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1.
BMC Infect Dis ; 20(1): 677, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32942991

RESUMO

BACKGROUND: Approximately 80% - 90% of individuals infected with latent Mycobacterium tuberculosis (Mtb) remain protected throughout their life-span. The release of unique, latent-phase antigens are known to have a protective role in the immune response against Mtb. Although the BCG vaccine has been administered for nine decades to provide immunity against Mtb, the number of TB cases continues to rise, thereby raising doubts on BCG vaccine efficacy. The shortcomings of BCG have been associated with inadequate processing and presentation of its antigens, an inability to optimally activate T cells against Mtb, and generation of regulatory T cells. Furthermore, BCG vaccination lacks the ability to eliminate latent Mtb infection. With these facts in mind, we selected six immunodominant CD4 and CD8 T cell epitopes of Mtb expressed during latent, acute, and chronic stages of infection and engineered a multi-epitope-based DNA vaccine (C6). RESULT: BALB/c mice vaccinated with the C6 construct along with a BCG vaccine exhibited an expansion of both CD4 and CD8 T cell memory populations and augmented IFN-γ and TNF-α cytokine release. Furthermore, enhancement of dendritic cell and macrophage activation was noted. Consequently, illustrating the elicitation of immunity that helps in the protection against Mtb infection; which was evident by a significant reduction in the Mtb burden in the lungs and spleen of C6 + BCG administered animals. CONCLUSION: Overall, the results suggest that a C6 + BCG vaccination approach may serve as an effective vaccination strategy in future attempts to control TB.


Assuntos
Vacina BCG/imunologia , Epitopos de Linfócito T , Tuberculose/prevenção & controle , Vacinas de DNA/imunologia , Animais , Antígenos de Bactérias/imunologia , Vacina BCG/genética , Vacina BCG/farmacologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/genética , Feminino , Memória Imunológica , Interferon gama/metabolismo , Tuberculose Latente/prevenção & controle , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Vacinas de DNA/farmacologia
2.
mBio ; 11(5)2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948688

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces a T cell response that most likely contributes to virus control in COVID-19 patients but may also induce immunopathology. Until now, the cytotoxic T cell response has not been very well characterized in COVID-19 patients. Here, we analyzed the differentiation and cytotoxic profile of T cells in 30 cases of mild COVID-19 during acute infection. SARS-CoV-2 infection induced a cytotoxic response of CD8+ T cells, but not CD4+ T cells, characterized by the simultaneous production of granzyme A and B as well as perforin within different effector CD8+ T cell subsets. PD-1-expressing CD8+ T cells also produced cytotoxic molecules during acute infection, indicating that they were not functionally exhausted. However, in COVID-19 patients over the age of 80 years, the cytotoxic T cell potential was diminished, especially in effector memory and terminally differentiated effector CD8+ cells, showing that elderly patients have impaired cellular immunity against SARS-CoV-2. Our data provide valuable information about T cell responses in COVID-19 patients that may also have important implications for vaccine development.IMPORTANCE Cytotoxic T cells are responsible for the elimination of infected cells and are key players in the control of viruses. CD8+ T cells with an effector phenotype express cytotoxic molecules and are able to perform target cell killing. COVID-19 patients with a mild disease course were analyzed for the differentiation status and cytotoxic profile of CD8+ T cells. SARS-CoV-2 infection induced a vigorous cytotoxic CD8+ T cell response. However, this cytotoxic profile of T cells was not detected in COVID-19 patients over the age of 80 years. Thus, the absence of a cytotoxic response in elderly patients might be a possible reason for the more frequent severity of COVID-19 in this age group than in younger patients.


Assuntos
Linfócitos T CD8-Positivos/patologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Linfócitos T Citotóxicos/patologia , Idoso de 80 Anos ou mais , Antígenos CD/metabolismo , Betacoronavirus/patogenicidade , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Citotoxinas/metabolismo , Feminino , Humanos , Imunidade Celular , Masculino , Pessoa de Meia-Idade , Pandemias , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Linfócitos T Citotóxicos/imunologia
3.
J Int Med Res ; 48(9): 300060520958594, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32962495

RESUMO

OBJECTIVE: Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asymptomatic presentation to a severe illness requiring intensive care unit admission. Identification of a strategy to manage the severity of this disease will not only help to reduce its case fatality but also help to remove some of the burden from the already overwhelmed health care systems. While successful management of symptoms in general is important, identifying measures to modify the severity of the illness is a key factor in the fight against this pandemic. METHODS: This paper presents a short literature review to suggest a new treatment modality for COVID-19. RESULTS: COVID-19 is less severe and rarely fatal in children than in adults, which could be caused by greater fluctuations of plasma epinephrine in children. Our literature survey endorses this hypothesis according to both the epidemiological and immunological findings. CONCLUSION: Application of epinephrine pulses with a specific amplitude may be considered an intervention to minimize the severity of COVID-19.


Assuntos
Linfócitos T CD8-Positivos/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Epinefrina/uso terapêutico , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/epidemiologia , Adulto , Fatores Etários , Doenças Assintomáticas , Biomarcadores/sangue , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Criança , Ritmo Circadiano/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Esquema de Medicação , Epinefrina/sangue , Epinefrina/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Modelos Imunológicos , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Prognóstico , Índice de Gravidade de Doença
4.
Medicine (Baltimore) ; 99(36): e20993, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32898991

RESUMO

Radiotherapy (RT) can affect the immune function of patients with cancer. The purpose of this study was to investigate the effect of RT on lymphocyte and its subsets in patients with esophageal cancer (EC).All patients received RT with a mean dose of 5369 cGy (gray). Blood parameters were measured in 31 patients on 3 occasions (before, at the end of radiotherapy, and at 3 months follow-up). The whole blood count and lymphocyte subsets were measured and correlated with short time efficiency and radiation dose parameters.White blood count (WBC) and lymphocyte count (ALC) were greatly decreased at the end of radiotherapy, and the percentages of CD3+, CD3+CD8+ T cells were significantly increased, on the other hand, a decrease in the CD4/CD8 ratio was observed. The percentages of CD3-CD16/56+NK cells and CD19+ B cell were decreased at the end of RT compared with prior RT. The percentages of CD3+ T cells before RT and the WBC and ALC count after RT can be used as prognostic indicators for survival. The PTV dose can cause significant changes in lymphocytes count after RT. CD3+T cells after RT were significantly correlated with mean heart dose and heart V50.Our study identified that RT causes changes in lymphocyte subsets, and these changes may indicate differences in immune function between individuals. Radiotherapy plan should be designed to minimize normal tissue dose to reduce the impact on WBC and lymphocytes.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/radioterapia , Subpopulações de Linfócitos/imunologia , Idoso , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/patologia , Feminino , Humanos , Contagem de Linfócitos , Masculino , Estudos Retrospectivos
5.
PLoS Pathog ; 16(9): e1008821, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32941545

RESUMO

MHC-I-restricted, virus-specific cytotoxic CD8+ T cells (CTLs) may control human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication via the recognition and killing of productively infected CD4+ T cells. Several studies in SIV-infected macaques suggest that CD8+ T cells may also decrease virus production by suppressing viral transcription. Here, we show that non-HIV-specific, TCR-activated non-cytolytic CD8+ T cells suppress HIV transcription via a virus- and MHC-independent immunoregulatory mechanism that modulates CD4+ T cell proliferation and activation. We also demonstrate that this CD8+ T cell-mediated effect promotes the survival of infected CD4+ T cells harboring integrated, inducible virus. Finally, we used RNA sequencing and secretome analyses to identify candidate cellular pathways that are involved in the virus-silencing mediated by these CD8+ T cells. This study characterizes a previously undescribed mechanism of immune-mediated HIV silencing that may be involved in the establishment and maintenance of the reservoir under antiretroviral therapy and therefore represent a major obstacle to HIV eradication.


Assuntos
Linfócitos T CD8-Positivos/imunologia , HIV-1/fisiologia , Antígenos de Histocompatibilidade Classe I/imunologia , Imunidade Inata , Transcrição Genética/imunologia , Replicação Viral/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Proliferação de Células , Humanos , Macaca
6.
Sci Rep ; 10(1): 15838, 2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32985562

RESUMO

The coronavirus disease 2019 (COVID-19) has been spreading worldwide. Severe cases quickly progressed with unfavorable outcomes. We aim to investigate the clinical features of COVID-19 and identify the risk factors associated with its progression. Data of confirmed SARS-CoV-2-infected patients and healthy participants were collected. Thirty-seven healthy people and 79 confirmed patients, which include 48 severe patients and 31 mild patients, were recruited. COVID-19 patients presented with dysregulated immune response (decreased T, B, and NK cells and increased inflammatory cytokines). Also, they were found to have increased levels of white blood cell, neutrophil count, and D-dimer in severe cases. Moreover, lymphocyte, CD4+ T cell, CD8+ T cell, NK cell, and B cell counts were lower in the severe group. Multivariate logistic regression analysis showed that CD4+ cell count, neutrophil-to-lymphocyte ratio (NLR) and D-dimer were risk factors for severe cases. Both CT score and clinical pulmonary infection score (CPIS) were associated with disease severity. The receiver operating characteristic (ROC) curve analysis has shown that all these parameters and scores had quite a high predictive value. Immune dysfunction plays critical roles in disease progression. Early and constant surveillance of complete blood cell count, T lymphocyte subsets, coagulation function, CT scan and CPIS was recommended for early screening of severe cases.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Fenômenos do Sistema Imunológico/fisiologia , Pneumonia Viral/imunologia , Adulto , Idoso , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Coronavirus/patologia , Feminino , Humanos , Células Matadoras Naturais/imunologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Pandemias , Pneumonia Viral/patologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Resultado do Tratamento
7.
Proc Natl Acad Sci U S A ; 117(39): 24384-24391, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32913053

RESUMO

An improved understanding of human T cell-mediated immunity in COVID-19 is important for optimizing therapeutic and vaccine strategies. Experience with influenza shows that infection primes CD8+ T cell memory to peptides presented by common HLA types like HLA-A2, which enhances recovery and diminishes clinical severity upon reinfection. Stimulating peripheral blood mononuclear cells from COVID-19 convalescent patients with overlapping peptides from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the clonal expansion of SARS-CoV-2-specific CD8+ and CD4+ T cells in vitro, with CD4+ T cells being robust. We identified two HLA-A*02:01-restricted SARS-CoV-2-specfic CD8+ T cell epitopes, A2/S269-277 and A2/Orf1ab3183-3191 Using peptide-HLA tetramer enrichment, direct ex vivo assessment of A2/S269 +CD8+ and A2/Orf1ab3183 +CD8+ populations indicated that A2/S269 +CD8+ T cells were detected at comparable frequencies (∼1.3 × 10-5) in acute and convalescent HLA-A*02:01+ patients. These frequencies were higher than those found in uninfected HLA-A*02:01+ donors (∼2.5 × 10-6), but low when compared to frequencies for influenza-specific (A2/M158) and Epstein-Barr virus (EBV)-specific (A2/BMLF1280) (∼1.38 × 10-4) populations. Phenotyping A2/S269 +CD8+ T cells from COVID-19 convalescents ex vivo showed that A2/S269 +CD8+ T cells were predominantly negative for CD38, HLA-DR, PD-1, and CD71 activation markers, although the majority of total CD8+ T cells expressed granzymes and/or perforin. Furthermore, the bias toward naïve, stem cell memory and central memory A2/S269 +CD8+ T cells rather than effector memory populations suggests that SARS-CoV-2 infection may be compromising CD8+ T cell activation. Priming with appropriate vaccines may thus be beneficial for optimizing CD8+ T cell immunity in COVID-19.


Assuntos
Betacoronavirus/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Coronavirus/imunologia , Antígeno HLA-A2/imunologia , Pneumonia Viral/imunologia , Linfócitos T CD4-Positivos/imunologia , Epitopos de Linfócito T , Feminino , Humanos , Memória Imunológica , Imunofenotipagem , Leucócitos Mononucleares/imunologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Pandemias , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Proteínas Virais/química , Proteínas Virais/imunologia
8.
PLoS Pathog ; 16(9): e1008827, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32886721

RESUMO

Global burden of cervical cancer, the most common cause of mortality caused by human papillomavirus (HPV), is expected to increase during the next decade, mainly because current alternatives for HPV vaccination and cervical cancer screening programs are costly to be established in low-and-middle income countries. Recently, we described the development of the broadly protective, thermostable vaccine antigen Trx-8mer-OVX313 based on the insertion of eight different minor capsid protein L2 neutralization epitopes into a thioredoxin scaffold from the hyperthermophilic archaeon Pyrococcus furiosus and conversion of the resulting antigen into a nanoparticle format (median radius ~9 nm) upon fusion with the heptamerizing OVX313 module. Here we evaluated whether the engineered thioredoxin scaffold, in addition to humoral immune responses, can induce CD8+ T-cell responses upon incorporation of MHC-I-restricted epitopes. By systematically examining the contribution of individual antigen modules, we demonstrated that B-cell and T-cell epitopes can be combined into a single antigen construct without compromising either immunogenicity. While CD8+ T-cell epitopes had no influence on B-cell responses, the L2 polytope (8mer) and OVX313-mediated heptamerization of the final antigen significantly increased CD8+ T-cell responses. In a proof-of-concept experiment, we found that vaccinated mice remained tumor-free even after two consecutive tumor challenges, while unvaccinated mice developed tumors. A cost-effective, broadly protective vaccine with both prophylactic and therapeutic properties represents a promising option to overcome the challenges associated with prevention and treatment of HPV-caused diseases.


Assuntos
Antígenos de Neoplasias , Antígenos Virais , Proteínas Arqueais , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer , Imunidade Celular/efeitos dos fármacos , Nanopartículas , Papillomaviridae , Vacinas contra Papillomavirus , Pyrococcus furiosus/química , Tiorredoxinas , Neoplasias do Colo do Útero/imunologia , Animais , Antígenos de Neoplasias/química , Antígenos de Neoplasias/farmacologia , Antígenos Virais/química , Antígenos Virais/farmacologia , Proteínas Arqueais/química , Proteínas Arqueais/farmacologia , Linfócitos T CD8-Positivos/patologia , Vacinas Anticâncer/química , Vacinas Anticâncer/farmacologia , Epitopos de Linfócito B/química , Epitopos de Linfócito B/farmacologia , Epitopos de Linfócito T/química , Epitopos de Linfócito T/farmacologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Nanopartículas/uso terapêutico , Papillomaviridae/química , Papillomaviridae/imunologia , Vacinas contra Papillomavirus/química , Vacinas contra Papillomavirus/farmacologia , Tiorredoxinas/química , Tiorredoxinas/farmacologia , Neoplasias do Colo do Útero/virologia
9.
Lancet ; 396(10254): 839-852, 2020 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-32888407

RESUMO

BACKGROUND: Lisocabtagene maraleucel (liso-cel) is an autologous, CD19-directed, chimeric antigen receptor (CAR) T-cell product. We aimed to assess the activity and safety of liso-cel in patients with relapsed or refractory large B-cell lymphomas. METHODS: We did a seamless design study at 14 cancer centres in the USA. We enrolled adult patients (aged ≥18 years) with relapsed or refractory large B-cell lymphomas. Eligible histological subgroups included diffuse large B-cell lymphoma, high-grade B-cell lymphoma with rearrangements of MYC and either BCL2, BCL6, or both (double-hit or triple-hit lymphoma), diffuse large B-cell lymphoma transformed from any indolent lymphoma, primary mediastinal B-cell lymphoma, and follicular lymphoma grade 3B. Patients were assigned to one of three target dose levels of liso-cel as they were sequentially tested in the trial (50 × 106 CAR+ T cells [one or two doses], 100 × 106 CAR+ T cells, and 150 × 106 CAR+ T cells), which were administered as a sequential infusion of two components (CD8+ and CD4+ CAR+ T cells) at equal target doses. Primary endpoints were adverse events, dose-limiting toxicities, and the objective response rate (assessed per Lugano criteria); endpoints were assessed by an independent review committee in the efficacy-evaluable set (comprising all patients who had confirmed PET-positive disease and received at least one dose of liso-cel). This trial is registered with ClinicalTrials.gov, NCT02631044. FINDINGS: Between Jan 11, 2016, and July 5, 2019, 344 patients underwent leukapheresis for manufacture of CAR+ T cells (liso-cel), of whom 269 patients received at least one dose of liso-cel. Patients had received a median of three (range 1-8) previous lines of systemic treatment, with 260 (97%) patients having had at least two lines. 112 (42%) patients were aged 65 years or older, 181 (67%) had chemotherapy-refractory disease, and seven (3%) had secondary CNS involvement. Median follow-up for overall survival for all 344 patients who had leukapheresis was 18·8 months (95% CI 15·0-19·3). Overall safety and activity of liso-cel did not differ by dose level. The recommended target dose was 100 × 106 CAR+ T cells (50 × 106 CD8+ and 50 × 106 CD4+ CAR+ T cells). Of 256 patients included in the efficacy-evaluable set, an objective response was achieved by 186 (73%, 95% CI 66·8-78·0) patients and a complete response by 136 (53%, 46·8-59·4). The most common grade 3 or worse adverse events were neutropenia in 161 (60%) patients, anaemia in 101 (37%), and thrombocytopenia in 72 (27%). Cytokine release syndrome and neurological events occurred in 113 (42%) and 80 (30%) patients, respectively; grade 3 or worse cytokine release syndrome and neurological events occurred in six (2%) and 27 (10%) patients, respectively. Nine (6%) patients had a dose-limiting toxicity, including one patient who died from diffuse alveolar damage following a dose of 50 × 106 CAR+ T cells. INTERPRETATION: Use of liso-cel resulted in a high objective response rate, with a low incidence of grade 3 or worse cytokine release syndrome and neurological events in patients with relapsed or refractory large B-cell lymphomas, including those with diverse histological subtypes and high-risk features. Liso-cel is under further evaluation at first relapse in large B-cell lymphomas and as a treatment for other relapsed or refractory B-cell malignancies. FUNDING: Juno Therapeutics, a Bristol-Myers Squibb Company.


Assuntos
Antígenos CD19/uso terapêutico , Imunoterapia Adotiva/métodos , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/terapia , Idoso , Idoso de 80 Anos ou mais , Anemia/epidemiologia , Antígenos CD19/administração & dosagem , Antígenos CD19/efeitos adversos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/transplante , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/transplante , Síndrome da Liberação de Citocina/epidemiologia , Feminino , Humanos , Imunoterapia Adotiva/efeitos adversos , Infusões Intravenosas , Leucaférese/métodos , Linfoma Difuso de Grandes Células B/classificação , Linfoma Difuso de Grandes Células B/imunologia , Masculino , Doenças do Sistema Nervoso/epidemiologia , Neutropenia/epidemiologia , Recidiva , Segurança , Análise de Sobrevida , Trombocitopenia/epidemiologia , Resultado do Tratamento
10.
PLoS Pathog ; 16(9): e1008840, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32913355

RESUMO

P. vivax-infected Retics (iRetics) express human leukocyte antigen class I (HLA-I), are recognized by CD8+ T cells and killed by granulysin (GNLY) and granzymes. However, how Plasmodium infection induces MHC-I expression on Retics is unknown. In addition, whether GNLY helps control Plasmodium infection in vivo has not been studied. Here, we examine these questions using rodent infection with the P. yoelii 17XNL strain, which has tropism for Retics. Infection with P. yoelii caused extramedullary erythropoiesis, reticulocytosis and expansion of CD8+CD44+CD62L- IFN-γ-producing T cells that form immune synapses with iRetics. We now provide evidence that MHC-I expression by iRetic is dependent on IFN-γ-induced transcription of IRF-1, MHC-I and ß2-microglobulin (ß2-m) in erythroblasts. Consistently, CTLs from infected wild type (WT) mice formed immune synapses with iRetics in an IFN-γ- and MHC-I-dependent manner. When challenged with P. yoelii 17XNL, WT mice cleared parasitemia and survived, while IFN-γ KO mice remained parasitemic and all died. ß2-m KO mice that do not express MHC-I and have virtually no CD8+ T cells had prolonged parasitemia, and 80% survived. Because mice do not express GNLY, GNLY-transgenic mice can be used to assess the in vivo importance of GNLY. Parasite clearance was accelerated in GNLY-transgenic mice and depletion of CD8+ T cells ablated the GNLY-mediated resistance to P. yoelii. Altogether, our results indicate that in addition to previously described mechanisms, IFN-γ promotes host resistance to the Retic-tropic P. yoelii 17XNL strain by promoting MHC-I expression on iRetics that become targets for CD8+ cytotoxic T lymphocytes and GNLY.


Assuntos
Antígenos de Diferenciação de Linfócitos T/imunologia , Linfócitos T CD8-Positivos/imunologia , Interferon gama/imunologia , Malária/imunologia , Plasmodium yoelii/imunologia , Animais , Antígenos de Diferenciação de Linfócitos T/genética , Linfócitos T CD8-Positivos/patologia , Interferon gama/genética , Malária/genética , Malária/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout
12.
J Immunol Res ; 2020: 2837670, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32964056

RESUMO

The novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has previously never been identified with humans, thereby creating devastation in public health. The need for an effective vaccine to curb this pandemic cannot be overemphasized. In view of this, we designed a subcomponent antigenic peptide vaccine targeting the N-terminal (NT) and C-terminal (CT) RNA binding domains of the nucleocapsid protein that aid in viral replication. Promising antigenic B cell and T cell epitopes were predicted using computational pipelines. The peptides "RIRGGDGKMKDL" and "AFGRRGPEQTQGNFG" were the B cell linear epitopes with good antigenic index and nonallergenic property. Two CD8+ and Three CD4+ T cell epitopes were also selected considering their safe immunogenic profiling such as allergenicity, antigen level conservancy, antigenicity, peptide toxicity, and putative restrictions to a number of MHC-I and MHC-II alleles. With these selected epitopes, a nonallergenic chimeric peptide vaccine incapable of inducing a type II hypersensitivity reaction was constructed. The molecular interaction between the Toll-like receptor-5 (TLR5) which was triggered by the vaccine was analyzed by molecular docking and scrutinized using dynamics simulation. Finally, in silico cloning was performed to ensure the expression and translation efficiency of the vaccine, utilizing the pET-28a vector. This research, therefore, provides a guide for experimental investigation and validation.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Proteínas do Nucleocapsídeo/imunologia , Nucleocapsídeo/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Proteínas do Nucleocapsídeo/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/imunologia , Motivos de Ligação ao RNA/imunologia , Receptor 5 Toll-Like/metabolismo , Vacinas Atenuadas/imunologia , Vacinas de Subunidades/imunologia
13.
APMIS ; 128(11): 593-602, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32870528

RESUMO

Induction of broad Th1 cellular immune responses and cytokines is crucial characteristics for vaccines against intracellular infections such as hepatitis C virus (HCV). Plants (especially oilseed tissues) and plant-immunomodulators (like oil bodies) offer cost-effective and scalable possibilities for the production of immunologically relevant and safe vaccine antigens and adjuvants, respectively. Herein, we provide data of the murine immunization by transgenic canola oilseed-derived HCV core protein (HCVcp) soluble extract (TSE) and Escherichia coli- derived rHCVcp in combination with Canola oil bodies (oil) compared to that of the Freund's (FA) adjuvant. Mice immunized by TSE+ oil developed both strong humeral (IgG) and Th1-biased cellular responses, manifested by high levels of IFN-γ and lower IgG1/IgG2a ratio and IL-4 secretion. Results of the intracellular cytokine staining indicated that TSE+ oil immunization in mice triggered both CD4+ and CD8+ T cells to release IFN-γ, while CD4+ cells were mostly triggered when FA was used. Analyses by qRT-PCR indicated that a combination of rHCVcp/TSE with oil body induced high levels of IL-10 cytokines compared to that of the FA adjuvant. These characteristics are important properties for the design of an HCV vaccine candidate and indicate the potential of Canola-derived antigen and oil bodies in addressing these concerns.


Assuntos
Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/prevenção & controle , Proteínas Recombinantes/administração & dosagem , Células Th1/efeitos dos fármacos , Proteínas do Core Viral/administração & dosagem , Vacinas contra Hepatite Viral/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/química , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Hepacivirus/imunologia , Hepacivirus/patogenicidade , Hepatite C Crônica/imunologia , Hepatite C Crônica/patologia , Hepatite C Crônica/virologia , Imunidade Celular/efeitos dos fármacos , Imunoglobulina G/biossíntese , Interferon gama/biossíntese , Interferon gama/imunologia , Interleucina-10/biossíntese , Interleucina-10/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Óleo de Brassica napus/administração & dosagem , Óleo de Brassica napus/química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Células Th1/imunologia , Células Th1/virologia , Proteínas do Core Viral/biossíntese , Proteínas do Core Viral/imunologia , Vacinas contra Hepatite Viral/biossíntese
14.
Nature ; 585(7824): 277-282, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32879489

RESUMO

Abnormal epigenetic patterns correlate with effector T cell malfunction in tumours1-4, but the cause of this link is unknown. Here we show that tumour cells disrupt methionine metabolism in CD8+ T cells, thereby lowering intracellular levels of methionine and the methyl donor S-adenosylmethionine (SAM) and resulting in loss of dimethylation at lysine 79 of histone H3 (H3K79me2). Loss of H3K79me2 led to low expression of STAT5 and impaired T cell immunity. Mechanistically, tumour cells avidly consumed methionine and outcompeted T cells for methionine by expressing high levels of the methionine transporter SLC43A2. Genetic and biochemical inhibition of tumour SLC43A2 restored H3K79me2 in T cells, thereby boosting spontaneous and checkpoint-induced tumour immunity. Moreover, methionine supplementation improved the expression of H3K79me2 and STAT5 in T cells, and this was accompanied by increased T cell immunity in tumour-bearing mice and patients with colon cancer. Clinically, tumour SLC43A2 correlated negatively with T cell histone methylation and functional gene signatures. Our results identify a mechanistic connection between methionine metabolism, histone patterns, and T cell immunity in the tumour microenvironment. Thus, cancer methionine consumption is an immune evasion mechanism, and targeting cancer methionine signalling may provide an immunotherapeutic approach.


Assuntos
Sistema L de Transporte de Aminoácidos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Histonas/metabolismo , Metionina/metabolismo , Metilação , Neoplasias/metabolismo , Sistema L de Transporte de Aminoácidos/deficiência , Animais , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Epigênese Genética , Feminino , Histonas/química , Humanos , Camundongos , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/patologia , Receptores de Antígenos de Linfócitos T/metabolismo , Fator de Transcrição STAT5/metabolismo
15.
Nat Commun ; 11(1): 4454, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901001

RESUMO

Chronic viral infections are often associated with impaired CD8+ T cell function, referred to as exhaustion. Although the molecular and cellular circuits involved in CD8+ T cell exhaustion are well defined, with sustained presence of antigen being one important parameter, how much T cell receptor (TCR) signaling is actually ongoing in vivo during established chronic infection is unclear. Here, we characterize the in vivo TCR signaling of virus-specific exhausted CD8+ T cells in a mouse model, leveraging TCR signaling reporter mice in combination with transcriptomics. In vivo signaling in exhausted cells is low, in contrast to their in vitro signaling potential, and despite antigen being abundantly present. Both checkpoint blockade and adoptive transfer of naïve target cells increase TCR signaling, demonstrating that engagement of co-inhibitory receptors curtails CD8+ T cell signaling and function in vivo.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transferência Adotiva , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/virologia , Doença Crônica , Citotoxicidade Imunológica , Modelos Animais de Doenças , Regulação para Baixo , Tolerância Imunológica , Imunidade Celular , Técnicas In Vitro , Ativação Linfocitária , Coriomeningite Linfocítica/genética , Vírus da Coriomeningite Linfocítica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/imunologia , Receptor de Morte Celular Programada 1/imunologia , RNA-Seq , Transdução de Sinais/imunologia
16.
Nat Commun ; 11(1): 4475, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901029

RESUMO

Tissue resident memory CD8+ T cells (Trm) are poised for immediate reactivation at sites of pathogen entry and provide optimal protection of mucosal surfaces. The intestinal tract represents a portal of entry for many infectious agents; however, to date specific strategies to enhance Trm responses at this site are lacking. Here, we present TMDI (Transient Microbiota Depletion-boosted Immunization), an approach that leverages antibiotic treatment to temporarily restrain microbiota-mediated colonization resistance, and favor intestinal expansion to high densities of an orally-delivered Listeria monocytogenes strain carrying an antigen of choice. By augmenting the local chemotactic gradient as well as the antigenic load, this procedure generates a highly expanded pool of functional, antigen-specific intestinal Trm, ultimately enhancing protection against infectious re-challenge in mice. We propose that TMDI is a useful model to dissect the requirements for optimal Trm responses in the intestine, and also a potential platform to devise novel mucosal vaccination approaches.


Assuntos
Microbioma Gastrointestinal/imunologia , Imunidade nas Mucosas , Administração Oral , Animais , Antígenos/administração & dosagem , Linfócitos T CD8-Positivos/imunologia , Quimiotaxia/imunologia , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Interações entre Hospedeiro e Microrganismos/imunologia , Imunidade nas Mucosas/efeitos dos fármacos , Memória Imunológica , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovalbumina/administração & dosagem , Estreptomicina/administração & dosagem
17.
Nat Commun ; 11(1): 4520, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908154

RESUMO

Tumor extracellular matrix has been associated with drug resistance and immune suppression. Here, proteomic and RNA profiling reveal increased collagen levels in lung tumors resistant to PD-1/PD-L1 blockade. Additionally, elevated collagen correlates with decreased total CD8+ T cells and increased exhausted CD8+ T cell subpopulations in murine and human lung tumors. Collagen-induced T cell exhaustion occurs through the receptor LAIR1, which is upregulated following CD18 interaction with collagen, and induces T cell exhaustion through SHP-1. Reduction in tumor collagen deposition through LOXL2 suppression increases T cell infiltration, diminishes exhausted T cells, and abrogates resistance to anti-PD-L1. Abrogating LAIR1 immunosuppression through LAIR2 overexpression or SHP-1 inhibition sensitizes resistant lung tumors to anti-PD-1. Clinically, increased collagen, LAIR1, and TIM-3 expression in melanoma patients treated with PD-1 blockade predict poorer survival and response. Our study identifies collagen and LAIR1 as potential markers for immunotherapy resistance and validates multiple promising therapeutic combinations.


Assuntos
Adenocarcinoma de Pulmão/tratamento farmacológico , Antineoplásicos Imunológicos/farmacologia , Linfócitos T CD8-Positivos/imunologia , Colágeno/metabolismo , Resistencia a Medicamentos Antineoplásicos/imunologia , Neoplasias Pulmonares/tratamento farmacológico , Receptores Imunológicos/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/patologia , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/metabolismo , Animais , Antineoplásicos Imunológicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Carcinoma Pulmonar de Lewis/imunologia , Carcinoma Pulmonar de Lewis/patologia , Linhagem Celular Tumoral , Conjuntos de Dados como Assunto , Modelos Animais de Doenças , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/imunologia , Matriz Extracelular/patologia , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Humanos , Pulmão/imunologia , Pulmão/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Transgênicos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , RNA-Seq , Receptores Imunológicos/genética
18.
Nat Commun ; 11(1): 4545, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917858

RESUMO

TGF-ß1, ß2 and ß3 bind a common receptor to exert vastly diverse effects in cancer, supporting either tumor progression by favoring metastases and inhibiting anti-tumor immunity, or tumor suppression by inhibiting malignant cell proliferation. Global TGF-ß inhibition thus bears the risk of undesired tumor-promoting effects. We show that selective blockade of TGF-ß1 production by Tregs with antibodies against GARP:TGF-ß1 complexes induces regressions of mouse tumors otherwise resistant to anti-PD-1 immunotherapy. Effects of combined GARP:TGF-ß1/PD-1 blockade are immune-mediated, do not require FcγR-dependent functions and increase effector functions of anti-tumor CD8+ T cells without augmenting immune cell infiltration or depleting Tregs within tumors. We find GARP-expressing Tregs and evidence that they produce TGF-ß1 in one third of human melanoma metastases. Our results suggest that anti-GARP:TGF-ß1 mAbs, by selectively blocking a single TGF-ß isoform emanating from a restricted cellular source exerting tumor-promoting activity, may overcome resistance to PD-1/PD-L1 blockade in patients with cancer.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas de Membrana/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Animais , Antineoplásicos Imunológicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral/transplante , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/imunologia , Células HEK293 , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Neoplasias/imunologia , Neoplasias/patologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
20.
Nat Commun ; 11(1): 4767, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958743

RESUMO

Psoriatic arthritis (PsA) is a debilitating immune-mediated inflammatory arthritis of unknown pathogenesis commonly affecting patients with skin psoriasis. Here we use complementary single-cell approaches to study leukocytes from PsA joints. Mass cytometry demonstrates a 3-fold expansion of memory CD8 T cells in the joints of PsA patients compared to peripheral blood. Meanwhile, droplet-based and plate-based single-cell RNA sequencing of paired T cell receptor alpha and beta chain sequences show pronounced CD8 T cell clonal expansions within the joints. Transcriptome analyses find these expanded synovial CD8 T cells to express cycling, activation, tissue-homing and tissue residency markers. T cell receptor sequence comparison between patients identifies clonal convergence. Finally, chemokine receptor CXCR3 is upregulated in the expanded synovial CD8 T cells, while two CXCR3 ligands, CXCL9 and CXCL10, are elevated in PsA synovial fluid. Our data thus provide a quantitative molecular insight into the cellular immune landscape of psoriatic arthritis.


Assuntos
Artrite Psoriásica/imunologia , Linfócitos T CD8-Positivos/imunologia , Seleção Clonal Mediada por Antígeno , Receptores de Retorno de Linfócitos/metabolismo , Líquido Sinovial/imunologia , Artrite Psoriásica/sangue , Linfócitos T CD8-Positivos/metabolismo , Perfilação da Expressão Gênica , Humanos , Memória Imunológica , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Receptores de Quimiocinas/metabolismo , Receptores de Retorno de Linfócitos/genética , Análise de Célula Única , Membrana Sinovial/imunologia
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