classe II/química , Humanos , Fígado/efeitos dos fármacos , Fígado/imunologia , Hepatopatias/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Nanomedicina/métodos , Nanopartículas/química , Peptídeos/química , Peptídeos/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia
15.
Parasit Vectors ; 12(1): 233, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31092283

RESUMO

BACKGROUND: Cryptosporidium parvum is a major cause of diarrhea in children and ruminants at the earliest stages of life. Maternal antibodies represent the main shield of neonate mammals for most of the infections. Two recombinant antigens (SA35 and SA40), portions of two C. parvum proteins, were tested for their ability to induce immune responses in adult mice and for protection on neonate BALB/c mice born from females immunised by mucosal delivery of both peptides. METHODS: Adult BALB/c mice were intraperitoneally immunised with SA35 and SA40, separately or mixed, and their immune response was characterised. Furthermore, BALB/c pregnant mice were immunised by mucosal delivery with an SA35/40 mix, before and during pregnancy. Soon after birth, their offspring were infected with two doses (1 × 105 and 5 × 103) of C. parvum oocysts and the parasitic burden was determined at 5 and 9 days post-infection. RESULTS: Intraperitoneal immunisation with SA35 and SA40 induced specific IgG and IgG1 in serum, specific IgA in the intestinal mucosa, increase of CD3+/CD4+ and CD30+ cells in splenocytes, which produced IFN-γ. Neonates born from immunised mice and infected with 1 × 105 oocysts showed a significant reduction of oocysts and intestinal forms (23 and 42%, respectively). A reduction of all parasitic forms (96%; P < 0.05) was observed when neonates were infected with 5 × 103 oocysts. CONCLUSIONS: SA35 and SA40 peptides induce specific humoral and cell-mediated immune responses to C. parvum in adult mice. Moreover, mucosal administration of the SA35/40 mix in pregnant mice reduces C. parvum burden in their litters.


Assuntos
Criptosporidiose/prevenção & controle , Imunidade Celular , Imunidade Humoral , Peptídeos/imunologia , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Criptosporidiose/imunologia , Cryptosporidium parvum , Feminino , Imunidade Materno-Adquirida , Imunização , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Mucosa Intestinal/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Oócitos/imunologia , Peptídeos/genética , Gravidez , Proteínas de Protozoários/genética
16.
Int J Mol Sci ; 20(10)2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-31130605

RESUMO

An understanding of the interaction between the antibody and its targeted antigen and knowing of the epitopes are critical for the development of monoclonal antibody drugs. Complement factor H (CFH) is implied to play a role in tumor growth and metastasis. An autoantibody to CHF is associated with anti-tumor cell activity. The interaction of a human monoclonal antibody Ab42 that was isolated from a cancer patient with CFH polypeptide (pCFH) antigen was analyzed by molecular docking, molecular dynamics (MD) simulation, free energy calculation, and computational alanine scanning (CAS). Experimental alanine scanning (EAS) was then carried out to verify the results of the theoretical calculation. Our results demonstrated that the Ab42 antibody interacts with pCFH by hydrogen bonds through the Tyr315, Ser100, Gly33, and Tyr53 residues on the complementarity-determining regions (CDRs), respectively, with the amino acid residues of Pro441, Ile442, Asp443, Asn444, Ile447, and Thr448 on the pCFH antigen. In conclusion, this study has explored the mechanism of interaction between Ab42 antibody and its targeted antigen by both theoretical and experimental analysis. Our results have important theoretical significance for the design and development of relevant antibody drugs.


Assuntos
Anticorpos Monoclonais/imunologia , Peptídeos/imunologia , Anticorpos Monoclonais/química , Reações Antígeno-Anticorpo , Autoanticorpos/química , Autoanticorpos/imunologia , Fator H do Complemento/química , Fator H do Complemento/imunologia , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/imunologia , Epitopos/química , Epitopos/imunologia , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Neoplasias/imunologia , Peptídeos/química , Conformação Proteica
17.
Acta Trop ; 196: 1-6, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31059707

RESUMO

Toxoplasmosis is a disease caused by Toxoplasma gondii, an intracellular protozoan able to infect a wide range of hosts. The infection is particularly severe in immunocompromised patients or during pregnancy, circumstances in which the parasite could find a more favorable microenvironment to replicate and invade host tissues. The current treatment consists in toxic drugs for the patients, being not appropriate for the fetuses and immunodeficient patients. So far, there is a lack of available vaccine to prevent the disease. The present study aimed to evaluate the immune response induced by peptides derived from parasite immunodominant proteins from key components, as surface, rhoptry, microneme and dense granule antigens. A panel of eleven peptides was selected considering the highest scores for B cell epitope prediction by in silico analyses. The peptides were divided in groups, according to the parasite organelle locations, and used to immunize C57BL/6 mice. The animals were submitted to three doses of immunization and infected by 10 cysts of T. gondii ME49 strain. Blood samples were collected and used to measure the production of antibodies and cytokines, while the brains were collected to determine the parasite burden by quantitative polymerase chain reaction (qPCR). It was found that synthetic peptides from all targets were able to induce IgG synthesis in immunized mice, as well as to modulate the Th1/Th2 cytokine production, particularly the MIC and SRS groups, which presented the IFN-γ/IL-10 and TNF-α/IL-10 ratios 30 and 10 times higher, respectively, when compared with non-immunized group. Interestingly, the animals from MIC and SRS groups had significantly lower levels of T. gondii DNA in their brains. In summary, it can be concluded that peptides mainly from SRS and MIC parasite components constitute relevant targets to design vaccine candidates against parasite burden observed during chronic toxoplasmosis.


Assuntos
Encéfalo/parasitologia , Epitopos Imunodominantes/imunologia , Vacinas Protozoárias/imunologia , Toxoplasma/imunologia , Toxoplasmose Animal/prevenção & controle , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Encéfalo/imunologia , Citocinas/metabolismo , Epitopos de Linfócito B/imunologia , Feminino , Imunização , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/imunologia , Proteínas de Protozoários/genética
18.
Int J Mol Sci ; 20(9)2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-31035335

RESUMO

The purpose of this paper was to outline the development of short peptide targeting of the human prostate specific antigen (hPSA), and to evaluate its effectiveness in staining PSA in human prostate cancer tissue. The targeting of the hPSA antigen by means of antisense peptide AVRDKVG was designed according to a three-step method involving: 1. The selection of the molecular target (hPSA epitope), 2. the modeling of an antisense peptide (paratope) based on the epitope sequence, and 3. the spectroscopic evaluation of sense-antisense peptide binding. We then modified standard hPSA immunohistochemical staining practice by using a biotinylated antisense peptide instead of the standard monoclonal antibody and compared the results of both procedures. Immunochemical testing on human tissue showed the applicability of the antisense peptide technology to human molecular targets. This methodology represents a new approach to deriving peptide ligands and potential lead compounds for the development of novel diagnostic substances, biopharmaceuticals and vaccines.


Assuntos
Biomarcadores Tumorais/imunologia , Peptídeos/imunologia , Antígeno Prostático Específico/imunologia , Neoplasias da Próstata/imunologia , Humanos , Imuno-Histoquímica , Masculino , Nanomedicina/métodos , Estrutura Secundária de Proteína
19.
Int J Mol Sci ; 20(9)2019 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-31060324

RESUMO

Antigen peptides and adjuvants have been extensively investigated for cancer immunotherapy, and they are expected to elicit specific immune responses for cancer treatment. However, the anti-cancer efficacy of antigen peptide and adjuvant-based cancer vaccines has been limited due to the inefficient delivery to draining lymph nodes after administration. Therefore, it is necessary to develop a suitable delivery system to transport antigen peptides and adjuvants. Here, we report a novel type of nanostructured lipovaccines for the treatment of melanoma by delivering antigen peptide (SL9) and oligodeoxynucleotide adjuvant (CpG) to the lymphatic vessels and to the draining lymph node. The SL9-CpG lipovaccines were characterized using dynamic laser scattering (DLS) and transmission electron microscopy (TEM). The lymph uptake, immune response elicitation and treatment effects were evaluated on melanoma-bearing C57BL/6 mice using flow cytometry (FCM), enzyme-linked immunosorbent assay (ELISA) and tumor inhibitory efficacy. The SL9-CpG lipovaccines were uniform with a nanoscale size (~70 nm), had high encapsulation efficiency, and exhibited effective lymph uptake, resulting in activation of specific cytotoxic CD8+ T cells, and release of IFN-γ, and a robust inhibition of tumor growth. Therefore, the nanostructured SL9-CpG lipovaccines offer a promising strategy for melanoma treatment.


Assuntos
Vacinas Anticâncer/imunologia , Glicina/análogos & derivados , Imunomodulação , Melanoma/imunologia , Melanoma/terapia , Peptídeos/imunologia , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Glicina/química , Glicina/imunologia , Humanos , Imunoterapia , Linfonodos/imunologia , Melanoma/metabolismo , Camundongos , Peptídeos/química , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Parasitol Res ; 118(7): 2263-2270, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31089811

RESUMO

Current diagnostic tools to determine infection with the helminth parasite Onchocerca volvulus have limited performance characteristics. In previous studies, a proteome-wide screen was conducted to identify linear epitopes in this parasite's proteome, resulting in the discovery of 1110 antigenic peptide fragments. Here, we investigated three of these peptides using peptide ELISA's and evaluated their sensitivity and specificity. Epitope mapping was performed, and peptides were constructed that contained only the minimal epitope, flanked by a linker. Investigation of the performance of these minimal epitope peptides demonstrated that all three of them have a specificity (as defined by lack of response in non-helminth-infected individuals) of 100%, low cross-reactivity (5.6%, 5.6%, and 9.3%, respectively), but low sensitivity (36.9%, 46.5%, and 41.2%, respectively). Some cross-reactivity was observed in samples from individuals infected with soil-transmitted helminths or Brugia malayi. Combining these three minimal epitopes in a single peptide, called OvNMP-48, resulted in a performance that exceeded the sum of the individual epitopes, with a sensitivity of 76.0%, a specificity of 97.4%, and a cross-reactivity of 11.1%. Cross-reactivity was observed in some STH and Brugia malayi-infected individuals. This work opens the opportunity to start exploring how these novel linear epitope markers might become part of the O. volvulus diagnostic toolbox.


Assuntos
Antígenos de Helmintos/imunologia , Epitopos/imunologia , Filariose/diagnóstico , Onchocerca volvulus/imunologia , Oncocercose/diagnóstico , Peptídeos/imunologia , Adulto , Idoso , Animais , Brugia Malayi/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Mapeamento de Epitopos , Feminino , Filariose/parasitologia , Humanos , Masculino , Pessoa de Meia-Idade , Oncocercose/parasitologia , Proteoma , Sensibilidade e Especificidade , Testes Sorológicos , Adulto Jovem
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