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1.
Cancer Immunol Immunother ; 68(9): 1401-1415, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31414180

RESUMO

Although CAR T-cell therapy has demonstrated tremendous clinical efficacy especially in hematological malignancies, severe treatment-associated toxicities still compromise the widespread application of this innovative technology. Therefore, developing novel approaches to abrogate CAR T-cell-mediated side effects is of great relevance. Several promising strategies pursue the selective antibody-based depletion of adoptively transferred T cells via elimination markers. However, given the limited half-life and tissue penetration, dependence on the patients' immune system and on-target/off-side effects of proposed monoclonal antibodies, we sought to exploit αCAR-engineered T cells to efficiently eliminate CAR T cells. For comprehensive and specific recognition, a small peptide epitope (E-tag) was incorporated into the extracellular spacer region of CAR constructs. We provide first proof-of-concept for targeting this epitope by αE-tag CAR T cells, allowing an effective killing of autologous E-tagged CAR T cells both in vitro and in vivo whilst sparing cells lacking the E-tag. In addition to CAR T-cell cytotoxicity, the αE-tag-specific T cells can be empowered with cancer-fighting ability in case of relapse, hence, have versatile utility. Our proposed methodology can most probably be implemented in CAR T-cell therapies regardless of the targeted tumor antigen aiding in improving overall safety and survival control of highly potent gene-modified cells.


Assuntos
Epitopos de Linfócito T/genética , Imunoterapia Adotiva/métodos , Fragmentos de Peptídeos/genética , Neoplasias da Próstata/terapia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos Quiméricos/genética , Linfócitos T Citotóxicos/imunologia , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Autoantígenos/imunologia , Citotoxicidade Imunológica , Epitopos de Linfócito T/imunologia , Engenharia Genética , Humanos , Masculino , Camundongos , Recidiva Local de Neoplasia , Células PC-3 , Neoplasias da Próstata/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Cancer Immunol Immunother ; 68(8): 1331-1340, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31317218

RESUMO

Expression of inhibitors of apoptosis protein (IAP) family members is associated with poor prognosis in cancer patients. Immunity to ML-IAP (livin) and survivin has been well studied in patients with a variety of tumors. XIAP, the most potent inhibitor of apoptosis, is widely expressed in melanoma. To better define its potential role as an immunogenic target, cellular and humoral responses to XIAP were investigated in patients with advanced melanoma. An overlapping peptide library covering the full length of the XIAP protein was used to screen T cell responses of peripheral blood mononuclear cells (PBMC) from stage-IV melanoma patients treated with or without anti-CTLA4 (ipilimumab). The screen identified an array of peptides that predominantly induced CD4+ T cell responses. XIAP epitope-specific CD4+ T cells revealed proliferative responses to melanoma cells that express XIAP. Humoral responses to XIAP were also explored. Cellular and humoral responses to XIAP were associated with beneficial clinical outcomes after ipilimumab-based treatment, supporting XIAP as a potential therapeutic target.


Assuntos
Antineoplásicos/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Imunoterapia/métodos , Ipilimumab/uso terapêutico , Melanoma/imunologia , Fragmentos de Peptídeos/imunologia , Neoplasias Cutâneas/imunologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/imunologia , Proliferação de Células , Células Cultivadas , ELISPOT , Humanos , Imunidade Humoral , Ativação Linfocitária , Melanoma/tratamento farmacológico , Estadiamento de Neoplasias , Neoplasias Cutâneas/tratamento farmacológico , Resultado do Tratamento
3.
Cancer Immunol Immunother ; 68(8): 1245-1261, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31222486

RESUMO

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


Assuntos
Aminopeptidases/metabolismo , Antígenos de Neoplasias/metabolismo , Antineoplásicos/farmacologia , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/metabolismo , Imunoterapia/métodos , Melanoma/tratamento farmacológico , Antígenos de Histocompatibilidade Menor/metabolismo , Peptídeos/metabolismo , Inibidores de Proteases/farmacologia , Linfócitos T Citotóxicos/imunologia , Aminopeptidases/antagonistas & inibidores , Apresentação do Antígeno , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imunogenicidade da Vacina , Ativação Linfocitária , Terapia de Alvo Molecular , Peptídeos/genética , Peptídeos/imunologia , Ligação Proteica
4.
Pol J Microbiol ; 68(2): 233-246, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250594

RESUMO

The aim of this study was to identify the potential vaccine antigens in Corynebacterium diphtheriae strains by in silico analysis of the amino acid variation in the 67-72p surface protein that is involved in the colonization and induction of epithelial cell apoptosis in the early stages of infection. The analysis of pili structural proteins involved in bacterial adherence to host cells and related to various types of infections was also performed. A polymerase chain reaction (PCR) was carried out to amplify the genes encoding the 67-72p protein and three pili structural proteins (SpaC, SpaI, SapD) and the products obtained were sequenced. The nucleotide sequences of the particular genes were translated into amino acid sequences, which were then matched among all the tested strains using bioinformatics tools. In the last step, the affinity of the tested proteins to major histocompatibility complex (MHC) classes I and II, and linear B-cell epitopes was analyzed. The variations in the nucleotide sequence of the 67-72p protein and pili structural proteins among C. diphtheriae strains isolated from various infections were noted. A transposition of the insertion sequence within the gene encoding the SpaC pili structural proteins was also detected. In addition, the bioinformatics analyses enabled the identification of epitopes for B-cells and T-cells in the conserved regions of the proteins, thus, demonstrating that these proteins could be used as antigens in the potential vaccine development. The results identified the most conserved regions in all tested proteins that are exposed on the surface of C. diphtheriae cells.The aim of this study was to identify the potential vaccine antigens in Corynebacterium diphtheriae strains by in silico analysis of the amino acid variation in the 67­72p surface protein that is involved in the colonization and induction of epithelial cell apoptosis in the early stages of infection. The analysis of pili structural proteins involved in bacterial adherence to host cells and related to various types of infections was also performed. A polymerase chain reaction (PCR) was carried out to amplify the genes encoding the 67­72p protein and three pili structural proteins (SpaC, SpaI, SapD) and the products obtained were sequenced. The nucleotide sequences of the particular genes were translated into amino acid sequences, which were then matched among all the tested strains using bioinformatics tools. In the last step, the affinity of the tested proteins to major histocompatibility complex (MHC) classes I and II, and linear B-cell epitopes was analyzed. The variations in the nucleotide sequence of the 67­72p protein and pili structural proteins among C. diphtheriae strains isolated from various infections were noted. A transposition of the insertion sequence within the gene encoding the SpaC pili structural proteins was also detected. In addition, the bioinformatics analyses enabled the identification of epitopes for B-cells and T-cells in the conserved regions of the proteins, thus, demonstrating that these proteins could be used as antigens in the potential vaccine development. The results identified the most conserved regions in all tested proteins that are exposed on the surface of C. diphtheriae cells.


Assuntos
Adesinas Bacterianas/genética , Antígenos de Bactérias/genética , Corynebacterium diphtheriae/genética , Toxoide Diftérico/genética , Difteria/prevenção & controle , Variação Genética , Proteínas de Membrana/genética , Adesinas Bacterianas/imunologia , Antígenos de Bactérias/imunologia , Biologia Computacional , Sequência Conservada , Corynebacterium diphtheriae/imunologia , Toxoide Diftérico/imunologia , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Proteínas de Membrana/imunologia , Reação em Cadeia da Polimerase , Ligação Proteica , Análise de Sequência de DNA
5.
Nat Commun ; 10(1): 2846, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253788

RESUMO

The magnitude of T cell responses to infection is a function of the naïve T cell repertoire combined with the context and duration of antigen presentation. Using mass spectrometry, we identify and quantify 21 class 1 MHC-restricted influenza A virus (IAV)-peptides following either direct or cross-presentation. All these peptides, including seven novel epitopes, elicit T cell responses in infected C57BL/6 mice. Directly presented IAV epitopes maintain their relative abundance across distinct cell types and reveal a broad range of epitope abundances. In contrast, cross-presented epitopes are more uniform in abundance. We observe a clear disparity in the abundance of the two key immunodominant IAV antigens, wherein direct infection drives optimal nucleoprotein (NP)366-374 presentation, while cross-presentation is optimal for acid polymerase (PA)224-233 presentation. The study demonstrates how assessment of epitope abundance in both modes of antigen presentation is necessary to fully understand the immunogenicity and response magnitude to T cell epitopes.


Assuntos
Apresentação do Antígeno/fisiologia , Epitopos de Linfócito T/fisiologia , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/imunologia , Linfócitos T Citotóxicos/fisiologia , Animais , Linhagem Celular , Epitopos de Linfócito T/imunologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , Análise Multivariada , Infecções por Orthomyxoviridae/virologia
6.
Mol Immunol ; 112: 93-102, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31079006

RESUMO

Multiepitope cancer vaccines are announcing themselves as the future of melanoma treatment. Herein, high immunogenic regions of transmembrane protein 31 (TMEM31) antigen were selected according to cytotoxic T lymphocytes' (CTL) epitopes and major histocompatibility complex (MHC) binding affinity through in silico analyses. The 32-62, 77-105, and 125-165 residues of the TMEM31 were selected as the immunodominant fragments. They were linked together by RVRR and HEYGAEALERAG motifs to improve epitopes separation and presentation. In addition, to activate helper T lymphocytes (HTL), Pan HLA DR-binding epitope (PADRE) peptide sequence and tetanus toxin fragment C (TTFrC) were incorporated into the final construct. Also, the Beta-defensin conserved domain was utilized in the final construct as a novel adjuvant for Toll-like receptor 4/myeloid differentiation factor (TLR4-MD) activation. The CTL epitopes, cleavage sites, post-translational modifications, TAP transport efficiency, and B cells epitopes were predicted for the peptide vaccine. The final construct contained multiple CTL and B cell epitopes. In addition, it showed 93.55% and 99.13% population coverage in the world for HLA I and HLA II, respectively. According to these preliminary results, the multiepitope cancer vaccine can be an appropriate choice for further experimental investigations.


Assuntos
Vacinas Anticâncer/imunologia , Melanoma/imunologia , Proteínas de Membrana/imunologia , Vacinas de DNA/imunologia , Simulação por Computador , DNA/imunologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Humanos , Vacinas Antimaláricas/imunologia , Fragmentos de Peptídeos/imunologia , Peptídeos/imunologia , Processamento de Proteína Pós-Traducional/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Toxina Tetânica/imunologia
7.
Mol Immunol ; 112: 151-162, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31108423

RESUMO

Pb27 antigen is an interesting alternative to immunological diagnosis of Paracoccidioidomycosis (PCM) and has demonstrated to be protective in experimental PCM. Its tertiary structure and possible function remained unknown till now. To study Pb27 at the atomic level, the recombinant protein was expressed in Escherichia coli BL21(DE3), purified, and its three-dimensional structure was solved by X-ray crystallography. Based on this structure, we performed a residue correlation analysis and in silico ligand search assays to address a possible biological function to Pb27. We identified Pb27 as a member of the extensive nucleotidyltransferase superfamily. The protein has an αßαßαß topology with two domains (N- and C-terminal domains) and adopts a monomeric form as its biological unit in solution. Structural comparisons with similar members of the superfamily clearly indicate Pb27 C-terminal domain is singular and may play an important role in its biological function. Bioinformatics analysis suggested that Pb27 might bind to ATP and CTP. This suggestion is corroborated by the fact that a magnesium cation is coordinated by two aspartic acid residues present at the active site (between N- and C-terminal domains), as evidenced by X-ray diffraction data. Besides, NMR assays (1H-15N HSQC spectra) confirmed the binding of CTP to Pb27, demonstrating for the first time an interaction between a nucleotide and this protein. Moreover, we evaluated the reactivity of sera from patients with Paracoccidioides brasiliensis infection against the recombinant form of Pb27 and showed that it was recognized by sera from infected and treated patients. Predicted B and T cell epitopes were synthesized and further evaluated against sera of PCM patients, providing information of the most reactive peptides in Pb27 primary structure which interact with specific Pb27 antibodies.


Assuntos
Proteínas Fúngicas/imunologia , Nucleotidiltransferases/imunologia , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Trifosfato de Adenosina/imunologia , Adolescente , Adulto , Idoso , Sequência de Aminoácidos , Citidina Trifosfato/imunologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Escherichia coli/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/imunologia , Adulto Jovem
8.
Microb Pathog ; 132: 243-253, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31075428

RESUMO

Ebola virus (EBOV), a non-segmented single-stranded RNA virus, is often-most transmitted through body fluids like sweat, tears, saliva, and nasal secretions. Till date, there is no licensed vaccine of EBOV is available in the market; however, the world is increasingly vulnerable to this emerging threat. Hence, it is the need of time to develop a vaccine for EBOV to hinder its dissemination. The current study has been designed for identification and characterization of the potential B and T-cell epitopes using the Immuno-informatics tools, and it helped in finding the potent vaccine candidates against EBOV. Prediction, antigenicity and allergenicity testing of predicted B and T cells' epitopes was done as well to identify their potential as a vaccine candidate and to measure their safety level respectively. Among B-cell epitopes "WIPAGIGVTGVIIA" showed a high antigenicity score and it would play an important role in evoking the immune response. In T-cell epitopes, peptides "AIGLAWIPY" and "IRGFPRCRY" presented high antigenicity score, which binds to MHC class-I and MHC class-II alleles respectively. All predicted epitopes were analyzed and compared with already reported peptides carefully. Comparatively, Peptides predicted in the present study showed more immunogenicity score than already reported peptides, used as positive control, and are more immunogenic as compared to them. Peptides reported in the present study do not target only Zaire EBOV (ZEBOV), as in previous studies, but also other species, i.e. Tai Forest EBOV (TAFV), Sudan EBOV (SUDV), Bundibugyo EBOV (BDBV), and Reston EBOV (RESTV) and would bring the promising results as potent vaccine candidates.


Assuntos
Vacinas contra Ebola/imunologia , Ebolavirus/imunologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Glicoproteínas/imunologia , Alelos , Sequência de Aminoácidos , Vacinas contra Ebola/genética , Ebolavirus/genética , Genes MHC Classe I , Genes MHC da Classe II , Glicoproteínas/química , Glicoproteínas/genética , Antígeno HLA-B7 , Imunogenicidade da Vacina , Simulação de Acoplamento Molecular , Estrutura Secundária de Proteína
9.
Microb Pathog ; 132: 275-281, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078709

RESUMO

Toxoplasma gondii is an obligate intracellular parasite that causes one of the most common parasitic infections in humans and other warm-blooded animals. Currently, there are no effective treatments for inhibiting the formation of chronic tissue cysts in infected hosts. Thus, the development of a vaccine to protect against toxoplasmosis is an attractive option for avoiding infection. The aim of this study was to design an epitope-based vaccine for T. gondii. In the present study, an in silico approach was used to predict and analyze B-cell and T-cell epitopes and the transmembrane domain of proteins SAG1, MIC3, and ROP8. We also predicted the antigenicity, allergenicity, secondary and tertiary structures, and physicochemical characteristics of a chimeric protein. Next, codon optimization and mRNA structure prediction were conducted using bioinformatics tools, and the designed construct was chemically synthesized and cloned into the pET28a vector. SAG1 (amino acid positions 85-235), MIC3 (30-180), and ROP8 (85-185) were found to have several strong immunodominant epitopes that were joined with a rigid linker A(EAAAK)2A. Although the resultant protein called MRS (MIC3, ROP8, and SAG1) did not turn out to be an allergen, its antigenicity was estimated to be 0.7983. Additionally, MRS was selected as the best vaccine candidate on the basis of its secondary and tertiary structures. The number of amino acids, molecular weight, and numbers of negatively and positively charged residues of MRS were 427 and 45,661.31 Da, 45, and 50, respectively. ΔG of the best-predicted structure was -413.0 kcal/mol, and the first nucleotides at the 5' end did not form a stable hairpin or pseudoknot. Finally, successful expression and verification of the expressed MRS protein showed that in silico analysis was almost accurate. This vaccine candidate selected by in silico tools should be validated in experimental studies.


Assuntos
Antígenos de Protozoários/imunologia , Imunogenicidade da Vacina/imunologia , Vacinas Protozoárias/imunologia , Proteínas Recombinantes de Fusão/imunologia , Toxoplasma/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Protozoários/genética , Biologia Computacional , Simulação por Computador , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Expressão Gênica , Humanos , Modelos Moleculares , Conformação Proteica , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , RNA Mensageiro/química , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Toxoplasmose/imunologia , Toxoplasmose/prevenção & controle
10.
Science ; 364(6439): 480-484, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-31048489

RESUMO

Mutationally constrained epitopes of variable pathogens represent promising targets for vaccine design but are not reliably identified by sequence conservation. In this study, we employed structure-based network analysis, which applies network theory to HIV protein structure data to quantitate the topological importance of individual amino acid residues. Mutation of residues at important network positions disproportionately impaired viral replication and occurred with high frequency in epitopes presented by protective human leukocyte antigen (HLA) class I alleles. Moreover, CD8+ T cell targeting of highly networked epitopes distinguished individuals who naturally control HIV, even in the absence of protective HLA alleles. This approach thereby provides a mechanistic basis for immune control and a means to identify CD8+ T cell epitopes of topological importance for rational immunogen design, including a T cell-based HIV vaccine.


Assuntos
Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Síndrome de Imunodeficiência Adquirida/prevenção & controle , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , HIV-1/imunologia , Alelos , Sequência Conservada , Antígenos HLA-B/genética , Antígenos HLA-B/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Mutação , Proteoma/genética , Proteoma/imunologia , Replicação Viral , Produtos do Gene gag do Vírus da Imunodeficiência Humana
11.
Virol J ; 16(1): 72, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138240

RESUMO

BACKGROUND: Human papillomavirus (HPV) E6 and E7 oncoproteins play a crucial role in HPV-related diseases, such as cervical cancer, and can be used as ideal targets for therapeutic vaccines. Human leukocyte antigen (HLA) participates in the immune response to block HPV infection and invasion by its target/recognition function. HPV-33 and HPV-58 are highly prevalent among Chinese women. Therefore, it is of great significance to study the E6 and E7 region-specific gene polymorphisms of HPV-33 and HPV-58 in Southwest China and to identify ideal epitopes for vaccine design. Both HPV-33 and HPV-58 belong to α-9 genus HPV and are highly homologous, so their correlations are included in our research. METHODS: To study the E6 and E7 variations and polymorphisms of HPV-33 and HPV-58 in Southwest China, we collected samples, extracted and sequenced DNA, and identified variants. Nucleotide sequences were translated into amino acids by Mega 6.0 software. The physical/chemical properties, amino acid-conserved sequences and secondary structure of protein sequences were analysed by the Protparam server, ConSurf server and PSIPRED software. The T and B cell epitopes of the E6/E7 reference and variant sequences in HPV-33 and HPV-58 were predicted by the Immune Epitope Database (IEDB) analysis server and the ABCpred server, respectively. RESULTS: Five and seven optimal HLA-I restricted T cell epitopes were selected from HPV-33 and HPV-58 E6, respectively, and these optimal epitopes are mainly located in 41-58EVYDFAFADLTVVYREGN of HPV-33 E6 and 40-60SEVYDFVFADLRIVYRDGNPF of HPV-58 E6. Six optimal HLA-I-restricted T cell epitopes were selected from HPV-33 and HPV-58 E7, and these epitopes are mainly located in 77-90RTIQQLLMGTVNIV of HPV-33 E7 and 78-91RTLQQLLMGTCTIV of HPV-58 E7. CONCLUSIONS: HPV-33/HPV-58 E6/E7 gene polymorphisms and T/B cell epitopes of their reference and variant sequences were studied, and candidate epitopes were selected by bioinformatics techniques for therapeutic vaccine design for people in Southwest China. This study was the first to investigate the correlation of epitopes between HPV-33 and HPV-58. After experimental validation, these selected epitopes will be employed to induce a wide range of immune responses in heterogeneous HLA populations.


Assuntos
Epitopos/imunologia , Variação Genética , Papillomaviridae/imunologia , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/imunologia , Infecções por Papillomavirus/imunologia , Epitopos/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Feminino , Humanos , Infecções por Papillomavirus/epidemiologia , Filogenia , Neoplasias do Colo do Útero/virologia
12.
Nat Commun ; 10(1): 1842, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015529

RESUMO

The CRISPR-Cas9 system has raised hopes for developing personalized gene therapies for complex diseases. Its application for genetic and epigenetic therapies in humans raises concerns over immunogenicity of the bacterially derived Cas9 protein. Here we detect antibodies to Streptococcus pyogenes Cas9 (SpCas9) in at least 5% of 143 healthy individuals. We also report pre-existing human CD8+T cell immunity in the majority of healthy individuals screened. We identify two immunodominant SpCas9 T cell epitopes for HLA-A*02:01 using an enhanced prediction algorithm that incorporates T cell receptor contact residue hydrophobicity and HLA binding and evaluated them by T cell assays using healthy donor PBMCs. In a proof-of-principle study, we demonstrate that Cas9 protein can be modified to eliminate immunodominant epitopes through targeted mutation while preserving its function and specificity. Our study highlights the problem of pre-existing immunity against CRISPR-associated nucleases and offers a potential solution to mitigate the T cell immune response.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Proteína 9 Associada à CRISPR/imunologia , Epitopos de Linfócito T/genética , Mutagênese/imunologia , Streptococcus pyogenes/imunologia , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Células Apresentadoras de Antígenos/imunologia , Proteína 9 Associada à CRISPR/genética , Engenharia Celular/métodos , Mapeamento de Epitopos/métodos , Epitopos de Linfócito T/imunologia , Terapia Genética/efeitos adversos , Terapia Genética/métodos , Células HEK293 , Antígenos HLA-A/imunologia , Voluntários Saudáveis , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Medicina de Precisão/efeitos adversos , Medicina de Precisão/métodos , Streptococcus pyogenes/genética
13.
Infect Immun ; 87(6)2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30910792

RESUMO

CD4+ T-cell mechanisms are implied in protection against pneumococcal colonization; however, their target antigens and function are not well defined. In contrast to high-throughput protein arrays for serology, basic antigen tools for CD4+ T-cell studies are lacking. Here, we evaluate the potential of a bioinformatics tool for in silico prediction of immunogenicity as a method to reveal domains of pneumococcal proteins targeted by human CD4+ T cells. For 100 pneumococcal proteins, CD4+ T-cell immunogenicity was predicted based on HLA-DRB1 binding motifs. For 20 potentially CD4+ T-cell immunogenic proteins, epitope regions were verified by testing synthetic peptides in T-cell assays using peripheral blood mononuclear cells from healthy adults. Peptide pools of 19 out of 20 proteins evoked T-cell responses. The most frequent responses (detectable in ≥20% of donors tested) were found to SP_0117 (PspA), SP_0468 (putative sortase), SP_0546 (BlpZ), SP_1650 (PsaA), SP_1923 (Ply), SP_2048 (conserved hypothetical protein), SP_2216 (PscB), and SPR_0907 (PhtD). Responding donors had diverging recognition patterns and profiles of signature cytokines (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], interleukin-13 [IL-13], and/or IL-17A) against single-epitope regions. Natural HLA-DR-restricted presentation and recognition of a predicted SP_1923-derived epitope were validated through the isolation of a CD4+ T-cell clone producing IFN-γ, TNF-α, and IL-17A in response to the synthetic peptide, whole protein, and heat-inactivated pneumococcus. This proof of principle for a bioinformatics tool to identify pneumococcal protein epitopes targeted by human CD4+ T cells provides a peptide-based strategy to study cell-mediated immune mechanisms for the pneumococcal proteome, advancing the development of immunomonitoring assays and targeted vaccine approaches.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Linfócitos T CD4-Positivos/imunologia , Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/imunologia , Proteínas de Bactérias/genética , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Humanos , Interferon gama/genética , Interferon gama/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Leucócitos Mononucleares/imunologia , Infecções Pneumocócicas/genética , Infecções Pneumocócicas/imunologia , Domínios Proteicos , Streptococcus pneumoniae/química , Streptococcus pneumoniae/genética
14.
Appl Microbiol Biotechnol ; 103(8): 3367-3379, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30888465

RESUMO

Many recent studies have shown that flagellin fused to heterologous antigens can induce significantly enhanced humoral and cellular immune responses through its adjuvant activity. Therefore, in this study, two key B cell epitopes and a truncated VP1 (ΔVP1) protein from foot-and-mouth disease virus (FMDV) were expressed as flagellin fusion proteins in different patterns. Specifically, ΔVP1 and two duplicates of two key B cell epitopes (2×B1B2) were fused separately to the C-terminus of flagellin with a universal exogenous T cell epitope to construct FT (Flagellin-Truncated VP1) and FME (Flagellin-Multiple Epitopes). In addition, the D3 domain of flagellin was replaced by ΔVP1 in FME, yielding FTME (Flagellin-Truncated VP1-Multiple Epitopes). The immunogenicity and protective efficacy of the three fusion proteins as novel FMDV vaccine candidates were evaluated. The results showed that FT, FME, and FTME elicited significant FMDV-specific IgG responses at 10 µg/dose compared with the mock group (P < 0.05), with FTME producing the highest response. No significant differences in the antibody response to FTME were observed between different immunization routes or among adjuvants (ISA-206, poly(I·C), MPLA, and CpG-ODN) in mice. In addition, at 30 µg/dose, all three fusion proteins significantly induced neutralizing antibody production and upregulated the levels of some cytokines, including TNF-α, IFN-γ, and IL-12, in guinea pigs. Importantly, all three fusion proteins provided effective protective immunity against FMDV challenge in guinea pigs, though different protection rates were found. The results presented in this study indicate that the FTME fusion protein is a promising novel vaccine candidate for the future prevention and control of foot-and-mouth disease.


Assuntos
Flagelina/imunologia , Vírus da Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Vacinação/métodos , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/genética , Antígenos Virais/imunologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Citocinas/sangue , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Feminino , Flagelina/genética , Vírus da Febre Aftosa/genética , Cobaias , Masculino , Camundongos Endogâmicos BALB C , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
15.
Blood Rev ; 35: 18-31, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30826141

RESUMO

Significant improvements in the survival of patients with hematological cancers following hematopoietic stem cell transplantation provide evidence supporting the potency of immune cell-mediated anti-leukemic effects. Studies focusing on immune cell-based cancer therapies have made significant breakthroughs in the last few years. Adoptive cellular therapy (ACT), and chimeric antigen receptor (CAR) T cell therapy, in particular, has significantly increased the survival of patients with B cell acute lymphoblastic leukemia and aggressive B cell lymphoma. Despite antigen-negative relapses and severe toxicities such as cytokine release syndrome after treatment, CAR-T cell therapies have been approved by the FDA in some conditions. Although a number of studies have tried to achieve similar results for acute myeloid leukemia (AML), clinical outcomes have not been as promising. In this review, we summarize recent and ongoing studies on cellular therapies for AML patients, with a focus on antigen-specific versus -nonspecific approaches.


Assuntos
Imunoterapia Adotiva , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/terapia , Animais , Antígenos de Neoplasias/imunologia , Ensaios Clínicos como Assunto , Células Matadoras Induzidas por Citocinas/imunologia , Células Matadoras Induzidas por Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Epitopos de Linfócito T/imunologia , Humanos , Imunoterapia Adotiva/efeitos adversos , Imunoterapia Adotiva/métodos , Leucemia Mieloide Aguda/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Especificidade do Receptor de Antígeno de Linfócitos T , Linfócitos T/imunologia , Linfócitos T/metabolismo , Resultado do Tratamento
16.
Nat Immunol ; 20(5): 652-662, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30858620

RESUMO

αß T cell antigen receptors (TCRs) bind complexes of peptide and major histocompatibility complex (pMHC) with low affinity, which poses a considerable challenge for the direct identification of αß T cell cognate peptides. Here we describe a platform for the discovery of MHC class II epitopes based on the screening of engineered reporter cells expressing novel pMHC-TCR (MCR) hybrid molecules carrying cDNA-derived peptides. This technology identifies natural epitopes of CD4+ T cells in an unbiased and efficient manner and allows detailed analysis of TCR cross-reactivity that provides recognition patterns beyond discrete peptides. We determine the cognate peptides of virus- and tumor-specific T cells in mouse disease models and present a proof of concept for human T cells. Furthermore, we use MCR to identify immunogenic tumor neo-antigens and show that vaccination with a peptide naturally recognized by tumor-infiltrating lymphocytes efficiently protects mice from tumor challenge. Thus, the MCR technology holds promise for basic research and clinical applications, allowing the personalized identification of T cell-specific neo-antigens in patients.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Linfócitos T CD4-Positivos/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/metabolismo , Humanos , Complexo Principal de Histocompatibilidade/genética , Camundongos Endogâmicos C57BL , Peptídeos/genética , Peptídeos/imunologia , Peptídeos/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo
17.
Parasit Vectors ; 12(1): 140, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30909938

RESUMO

BACKGROUND: The 90-kDa heat-shock protein (Hsp90) from Nicotiana benthamiana (NbHsp90.3) is a promising adjuvant, especially for those vaccines that require a T cell-mediated immune response. Toxoplasma gondii SAG1 is considered one of the most important antigens for the development of effective subunit vaccines. Some epitopes located in the SAG1 C-terminus region have showed a strong humoral and cellular immune response. In the present study, we aimed to assess the efficacy of NbHsp90.3 as carrier/adjuvant of SAG1-derived peptide (SAG1HC) in a T. gondii infection murine model. METHODS: In the present study, C57BL/6 mice were intraperitoneal immunized with the NbHsp90.3-SAG1HC fusion protein (NbHsp90.3-SAG1HC group), mature SAG1 (SAG1m group), NbHsp90.3 (NbHsp90.3 group) or PBS buffer 1× (PBS group). The levels of IgG antibodies and the cytokine profile were determined by ELISA. Two weeks after the last immunization, all mice were orally challenged with 20 cysts of T. gondii Me49 strain and the number of brain cysts was determined. In addition, both humoral and cellular immune responses were also evaluated during the acute and chronic phase of T. gondii infection by ELISA. RESULTS: The characterization of the immune response generated after vaccination with NbHsp90.3 as an adjuvant showed that NbHsp90.3-SAG1HC-immunized mice produced antibodies that were able to recognize not only rSAG1m but also the native SAG1 present in the total lysate antigen extract (SAG1TLA) from T. gondii tachyzoites, while control groups did not. Furthermore, anti-rSAG1m IgG2a/2b antibodies were significantly induced. In addition, only the spleen cell cultures from NbHsp90.3-SAG1HC-immunized mice showed a significantly increased production of IFN-γ. During the chronic phase of T. gondii infection, the antibodies generated by the infection were unable to detect the recombinant protein, but they did react with TLA extract. In addition, splenocytes from all groups showed a high production of IFN-γ when stimulated with rGRA4, but only those from NbHsp90.3-SAG1HC group stimulated with rSAG1m showed high production of IFN-γ. Finally, NbHsp90.3-SAG1HC-immunized mice exhibited a significant reduction in the cyst load (56%) against T. gondii infection. CONCLUSIONS: We demonstrated that NbHsp90.3 enhances the humoral and cell-mediated immune response through a Th1 type cytokine production. Mice vaccinated with NbHsp90.3-SAG1HC exhibited a partial protection against T. gondii infection and it was correlated with the induction of memory immune response. We developed and validated a vaccine formulation which, to our knowledge, for the first time includes the NbHsp90.3 protein covalently fused to a peptide from T. gondii SAG1 protein that contains T- and B-cell epitopes.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Antígenos de Protozoários/imunologia , Chaperonina 60/imunologia , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/imunologia , Tabaco/química , Animais , Anticorpos Antiprotozoários/sangue , Citocinas/imunologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Feminino , Imunidade Celular , Imunidade Humoral , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos C57BL , Vacinas Protozoárias/administração & dosagem , Toxoplasma , Toxoplasmose Animal/prevenção & controle
18.
Med Microbiol Immunol ; 208(2): 239-251, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30848362

RESUMO

T cell epitopes restricted by several protective HLA alleles, such as B*57, B*5801, B*27, B*51 and B*13, have been very well defined over the past two decades. We investigated 32 well-known T cell epitopes restricted by protective HLA molecules among 54 Chinese men who have sex with men (MSM) at the early stage of HIV-1 infection. Subjects in our cohort carrying protective HLA types did not exhibit slow CD4 T cell count decline (P = 0.489) or low viral load set points (P = 0.500). Variations occurred in 96.88% (31/32) of the known wild-type epitopes (rate 1.85-100%), and the variation rates of the strains of two CRF01_AE lineages were significantly higher than those of non-CRF01_AE strains (76.82% vs. 48.96%, P = 0.004; 71.27% vs. 8.96%, P = 0.025). Subjects infected with CRF01_AE exhibited relatively rapid disease progression (P = 0.035). Therefore, the lack of wild-type protective T cell epitopes restricted by classic protective HLA alleles in CRF01_AE HIV-1 strains may be one of the reasons why rapid disease progression is observed in Chinese MSM with HIV-1 infection.


Assuntos
Alelos , Progressão da Doença , Epitopos de Linfócito T/imunologia , Infecções por HIV/imunologia , Infecções por HIV/patologia , Antígenos HLA/genética , Polimorfismo Genético , Adulto , China , Seguimentos , Homossexualidade Masculina , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Carga Viral , Adulto Jovem
19.
Gastroenterology ; 156(6): 1862-1876.e9, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30711630

RESUMO

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is often associated with hepatitis B virus (HBV) infection. Cells of most HBV-related HCCs contain HBV-DNA fragments that do not encode entire HBV antigens. We investigated whether these integrated HBV-DNA fragments encode epitopes that are recognized by T cells and whether their presence in HCCs can be used to select HBV-specific T-cell receptors (TCRs) for immunotherapy. METHODS: HCC cells negative for HBV antigens, based on immunohistochemistry, were analyzed for the presence of HBV messenger RNAs (mRNAs) by real-time polymerase chain reaction, sequencing, and Nanostring approaches. We tested the ability of HBV mRNA-positive HCC cells to generate epitopes that are recognized by T cells using HBV-specific T cells and TCR-like antibodies. We then analyzed HBV gene expression profiles of primary HCCs and metastases from 2 patients with HCC recurrence after liver transplantation. Using the HBV-transcript profiles, we selected, from a library of TCRs previously characterized from patients with self-limited HBV infection, the TCR specific for the HBV epitope encoded by the detected HBV mRNA. Autologous T cells were engineered to express the selected TCRs, through electroporation of mRNA into cells, and these TCR T cells were adoptively transferred to the patients in increasing numbers (1 × 104-10 × 106 TCR+ T cells/kg) weekly for 112 days or 1 year. We monitored patients' liver function, serum levels of cytokines, and standard blood parameters. Antitumor efficacy was assessed based on serum levels of alpha fetoprotein and computed tomography of metastases. RESULTS: HCC cells that did not express whole HBV antigens contained short HBV mRNAs, which encode epitopes that are recognized by and activate HBV-specific T cells. Autologous T cells engineered to express TCRs specific for epitopes expressed from HBV-DNA in patients' metastases were given to 2 patients without notable adverse events. The cells did not affect liver function over a 1-year period. In 1 patient, 5 of 6 pulmonary metastases decreased in volume during the 1-year period of T-cell administration. CONCLUSIONS: HCC cells contain short segments of integrated HBV-DNA that encodes epitopes that are recognized by and activate T cells. HBV transcriptomes of these cells could be used to engineer T cells for personalized immunotherapy. This approach might be used to treat a wider population of patients with HBV-associated HCC.


Assuntos
Carcinoma Hepatocelular/terapia , DNA Viral , Vírus da Hepatite B/genética , Imunoterapia Adotiva/métodos , Neoplasias Hepáticas/terapia , Neoplasias Pulmonares/terapia , Recidiva Local de Neoplasia/genética , Linfócitos T/imunologia , Transcriptoma/imunologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/secundário , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , Eletroporação , Epitopos de Linfócito T/biossíntese , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos da Hepatite B/genética , Antígenos da Hepatite B/imunologia , Humanos , Imunoterapia Adotiva/efeitos adversos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Transplante de Fígado , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Biossíntese de Proteínas , RNA Viral/genética , Receptores de Antígenos de Linfócitos T , Integração Viral , alfa-Fetoproteínas/metabolismo
20.
Viruses ; 11(2)2019 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-30717485

RESUMO

For the development of an effective HIV-1 vaccine, evolutionarily conserved epitopes between feline and human immunodeficiency viruses (FIV and HIV-1) were determined by analyzing overlapping peptides from retroviral genomes that induced both anti-FIV/HIV T cell-immunity in the peripheral blood mononuclear cells from the FIV-vaccinated cats and the HIV-infected humans. The conserved T-cell epitopes on p24 and reverse transcriptase were selected based on their robust FIV/HIV-specific CD8⁺ cytotoxic T lymphocyte (CTL), CD4⁺ CTL, and polyfunctional T-cell activities. Four such evolutionarily conserved epitopes were formulated into four multiple antigen peptides (MAPs), mixed with an adjuvant, to be tested as FIV vaccine in cats. The immunogenicity and protective efficacy were evaluated against a pathogenic FIV. More MAP/peptide-specific CD4⁺ than CD8⁺ T-cell responses were initially observed. By post-third vaccination, half of the MAP/peptide-specific CD8⁺ T-cell responses were higher or equivalent to those of CD4⁺ T-cell responses. Upon challenge, 15/19 (78.9%) vaccinated cats were protected, whereas 6/16 (37.5%) control cats remained uninfected, resulting in a protection rate of 66.3% preventable fraction (p = 0.0180). Thus, the selection method used to identify the protective FIV peptides should be useful in identifying protective HIV-1 peptides needed for a highly protective HIV-1 vaccine in humans.


Assuntos
Epitopos de Linfócito T/imunologia , Síndrome de Imunodeficiência Adquirida Felina/prevenção & controle , Imunogenicidade da Vacina , Peptídeos/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Linfócitos T CD4-Positivos/imunologia , Gatos , Reações Cruzadas , Síndrome de Imunodeficiência Adquirida Felina/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1 , Humanos , Imunidade Celular , Vírus da Imunodeficiência Felina , Ativação Linfocitária , Organismos Livres de Patógenos Específicos , Vacinação/veterinária , Vacinas de Subunidades/imunologia
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