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1.
J Virol ; 96(22): e0121722, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36326275

RESUMO

Rabbit hemorrhagic disease virus (RHDV) typically causes a fatal disease in rabbits. In Australia, RHDV was imported to control the feral rabbit population, while it poses a severe threat to native rabbits in other countries. RHDV variants are genetically diverse and serological studies using antibodies isolated from infected rabbits or raised against RHDV virus-like particles (VLPs) have found RHDV variants antigenically distinct. In this study, we determined the X-ray crystal structure of an RHDV GI.2 (N11 strain) protruding (P) domain in complex with a diagnostic monoclonal antibody (2D9) Fab. We showed that 2D9 interacted with conserved and variable residues on top of the P domain with nanomolar affinity. To better illustrate 2D9 specificity, we determined the X-ray crystal structure of an RHDV GI.1b (Ast89 strain) that was a 2D9 non-binder. Structural analysis indicated that amino acid substitutions on the GI.1b P domain likely restricted 2D9 binding. Interestingly, a model of the GI.2 P domain-Fab complex superimposed onto a cryo-EM structure of an RHDV VLP revealed that 2D9 Fab molecules clashed with neighboring Fabs and indicated that there was a reduced antibody binding occupancy. Moreover, the RHDV GI.2 histo-blood group antigen (HBGA) co-factor binding site appeared obstructed when 2D9 was modeled on the VLP and suggested that 2D9 might also function by blocking HBGA attachment. Overall, this new data provides the first structural basis of RHDV antibody specificity and explains how amino acid variation at the binding site likely restricts 2D9 cross-reactivity. IMPORTANCE Isolated RHDV antibodies have been used for decades to distinguish between antigenic variants, monitor temporal capsid evolution, and examine neutralizing capacities. In this study, we provided the structural basis for an RHDV GI.2 specific diagnostic antibody (2D9) binding and reveal that a small number of amino acid substitutions at the binding site could differentiate between RHDV GI.2 and GI.1b. This novel structural information provides a framework for understanding how RHDV displays a specific antigenic epitope and engages an antibody at the atomic level. Importantly, part of the 2D9 binding region was earlier reported to contain a neutralizing epitope and our structural modeling as well as recent human norovirus antibody-mediated neutralization studies, suggest that the 2D9 antibody has the potential to block HBGA attachment. These new findings should aid in characterizing antigenic variants and advance the development of novel monoclonal antibodies for diagnostics and therapeutics.


Assuntos
Especificidade de Anticorpos , Antígenos de Grupos Sanguíneos , Infecções por Caliciviridae , Vírus da Doença Hemorrágica de Coelhos , Animais , Coelhos , Antígenos de Grupos Sanguíneos/metabolismo , Infecções por Caliciviridae/veterinária , Epitopos/metabolismo
2.
Curr Microbiol ; 79(12): 378, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36329326

RESUMO

It is widely acknowledged that pseudogenes play important roles in bacterial diversification and evolution and participate in gene regulation and RNA interference (RNAi). However, the function of most pseudogenes in Brucella spp remains poorly understood, warranting further studies.To comprehensively analyze the function of the pseudogenes BMEA_B0173 in Brucella melitensis strain 63/9, a BMEA_B0173 in-frame deleted mutant strain was constructed. Then, the phenotypes of the mutant strain, such as growth characteristics and bacterial virulence, were assessed in mice infection models. Finally, iTRAQ analysis was performed to investigate the gene expression profile affected by the pseudogenes BMEA_B0173. In this study, we found that BMEA_B0173 deletion exhibited increased agglutination with M monospecific sera. In a mouse model of chronic infection, the BMEA_B0173 deletion strain displayed increased colonization in the spleen compared to the wild-type pathogen. The iTRAQ assay revealed that 252 proteins were differentially expressed between the BMEA_B0173 deletion and the wild-type strains. In addition, deletion of BMEA_B0173 significantly increased the expression of proteins involved in the denitrification pathway, iron metabolism, and several transcriptional regulators, which might cause increased virulence of the mutant strain. In conclusion, this study preliminary uncovered the function of the pseudogene BMEA_B0173 in Brucella melitensis 63/9 and provided novel insights for studying the pathogenesis of Brucella strains.


Assuntos
Brucella melitensis , Brucelose , Camundongos , Animais , Brucella melitensis/genética , Brucella melitensis/metabolismo , Virulência/genética , Pseudogenes , Epitopos/metabolismo , Brucelose/microbiologia , Modelos Animais de Doenças , Proteínas de Bactérias/genética
3.
Int J Mol Sci ; 23(19)2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36233218

RESUMO

Specific antibodies are necessary for cellular and tissue expression, biochemical, and functional analyses of protein complexes. However, generating a specific antibody is often time-consuming and effort-intensive. The epitope tagging of an endogenous protein at an appropriate position can overcome this problem. Here, we investigated epitope tag position using AlphaFold2 protein structure prediction and developed Flag/DYKDDDDK tag knock-in CaMKIIα and CaMKIIß mice by combining CRISPR-Cas9 genome editing with electroporation (i-GONAD). With i-GONAD, it is possible to insert a small fragment of up to 200 bp into the genome of the target gene, enabling efficient and convenient tagging of a small epitope. Experiments with commercially available anti-Flag antibodies could readily detect endogenous CaMKIIα and ß proteins by Western blotting, immunoprecipitation, and immunohistochemistry. Our data demonstrated that the generation of Flag/DYKDDDDK tag knock-in mice by i-GONAD is a useful and convenient choice, especially if specific antibodies are unavailable.


Assuntos
Eletroporação , Edição de Genes , Animais , Anticorpos/metabolismo , Western Blotting , Sistemas CRISPR-Cas/genética , Epitopos/genética , Epitopos/metabolismo , Gônadas/metabolismo , Camundongos
4.
Int J Mol Sci ; 23(19)2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36233334

RESUMO

Mutations in C8orf37 cause Bardet-Biedl syndrome (BBS), retinitis pigmentosa (RP), and cone-rod dystrophy (CRD), all manifest in photoreceptor degeneration. Little is known about which proteins C8orf37 interacts with to contribute to photoreceptor survival. To determine the proteins that potentially interact with C8orf37, we carried out a yeast two-hybrid (Y2H) screen using C8orf37 as a bait. FAM161A, a microtubule-binding protein localized at the photoreceptor cilium required for photoreceptor survival, was identified as one of the preys. Double immunofluorescence staining and proximity ligation assay (PLA) of marmoset retinal sections showed that C8orf37 was enriched and was co-localized with FAM161A at the ciliary base of photoreceptors. Epitope-tagged C8orf37 and FAM161A, expressed in HEK293 cells, were also found to be co-localized by double immunofluorescence staining and PLA. Furthermore, interaction domain mapping assays identified that the N-terminal region of C8orf37 and amino acid residues 341-517 within the PFAM UPF0564 domain of FAM161A were critical for C8orf37-FAM161A interaction. These data suggest that the two photoreceptor survival proteins, C8orf37 and FAM161A, interact with each other which may contribute to photoreceptor health.


Assuntos
Proteínas do Olho , Proteínas , Retinite Pigmentosa , Aminoácidos/metabolismo , Epitopos/metabolismo , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Células HEK293 , Humanos , Células Fotorreceptoras/metabolismo , Proteínas/genética , Proteínas/metabolismo , Retinite Pigmentosa/genética , Retinite Pigmentosa/metabolismo
5.
Int J Mol Sci ; 23(19)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36232898

RESUMO

Pseudorabies (also called Aujeszky's disease) is a highly infectious viral disease caused by the pseudorabies virus (PRV, or Suid herpesvirus 1). Although the disease has been controlled by immunization with the PRV-attenuated vaccine, the emerging PRV variants can escape the immune surveillance in the vaccinated pig, resulting in recent outbreaks. Furthermore, the virus has been detected in other animals and humans, indicating cross-transmission of PRV. However, the mechanism of PRV cross-species transmission needs further study. In this study, we compared the amino acid sequences of glycoproteins (gD), gL, and thymidine kinase (TK) of PRV strains, human PRV hSD-1 2019 strain, and the attenuated strain Bartha-K61, followed by predication of their spatial conformation. In addition, the interactions between the viral gD protein and host nectin-1, nectin-2, and HS were also evaluated via molecular docking. The results showed that the amino acid sequence homology of the gD, gL, and TK proteins of hSD-1 2019 and JL-CC was 97.5%, 94.4%, and 99.1%, respectively. Moreover, there were mutations in the amino acid sequences of gD, gL, and TK proteins of hSD-1 2019 and JL-CC compared with the corresponding reference sequences of the Bartha strain. The mutations of gD, gL, and TK might not affect the spatial conformation of the protein domain but may affect the recognition of antibodies and antigen epitopes. Moreover, the gD protein of JL-CC, isolated previously, can bind to human nectin-1, nectin-2, and HS, suggesting the virus may be highly infectious and pathogenic to human beings.


Assuntos
Herpesvirus Suídeo 1 , Pseudorraiva , Doenças dos Suínos , Animais , Epitopos/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Herpesvirus Suídeo 1/genética , Humanos , Simulação de Acoplamento Molecular , Mutação , Nectinas/metabolismo , Suínos , Timidina Quinase/genética , Timidina Quinase/metabolismo , Vacinas Atenuadas , Proteínas do Envelope Viral/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo
6.
Vaccine ; 40(45): 6520-6527, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36202640

RESUMO

Moraxella catarrhalis is an important and common respiratory pathogen that can cause Otitis Media, Community Acquired Pneumonia, and has been associated with an increased risk of exacerbations in chronic obstructive pulmonary disease in adults, leading to morbidity and mortality. Its ubiquitous surface protein A2 (UspA2) has been shown to interact with host structures and extracellular matrix proteins, suggesting a role at an early stage of infection and a contribution to bacterial serum resistance. The UspA proteins are homo-trimeric autotransporters that appear as a lollipop-shaped structure in electron micrographs. They are composed of an N-terminal head with adhesive properties, followed by a stalk, which ends by an amphipathic helix and a C-terminal membrane domain. The three family members UspA1, UspA2 and UspA2H, present different amino acid signatures both at the head and membrane-spanning regions. By combining electron microscopy, hydrogen deuterium exchange mass spectrometry and protein modeling, we identified a shared and repeated epitope recognized by FHUSPA2/10, a potent cross-bactericidal monoclonal antibody raised by UspA2 and deduced key amino acids involved in the binding. The finding strengthens the potential of UspA2 to be incorporated in a vaccine formulation against M. catarrhalis.


Assuntos
Antibacterianos , Anticorpos Monoclonais , Moraxella catarrhalis , Adulto , Humanos , Aminoácidos/metabolismo , Anticorpos Monoclonais/farmacologia , Proteínas da Membrana Bacteriana Externa/imunologia , Epitopos/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Sistemas de Secreção Tipo V/metabolismo , Antibacterianos/farmacologia
7.
Sci Adv ; 8(40): eabn3777, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36206332

RESUMO

Patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can experience life-threatening respiratory distress, blood pressure dysregulation, and thrombosis. This is thought to be associated with an impaired activity of angiotensin-converting enzyme 2 (ACE2), which is the main entry receptor of SARS-CoV-2 and which also tightly regulates blood pressure by converting the vasoconstrictive peptide angiotensin II (AngII) to a vasopressor peptide. Here, we show that a significant proportion of hospitalized patients with COVID-19 developed autoantibodies against AngII, whose presence correlates with lower blood oxygenation, blood pressure dysregulation, and overall higher disease severity. Anti-AngII antibodies can develop upon specific immune reaction to the SARS-CoV-2 proteins Spike or receptor-binding domain (RBD), to which they can cross-bind, suggesting some epitope mimicry between AngII and Spike/RBD. These results provide important insights on how an immune reaction against SARS-CoV-2 can impair blood pressure regulation.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Angiotensina II , Autoanticorpos , Pressão Sanguínea , Epitopos/metabolismo , Humanos , Peptidil Dipeptidase A/metabolismo , Ligação Proteica , SARS-CoV-2 , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus
8.
Bull Cancer ; 109(11): 1202-1216, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36184332

RESUMO

MUC1 is a highly glycosylated transmembrane mucin on the luminal surface of epithelial cells, protecting them from extreme factors. In cancer cells, MUC1 expression is upregulated and the protein structure, glycosylation level and spatial distribution are altered. It was found that upregulated MUC1 is involved in the regulation of several signaling pathways and plays an instrumental role in tumor cell metabolism, apoptosis, epithelial mesenchymal transition and distant metastasis. MUC1 glycosylation insufficiency leads to exposure of novel antigenic epitopes that can be used as specific targets for therapy and diagnosis. In addition, MUC1 was found to be closely related to HIF and can form a positive feedback loop leading to hypoxic malignant tumor progression. Currently, MUC1-based targeted drugs include monoclonal antibodies, antibody-coupled drugs, aptamers and cancer vaccines, some of which have already entered clinical trials. This paper reviews the role and mechanism of MUC1 in the biological function of malignant tumors and describes the potential of MUC1 in tumor-targeted chemotherapy, targeted radiotherapy and diagnostic imaging.


Assuntos
Mucina-1 , Neoplasias , Humanos , Anticorpos Monoclonais , Vacinas Anticâncer , Epitopos/química , Epitopos/metabolismo , Glicosilação , Mucinas , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico
9.
Front Immunol ; 13: 991092, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36119032

RESUMO

Ciltacabtagene autoleucel (also known as cilta-cel) is a chimeric antigen receptor (CAR) T-cell therapy that targets B-cell maturation antigen (BCMA) on the surface of cancer cells in B cell malignancies, such as multiple myeloma (MM). It is a second-generation CAR that is outfitted with an ectodomain comprising two BCMA-binding single chain variable fragment (ScFv) domains, a transmembrane domain, and an endodomain possessing CD3ζ and 4-1BB. Cilta-cel is an autologous, gene-edited CAR T-cell that is prepared by collecting and modifying the recipient's T-cells to create a patient personalized treatment in the laboratory to be infused back. This CAR T-cell product exceptionally entails CARs with two BCMA-targeting single-domain antibodies that detect two epitopes of BCMA expressed on the malignant cells of MM. Cilta-cel is the current addition to the treatment armamentarium of relapsed or refractory (r/r) MM after its approval by the FDA on February 28, 2022, based on the results of the Phase 1b/2 CARTITUDE-1 study. It was the second approved anti-BCMA CAR T-cell product after idecabtagene vicleucel (ide-cel) to treat myeloma patients. It induces early, deep, and long-lasting responses with a tolerable safety profile in r/r MM. Cilta-cel-treated myeloma patients may potentially experience adverse effects ranging from mild to life-threatening, but they are mostly manageable toxicities. Besides, it has a consistent safety profile upon a longer follow-up of patients. Cilta-cel generally outperforms ide cel in terms of efficacy in MM, but shows comparable adverse events. This review highlights the current updates on cilta-cel efficacy, adverse events, comparison with ide-cel, and its future direction in the treatment of MM.


Assuntos
Mieloma Múltiplo , Receptores de Antígenos Quiméricos , Anticorpos de Cadeia Única , Anticorpos de Domínio Único , Antígeno de Maturação de Linfócitos B , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Epitopos/metabolismo , Humanos , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/metabolismo , Anticorpos de Domínio Único/metabolismo , Linfócitos T
10.
Front Immunol ; 13: 942907, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36110855

RESUMO

Clostridium perfringens is a dangerous bacterium and known biological warfare weapon associated with several diseases, whose lethal toxins can produce necrosis in humans. However, there is no safe and fully effective vaccine against C. perfringens for humans yet. To address this problem, we computationally screened its whole proteome, identifying highly immunogenic proteins, domains, and epitopes. First, we identified that the proteins with the highest epitope density are Collagenase A, Exo-alpha-sialidase, alpha n-acetylglucosaminidase and hyaluronoglucosaminidase, representing potential recombinant vaccine candidates. Second, we further explored the toxins, finding that the non-toxic domain of Perfringolysin O is enriched in CTL and HTL epitopes. This domain could be used as a potential sub-unit vaccine to combat gas gangrene. And third, we designed a multi-epitope protein containing 24 HTL-epitopes and 34 CTL-epitopes from extracellular regions of transmembrane proteins. Also, we analyzed the structural properties of this novel protein using molecular dynamics. Altogether, we are presenting a thorough immunoinformatic exploration of the whole proteome of C. perfringens, as well as promising whole-protein, domain-based and multi-epitope vaccine candidates. These can be evaluated in preclinical trials to assess their immunogenicity and protection against C. perfringens infection.


Assuntos
Clostridium perfringens , Proteoma , Acetilglucosaminidase , Epitopos/metabolismo , Humanos , Hialuronoglucosaminidase/metabolismo , Neuraminidase/metabolismo , Proteoma/metabolismo , Vacinas Sintéticas
11.
Front Immunol ; 13: 953151, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36159876

RESUMO

Chronic hepatitis C virus (HCV) infection is a curable disease, but the absence of a vaccine remains a major problem in infection prevention. The lack of small animal models and limited access to human liver tissue impede the study of hepatic antiviral immunity and the development of new vaccine strategies. We recently developed an immune-competent mouse model using an HCV-related rodent hepacivirus which shares immunological features with human viral hepatitis. In this study, we used this new model to investigate the role of invariant natural killer T (iNKT) cells during hepacivirus infection in vivo. These cells are enriched in the liver, however their role in viral hepatitis is not well defined. Using high-dimensional flow cytometry and NKT cell deficient mice we analyzed a potential role of iNKT cells in mediating viral clearance, liver pathology or immune-regulation during hepacivirus infection. In addition, we identified new immune-dominant MHC class I restricted viral epitopes and analyzed the impact of iNKT cells on virus-specific CD8+ T cells. We found that rodent hepacivirus infection induced the activation of iNKT cell subsets with a mixed NKT1/NKT2 signature and significant production of type 2 cytokines (IL-4 and IL-13) during acute infection. While iNKT cells were dispensable for viral clearance, the lack of these cells caused higher levels of liver injury during infection. In addition, the absence of iNKT cells resulted in increased effector functions of hepatic antiviral T cells. In conclusion, our study reports a regulatory role of hepatic iNKT cells during hepacivirus infection in vivo. Specifically, our data suggest that iNKT cells skewed towards type 2 immunity limit liver injury during acute infection by mechanisms that include the regulation of effector functions of virus-specific T cells.


Assuntos
Hepatite C Crônica , Células T Matadoras Naturais , Animais , Antivirais/metabolismo , Citocinas/metabolismo , Epitopos/metabolismo , Hepacivirus/metabolismo , Humanos , Interleucina-13/metabolismo , Interleucina-4/metabolismo , Camundongos
12.
Elife ; 112022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36125123

RESUMO

Pharmacological and genetic studies over the past decade have established the follicle-stimulating hormone (FSH) as an actionable target for diseases affecting millions, namely osteoporosis, obesity, and Alzheimer's disease. Blocking FSH action prevents bone loss, fat gain, and neurodegeneration in mice. We recently developed a first-in-class, humanized, epitope-specific FSH-blocking antibody, MS-Hu6, with a KD of 7.52 nM. Using a Good Laboratory Practice (GLP)-compliant platform, we now report the efficacy of MS-Hu6 in preventing and treating osteoporosis in mice and parameters of acute safety in monkeys. Biodistribution studies using 89Zr-labeled, biotinylated or unconjugated MS-Hu6 in mice and monkeys showed localization to bone and bone marrow. The MS-Hu6 displayed a ß phase t½ of 7.5 days (180 hr) in humanized Tg32 mice. We tested 217 variations of excipients using the protein thermal shift assay to generate a final formulation that rendered MS-Hu6 stable in solution upon freeze-thaw and at different temperatures, with minimal aggregation, and without self-, cross-, or hydrophobic interactions or appreciable binding to relevant human antigens. The MS-Hu6 showed the same level of "humanness" as human IgG1 in silico and was non-immunogenic in ELISpot assays for IL-2 and IFN-γ in human peripheral blood mononuclear cell cultures. We conclude that MS-Hu6 is efficacious, durable, and manufacturable, and is therefore poised for future human testing.


Assuntos
Hormônio Foliculoestimulante , Osteoporose , Animais , Epitopos/metabolismo , Excipientes , Hormônio Foliculoestimulante/metabolismo , Humanos , Imunoglobulina G/metabolismo , Interleucina-2/metabolismo , Leucócitos Mononucleares/metabolismo , Camundongos , Osteoporose/tratamento farmacológico , Distribuição Tecidual
13.
Org Biomol Chem ; 20(39): 7694-7712, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36165239

RESUMO

Vancomycin is the best-known of the glycopeptide group antibiotics (GPAs), a family of agents which operate by binding the C-terminal deptide D-Ala-D-Ala. This anionic epitope is an interesting target because it plays a central role in bacterial cell wall synthesis, and is not readily modified by evolution. Accordingly, vancomycin has been in use for >60 years but has only provoked limited resistance. Agents which mimic vancomycin but are easier to synthesise and modify could serve as valuable weapons against pathogenic bacteria, broadening the scope of the GPAs and addressing the resistance that does exist. This article gives an overview of vancomycin's structure and action, surveys past work on vancomycin mimicry, and makes the case for renewed effort in the future.


Assuntos
Antibacterianos , Vancomicina , Antibacterianos/química , Bactérias/metabolismo , Epitopos/metabolismo , Glicopeptídeos/metabolismo , Vancomicina/farmacologia
14.
Int Immunopharmacol ; 112: 109238, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36116151

RESUMO

During latency, DosR proteins of Mycobacterium tuberculosis (M.tb) get activated and help the bacterium to remain dormant. We have shown earlier that 2 such proteins Rv2627c and Rv2628 are immunogenic and induce a TH1 kind of immune response. In this study, through in-vitro experiments we have confirmed that Rv2627c and Rv2628 proteins act as protein Toll-Like Receptor (TLR) agonist-adjuvant. Rv2627c and Rv2628 stimulated THP-1 macrophages showed an increased expression of TLR2, TLR4 and co-stimulatory molecules CD40, CD80, CD86 and antigen presenting molecule HLA-DR. Further studies also found enhanced expression of downstream signaling molecules of TLR activation like MyD88, NF-κB-p65 and pro-inflammatory cytokines. Inhibition studies using TLR blocking antibodies decreased the expression of co-stimulatory molecules, MyD88, NF-κB-p65, and pro-inflammatory cytokines. Rv2627c and Rv2628 stimulation of HEK-TLR2 reporter cell line confirmed the interaction of these proteins with TLR2. Moreover, molecular docking and simulations of Rv2627c and Rv2628 proteins with TLR2 and TLR4 showed stable interactions. The adjuvant activity of Rv2628 was further validated by a protein adjuvanted with pre-clinically validated peptides as multi-epitope vaccine construct which showed good binding with TLR2 and TLR4 and activate dendritic cells and induce sustained pro-inflammatory cytokine response by C-ImmSim analysis. We propose that our vaccine construct will produce a better immune response than BCG and can be taken up as a post-exposure therapeutic subunit vaccine along with standard TB therapy. We also anticipate that our construct can be taken up as a protein adjuvant with other vaccine candidates as these can activate macrophages through TLR signaling.


Assuntos
Mycobacterium tuberculosis , Regulon , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Anticorpos Bloqueadores/metabolismo , Simulação de Acoplamento Molecular , Vacina BCG , Citocinas/metabolismo , Adjuvantes Imunológicos , Vacinas de Subunidades , Epitopos/metabolismo
15.
Nat Commun ; 13(1): 5570, 2022 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-36138008

RESUMO

Following CART-19 immunotherapy for B-cell acute lymphoblastic leukaemia (B-ALL), many patients relapse due to loss of the cognate CD19 epitope. Since epitope loss can be caused by aberrant CD19 exon 2 processing, we herein investigate the regulatory code that controls CD19 splicing. We combine high-throughput mutagenesis with mathematical modelling to quantitatively disentangle the effects of all mutations in the region comprising CD19 exons 1-3. Thereupon, we identify ~200 single point mutations that alter CD19 splicing and thus could predispose B-ALL patients to developing CART-19 resistance. Furthermore, we report almost 100 previously unknown splice isoforms that emerge from cryptic splice sites and likely encode non-functional CD19 proteins. We further identify cis-regulatory elements and trans-acting RNA-binding proteins that control CD19 splicing (e.g., PTBP1 and SF3B4) and validate that loss of these factors leads to pervasive CD19 mis-splicing. Our dataset represents a comprehensive resource for identifying predictive biomarkers for CART-19 therapy.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Sítios de Splice de RNA , Processamento Alternativo/genética , Antígenos CD19/genética , Antígenos CD19/metabolismo , Epitopos/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Humanos , Mutagênese/genética , Mutação , Recidiva Local de Neoplasia/genética , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Isoformas de Proteínas/genética , Splicing de RNA , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
16.
Cells ; 11(17)2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-36078121

RESUMO

Leucine-rich Glioma-Inactivated protein 1 (LGI1) is expressed in the central nervous system and its genetic loss of function is associated with epileptic disorders. Additionally, patients with LGI1-directed autoantibodies have frequent focal seizures as a key feature of their disease. LGI1 is composed of a Leucine-Rich Repeat (LRR) and an Epitempin (EPTP) domain. These domains are reported to interact with different members of the transsynaptic complex formed by LGI1 at excitatory synapses, including presynaptic Kv1 potassium channels. Patient-derived recombinant monoclonal antibodies (mAbs) are ideal reagents to study whether domain-specific LGI1-autoantibodies induce epileptiform activities in neurons and their downstream mechanisms. We measured the intrinsic excitability of CA3 pyramidal neurons in organotypic cultures from rat hippocampus treated with either an LRR- or an EPTP-reactive patient-derived mAb, or with IgG from control patients. We found an increase in intrinsic excitability correlated with a reduction of the sensitivity to a selective Kv1.1-channel blocker in neurons treated with the LRR mAb, but not in neurons treated with the EPTP mAb. Our findings suggest LRR mAbs are able to modulate neuronal excitability that could account for epileptiform activity observed in patients.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Proteínas do Tecido Nervoso , Animais , Autoanticorpos/metabolismo , Epitopos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Leucina , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Ratos
17.
Cell Stem Cell ; 29(10): 1459-1474.e9, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36113462

RESUMO

Fibrosis is the final path of nearly every form of chronic disease, regardless of the pathogenesis. Upon chronic injury, activated, fibrogenic fibroblasts deposit excess extracellular matrix, and severe tissue fibrosis can occur in virtually any organ. However, antifibrotic therapies that target fibrogenic cells, while sparing homeostatic fibroblasts in healthy tissues, are limited. We tested whether specific immunization against endogenous proteins, strongly expressed in fibrogenic cells but highly restricted in quiescent fibroblasts, can elicit an antigen-specific cytotoxic T cell response to ameliorate organ fibrosis. In silico epitope prediction revealed that activation of the genes Adam12 and Gli1 in profibrotic cells and the resulting "self-peptides" can be exploited for T cell vaccines to ablate fibrogenic cells. We demonstrate the efficacy of a vaccination approach to mount CD8+ T cell responses that reduce fibroblasts and fibrosis in the liver and lungs in mice. These results provide proof of principle for vaccination-based immunotherapies to treat fibrosis.


Assuntos
Fibroblastos , Pulmão , Animais , Epitopos/metabolismo , Fibroblastos/metabolismo , Fibrose , Imunoterapia , Fígado/patologia , Pulmão/metabolismo , Camundongos , Vacinação , Proteína GLI1 em Dedos de Zinco/metabolismo
18.
J Reprod Immunol ; 154: 103694, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36063659

RESUMO

Regulatory T cells (Tregs) proliferate after encountering the fetal antigen, which plays an important role in maintaining maternal-fetal tolerance. Activated Tregs increase number and function after antigen encounter and develop memory. Upon subsequent antigen exposure, Treg cells re-expand more rapidly. However, the characteristics of memory regulatory T cells (mTregs) during normal pregnancy and unexplained recurrent pregnancy loss (URPL) have not been elucidated well. In this study, we analyzed the proportion of Tregs and mTregs in the peripheral blood and their surface expression of PD-1, CCR6, and HLA-G in normal non-pregnant (n = 20) and pregnant (n = 20) women, and non-pregnant (n = 20) and pregnant URPL (n = 20) women. We found that the proportions of mTregs in lymphocytes, CD3+ T cells, CD4+ T cells, and Tregs were lower in pregnant URPL patients than in normal pregnant women. The proportions of CD4+CD45RO+ Th cells in lymphocytes, CD3+ T, and CD4+ T cells in the pregnant URPL group were the highest among the four groups (P < 0.05). There were no significant differences among the other three groups (P > 0.05). The proportions of CD4+/CCR6+/mTregs, CD4+/PD-1+/mTregs, CD4+/HLA-G+/mTregs were significantly lower in the non-pregnant normal group and non-pregnant URPL group than in normal pregnant group and pregnant URPL group (P < 0.05, respectively). The proportions of CD4+/CCR6+ mTregs, CD4+/PD-1+/mTregs, CD4+/HLA-G+/mTregs were lower in pregnant URPL group than in normal pregnant group (P < 0.05, respectively). These findings indicate that fetal antigen-specific mTregs play an important role in pregnancy maintenance, and the dysregulation of mTreg may contribute to URPL.


Assuntos
Aborto Habitual , Linfócitos T Reguladores , Feminino , Humanos , Gravidez , Epitopos/metabolismo , Antígenos HLA-G/metabolismo , Receptor de Morte Celular Programada 1/metabolismo
19.
ACS Chem Biol ; 17(10): 2911-2922, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36174018

RESUMO

Using the regioselective cyanobenzothiazole condensation reaction with an N-terminal cysteine and the chloroacetamide reaction with an internal cysteine, a phage-displayed macrocyclic 12-mer peptide library was constructed and subsequently validated. Using this library in combination with iterative selections against two epitopes from the receptor binding domain (RBD) of the novel severe acute respiratory syndrome virus 2 (SARS-CoV-2) Spike protein, macrocyclic peptides that strongly inhibit the interaction between the Spike RBD and angiotensin-converting enzyme 2 (ACE2), the human host receptor of SARS-CoV-2, were identified. The two epitopes were used instead of the Spike RBD to avoid selection of nonproductive macrocyclic peptides that bind RBD but do not directly inhibit its interactions with ACE2. Antiviral tests against SARS-CoV-2 showed that one macrocyclic peptide is highly potent against viral reproduction in Vero E6 cells with an EC50 value of 3.1 µM. The AlphaLISA-detected IC50 value for this macrocyclic peptide was 0.3 µM. The current study demonstrates that two kinetically controlled reactions toward N-terminal and internal cysteines, respectively, are highly effective in the construction of phage-displayed macrocyclic peptides, and the selection based on the SARS-CoV-2 Spike epitopes is a promising methodology in the identification of peptidyl antivirals.


Assuntos
Bacteriófagos , COVID-19 , Humanos , Enzima de Conversão de Angiotensina 2 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Epitopos/metabolismo , Biblioteca de Peptídeos , Cisteína/metabolismo , COVID-19/tratamento farmacológico , Ligação Proteica , Peptídeos/farmacologia , Peptídeos/metabolismo , Antivirais/farmacologia , Bacteriófagos/metabolismo
20.
Biomolecules ; 12(9)2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-36139007

RESUMO

Monocytes are circulating blood cells that rapidly mobilize to inflamed sites where they serve diverse effector functions shaped in part by microenvironmental cues. The establishment of specific glycosylation patterns on the immune cell glycocalyx is fundamental to direct the inflammatory response, but relatively little is known about the mechanisms whereby the microenvironment controls this process. Here, we report that galectins differentially participate in remodeling the surface glycosylation of human primary CD14+CD16- monocytes under proinflammatory conditions. Using a lectin array on biotinylated protein, we found that the prototypic galectin-1 negatively influenced the expression of galactose epitopes on the surface of monocytic cells. On the other hand, the tandem-repeat galectin-8 and, to a certain extent, the chimeric galectin-3 promoted the expression of these residues. Jacalin flow cytometry and pull-down experiments further demonstrated that galectin-8 causes a profound upregulation of mucin-type O-glycosylation in cell surface proteins from primary monocytes and THP-1 cells. Overall, these results highlight the emerging role of the galectin signature on inflamed tissues and provide new insights into the contribution of extracellular galectins to the composition of the glycocalyx in human monocytes.


Assuntos
Galectina 1 , Monócitos , Epitopos/metabolismo , Galactose/metabolismo , Galectina 1/genética , Galectina 1/metabolismo , Galectina 3/genética , Galectina 3/metabolismo , Galectinas/metabolismo , Glicosilação , Humanos , Monócitos/metabolismo , Mucinas/metabolismo
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