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1.
Proc Natl Acad Sci U S A ; 117(2): 1119-1128, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31888983

RESUMO

Reprogramming the tumor microenvironment to increase immune-mediated responses is currently of intense interest. Patients with immune-infiltrated "hot" tumors demonstrate higher treatment response rates and improved survival. However, only the minority of tumors are hot, and a limited proportion of patients benefit from immunotherapies. Innovative approaches that make tumors hot can have immediate impact particularly if they repurpose drugs with additional cancer-unrelated benefits. The seasonal influenza vaccine is recommended for all persons over 6 mo without prohibitive contraindications, including most cancer patients. Here, we report that unadjuvanted seasonal influenza vaccination via intratumoral, but not intramuscular, injection converts "cold" tumors to hot, generates systemic CD8+ T cell-mediated antitumor immunity, and sensitizes resistant tumors to checkpoint blockade. Importantly, intratumoral vaccination also provides protection against subsequent active influenza virus lung infection. Surprisingly, a squalene-based adjuvanted vaccine maintains intratumoral regulatory B cells and fails to improve antitumor responses, even while protecting against active influenza virus lung infection. Adjuvant removal, B cell depletion, or IL-10 blockade recovers its antitumor effectiveness. Our findings propose that antipathogen vaccines may be utilized for both infection prevention and repurposing as a cancer immunotherapy.


Assuntos
Imunoterapia/métodos , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/uso terapêutico , Injeções Intralesionais , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Linfócitos B , Fatores de Transcrição de Zíper de Leucina Básica/genética , Linfócitos T CD8-Positivos/imunologia , Humanos , Imunidade Celular , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana , Interleucina-10 , Pulmão/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Repressoras/genética , Estações do Ano , Pele , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia , Esqualeno/administração & dosagem , Microambiente Tumoral/efeitos dos fármacos , Vacinação
2.
Biomacromolecules ; 23(3): 1183-1194, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35170303

RESUMO

Alginate hydrogels are widely used for tissue engineering and regenerative medicine due to their excellent biocompatibility. A facile and commonly used strategy to crosslink alginate is the addition of Ca2+ that leads to hydrogelation. However, extracellular Ca2+ is a secondary messenger in activating inflammasome pathways following physical injury or pathogenic insult, which carries the risk of persistent inflammation and scaffold rejection. Here, we present graft copolymers of charge complementary heterodimeric coiled coil (CC) peptides and alginate that undergo supramolecular self-assembly to form Ca2+ free alginate hydrogels. The formation of heterodimeric CCs was confirmed using circular dichroism spectroscopy, and scanning electron microscopy revealed a significant difference in crosslink density and homogeneity between Ca2+ and CC crosslinked gels. The resulting hydrogels were self-supporting and display shear-thinning and shear-recovery properties. In response to lipopolysaccharide (LPS) stimulation, peritoneal macrophages and bone marrow-derived dendritic cells cultured in the CC crosslinked gels exhibited a 10-fold reduction in secretion of the proinflammatory cytokine IL-1ß compared to Ca2+ crosslinked gels. A similar response was also observed in vivo upon peritoneal delivery of Ca2+ or CC crosslinked gels. Analysis of peritoneal lavage showed that macrophages in mice injected with Ca2+ crosslinked gels display a more inflammatory phenotype compared to macrophages from mice injected with CC crosslinked gels. These results suggest that CC peptides by virtue of their tunable sequence-structure-function relationship and mild gelation conditions are promising alternative crosslinkers for alginate and other biopolymer scaffolds used in tissue engineering.


Assuntos
Alginatos , Hidrogéis , Alginatos/química , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Inflamação/patologia , Macrófagos/patologia , Camundongos , Engenharia Tecidual/métodos
3.
J Am Chem Soc ; 142(47): 19809-19813, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-32338879

RESUMO

Patterned substitution of d-amino acids into the primary sequences of self-assembling peptides influences molecular-level packing and supramolecular morphology. We report that block heterochiral analogs of the model amphipathic peptide KFE8 (Ac-FKFEFKFE-NH2), composed of two FKFE repeat motifs with opposite chirality, assemble into helical tapes with dimensions greatly exceeding those of their fibrillar homochiral counterparts. At sufficient concentrations, these tapes form hydrogels with reduced storage moduli but retain the shear-thinning behavior and consistent mechanical recovery of the homochiral analogs. Varying the identity of charged residues (FRFEFRFE and FRFDFRFD) produced similarly sized nonhelical tapes, while a peptide with nonenantiomeric l- and d-blocks (FKFEFRFD) formed helical tapes closely resembling those of the heterochiral KFE8 analogs. A proposed energy-minimized model suggests that a kink at the interface between l- and d-blocks leads to the assembly of flat monolayers with nonidentical surfaces that display alternating stacks of hydrophobic and charged groups.


Assuntos
Peptídeos/química , Sequência de Aminoácidos , Dicroísmo Circular , Hidrogéis/química , Peptídeos/metabolismo , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Reologia , Espalhamento a Baixo Ângulo , Estereoisomerismo , Difração de Raios X
4.
FASEB J ; 30(6): 2171-86, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26917740

RESUMO

Recent data shows that fibroblast growth factor 14 (FGF14) binds to and controls the function of the voltage-gated sodium (Nav) channel with phenotypic outcomes on neuronal excitability. Mutations in the FGF14 gene in humans have been associated with brain disorders that are partially recapitulated in Fgf14(-/-) mice. Thus, signaling pathways that modulate the FGF14:Nav channel interaction may be important therapeutic targets. Bioluminescence-based screening of small molecule modulators of the FGF14:Nav1.6 complex identified 4,5,6,7 -: tetrabromobenzotriazole (TBB), a potent casein kinase 2 (CK2) inhibitor, as a strong suppressor of FGF14:Nav1.6 interaction. Inhibition of CK2 through TBB reduces the interaction of FGF14 with Nav1.6 and Nav1.2 channels. Mass spectrometry confirmed direct phosphorylation of FGF14 by CK2 at S228 and S230, and mutation to alanine at these sites modified FGF14 modulation of Nav1.6-mediated currents. In 1 d in vitro hippocampal neurons, TBB induced a reduction in FGF14 expression, a decrease in transient Na(+) current amplitude, and a hyperpolarizing shift in the voltage dependence of Nav channel steady-state inactivation. In mature neurons, TBB reduces the axodendritic polarity of FGF14. In cornu ammonis area 1 hippocampal slices from wild-type mice, TBB impairs neuronal excitability by increasing action potential threshold and lowering firing frequency. Importantly, these changes in excitability are recapitulated in Fgf14(-/-) mice, and deletion of Fgf14 occludes TBB-dependent phenotypes observed in wild-type mice. These results suggest that a CK2-FGF14 axis may regulate Nav channels and neuronal excitability.-Hsu, W.-C. J., Scala, F., Nenov, M. N., Wildburger, N. C., Elferink, H., Singh, A. K., Chesson, C. B., Buzhdygan, T., Sohail, M., Shavkunov, A. S., Panova, N. I., Nilsson, C. L., Rudra, J. S., Lichti, C. F., Laezza, F. CK2 activity is required for the interaction of FGF14 with voltage-gated sodium channels and neuronal excitability.


Assuntos
Caseína Quinase II/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Neurônios/fisiologia , Canais de Sódio Disparados por Voltagem/fisiologia , Animais , Caseína Quinase II/genética , Feminino , Fatores de Crescimento de Fibroblastos/genética , Regulação Enzimológica da Expressão Gênica , Células HEK293 , Hipocampo/citologia , Hipocampo/fisiologia , Humanos , Masculino , Camundongos , Camundongos Knockout , Técnicas de Patch-Clamp
5.
Biochim Biophys Acta ; 1850(4): 832-44, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25615535

RESUMO

BACKGROUND: Phosphorylation plays an essential role in regulating voltage-gated sodium (Na(v)) channels and excitability. Yet, a surprisingly limited number of kinases have been identified as regulators of Na(v) channels. We posited that glycogen synthase kinase 3 (GSK3), a critical kinase found associated with numerous brain disorders, might directly regulate neuronal Na(v) channels. METHODS: We used patch-clamp electrophysiology to record sodium currents from Na(v)1.2 channels stably expressed in HEK-293 cells. mRNA and protein levels were quantified with RT-PCR, Western blot, or confocal microscopy, and in vitro phosphorylation and mass spectrometry to identify phosphorylated residues. RESULTS: We found that exposure of cells to GSK3 inhibitor XIII significantly potentiates the peak current density of Na(v)1.2, a phenotype reproduced by silencing GSK3 with siRNA. Contrarily, overexpression of GSK3ß suppressed Na(v)1.2-encoded currents. Neither mRNA nor total protein expression was changed upon GSK3 inhibition. Cell surface labeling of CD4-chimeric constructs expressing intracellular domains of the Na(v)1.2 channel indicates that cell surface expression of CD4-Na(v)1.2 C-tail was up-regulated upon pharmacological inhibition of GSK3, resulting in an increase of surface puncta at the plasma membrane. Finally, using in vitro phosphorylation in combination with high resolution mass spectrometry, we further demonstrate that GSK3ß phosphorylates T(1966) at the C-terminal tail of Na(v)1.2. CONCLUSION: These findings provide evidence for a new mechanism by which GSK3 modulates Na(v) channel function via its C-terminal tail. GENERAL SIGNIFICANCE: These findings provide fundamental knowledge in understanding signaling dysfunction common in several neuropsychiatric disorders.


Assuntos
Quinase 3 da Glicogênio Sintase/fisiologia , Canal de Sódio Disparado por Voltagem NAV1.2/fisiologia , Sequência de Aminoácidos , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Células HEK293 , Humanos , Dados de Sequência Molecular , Canal de Sódio Disparado por Voltagem NAV1.2/química , Fosforilação
6.
ACS Nano ; 18(12): 8798-8810, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38478911

RESUMO

Synthetic peptides that self-assemble into cross-ß fibrils are versatile building blocks for engineered biomaterials due to their modularity and biocompatibility, but their structural and morphological similarities to amyloid species have been a long-standing concern for their translation. Further, their polymorphs are difficult to characterize by using spectroscopic and imaging techniques that rely on ensemble averaging to achieve high resolution. Here, we utilize Nile red (NR), an amyloidophilic fluorogenic probe, and single-molecule orientation-localization microscopy (SMOLM) to characterize fibrils formed by the designed amphipathic enantiomers KFE8L and KFE8D and the pathological amyloid-beta peptide Aß42. Importantly, NR SMOLM reveals the helical (bilayer) ribbon structure of both KFE8 and Aß42 and quantifies the precise tilt of the fibrils' inner and outer backbones in relevant buffer conditions without the need for covalent labeling or sequence mutations. SMOLM also distinguishes polymorphic branched and curved morphologies of KFE8, whose backbones exhibit much more heterogeneity than those of typical straight fibrils. Thus, SMOLM is a powerful tool to interrogate the structural differences and polymorphism between engineered and pathological cross-ß-rich fibrils.


Assuntos
Peptídeos beta-Amiloides , Microscopia , Conformação Proteica em Folha beta , Estrutura Secundária de Proteína , Peptídeos beta-Amiloides/química , Amiloide/química
7.
Proc Natl Acad Sci U S A ; 107(2): 622-7, 2010 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-20080728

RESUMO

The development of vaccines and other immunotherapies has been complicated by heterogeneous antigen display and the use of incompletely defined immune adjuvants with complex mechanisms of action. We have observed strong antibody responses in mice without the coadministration of any additional adjuvant by noncovalently assembling a T and B cell epitope peptide into nanofibers using a short C-terminal peptide extension. Self-assembling peptides have been explored recently as scaffolds for tissue engineering and regenerative medicine, but our results indicate that these materials may also be useful as chemically defined adjuvants. In physiological conditions, these peptides self-assembled into long, unbranched fibrils that displayed the epitope on their surfaces. IgG1, IgG2a, and IgG3 were raised against epitope-bearing fibrils in levels similar to the epitope peptide delivered in complete Freund's adjuvant (CFA), and IgM production was even greater for the self-assembled epitope. This response was dependent on self-assembly, and the self-assembling sequence was not immunogenic by itself, even when delivered in CFA. Undetectable levels of interferon-gamma, IL-2, and IL-4 in cultures of peptide-challenged splenocytes from immunized mice suggested that the antibody responses did not involve significant T cell help.


Assuntos
Adjuvantes Imunológicos/farmacologia , Imunoglobulina G/imunologia , Adjuvantes Imunológicos/uso terapêutico , Sequência de Aminoácidos , Animais , Linfócitos B/imunologia , Ensaio de Imunoadsorção Enzimática , Epitopos/imunologia , Adjuvante de Freund/imunologia , Adjuvante de Freund/farmacologia , Adjuvante de Freund/uso terapêutico , Imunoterapia/métodos , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Nanofibras , Ovalbumina/química , Ovalbumina/imunologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Conformação Proteica , Linfócitos T/imunologia , Engenharia Tecidual/métodos
8.
bioRxiv ; 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37745382

RESUMO

Synthetic peptides that self-assemble into cross-ß fibrils have remarkable utility as engineered biomaterials due to their modularity and biocompatibility, but their structural and morphological similarity to amyloid species has been a long-standing concern for their translation. Further, their polymorphs are difficult to characterize using spectroscopic and imaging techniques that rely on ensemble averaging to achieve high resolution. Here, we utilize single-molecule orientation-localization microscopy (SMOLM) to characterize fibrils formed by the designed amphipathic enantiomers, KFE8L and KFE8D, and the pathological amyloid-beta peptide Aß42. SMOLM reveals that the orientations of Nile red, as it transiently binds to both KFE8 and Aß42, are consistent with a helical (bilayer) ribbon structure and convey the precise tilt of the fibrils' inner and outer backbones. SMOLM also finds polymorphic branched and curved morphologies of KFE8 whose backbones exhibit much more heterogeneity than those of more typical straight fibrils. Thus, SMOLM is a powerful tool to interrogate the structural differences and polymorphism between engineered and pathological cross ß-rich fibrils.

9.
Acta Biomater ; 169: 464-476, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37586449

RESUMO

De novo designed peptides that self-assemble into cross-ß rich fibrillar biomaterials have been pursued as an innovative platform for the development of adjuvant- and inflammation-free vaccines. However, they share structural and morphological properties similar to amyloid species implicated in neurodegenerative diseases, which has been a long-standing concern for their successful translation. Here, we comprehensively characterize the amyloidogenic character of the amphipathic self-assembling cross-ß peptide KFE8, compared to pathological amyloid and amyloid-like proteins α-synuclein (α-syn) and TDP-43. Further, we developed plasmid-based DNA vaccines with the KFE8 backbone serving as a scaffold for delivery of a GFP model antigen. We find that expression of tandem repeats of KFE8 is non-toxic and efficiently cleared by autophagy. We also demonstrate that preformed KFE8 fibrils do not cross-seed amyloid formation of α-syn in mammalian cells compared to α-syn preformed fibrils. In mice, vaccination with plasmids encoding the KFE32-GFP fusion protein elicited robust immune responses, inducing production of significantly higher levels of anti-GFP antibodies compared to soluble GFP. Antigen-specific CD8+T cells were also detected in the spleens of vaccinated mice and cytokine profiles from antigen recall assays indicate a balanced Th1/Th2 response. These findings illustrate that cross-ß-rich peptide nanofibers have distinct physicochemical properties from those of pathological amyloidogenic proteins, and are an attractive platform for the development of DNA vaccines with self-adjuvanting properties and improved safety profiles. STATEMENT OF SIGNIFICANCE: Biomaterials comprised of self-assembling peptides hold great promise for the development of new vaccines that do not require use of adjuvants. However, these materials have safety concerns, as they self-assemble into cross-ß rich fibrils that are structurally similar to amyloid species implicated in disease. Here, we comprehensively study the properties of these biomaterials. We demonstrate that they have distinct properties from pathological proteins. They are non-toxic and do not trigger amyloidogenesis. Vaccination of these materials in mice elicited a robust immune response. Most excitingly, our work suggests that this platform could be used to develop DNA-based vaccines, which have few storage requirements. Further, due to their genetic encoding, longer sequences can be generated and the vaccines will be amenable to modification.


Assuntos
Vacinas de DNA , Camundongos , Animais , Peptídeos/química , Adjuvantes Imunológicos/farmacologia , Linfócitos T CD8-Positivos , Materiais Biocompatíveis , Mamíferos
10.
Front Microbiol ; 13: 1040105, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36466676

RESUMO

Development of novel immunization approaches to combat a growing list of emerging and ancient infectious agents is a global health priority. Intensive efforts over the last several decades have identified alternative approaches to improve upon traditional vaccines that are based on live, attenuated agents, or formulations of inactivated agents with adjuvants. Rapid advances in RNA-based and other delivery systems for immunization have recently revolutionized the potential to protect populations from viral pathogens, such as SARS-CoV-2. Similar efforts to combat bacterial pathogens, especially species with an intracellular niche, have lagged significantly. In the past decade, advances in nanotechnology have yielded a variety of new antigen/adjuvant carrier systems for use in vaccine development against infectious viruses and bacteria. The tunable properties of nanomaterial-based vaccines allow for balancing immunogenicity and safety which is a key hurdle in traditional antigen and adjuvant formulations. In this review, we discuss several novel nanoparticle-based vaccine platforms that show promise for use against intracellular bacteria as demonstrated by the feasibility of construction, enhanced antigen presentation, induction of cell mediated and humoral immune responses, and improved survival outcomes in in vivo models.

11.
NPJ Vaccines ; 7(1): 48, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35474079

RESUMO

Heterologous vaccine regimens could extend waning protection in the global population immunized with Mycobacterium bovis Bacille Calmette-Guerin (BCG). We demonstrate that pulmonary delivery of peptide nanofibers (PNFs) bearing an Ag85B CD4+ T cell epitope increased the frequency of antigen-specific T cells in BCG-primed mice, including heterogenous populations with tissue resident memory (Trm) and effector memory (Tem) phenotype, and functional cytokine recall. Adoptive transfer of dendritic cells pulsed with Ag85B-bearing PNFs further expanded the frequency and functional repertoire of memory CD4+ T cells. Transcriptomic analysis suggested that the adjuvanticity of peptide nanofibers is, in part, due to the release of damage-associated molecular patterns. A single boost with monovalent Ag85B PNF in BCG-primed mice did not reduce lung bacterial burden compared to BCG alone following aerosol Mtb challenge. These findings support the need for novel BCG booster strategies that activate pools of Trm cells with potentially diverse localization, trafficking, and immune function.

12.
Chem Soc Rev ; 39(9): 3413-24, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20603663

RESUMO

Extracellular matrices (ECMs) are challenging design targets for materials synthesis because they serve multiple biological roles, and they are composed of multiple molecular constituents. In addition, their composition and activities are dynamic and variable between tissues, and they are difficult to study mechanistically in physiological contexts. Nevertheless, the design of synthetic ECMs is a central consideration in applications such as regenerative medicine and 3D cell culture. In order to produce synthetic matrices having both multi-component construction and high levels of compositional definition, strategies based on molecular self-assembly are receiving increasing interest. These approaches are described in this tutorial review and compared with the structures and processes in native ECMs that serve as their inspiration.


Assuntos
Materiais Biocompatíveis/química , Matriz Extracelular/química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Animais , Humanos
13.
Acta Biomater ; 133: 153-167, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34010691

RESUMO

Currently approved replication-competent and inactivated vaccines are limited by excessive reactogenicity and poor safety profiles, while subunit vaccines are often insufficiently immunogenic without co-administering exogenous adjuvants. Self-assembling peptide-, peptidomimetic-, and protein-based biomaterials offer a means to overcome these challenges through their inherent modularity, multivalency, and biocompatibility. As these scaffolds are biologically derived and present antigenic arrays reminiscent of natural viruses, they are prone to immune recognition and are uniquely capable of functioning as self-adjuvanting vaccine delivery vehicles that improve humoral and cellular responses. Beyond this intrinsic immunological advantage, the wide range of available amino acids allows for facile de novo design or straightforward modifications to existing sequences. This has permitted the development of vaccines and immunotherapies tailored to specific disease models, as well as generalizable platforms that have been successfully applied to prevent or treat numerous infectious and non-infectious diseases. In this review, we briefly introduce the immune system, discuss the structural determinants of coiled coils, ß-sheets, peptide amphiphiles, and protein subunit nanoparticles, and highlight the utility of these materials using notable examples of their innate and adaptive immunomodulatory capacity. STATEMENT OF SIGNIFICANCE: Subunit vaccines have recently gained considerable attention due to their favorable safety profiles relative to traditional whole-cell vaccines; however, their reduced efficacy requires co-administration of reactogenic adjuvants to boost immune responses. This has led to collaborative efforts between engineers and immunologists to develop nanomaterial-based vaccination platforms that can elicit protection without deleterious side effects. Self-assembling peptidic biomaterials are a particularly attractive approach to this problem, as their structure and function can be controlled through primary sequence design and their capacity for multivalent presentation of antigens grants them intrinsic self-adjuvanticity. This review introduces the various architectures adopted by self-assembling peptides and discusses their application as modulators of innate and adaptive immunity.


Assuntos
Adjuvantes Imunológicos , Antígenos , Imunidade Adaptativa , Adjuvantes Imunológicos/farmacologia , Peptídeos , Vacinas de Subunidades Antigênicas
14.
Nat Biomed Eng ; 5(1): 64-76, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33483710

RESUMO

The detection and quantification of protein biomarkers in interstitial fluid is hampered by challenges in its sampling and analysis. Here we report the use of a microneedle patch for fast in vivo sampling and on-needle quantification of target protein biomarkers in interstitial fluid. We used plasmonic fluor-an ultrabright fluorescent label-to improve the limit of detection of various interstitial fluid protein biomarkers by nearly 800-fold compared with conventional fluorophores, and a magnetic backing layer to implement conventional immunoassay procedures on the patch and thus improve measurement consistency. We used the microneedle patch in mice for minimally invasive evaluation of the efficiency of a cocaine vaccine, for longitudinal monitoring of the levels of inflammatory biomarkers, and for efficient sampling of the calvarial periosteum-a challenging site for biomarker detection-and the quantification of its levels of the matricellular protein periostin, which cannot be accurately inferred from blood or other systemic biofluids. Microneedle patches for the minimally invasive collection and analysis of biomarkers in interstitial fluid might facilitate point-of-care diagnostics and longitudinal monitoring.


Assuntos
Biomarcadores/análise , Líquido Extracelular/química , Microtecnologia/instrumentação , Agulhas , Animais , Cocaína/análise , Citocinas/análise , Desenho de Equipamento , Feminino , Corantes Fluorescentes/química , Técnicas de Imunoadsorção/instrumentação , Limite de Detecção , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
15.
Artigo em Inglês | MEDLINE | ID: mdl-32373548

RESUMO

Tuberculosis relapse following drug treatment of active disease is an important global public health problem due to the poorer clinical outcomes and increased risk of drug resistance development. Concurrent infection with HIV, including in those receiving anti-retroviral therapy (ART), is an important risk factor for relapse and expansion of drug resistant Mycobacterium tuberculosis (Mtb) isolates. A greater understanding of the HIV-associated factors driving TB relapse is important for development of interventions that support immune containment and complement drug therapy. We employed the humanized mouse to develop a new model of post-chemotherapy TB relapse in the setting of HIV infection. Paucibacillary TB infection was observed following treatment with Rifampin and Isoniazid and subsequent infection with HIV-1 was associated with increased Mtb burden in the post-drug phase. Organized granulomas were observed during development of acute TB and appeared to resolve following TB drug therapy. At relapse, granulomatous pathology in the lung was infrequent and mycobacteria were most often observed in the interstitium and at sites of diffuse inflammation. Compared to animals with HIV mono-infection, higher viral replication was observed in the lung and liver, but not in the periphery, of animals with post-drug TB relapse. The results demonstrate a potential role for the humanized mouse as an experimental model of TB relapse in the setting of HIV. Long term, the model could facilitate discovery of disease mechanisms and development of clinical interventions.


Assuntos
Coinfecção , Infecções por HIV , Mycobacterium tuberculosis , Tuberculose , Animais , Antituberculosos/uso terapêutico , Coinfecção/tratamento farmacológico , Modelos Animais de Doenças , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Camundongos , Recidiva , Tuberculose/complicações , Tuberculose/tratamento farmacológico
16.
J Membr Biol ; 228(2): 111-24, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19294449

RESUMO

The sodium-bicarbonate cotransporter NBC1 is targeted exclusively at the basolateral membrane. Mutagenesis of a dihydrophobic FL motif (residues 1013-1014) in the C-terminal domain disrupts the targeting of NBC1. In the present study, we determined the precise constraints of the FL motif required for basolateral targeting of NBC1 by expressing epitope-tagged wild-type and mutant NBC1 in MDCK cells and RNA-injected Xenopus oocytes and examining their subcellular localization. We assayed the functional activity of the mutants by measuring bicarbonate-induced currents in oocytes. Wild-type NBC1 (containing PFLS) was expressed exclusively on the basolateral membrane in MDCK cells. Reversal of the FL motif (PLFS) had no effect on basolateral targeting or activity. Shifting the FL motif one residue upstream (FLPS) resulted in mistargeting of the apical membrane but the FLPS mutant retained its functional activity in oocytes. Shifting the FL motif one residue downstream resulted in a mutant (PSFL) that did not efficiently translocate to the plasma membrane and was instead colocalized with the ER marker, protein disulfide isomerase (PDI). Analysis of circular dichroism (CD) revealed that a short peptide, 20 amino acid residues, of wild-type NBC1 contained a significant alpha-helical structure, whereas peptides in which the FL motif was reversed or C-terminally shifted were disordered. We therefore propose that the specific orientation and the precise location of the FL motif in the primary sequence of NBC1 are strict requirements for the alpha-helical structure of the C-terminal cytoplasmic domain and for targeting of NBC1 to the basolateral membrane.


Assuntos
Mutação/genética , Simportadores de Sódio-Bicarbonato/genética , Simportadores de Sódio-Bicarbonato/metabolismo , Motivos de Aminoácidos , Animais , Western Blotting , Linhagem Celular , Dicroísmo Circular , Cães , Humanos , Microscopia Confocal , Oócitos , Estrutura Secundária de Proteína , Transporte Proteico/genética , Transporte Proteico/fisiologia , Simportadores de Sódio-Bicarbonato/química , Relação Estrutura-Atividade , Xenopus laevis
17.
ACS Appl Bio Mater ; 2(8): 3562-3572, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35030742

RESUMO

Three-dimensional matrices of collagen type I (Col I) are widely used in tissue engineering applications for its abundance in many tissues, bioactivity with many cell types, and excellent biocompatibility. Inspired by the structural role of lignin in a plant tissue, we found that sodium lignosulfonate (SLS) and an alkali-extracted lignin from switchgrass (SG) increased the stiffness of Col I gels. SLS and SG enhanced the stiffness of Col I gels from 52 to 670 Pa and 52 to 320 Pa, respectively, and attenuated shear-thinning properties, with the formulation of 1.8 mg/mL Col I and 5.0 mg/mL SLS or SG. In 2D cultures, the cytotoxicity of collagen-SLS to adipose-derived stromal cells was not observed and the cell viability was maintained over 7 days in 3D cultures. Collagen-SLS composites did not elicit immunogenicity when compared to SLS-only groups. Our collagen-SLS composites present a case that exploits lignins as an enhancer of mechanical properties of Col I without adverse cytotoxicity and immunogenicity for in vitro scaffolds or in vivo tissue repairs.

18.
Biomacromolecules ; 9(9): 2438-46, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18712921

RESUMO

Biomaterials constructed from self-assembling peptides, peptide derivatives, and peptide-polymer conjugates are receiving increasing attention as defined matrices for tissue engineering, controlled therapeutic release, and in vitro cell expansion, but many are constructed from peptide structures not typically found in the human extracellular matrix. Here we report a self-assembling biomaterial constructed from a designed peptide inspired by the coiled coil domain of human fibrin, the major protein constituent of blood clots and the provisional scaffold of wound healing. Targeted substitutions were made in the residues forming the interface between coiled coil strands for a 37-amino acid peptide from human fibrinogen to stabilize the coiled coil peptide bundle, while the solvent-exposed residues were left unchanged to provide a surface similar to that of the native protein. This peptide, which self-assembled into coiled coil dimers and tetramers, was then used to produce triblock peptide-PEG-peptide bioconjugates that self-assembled into viscoelastic hydrogel biomaterials.


Assuntos
Fibrina/química , Hidrogéis/química , Hidrogéis/síntese química , Peptídeos/química , Polietilenoglicóis/química , Sequência de Aminoácidos , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Humanos , Hidrogéis/farmacologia , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína
19.
Vaccine ; 36(4): 438-441, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29248267

RESUMO

Improving CD8+ T cell responses activated by subunit vaccination is crucial for improving vaccine efficacy and safety. Here we report a carrier-adjuvant system composed of self-assembling peptide nanofibers presenting an immunodominant antigen from herpes simplex virus (HSV) and toll-like receptor (TLR) agonists that induces robust effector and memory CD8+ T cell responses in mice. The effector function of vaccine-induced CD8+ T cells was influenced by the type of TLR agonist. The use of CpG (TLR9 agonist) resulted in significantly greater specific in vivo cytotoxicity and trended towards more cells producing both IFN-γ and TNF-α compared to gardiquimod (TLR7 agonist). Prime-boost immunization with peptide nanofibers combined with either adjuvant resulted in development of HSV-specific CD8+ memory T cells further demonstrating the capability of the carrier-adjuvant system to induce strong HSV-specific CD8+ T cell responses. Inclusion of peptide epitope-nanofibers in protein-based subunit vaccines should increase the functional spectrum of the vaccine-elicited immune response and protection.


Assuntos
Adjuvantes Imunológicos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Nanofibras , Peptídeos/imunologia , Receptores Toll-Like/agonistas , Sequência de Aminoácidos , Animais , Citotoxicidade Imunológica , Epitopos de Linfócito T/imunologia , Herpesvirus Humano 2/imunologia , Humanos , Memória Imunológica , Ativação Linfocitária/imunologia , Camundongos , Oligodesoxirribonucleotídeos/imunologia , Oligodesoxirribonucleotídeos/farmacologia , Peptídeos/química , Especificidade do Receptor de Antígeno de Linfócitos T , Vacinas de Subunidades Antigênicas/imunologia
20.
Methods Mol Biol ; 1777: 249-259, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29744840

RESUMO

Self-assembling peptides spontaneously associate into functional supramolecular scaffolds, which have found numerous biomedical applications. These molecular assemblies have applications in nerve regeneration, wound healing, and both prophylactic and therapeutic vaccination. They can also be useful tools for proliferation assays, sustained culture of difficult cell lines, or activation of cell lines for immunoassays. This protocol will describe the basic peptide synthesis and purification of model self-assembling peptide immunogen and methods for vaccinating mice, collecting lymph nodes, and stimulating cells ex vivo.


Assuntos
Técnicas de Química Sintética , Imunogenicidade da Vacina , Micro-Ondas , Multimerização Proteica , Vacinas de Subunidades Antigênicas/síntese química , Vacinas de Subunidades Antigênicas/imunologia , Animais , Cromatografia Líquida de Alta Pressão , Imunização , Linfonodos/imunologia , Camundongos , Nanofibras , Proteólise , Vacinas de Subunidades Antigênicas/química , Vacinas de Subunidades Antigênicas/isolamento & purificação
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