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1.
Mol Aspects Med ; 96: 101254, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38354548

RESUMO

Although significant advances in immunotherapy have revolutionized the treatment of many cancer types over the past decade, the field of vaccine therapy, an important component of cancer immunotherapy, despite decades-long intense efforts, is still transmitting signals of promises and awaiting strong data on efficacy to proceed with regulatory approval. The field of cancer vaccines faces standard challenges, such as tumor-induced immunosuppression, immune response in inhibitory tumor microenvironment (TME), intratumor heterogeneity (ITH), permanently evolving cancer mutational landscape leading to neoantigens, and less known obstacles: neoantigen gain/loss upon immunotherapy, the timing and speed of appearance of neoantigens and responding T cell clonotypes and possible involvement of immune interference/heterologous immunity, in the complex interplay between evolving tumor epitopes and the immune system. In this review, we discuss some key issues related to challenges hampering the development of cancer vaccines, along with the current approaches focusing on neoantigens. We summarize currently well-known ideas/rationales, thus revealing the need for alternative vaccine approaches. Such a discussion should stimulate vaccine researchers to apply out-of-box, unconventional thinking in search of new avenues to deal with critical, often yet unaddressed challenges on the road to a new generation of therapeutics and vaccines.


Assuntos
Vacinas Anticâncer , Neoplasias , Humanos , Antígenos de Neoplasias/genética , Vacinas Anticâncer/uso terapêutico , Neoplasias/terapia , Linfócitos T , Imunoterapia , Microambiente Tumoral
2.
BioDrugs ; 38(2): 249-257, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38280078

RESUMO

Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder. Multiple genetic and environmental factors leading to progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SN) and consequent depletion of dopamine were described. Current clinical approaches, such as dopamine replacement or deep brain stimulation using surgically implanted probes, provide symptomatic relief but cannot modify disease progression. Therefore, disease-modifying therapeutic tools are urgently needed. Immunotherapy approaches, including passive transfer of protective antibodies and their fragments, have shown therapeutic efficacy in several animal models of neurodegenerative diseases, including PD. Recombinant antibody fragments are promising alternatives to conventional full-length antibodies. Modern computational approaches and molecular biology tools, directed evolution methodology, and the design of tissue-penetrating fusion peptides allowed for the development of recombinant antibody fragments with superior specificity and affinity, reduced immunogenicity, the capacity to target hidden epitopes and cross the blood-brain barrier (BBB), higher solubility and stability, the ability to refold after heat denaturation, and inexpensive large-scale production. In addition, antibody fragments do not induce microglia Fcγ receptor (FcγR)-mediated proinflammatory response and tissue damage in the central nervous system (CNS), because they lack the Fc portion of the immunoglobulin molecule. In the present review, we summarized data on recombinant antibody fragments evaluated as immunotherapeutics in preclinical models of PD and discussed their potential for developing therapeutic and preventive protocols for patients with PD.


Assuntos
Doença de Parkinson , Animais , Humanos , Doença de Parkinson/terapia , Dopamina , Substância Negra , Anticorpos , Fragmentos de Imunoglobulinas , Imunoterapia
3.
Curr Neuropharmacol ; 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37646225

RESUMO

Recombinant antibody fragments are promising alternatives to full-length immunoglobulins, creating big opportunities for the pharmaceutical industry. Nowadays, antibody fragments such as antigen-binding fragments (Fab), single-chain fragment variable (scFv), single-domain antibodies (sdAbs), and bispecific antibodies (bsAbs) are being evaluated as diagnostics or therapeutics in pre-clinical models and in clinical trials. Immunotherapy approaches, including passive transfer of protective antibodies, have shown therapeutic efficacy in several animal models of Alzheimer ́s disease(AD), Parkinson ́s disease (PD), frontotemporal dementia (FTD), Huntington ́s disease (HD), transmissible spongiform encephalopathies (TSEs) and multiple sclerosis (MS). There are various antibodies approved by the Food and Drug Administration (FDA) for treating multiple sclerosis and two amyloid beta-specific humanized antibodies, Aducanumab and Lecanemab, for AD. Our previous review summarized data on recombinant antibodies evaluated in pre-clinical models for immunotherapy of neurodegenerative diseases. Here, we explore recent studies in this fascinating research field, give an update on new preventive and therapeutic applications of recombinant antibody fragments for neurological disorders and discuss the potential of antibody fragments for developing novel approaches for crossing the blood-brain barrier (BBB) and targeting cells and molecules of interest in the brain.

4.
Fish Shellfish Immunol ; 138: 108808, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37169114

RESUMO

The development of recombinant antibody fragments as promising alternatives to full-length immunoglobulins offers vast opportunities for biomedicine. Antibody fragments have important advantages compared with conventional monoclonal antibodies that make them attractive for the biotech industry: superior stability and solubility, reduced immunogenicity, higher specificity and affinity, capacity to target the hidden epitope and cross the blood-brain barrier, the ability to refold after heat denaturation and inexpensive and easy large-scale production. Different antibody formats such as antigen-binding fragments (Fab), single-chain fragment variable (scFv) consisting of the antigen-binding domains of Ig heavy (VH) and light (VL) chain regions connected by a flexible peptide linker, single-domain antibody fragments (sdAbs) like camelid heavy-chain variable domains (VHHs) and shark variable new antigen receptor (VNARs), and bispecific antibodies (bsAbs) are currently being evaluated as diagnostics or therapeutics in preclinical studies and clinical trials. In the present review, we summarize and discuss studies on VNARs, the smallest recombinant antibody fragment, obtained after the screening of different types of phage display antibody libraries. Results published until March 2023 are discussed.


Assuntos
Bacteriófagos , Tubarões , Animais , Fragmentos de Imunoglobulinas , Tubarões/genética , Proteínas Recombinantes/genética , Anticorpos Monoclonais , Biblioteca de Peptídeos
5.
Mol Immunol ; 157: 91-100, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37002957

RESUMO

Breast cancer is one of the leading causes of death that affects the female population worldwide. Despite advances in treatments and a greater understanding of the disease, there are still difficulties in successfully treating patients. Currently, the main challenge in the field of cancer vaccines is antigenic variability which can reduce antigen-specific T- cell response efficacy. The search for and validation of immunogenic antigen targets increased dramatically over the past few decades and, with the advent of modern sequencing techniques, permitting the fast and accurate identification of the neoantigen landscape of tumor cells, will undoubtedly continue to grow exponentially for years to come. We have previously implemented Variable Epitope Libraries (VEL) as an unconventional vaccine strategy in preclinical models and for identifying and selecting mutant epitope variants. Here, we used an alanine-based sequence to generate a 9-mer VEL-like combinatorial mimotope library G3d as a new class of vaccine immunogen. An in silico analysis of the 16,000 G3d-derived sequences revealed potential MHC-I binders and immunogenic mimotopes. We demonstrated the antitumor effect of treatment with G3d in the 4T1 murine model of breast cancer. Moreover, two different T cell proliferation screening assays against a panel of randomly selected G3d-derived mimotopes allowed the isolation of both stimulatory and inhibitory mimotopes showing differential therapeutic vaccine efficacy. Thus, the mimotope library is a promising vaccine immunogen and a reliable source for isolating molecular cancer vaccine components.


Assuntos
Neoplasias , Biblioteca de Peptídeos , Feminino , Animais , Camundongos , Epitopos , Modelos Animais de Doenças , Antígenos de Neoplasias
6.
Vaccine ; 40(33): 4796-4805, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35788294

RESUMO

The identification of novel targets for cancer immunotherapy and the development of new vaccine immunogens are subjects of permanent interest. MUC1 is an overexpressed antigen found in most tumors, and its overexpression correlates with poor prognosis. Many attempts to direct the immune response against MUC1 in tumor cells have failed, including several clinical trials. We have previously developed an innovative Variable Epitope Library (VEL) vaccine platform that carries massively substituted mutant variants of defined epitopes or epitope regions as an alternative to using wild-type peptide sequences-based immunogens. Here, two murine MUC1-derived epitopes equivalent to the previously tested in cancer immunotherapy human MUC1 regions were used to generate VELs. We observed that vaccination with the 23L VEL immunogens, encompassing the entire signal peptide region of MUC1, reduces the tumor area compared to the wild-type sequence treatment. Contrastingly, vaccination with the MUC1 signal peptide-derived predicted CD8++ T cell epitope-based VEL, 9MUC1spL, showed similar tumor area reduction as the wild-type treatment; however, a decrease in lung metastasis after 9MUC1spL treatment was observed. In addition, vaccination induced a large pool of CD8+ T cells which recognized most variant epitopes from 9MUC1spL. Also, we generated MUC1 variable number tandem repeat (VNTR)-based VELs that reduced the metastatic burden when dendritic cells and M13 recombinant bacteriophages were used as vaccine carriers. Collectively, our data demonstrate the immunogenic and antitumor properties of MUC1 signal peptide- and VNTR-derived VEL immunogens.


Assuntos
Neoplasias da Mama , Vacinas Anticâncer , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Linfócitos T CD8-Positivos , Modelos Animais de Doenças , Epitopos de Linfócito T/genética , Feminino , Humanos , Camundongos , Mucina-1/genética , Sinais Direcionadores de Proteínas
7.
Mol Immunol ; 139: 65-75, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34454186

RESUMO

After decades of cancer vaccine efforts, there is an imperious necessity for novel ideas that may result in better tumor control in patients. We have proposed the use of a novel Variable Epitope Library (VEL) vaccine strategy, which incorporates an unprecedented number of mutated epitopes to target antigenic variability and break tolerance against tumor-associated antigens. Here, we used an oncofetal antigen/immature laminin receptor protein-derived sequence to generate 9-mer and 43-mer VEL immunogens. 4T1 tumor-bearing mice developed epitope-specific CD8+IFN-γ+ and CD4+IFN-γ+ T cell responses after treatment. Tumor and lung analysis demonstrated that VELs could increase the number of tumor-infiltrating lymphocytes with diverse effector functions while reducing the number of immunosuppressive myeloid-derived suppressor and regulatory T cells. Most importantly, VEL immunogens inhibited tumor growth and metastasis after a single dose. The results presented here are consistent with our previous studies and provide evidence for VEL immunogens' feasibility as promising cancer immunotherapy.


Assuntos
Antígenos de Neoplasias/imunologia , Neoplasias da Mama , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/imunologia , Receptores de Laminina/imunologia , Animais , Vacinas Anticâncer/farmacologia , Modelos Animais de Doenças , Mapeamento de Epitopos/métodos , Feminino , Camundongos , Camundongos Endogâmicos BALB C
8.
Arch Immunol Ther Exp (Warsz) ; 69(1): 12, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33909124

RESUMO

In this communication, we will analyze some important factors and immunological phenomena related to neoantigen cancer vaccines, with particular emphasis on recently published Phase I clinical trials. Several obstacles and issues are addressed that challenge the current paradigm and inquire if neoantigens, which are essentially single-use vaccine candidates, are legitimate targets to induce protective immune responses with regard to the evolving mutational landscape. We also share insights into the striking similarities between cancer and antigenically variable pathogens and suggest that any successful vaccine against either should demonstrate a similar property: efficient induction of a diverse pool of immune cells equipped to prevent immune escape. Hence, to confront antigenic variability directly, we have employed our innovative vaccine concept, Variable Epitope Libraries, composed of large combinatorial libraries of heavily mutated epitopes, as a "universal" vaccine platform. Collectively, we offer critical analyses on key issues, which ultimately reflect on the prospective clinical relevance of personalized neoantigen vaccines which is still undefined.


Assuntos
Antígenos de Neoplasias/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Neoplasias/terapia , Desenvolvimento de Vacinas/métodos , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Ensaios Clínicos Fase I como Assunto , Epitopos/genética , Epitopos/imunologia , Humanos , Imunogenicidade da Vacina , Mutação , Neoplasias/genética , Neoplasias/imunologia , Resultado do Tratamento , Evasão Tumoral/genética , Desenvolvimento de Vacinas/tendências
9.
Cell Immunol ; 358: 104235, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33137645

RESUMO

Antibodies, T cell receptors and major histocompatibility complex molecules are members of the immunoglobulin superfamily and have pivotal roles in the immune system. The fine interrelation between them regulates several immune functions. Here, we describe lesser-known functions ascribed to these molecules in generating and maintaining immune response. Particularly, we outline the contribution of antibody- and T cell receptor-derived complementarity-determining region neoantigens, antigenized antibodies, as well as major histocompatibility complex class I molecules-derived epitopes to the induction of protective/therapeutic immune responses against pathogens and cancer. We discuss findings of our own and other studies describing protective mechanisms, based on immunogenic properties of immunoglobulin superfamily members, and evaluate the perspectives of application of this class of immunogens in molecular vaccines design.


Assuntos
Anticorpos/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Sequência de Aminoácidos/genética , Animais , Formação de Anticorpos , Epitopos/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunidade/imunologia , Cadeias Pesadas de Imunoglobulinas , Região Variável de Imunoglobulina , Imunoglobulinas/imunologia , Imunoglobulinas/metabolismo
10.
Immunology ; 161(2): 123-138, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32619293

RESUMO

Immune tolerance is the main challenge in the field of cancer vaccines, so modified peptide sequences or naturally occurring mutated versions of cancer-related wild-type (WT) antigens represent a promising pathway. However, the low immunogenicity of mutation-induced neoantigens and, particularly, their incapacity to activate CD8+ T cells are generating doubts on the success of neoantigen-based cancer vaccines in clinical trials. We developed a novel vaccine approach based on a new class of vaccine immunogens, called variable epitope libraries (VELs). We used three regions of survivin (SVN), composed of 40, 49 and 51 amino acids, along with the complete SVN protein to generate the VELs as multiepitope vaccines. BALB/c mice, challenged with the aggressive and highly metastatic 4T1 cell line, were vaccinated in a therapeutic setting. We showed significant tumor growth inhibition and, most importantly, strong suppression of lung metastasis after a single immunization using VEL vaccines. We demonstrated vaccine-induced broad cellular immune responses concomitant with extensive tumor infiltration of T cells, the activation of CD107a+  IFN-γ+ T cells in the spleen and a significant increase in the number of CD3+  CD8+  Ly6C+ effector T cells. In addition, we observed the presence of interferon-γ-, granzyme B- and perforin-producing lymphocytes along with modifications in the amount of CD11b+  Ly6Cint/low  Ly6G+ granulocytic myeloid-derived suppressor cells and CD4+  CD25+  FoxP3+ regulatory T cells in the lungs and tumors of mice. In summary, we showed that the VELs represent a potent new class of cancer immunotherapy and propose the application of the VEL vaccine concept as a true alternative to currently available vaccine platforms.


Assuntos
Neoplasias da Mama/imunologia , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/imunologia , Imunoterapia/métodos , Linfócitos do Interstício Tumoral/imunologia , Células Supressoras Mieloides/imunologia , Survivina/metabolismo , Linfócitos T Reguladores/imunologia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Biblioteca de Peptídeos , Survivina/genética , Survivina/imunologia , Vacinação
11.
Int J Biol Macromol ; 121: 829-838, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30336243

RESUMO

It is generally accepted that carbohydrate binding modules (CBMs) recognize their carbohydrate ligands by hydrophobic and CH-π interactions. Point mutations of one CBM26 of the Lactobacillus amylovorus α-amylase starch-binding domain (LaCBM26) showed that conserved non-aromatic residue are essential in the starch recognition function of the domain, as the mutation of a single glutamine (Q68L) eliminates binding to starch and ß-cyclodextrin, even in the presence of aromatic amino acids necessary for ligand binding. The secondary structure of mutated proteins was verified and showed no differences from the wild-type domain. However, random mutations of five residues involved in binding (Y18, Y20, Q68, E74, and F77) did cause change in the secondary structure of the protein, which also causes loss of function. Much of the diversity introduced in the LaCBM26 was probably incompatible with the appropriate folding of these proteins, suggesting that the domain has little tolerance to change.


Assuntos
Sequência Conservada , Lactobacillus acidophilus/enzimologia , Amido/metabolismo , alfa-Amilases/química , alfa-Amilases/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Glucanos/metabolismo , Mutagênese , Mutação Puntual , Ligação Proteica , Domínios Proteicos , Homologia de Sequência de Aminoácidos , alfa-Amilases/genética
12.
Data Brief ; 21: 1944-1949, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30519620

RESUMO

Carbohydrate-binding modules (CBMs) are auxiliary domains into glycoside-hydrolases that allow the interaction between the insoluble substrate and the solubilized enzyme, through hydrophobic, CH-π interactions and hydrogen bonds. Here, we present the data article related to the interaction of one LaCBM26 and some mutated proteins with soluble α-glucans determined by enzyme-linked carbohydrate-binding assay, isothermal titration calorimetry (ITC), and affinity gel electrophoresis (AGE). The data of the behavior of proteins in presence and absence of substrate analyzed by circular dichroism CD and thermofluor are also presented. These results are complementary to the research article "The role of conserved non-aromatic residues in the Lactobacillus amylovorus α-amylase CBM26-starch interaction" (Armenta et al., 2019).

13.
Immunol Lett ; 204: 47-54, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30339819

RESUMO

Although various immune checkpoint inhibitors (ICIs), used for the treatment of advanced cancer, showed remarkably durable tumor regression in a subset of patients, there are important limitations in a large group of non-responders, and the generation of novel immunogens capable of inducing protective cellular immune responses is a priority in cancer immunotherapy field. During the last decades, several types of vaccine immunogens have been used in numerous preclinical studies and clinical trials. However, although immunity to tumor Ags can be elicited by most vaccines tested, their clinical efficacy remains modest. Recently, we have developed an innovative vaccine concept, called Variable Epitope Libraries (VELs), with the purpose to exploit the high antigenic variability of many important pathogens and tumor cells as starting points for the construction of a new class of vaccine immunogens capable of inducing the largest possible repertoire of both B and T cells. In the present study, we decided to generate VEL immunogens derived from both classical and non-classical major histocompatibility complex (MHC) class I molecules. The MHC molecules, responsible for antigen presentation and subsequent activation of T lymphocytes, undergo multiple modifications that directly affect their proper function, resulting in immune escape of tumor cells. Two large VELs derived from multi-epitope region of H2-Kd and Qa-2 sequences (46 and 34 amino acids long, respectively), along with their wild type counterparts have been generated as synthetic peptides and tested in an aggressive 4T1 mouse model of breast cancer. Significant inhibition of tumor growth and the reduction of metastatic lesions in the lungs of immunized mice were observed. This study demonstrated for the first time the successful application of VELs carrying combinatorial libraries of epitope variants derived from MHC class I molecules as novel vaccine immunogens.


Assuntos
Vacinas Anticâncer/imunologia , Epitopos/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Animais , Vacinas Anticâncer/genética , Proliferação de Células , Modelos Animais de Doenças , Epitopos/genética , Feminino , Biblioteca Gênica , Humanos , Imunidade , Camundongos , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Vacinação
14.
Curr Neuropharmacol ; 15(5): 779-788, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27697033

RESUMO

BACKGROUND: Recombinant antibody fragments are promising alternatives to full-length immunoglobulins and offer important advantages compared with conventional monoclonal antibodies: extreme specificity, higher affinity, superior stability and solubility, reduced immunogenicity as well as easy and inexpensive large-scale production. OBJECTIVE: In this article we will review and discuss recombinant antibodies that are being evaluated for neurodegenerative diseases in pre-clinical models and in clinical studies and will summarize new strategies that are being developed to optimize their stability, specificity and potency for advancing their use. METHODS: Articles describing recombinant antibody fragments used for neurological diseases were selected (PubMed) and evaluated for their significance. RESULTS: Different antibody formats such as single-chain fragment variable (scFv), single-domain antibody fragments (VHHs or sdAbs), bispecific antibodies (bsAbs), intrabodies and nanobodies, are currently being studied in pre-clinical models of cancer as well as infectious and autoimmune diseases and many of them are being tested as therapeutics in clinical trials. Immunotherapy approaches have shown therapeutic efficacy in several animal models of Alzheimer´s disease (AD), Parkinson disease (PD), dementia with Lewy bodies (DLB), frontotemporal dementia (FTD), Huntington disease (HD), transmissible spongiform encephalopathies (TSEs) and multiple sclerosis (MS). It has been demonstrated that recombinant antibody fragments may neutralize toxic extra- and intracellular misfolded proteins involved in the pathogenesis of AD, PD, DLB, FTD, HD or TSEs and may target toxic immune cells participating in the pathogenesis of MS. CONCLUSION: Recombinant antibody fragments represent a promising tool for the development of antibody-based immunotherapeutics for neurodegenerative diseases.


Assuntos
Imunização Passiva/métodos , Fragmentos de Imunoglobulinas/imunologia , Doenças Neurodegenerativas , Proteínas Recombinantes/imunologia , Animais , Anticorpos/sangue , Anticorpos/uso terapêutico , Humanos , Doenças Neurodegenerativas/sangue , Doenças Neurodegenerativas/imunologia , Doenças Neurodegenerativas/terapia
15.
Hum Vaccin Immunother ; 10(11): 3201-13, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25483665

RESUMO

The antigenic variability of tumor cells leading to dynamic changes in cancer epitope landscape along with escape from immune surveillance by down-regulating tumor antigen expression/presentation and immune tolerance are major obstacles for the design of effective vaccines. We have developed a novel concept for immunogen construction based on introduction of massive mutations within the epitopes targeting antigenically variable pathogens and diseases. Previously, we showed that these immunogens carrying large combinatorial libraries of mutated epitope variants, termed as variable epitope libraries (VELs), induce potent, broad and long lasting CD8+IFN-γ+ T-cell response as well as HIV-neutralizing antibodies. In this proof-of-concept study, we tested immunogenic properties and anti-tumor effects of the VELs bearing survivin-derived CTL epitope (GWEPDDNPI) variants in an aggressive metastatic mouse 4T1 breast tumor model. The constructed VELs had complexities of 10,500 and 8,000 individual members, generated as combinatorial M13 phage display and synthetic peptide libraries, respectively, with structural composition GWXPXDXPI, where X is any of 20 natural amino acids. Statistically significant tumor growth inhibition was observed in BALB/c mice immunized with the VELs in both prophylactic and therapeutic settings. Vaccinated mice developed epitope-specific spleen cell and CD8+ IFN-γ+ T-cell responses that recognize more than 50% of the panel of 87 mutated epitope variants, as demonstrated in T-cell proliferation assays and FACS analysis. These data indicate the feasibility of the application of this new class of immunogens based on VEL concept as an alternative approach for the development of molecular vaccines against cancer.


Assuntos
Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/imunologia , Proteínas Inibidoras de Apoptose/genética , Neoplasias Mamárias Experimentais/imunologia , Proteínas Repressoras/genética , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Neoplasias/imunologia , Linfócitos T CD4-Positivos/imunologia , Proliferação de Células , Células Cultivadas , Epitopos de Linfócito T/genética , Feminino , Tolerância Imunológica/imunologia , Interferon gama/imunologia , Ativação Linfocitária/imunologia , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/prevenção & controle , Camundongos , Camundongos Endogâmicos BALB C , Biblioteca de Peptídeos , Survivina , Evasão Tumoral/imunologia , Vacinação , Vacinas Sintéticas/imunologia
16.
J Cancer Res Clin Oncol ; 140(2): 291-301, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24337403

RESUMO

PURPOSE: Glioblastoma multiforme is the most frequent primary brain tumor, it has poor prognosis, and it remains refractory to current treatment. The success of temozolomide (TMZ) appears to be limited by the occurrence of chemoresistance. Recently, we report the use of pertussis toxin as adjuvant immunotherapy in a C6 glioma model; showing a decrease in tumoral size, it induced selective cell death in Treg cells, and it elicited less infiltration of tumoral macrophages. Here, we evaluated the cytotoxic effect of pertussis toxin in combination with TMZ for glioma treatment, both in vitro and in vivo RG2 glioma model. METHODS: We determined cell viability, cell cycle, apoptosis, and autophagy on treated RG2 cells through flow cytometry, immunofluorescence, and Western blot assays. Twenty-eight rats were divided in four groups (n = 7) for each treatment. After intracranial implantation of RG2 cells, animals were treated with TMZ (10 mg/Kg/200 µl of apple juice), PTx (2 µg/200 µl of saline solution), and TMZ + PTx. Animals without treatment were considered as control. RESULTS: We found an induction of apoptosis in around 20 % of RG2 cells, in both single treatments and in their combination. Also, we determined the presence of autophagy vesicles, without any modifications in the cell cycle in the TMZ - PTx-treated groups. The survival analyses showed an increase due to individual treatments; while in the group treated with the combination TMZ - PTx, this effect was enhanced. CONCLUSION: We show that the concomitant use of pertussis toxin plus TMZ could represent an advantage to improve the glioma treatment.


Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Dacarbazina/análogos & derivados , Modelos Animais de Doenças , Glioma/tratamento farmacológico , Glioma/mortalidade , Toxina Pertussis/uso terapêutico , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptose/efeitos dos fármacos , Autofagia , Western Blotting , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Dacarbazina/uso terapêutico , Glioma/patologia , Masculino , Ratos , Ratos Wistar , Taxa de Sobrevida , Temozolomida
17.
PLoS One ; 7(8): e42344, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22927926

RESUMO

Extracellular and intraneuronal accumulation of amyloid-beta aggregates has been demonstrated to be involved in the pathogenesis of Alzheimer's disease (AD). However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of macromolecules has deleterious effects on cellular functions. Mitochondria were found to be the target for amyloid-beta, and mitochondrial dysfunction is well documented in AD. In the present study we have shown for the first time that Aß 1-42 bound to a peptide comprising the amino-terminal region of cytochrome c oxidase subunit 1. Phage clone, selected after screening of a human brain cDNA library expressed on M13 phage and bearing a 61 amino acid fragment of cytochrome c oxidase subunit 1, bound to Aß 1-42 in ELISA as well as to Aß aggregates present in AD brain. Aß 1-42 and cytochrome c oxidase subunit 1 co-immunoprecipitated from mitochondrial fraction of differentiated human neuroblastoma cells. Likewise, molecular dynamics simulation of the cytochrome c oxidase subunit 1 and the Aß 1-42 peptide complex resulted in a reliable helix-helix interaction, supporting the experimental results. The interaction between Aß 1-42 and cytochrome c oxidase subunit 1 may explain, in part, the diminished enzymatic activity of respiratory chain complex IV and subsequent neuronal metabolic dysfunction observed in AD.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Peptídeos beta-Amiloides/química , Animais , Bovinos , Complexo IV da Cadeia de Transporte de Elétrons/química , Humanos , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Ligação Proteica , Multimerização Proteica , Estrutura Secundária de Proteína
18.
Vaccine ; 29(32): 5313-21, 2011 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-21600948

RESUMO

The extreme antigenic variability of human immunodeficiency virus (HIV) leads to immune escape of the virus, representing a major challenge in the design of effective vaccine. We have developed a novel concept for immunogen construction based on introduction of massive mutations within the epitopes targeting antigenically variable pathogens and diseases. Previously, we showed that these immunogens carrying large combinatorial libraries of mutated epitope variants, termed as variable epitope libraries (VELs), induce potent, broad and long lasting CD8+IFN-γ+ T-cell response. Moreover, we demonstrated that these T cells recognize more than 50% of heavily mutated variants (5 out of 10 amino acid positions were mutated in each epitope variant) of HIV-1 gp120 V3 loop-derived cytotoxic T lymphocyte epitope (RGPGRAFVTI) in mice. The constructed VELs had complexities of 10000 and 12500 individual members, generated as plasmid DNA or as M13 phage display combinatorial libraries, respectively, and with structural composition RGPGXAXXXX or XGXGXAXVXI, where X is any of 20 natural amino acids. Here, we demonstrated that sera from mice immunized with these VELs are capable of neutralizing 5 out of 10 viral isolates from Tier 2 reference panel of subtype B envelope clones, including HIV-1 isolates which are known to be resistant to neutralization by several potent monoclonal antibodies, described previously. These data indicate the feasibility of the application of immunogens based on VEL concept as an alternative approach for the development of molecular vaccines against antigenically variable pathogens.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Formação de Anticorpos , Epitopos/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Animais , Bases de Dados de Proteínas , Feminino , Biblioteca Gênica , Proteína gp120 do Envelope de HIV/imunologia , Evasão da Resposta Imune , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Fragmentos de Peptídeos/imunologia , Linfócitos T Citotóxicos/imunologia
19.
Vet Parasitol ; 176(1): 53-8, 2011 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-21251758

RESUMO

This paper provides macroscopic and histological evidence on the statistically significant protective effects of S3Pvac-phage vaccination against porcine cysticercosis and hydatidosis. The study included 391 rustically bred pigs (187 vaccinated and 204 controls). Vaccination significantly reduced the prevalence of cysticercosis by 61.7%. Vaccination also significantly reduced by 56.1% the prevalence of hydatidosis caused by Echinococcus granulosus in pigs. The presence of the vaccine epitopes in both cestodes is probably involved in the cross-protection observed. Increased inflammation was found in 5% of cysticerci recovered from controls, versus 24% from vaccinated pigs (P<0.01). Hydatid cysts were non-inflammatory in either group. Vaccination was effective to prevent one single disease, but it failed to prevent the simultaneous infections with both parasites in a same pig. The widening of the S3Pvac-phage vaccine protective repertoire to include hydatidosis is a convenient feature that should reduce the prevalence of two frequent zoonoses that affect rustic porcine breading with a single action. Thus, the costs of two different vaccination programs would be reduced to a single one with significant reduction in both zoonoses.


Assuntos
Cisticercose/veterinária , Equinococose/veterinária , Proteínas de Helminto/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas/imunologia , Animais , Cisticercose/prevenção & controle , Equinococose/prevenção & controle , Proteínas de Helminto/genética , Proteínas Recombinantes , Suínos , Doenças dos Suínos/parasitologia
20.
J Biomol Screen ; 15(10): 1268-73, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20974903

RESUMO

In this study, the authors have generated a tapeworm Taenia solium genomic DNA expression library where foreign peptides/proteins were fused to N-termini of M13 cpVIII and expressed at a high copy number on the phage surface, and they showed that this library may be used in bioselection against antipathogen immune sera, allowing the identification of disease-related antigens recognizing antibodies present in clinical samples. They isolated 2 phage clones expressing T. solium-derived antigens specifically reacting with antibodies present in plasma and cerebrospinal fluid samples of neuroimaging-confirmed neurocysticercosis patients. The described antigen discovery strategy may be used for the direct identification of antigens useful for host-pathogen interaction studies as well as for the development of molecular vaccines and diagnostics.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/líquido cefalorraquidiano , Anticorpos Anti-Helmínticos/imunologia , Neurocisticercose/imunologia , Taenia solium/imunologia , Animais , Anticorpos Anti-Helmínticos/genética , Antígenos de Helmintos/genética , Antígenos de Helmintos/imunologia , Bacteriófago M13/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Biblioteca Genômica , Interações Hospedeiro-Parasita , Humanos , Imunoglobulina G/líquido cefalorraquidiano , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Neurocisticercose/diagnóstico , Biblioteca de Peptídeos , Taenia solium/genética
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