scholarly journals Peptides derived from gp43, the most antigenic protein from Paracoccidioides brasiliensis, form amyloid fibrils in vitro: implications for vaccine development

2021 ◽  
Author(s):  
Thyago R Cardim-Pires ◽  
Sant'Anna Ricardo ◽  
Debora Foguel
Keyword(s):  
In Silico ◽  
Mononuclear Cells ◽  
Vaccine Development ◽  
Paracoccidioides Brasiliensis ◽  
Public Health Problem ◽  
Proteinase K ◽  
Important Public Health Problem ◽  
Peripheral Blood Mononuclear ◽  
Potential Vaccine

Fungal infection is an important public health problem afflicting more than a billion people worldwide. Mycoses are especially important in Latin America, and in Brazil in particular. Paracoccidioides is the genus of fungi responsible for paracoccidioidomycosis comprising two species, P. brasiliensis and P. lutzii. The lungs are the primary infection site, but oral mucosa and airways can also be affected. The glycoprotein gp43 is involved in fungi adhesion to epithelial cells and is the most studied protein of P. brasiliensis. Seminal work identified a specific stretch of 15 amino acids that spans the region 181-195 (called P10) as an important epitope of gp43, being recognized by T lymphocytes in peripheral blood mononuclear cells of mice and humans and is envisioned as a potential vaccine component. Here, we show by using thioflavin T (ThT), transmission electron microscopy and other methods that synthetic P10 forms typical amyloid aggregates in solution in very short times, a property that could hamper vaccine development. In silico, aggregation analysis reveals several aggregation-prone regions (APR) in the P10 sequence that are capable of forming amyloid cores with steric zipper architecture. Seeds of P10 obtained by fibril mechanical fragmentation were able to induce the aggregation of P4 but not P23, as evidenced by ThT binding and mass spectrometry. These two peptides, also derived from gp43, are potent modulators of local and systemic inflammation. In-silico proteolysis studies with gp43 revealed that aggregation-prone, P10-like peptides could be generated by the action of several proteases such as proteinase K, trypsin and pepsin, which suggests that P10 could be formed upon gp43 digestion in a physiological condition. Considering our data in the context of a potential vaccine development, we redesigned the sequence of the P10 peptide, maintaining the antigenic region (HTLAIR), but drastically reducing its aggregation propensity.

scholarly journals Peptides derived from gp43, the most antigenic protein from Paracoccidioides brasiliensis, form amyloid fibrils in vitro: implications for vaccine development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thyago R. Cardim-Pires ◽  
Ricardo Sant’Anna ◽  
Debora Foguel
Keyword(s):  
In Silico ◽  
Amyloid Fibrils ◽  
Vaccine Development ◽  
Paracoccidioides Brasiliensis ◽  
In Silico Analysis ◽  
Antigenic Protein ◽  
Amyloid Aggregates ◽  
Important Health ◽  
Potential Vaccine

AbstractFungal infection is an important health problem in Latin America, and in Brazil in particular. Paracoccidioides (mainly P. brasiliensis and P. lutzii) is responsible for paracoccidioidomycosis, a disease that affects mainly the lungs. The glycoprotein gp43 is involved in fungi adhesion to epithelial cells, which makes this protein an interesting target of study. A specific stretch of 15 amino acids that spans the region 181–195 (named P10) of gp43 is an important epitope of gp43 that is being envisioned as a vaccine candidate. Here we show that synthetic P10 forms typical amyloid aggregates in solution in very short times, a property that could hamper vaccine development. Seeds obtained by fragmentation of P10 fibrils were able to induce the aggregation of P4, but not P23, two other peptides derived from gp43. In silico analysis revealed several regions within the P10 sequence that can form amyloid with steric zipper architecture. Besides, in-silico proteolysis studies with gp43 revealed that aggregation-prone, P10-like peptides could be generated by several proteases, which suggests that P10 could be formed under physiological conditions. Considering our data in the context of a potential vaccine development, we redesigned the sequence of P10, maintaining the antigenic region (HTLAIR), but drastically reducing its aggregation propensity.

scholarly journals Peptides derived from gp43, the most antigenic protein from Paracoccidioides brasiliensis, form amyloid fibrils in vitro: implications for vaccine development

2021 ◽  
Author(s):  
Thyago R. Cardim-Pires ◽  
Ricardo Sant’Anna ◽  
Debora Foguel
Keyword(s):  
In Silico ◽  
Amyloid Fibrils ◽  
Vaccine Development ◽  
Paracoccidioides Brasiliensis ◽  
In Silico Analysis ◽  
Antigenic Protein ◽  
Amyloid Aggregates ◽  
Important Health ◽  
Potential Vaccine

Abstract Fungal infection is an important health problem in Latin America, and in Brazil in particular. Paracoccidioides (P. brasiliensis and P. lutzii) is responsible for paracoccidioidomycosis, a disease that affects mainly the lungs. The glycoprotein gp43 is involved in fungi adhesion to epithelial cells, which makes this protein an interesting target of study. A specific stretch of 15 amino acids that spans the region 181-195 (named P10) of gp43 is an important epitope of gp43 that is being envisioned as a vaccine candidate. Here we show that synthetic P10 forms typical amyloid aggregates in solution in very short times, a property that could hamper vaccine development. Seeds obtained by fragmentation of P10 fibrils were able to induce the aggregation of P4, but not P23, two other peptides derived from gp43. In silico analysis revealed several regions within the P10 sequence that are capable of forming amyloid with steric zipper architecture. Besides, in-silico proteolysis studies with gp43 revealed that aggregation-prone, P10-like peptides could be generated by several proteases, which suggests that P10 could be formed under physiological conditions. Considering our data in the context of a potential vaccine development, we redesigned the sequence of P10, maintaining the antigenic region (HTLAIR), but drastically reducing its aggregation propensity.

scholarly journals Novel Immunodominant Peptide Presentation Strategy: a Featured HLA-A*2402-Restricted Cytotoxic T-Lymphocyte Epitope Stabilized by Intrachain Hydrogen Bonds from Severe Acute Respiratory Syndrome Coronavirus Nucleocapsid Protein

2010 ◽  
Vol 84 (22) ◽  
pp. 11849-11857 ◽  
Author(s):  
Jun Liu ◽  
Peng Wu ◽  
Feng Gao ◽  
Jianxun Qi ◽  
Ai Kawana-Tachikawa ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Hydrogen Bonds ◽  
Mononuclear Cells ◽  
Vaccine Development ◽  
Computer Assisted ◽  
Antigenic Peptides ◽  
Peripheral Blood Mononuclear ◽  
Presentation Strategy ◽  
Peptide Presentation

ABSTRACT Antigenic peptides recognized by virus-specific cytotoxic T lymphocytes (CTLs) are presented by major histocompatibility complex (MHC; or human leukocyte antigen [HLA] in humans) molecules, and the peptide selection and presentation strategy of the host has been studied to guide our understanding of cellular immunity and vaccine development. Here, a severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid (N) protein-derived CTL epitope, N1 (QFKDNVILL), restricted by HLA-A*2402 was identified by a series of in vitro studies, including a computer-assisted algorithm for prediction, stabilization of the peptide by co-refolding with HLA-A*2402 heavy chain and β2-microglobulin (β2m), and T2-A24 cell binding. Consequently, the antigenicity of the peptide was confirmed by enzyme-linked immunospot (ELISPOT), proliferation assays, and HLA-peptide complex tetramer staining using peripheral blood mononuclear cells (PBMCs) from donors who had recovered from SARS donors. Furthermore, the crystal structure of HLA-A*2402 complexed with peptide N1 was determined, and the featured peptide was characterized with two unexpected intrachain hydrogen bonds which augment the central residues to bulge out of the binding groove. This may contribute to the T-cell receptor (TCR) interaction, showing a host immunodominant peptide presentation strategy. Meanwhile, a rapid and efficient strategy is presented for the determination of naturally presented CTL epitopes in the context of given HLA alleles of interest from long immunogenic overlapping peptides.

scholarly journals Leishmania spp Epitopes in Humans Naturally Resistant to the Disease: Working Toward a Synthetic Vaccine

2021 ◽  
Vol 11 ◽  
Author(s):  
Magda Melissa Flórez ◽  
Rocío Rodríguez ◽  
José Antonio Cabrera ◽  
Sara M. Robledo ◽  
Gabriela Delgado
Keyword(s):  
Immune Response ◽  
In Silico ◽  
Large Scale ◽  
Mononuclear Cells ◽  
Clinical Symptoms ◽  
Epitope Prediction ◽  
Effective Vaccine ◽  
Peripheral Blood Mononuclear

Vaccines are one of the most effective strategies to fight infectious diseases. Reverse vaccinology strategies provide tools to perform in silico screening and a rational selection of potential candidates on a large scale before reaching in vitro and in vivo evaluations. Leishmania infection in humans produces clinical symptoms in some individuals, while another part of the population is naturally resistant (asymptomatic course) to the disease, and therefore their immune response controls parasite replication. By the identification of epitopes directly in humans, especially in those resistant to the disease, the probabilities of designing an effective vaccine are higher. The aim of this work was the identification of Leishmania epitopes in resistant humans. To achieve that, 11 peptide sequences (from Leishmania antigenic proteins) were selected using epitope prediction tools, and then, peripheral blood mononuclear cells (PBMCs) were isolated from human volunteers who were previously divided into four clinical groups: susceptible, resistant, exposed and not exposed to the parasite. The induction of inflammatory cytokines and lymphoproliferation was assessed using monocyte-derived dendritic cells (moDCs) as antigen-presenting cells (APCs). The response was evaluated after exposing volunteers’ cells to each peptide. As a result, we learned that STI41 and STI46 peptides induced IL-8 and IL-12 in moDCs and lymphoproliferation and low levels of IL-10 in lymphocytes differentially in resistant volunteers, similar behavior to that observed in those individuals to L. panamensis lysate antigens. We conclude that, in silico analysis allowed for the identification of natural Leishmania epitopes in humans, and also STI41 and STI46 peptides could be epitopes that lead to a cellular immune response directed at parasite control.

scholarly journals EGFR-Targeted Pentacyclic Triterpene Analogues for Glioma Therapy

2021 ◽  
Vol 22 (20) ◽  
pp. 10945
Author(s):  
Halil I. Ciftci ◽  
Mohamed O. Radwan ◽  
Belgin Sever ◽  
Ahmed K. Hamdy ◽  
Safiye Emirdağ ◽  
...  
Keyword(s):  
In Silico ◽  
Mononuclear Cells ◽  
Survival Rates ◽  
Growth Factor Receptor ◽  
Antitumor Action ◽  
Central Nervous System Tumor ◽  
Pentacyclic Triterpene ◽  
Peripheral Blood Mononuclear ◽  
Ic50 Value

Glioma, particularly its most malignant form, glioblastoma multiforme (GBM), is the most common and aggressive malignant central nervous system tumor. The drawbacks of the current chemotherapy for GBM have aroused curiosity in the search for targeted therapies. Aberrantly overexpressed epidermal growth factor receptor (EGFR) in GBM results in poor prognosis, low survival rates, poor responses to therapy and recurrence, and therefore EGFR-targeted therapy stands out as a promising approach for the treatment of gliomas. In this context, a series of pentacyclic triterpene analogues were subjected to in vitro and in silico assays, which were conducted to assess their potency as EGFR-targeted anti-glioma agents. In particular, compound 10 was the most potent anti-glioma agent with an IC50 value of 5.82 µM towards U251 human glioblastoma cells. Taking into account its low cytotoxicity to peripheral blood mononuclear cells (PBMCs), compound 10 exerts selective antitumor action towards Jurkat human leukemic T-cells. This compound also induced apoptosis and inhibited EGFR with an IC50 value of 9.43 µM compared to erlotinib (IC50 = 0.06 µM). Based on in vitro and in silico data, compound 10 stands out as a potential orally bioavailable EGFR-targeted anti-glioma agent endowed with the ability to cross the blood–brain barrier (BBB).

scholarly journals A New Series of Indeno[1,2-c]pyrazoles as EGFR TK Inhibitors for NSCLC Therapy

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 485
Author(s):  
Ahmet Özdemir ◽  
Halilibrahim Ciftci ◽  
Belgin Sever ◽  
Hiroshi Tateishi ◽  
Masami Otsuka ◽  
...  
Keyword(s):  
In Silico ◽  
Mononuclear Cells ◽  
Kinase Inhibitor ◽  
Growth Factor Receptor ◽  
Antitumor Agent ◽  
In Vitro Assays ◽  
Antitumor Action ◽  
Peripheral Blood Mononuclear ◽  
Ic50 Value

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death throughout the world. Due to the shortcomings of traditional chemotherapy, targeted therapies have come into prominence for the management of NSCLC. In particular, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) therapy has emerged as a first-line therapy for NSCLC patients with EGFR-activating mutations. In this context, new indenopyrazoles, which were prepared by an efficient microwave-assisted method, were subjected to in silico and in vitro assays to evaluate their potency as EGFR TK-targeted anti-NSCLC agents. Compound 4 was the most promising antitumor agent towards A549 human lung adenocarcinoma cells, with an IC50 value of 6.13 µM compared to erlotinib (IC50 = 19.67 µM). Based on its low cytotoxicity to peripheral blood mononuclear cells (PBMCs), it can be concluded that compound 4 exerts selective antitumor action. This compound also inhibited EGFR TK with an IC50 value of 17.58 µM compared to erlotinib (IC50 = 0.04 µM) and induced apoptosis (56.30%). Taking into account in silico and in vitro data, compound 4 stands out as a potential EGFR TKI for the treatment of NSCLC.

Preliminary Report of In vitro and In vivo Effectiveness of Dornase Alfa on SARS-CoV-2 Infection (Preprint)

2020 ◽  
Author(s):  
Hacer Kuzu Okur ◽  
Koray Yalcin ◽  
Cihan Tastan ◽  
Sevda Demir ◽  
Bulut Yurtsever ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Mononuclear Cells ◽  
Multiple Organ ◽  
Peripheral Blood Mononuclear ◽  
Dornase Alfa ◽  
Tract Infections ◽  
Adult Peripheral Blood

UNSTRUCTURED Dornase alfa, the recombinant form of the human DNase I enzyme, breaks down neutrophil extracellular traps (NET) that include a vast amount of DNA fragments, histones, microbicidal proteins and oxidant enzymes released from necrotic neutrophils in the highly viscous mucus of cystic fibrosis patients. Dornase alfa has been used for decades in patients with cystic fibrosis to reduce the viscoelasticity of respiratory tract secretions, to decrease the severity of respiratory tract infections, and to improve lung function. Previous studies have linked abnormal NET formations to lung diseases, especially to acute respiratory distress syndrome (ARDS). Coronavirus disease 2019 (COVID-19) pandemic affected more than two million people over the world, resulting in unprecedented health, social and economic crises. The COVID-19, viral pneumonia that progresses to ARDS and even multiple organ failure, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). High blood neutrophil levels are an early indicator of SARS-CoV-2 infection and predict severe respiratory diseases. A similar mucus structure is detected in COVID-19 patients due to the accumulation of excessive NET in the lungs. Here, we show our preliminary results with dornase alfa that may have an in-vitro anti-viral effect against SARS-CoV-2 infection in a bovine kidney cell line, MDBK without drug toxicity on healthy adult peripheral blood mononuclear cells. In this preliminary study, we also showed that dornase alfa can promote clearance of NET formation in both an in-vitro and three COVID-19 cases who showed clinical improvement in radiological analysis (2-of-3 cases), oxygen saturation (SpO2), respiratory rate, disappearing of dyspnea and coughing.

scholarly journals Potential Role and Impact of Peripheral Blood Mononuclear Cells in Radiographic Axial Spondyloarthritis-Associated Endothelial Dysfunction

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1037
Author(s):  
Patricia Ruiz-Limon ◽  
Maria L. Ladehesa-Pineda ◽  
Clementina Lopez-Medina ◽  
Chary Lopez-Pedrera ◽  
Maria C. Abalos-Aguilera ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Axial Spondyloarthritis ◽  
Endothelial Injury ◽  
In Vitro Studies ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

Endothelial dysfunction (ED) is well known as a process that can lead to atherosclerosis and is frequently presented in radiographic axial spondyloarthritis (r-axSpA) patients. Here, we investigated cellular and molecular mechanisms underlying r-axSpA-related ED, and analyzed the potential effect of peripheral blood mononuclear cells (PBMCs) in promoting endothelial injury in r-axSpA. A total of 30 r-axSpA patients and 32 healthy donors (HDs) were evaluated. The endothelial function, inflammatory and atherogenic profile, and oxidative stress were quantified. In vitro studies were designed to evaluate the effect of PBMCs from r-axSpA patients on aberrant endothelial activation. Compared to HDs, our study found that, associated with ED and the plasma proatherogenic profile present in r-axSpA, PBMCs from these patients displayed a pro-oxidative, proinflammatory, and proatherogenic phenotype, with most molecular changes noticed in lymphocytes. Correlation studies revealed the relationship between this phenotype and the microvascular function. Additional in vitro studies confirmed that PBMCs from r-axSpA patients promoted endothelial injury. Altogether, this study suggests the relevance of r-axSpA itself as a strong and independent cardiovascular risk factor, contributing to a dysfunctional endothelium and atherogenic status by aberrant activation of PBMCs. Lymphocytes could be the main contributors in the development of ED and subsequent atherosclerosis in this pathology.

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