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1.
Sci Immunol ; 6(57)2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653907

RESUMO

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8+ T cells that correlated with the use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct from one another and implicate CD8+ T cells in the clinical presentation and trajectory of MIS-C.


Assuntos
/imunologia , Ativação Linfocitária , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Envelhecimento/imunologia , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Humanos , Leucopenia/imunologia , Masculino , Adulto Jovem
2.
Cell ; 184(7): 1858-1864.e10, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33631096

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the coronavirus disease 2019 (COVID-19) pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 431 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 251 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ∼20% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but they were boosted upon SARS-CoV-2 infection.

3.
Lancet Oncol ; 22(1): 118-131, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33387490

RESUMO

BACKGROUND: Standard chemotherapy remains inadequate in metastatic pancreatic adenocarcinoma. Combining an agonistic CD40 monoclonal antibody with chemotherapy induces T-cell-dependent tumour regression in mice and improves survival. In this study, we aimed to evaluate the safety of combining APX005M (sotigalimab) with gemcitabine plus nab-paclitaxel, with and without nivolumab, in patients with pancreatic adenocarcinoma to establish the recommended phase 2 dose. METHODS: This non-randomised, open-label, multicentre, four-cohort, phase 1b study was done at seven academic hospitals in the USA. Eligible patients were adults aged 18 years and older with untreated metastatic pancreatic adenocarcinoma, Eastern Cooperative Oncology Group performance status score of 0-1, and measurable disease by Response Evaluation Criteria in Solid Tumors version 1.1. All patients were treated with 1000 mg/m2 intravenous gemcitabine and 125 mg/m2 intravenous nab-paclitaxel. Patients received 0·1 mg/kg intravenous APX005M in cohorts B1 and C1 and 0·3 mg/kg in cohorts B2 and C2. In cohorts C1 and C2, patients also received 240 mg intravenous nivolumab. Primary endpoints comprised incidence of adverse events in all patients who received at least one dose of any study drug, incidence of dose-limiting toxicities (DLTs) in all patients who had a DLT or received at least two doses of gemcitabine plus nab-paclitaxel and one dose of APX005M during cycle 1, and establishing the recommended phase 2 dose of intravenous APX005M. Objective response rate in the DLT-evaluable population was a key secondary endpoint. This trial (PRINCE, PICI0002) is registered with ClinicalTrials.gov, NCT03214250 and is ongoing. FINDINGS: Between Aug 22, 2017, and July 10, 2018, of 42 patients screened, 30 patients were enrolled and received at least one dose of any study drug; 24 were DLT-evaluable with median follow-up 17·8 months (IQR 16·0-19·4; cohort B1 22·0 months [21·4-22·7], cohort B2 18·2 months [17·0-18·9], cohort C1 17·9 months [14·3-19·7], cohort C2 15·9 months [12·7-16·1]). Two DLTs, both febrile neutropenia, were observed, occurring in one patient each for cohorts B2 (grade 3) and C1 (grade 4). The most common grade 3-4 treatment-related adverse events were lymphocyte count decreased (20 [67%]; five in B1, seven in B2, four in C1, four in C2), anaemia (11 [37%]; two in B1, four in B2, four in C1, one in C2), and neutrophil count decreased (nine [30%]; three in B1, three in B2, one in C1, two in C2). 14 (47%) of 30 patients (four each in B1, B2, C1; two in C2) had a treatment-related serious adverse event. The most common serious adverse event was pyrexia (six [20%] of 30; one in B2, three in C1, two in C2). There were two chemotherapy-related deaths due to adverse events: one sepsis in B1 and one septic shock in C1. The recommended phase 2 dose of APX005M was 0·3 mg/kg. Responses were observed in 14 (58%) of 24 DLT-evaluable patients (four each in B1, C1, C2; two in B2). INTERPRETATION: APX005M and gemcitabine plus nab-paclitaxel, with or without nivolumab, is tolerable in metastatic pancreatic adenocarcinoma and shows clinical activity. If confirmed in later phase trials, this treatment regimen could replace chemotherapy-only standard of care in this population. FUNDING: Parker Institute for Cancer Immunotherapy, Cancer Research Institute, and Bristol Myers Squibb.


Assuntos
Adenocarcinoma/tratamento farmacológico , Albuminas/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígenos CD40/antagonistas & inibidores , Desoxicitidina/análogos & derivados , Nivolumabe/administração & dosagem , Paclitaxel/administração & dosagem , Neoplasias Pancreáticas/tratamento farmacológico , Adenocarcinoma/imunologia , Adenocarcinoma/secundário , Idoso , Albuminas/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Antígenos CD40/imunologia , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nivolumabe/efeitos adversos , Paclitaxel/efeitos adversos , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
4.
medRxiv ; 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33200143

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the COVID-19 pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 204 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 252 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ∼23% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but paradoxically these hCoV cross-reactive antibodies were boosted upon SARS-CoV-2 infection.

5.
medRxiv ; 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32995826

RESUMO

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8 T cells that correlated with use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct and implicate CD8 T cells in clinical presentation and trajectory of MIS-C.

6.
Science ; 369(6508)2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32669297

RESUMO

Coronavirus disease 2019 (COVID-19) is currently a global pandemic, but human immune responses to the virus remain poorly understood. We used high-dimensional cytometry to analyze 125 COVID-19 patients and compare them with recovered and healthy individuals. Integrated analysis of ~200 immune and ~50 clinical features revealed activation of T cell and B cell subsets in a proportion of patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses reaching >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable with that in uninfected individuals. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. Our analyses identified three immunotypes associated with poor clinical trajectories versus improving health. These immunotypes may have implications for the design of therapeutics and vaccines for COVID-19.


Assuntos
Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Imunidade Adaptativa , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Subpopulações de Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Citocinas/sangue , Feminino , Humanos , Memória Imunológica , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Pandemias , Plasmócitos/imunologia , Índice de Gravidade de Doença , Subpopulações de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Fatores de Tempo , Adulto Jovem
7.
bioRxiv ; 2020 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-32511371

RESUMO

COVID-19 has become a global pandemic. Immune dysregulation has been implicated, but immune responses remain poorly understood. We analyzed 71 COVID-19 patients compared to recovered and healthy subjects using high dimensional cytometry. Integrated analysis of ~200 immune and >30 clinical features revealed activation of T cell and B cell subsets, but only in some patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses could reach >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. These analyses identified three "immunotypes" associated with poor clinical trajectories versus improving health. These immunotypes may have implications for therapeutics and vaccines.

8.
Methods Mol Biol ; 2111: 1-20, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31933194

RESUMO

T-cell diversity is multifactorial and includes variability in antigen specificity, differentiation, function, and cell-trafficking potential. Spectral overlap limits the ability of traditional flow cytometry to fully capture the diversity of T-cell subsets and function. The development of mass cytometry permits deep immunoprofiling of T-cell subsets, activation state, and function simultaneously from even small volumes of blood. This chapter describes our methods for mass cytometry and high-throughput data analysis of T cells in patient cohorts. We provide a pipeline that includes practical considerations when customizing a panel for mass cytometry. We also provide protocols for the conjugation and titration of metal-labeled antibodies (including two T-cell panels) and a staining procedure. Finally, with the aim to support translational science, we provide R scripts that contain a detailed workflow for initial evaluation of high-dimensional data generated from cohorts of patients.

9.
Microbiome ; 7(1): 130, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519223

RESUMO

BACKGROUND: The gut microbiome is an important determinant of human health. Its composition has been shown to be influenced by multiple environmental factors and likely by host genetic variation. In the framework of the Milieu Intérieur Consortium, a total of 1000 healthy individuals of western European ancestry, with a 1:1 sex ratio and evenly stratified across five decades of life (age 20-69), were recruited. We generated 16S ribosomal RNA profiles from stool samples for 858 participants. We investigated genetic and non-genetic factors that contribute to individual differences in fecal microbiome composition. RESULTS: Among 110 demographic, clinical, and environmental factors, 11 were identified as significantly correlated with α-diversity, ß-diversity, or abundance of specific microbial communities in multivariable models. Age and blood alanine aminotransferase levels showed the strongest associations with microbiome diversity. In total, all non-genetic factors explained 16.4% of the variance. We then searched for associations between > 5 million single nucleotide polymorphisms and the same indicators of fecal microbiome diversity, including the significant non-genetic factors as covariates. No genome-wide significant associations were identified after correction for multiple testing. A small fraction of previously reported associations between human genetic variants and specific taxa could be replicated in our cohort, while no replication was observed for any of the diversity metrics. CONCLUSION: In a well-characterized cohort of healthy individuals, we identified several non-genetic variables associated with fecal microbiome diversity. In contrast, host genetics only had a negligible influence. Demographic and environmental factors are thus the main contributors to fecal microbiome composition in healthy individuals. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01699893.


Assuntos
Bactérias/classificação , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Adulto , Idoso , Bactérias/isolamento & purificação , Estudos de Coortes , Demografia , Meio Ambiente , Feminino , Voluntários Saudáveis , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Sci Transl Med ; 10(457)2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-30185651

RESUMO

The thymus is the primary lymphoid organ where naïve T cells are generated; however, with the exception of age, the parameters that govern its function in healthy humans remain unknown. We characterized the variability of thymic function among 1000 age- and sex-stratified healthy adults of the Milieu Intérieur cohort, using quantification of T cell receptor excision circles (TRECs) in peripheral blood T cells as a surrogate marker of thymopoiesis. Age and sex were the only nonheritable factors identified that affect thymic function. TREC amounts decreased with age and were higher in women compared to men. In addition, a genome-wide association study revealed a common variant (rs2204985) within the T cell receptor TCRA-TCRD locus, between the DD2 and DD3 gene segments, which associated with TREC amounts. Strikingly, transplantation of human hematopoietic stem cells with the rs2204985 GG genotype into immunodeficient mice led to thymopoiesis with higher TRECs, increased thymocyte counts, and a higher TCR repertoire diversity. Our population immunology approach revealed a genetic locus that influences thymopoiesis in healthy adults, with potentially broad implications in precision medicine.


Assuntos
Loci Gênicos , Variação Genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T gama-delta/genética , Timo/crescimento & desenvolvimento , Adulto , Idoso , Animais , Biomarcadores/metabolismo , Estudos de Coortes , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Camundongos SCID , Pessoa de Meia-Idade , Fenótipo , Linfócitos T/metabolismo , Adulto Jovem
11.
Genome Med ; 10(1): 59, 2018 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-30053915

RESUMO

BACKGROUND: Humoral immune responses to infectious agents or vaccination vary substantially among individuals, and many of the factors responsible for this variability remain to be defined. Current evidence suggests that human genetic variation influences (i) serum immunoglobulin levels, (ii) seroconversion rates, and (iii) intensity of antigen-specific immune responses. Here, we evaluated the impact of intrinsic (age and sex), environmental, and genetic factors on the variability of humoral response to common pathogens and vaccines. METHODS: We characterized the serological response to 15 antigens from common human pathogens or vaccines, in an age- and sex-stratified cohort of 1000 healthy individuals (Milieu Intérieur cohort). Using clinical-grade serological assays, we measured total IgA, IgE, IgG, and IgM levels, as well as qualitative (serostatus) and quantitative IgG responses to cytomegalovirus, Epstein-Barr virus, herpes simplex virus 1 and 2, varicella zoster virus, Helicobacter pylori, Toxoplasma gondii, influenza A virus, measles, mumps, rubella, and hepatitis B virus. Following genome-wide genotyping of single nucleotide polymorphisms and imputation, we examined associations between ~ 5 million genetic variants and antibody responses using single marker and gene burden tests. RESULTS: We identified age and sex as important determinants of humoral immunity, with older individuals and women having higher rates of seropositivity for most antigens. Genome-wide association studies revealed significant associations between variants in the human leukocyte antigen (HLA) class II region on chromosome 6 and anti-EBV and anti-rubella IgG levels. We used HLA imputation to fine map these associations to amino acid variants in the peptide-binding groove of HLA-DRß1 and HLA-DPß1, respectively. We also observed significant associations for total IgA levels with two loci on chromosome 2 and with specific KIR-HLA combinations. CONCLUSIONS: Using extensive serological testing and genome-wide association analyses in a well-characterized cohort of healthy individuals, we demonstrated that age, sex, and specific human genetic variants contribute to inter-individual variability in humoral immunity. By highlighting genes and pathways implicated in the normal antibody response to frequently encountered antigens, these findings provide a basis to better understand disease pathogenesis. TRIALS REGISTRATION: ClinicalTrials.gov , NCT01699893.


Assuntos
Envelhecimento/imunologia , Antígenos HLA-D/genética , Imunidade Humoral/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Infecções Bacterianas/imunologia , Feminino , Antígenos HLA-D/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Vacinas/imunologia , Viroses/imunologia
13.
Nat Immunol ; 19(3): 302-314, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29476184

RESUMO

The quantification and characterization of circulating immune cells provide key indicators of human health and disease. To identify the relative effects of environmental and genetic factors on variation in the parameters of innate and adaptive immune cells in homeostatic conditions, we combined standardized flow cytometry of blood leukocytes and genome-wide DNA genotyping of 1,000 healthy, unrelated people of Western European ancestry. We found that smoking, together with age, sex and latent infection with cytomegalovirus, were the main non-genetic factors that affected variation in parameters of human immune cells. Genome-wide association studies of 166 immunophenotypes identified 15 loci that showed enrichment for disease-associated variants. Finally, we demonstrated that the parameters of innate cells were more strongly controlled by genetic variation than were those of adaptive cells, which were driven by mainly environmental exposure. Our data establish a resource that will generate new hypotheses in immunology and highlight the role of innate immunity in susceptibility to common autoimmune diseases.


Assuntos
Variação Genética/imunologia , Imunidade Inata/genética , Imunidade Adaptativa/genética , Adulto , Idoso , Feminino , Estudo de Associação Genômica Ampla , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
J Immunol ; 200(1): 139-146, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29187588

RESUMO

The preimmune repertoire consists of mature T lymphocytes that have not yet been stimulated in the periphery. Memory phenotype (MP) cells have been reported as part of the preimmune repertoire (i.e., T cells bearing memory markers despite lack of engagement with cognate Ag); however, little is known about their trafficking and function. In this study, we hypothesized that MP cells, naive to TCR stimulation, constitute a transient population that traffics to tissues during development. Using mutant and transgenic animals with a monospecific TCR, we discovered increased numbers of MP CD8+ T cells circulating in nonimmunized Cxcr3-/- and Cxcl10-/- mice compared with wild-type animals. Phenotypic differences included decreased numbers of preimmune MP Ag-specific T cells in the skin and thymus and a distinct pattern of activation upon TCR engagement. Our results show for the first time, to our knowledge, an important role for CXCR3 and CXCL10 in the tissue distribution of preimmune MP cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Quimiocina CXCL10/metabolismo , Receptores CXCR3/metabolismo , Animais , Células Cultivadas , Quimiocina CXCL10/genética , Quimiocina CXCL9/genética , Quimiocina CXCL9/metabolismo , Memória Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores CXCR3/genética
15.
J Hepatol ; 67(6): 1334-1339, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28860025

RESUMO

BACKGROUND & AIM: Several types of unexplained extra-hepatic manifestations, including haematological disorders, have been reported in the context of hepatitis E virus (HEV) infection. However, the underlying mechanism(s) of these manifestations are unknown. We provide evidence that HEV has an extra-hepatic endothelial tropism that can engage cutaneous T cells towards clonality. METHODS: A patient with a CD30(+) cutaneous T cell lymphoproliferative disorder (T-LPD) and biopsy-proven chronic HEV infection received three rounds of oral ribavirin treatment, administered either without or with interferon, and eventually achieved a sustained virologic response (SVR). Pathologic, virologic and immunologic investigations were carried out on biopsied skin lesion, and peripheral blood mononuclear cells between the 2nd and 3rd round of antiviral treatment and biopsied liver. RESULTS: Remission of T-LPD was observed upon antiviral treatment, and the patient remained in complete remission after achieving SVR. The T cell analysis showed large CD30(+) lymphocytes surrounding the blood vessels within the CD8(+) T cell infiltrate. HEV was detected within dermal microvascular endothelial cells using immunofluorescence staining, in situ hybridisation and electron microscopy. Infiltrating T cells mostly comprised memory CD8(+) T cells with a tissue-resident memory T cell phenotype. Overall, 98% of extracted T cells were CD8(+) T cells with aVß signature skewed towards Vß4 and with an oligoclonal profile. T cell clones from T-LPD were more like T cells in the liver than T cells in the blood [odds ratio=4.55, (3.70-5.60), p<0.0001]. No somatic mutations were found in the T-LPD exomes. CONCLUSION: HEV has an extra-hepatic tissue tropism in humans, including dermal endothelium, and can induce CD30(+) T-LPD that is sensitive to antivirals. LAY SUMMARY: Hepatitis E virus (HEV) has an extra-hepatic tissue tropism and should be added to the list of viruses associated with lymphoproliferative disorders. As such, HEV should be part of the laboratory workup of any lymphoproliferation, particularly those of the T cell phenotype that involve the skin. In the context of HEV-associated cutaneous T cell lymphoproliferative disorders, antiviral treatment could be considered a first-line treatment instead of chemotherapy.


Assuntos
Hepatite E/complicações , Antígeno Ki-1/análise , Linfoma Cutâneo de Células T/etiologia , Neoplasias Cutâneas/etiologia , Vírus da Hepatite E/genética , Vírus da Hepatite E/isolamento & purificação , Humanos , Linfoma Cutâneo de Células T/virologia , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/virologia , Tropismo Viral
16.
Elife ; 42015 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-26568315

RESUMO

Chronic infection perturbs immune homeostasis. While prior studies have reported dysregulation of effector and memory cells, little is known about the effects on naïve T cell populations. We performed a cross-sectional study of chronic hepatitis C (cHCV) patients using tetramer-associated magnetic enrichment to study antigen-specific inexperienced CD8(+) T cells (i.e., tumor or unrelated virus-specific populations in tumor-free and sero-negative individuals). cHCV showed normal precursor frequencies, but increased proportions of memory-phenotype inexperienced cells, as compared to healthy donors or cured HCV patients. These observations could be explained by low surface expression of CD5, a negative regulator of TCR signaling. Accordingly, we demonstrated TCR hyperactivation and generation of potent CD8(+) T cell responses from the altered T cell repertoire of cHCV patients. In sum, we provide the first evidence that naïve CD8(+) T cells are dysregulated during cHCV infection, and establish a new mechanism of immune perturbation secondary to chronic infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Hepacivirus/imunologia , Hepatite C Crônica/patologia , Ativação Linfocitária , Antígenos CD5/metabolismo , Estudos Transversais , Humanos , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais
17.
Clin Immunol ; 157(2): 277-93, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25562703

RESUMO

The Milieu Intérieur Consortium has established a 1000-person healthy population-based study (stratified according to sex and age), creating an unparalleled opportunity for assessing the determinants of human immunologic variance. Herein, we define the criteria utilized for participant enrollment, and highlight the key data that were collected for correlative studies. In this report, we analyzed biological correlates of sex, age, smoking-habits, metabolic score and CMV infection. We characterized and identified unique risk factors among healthy donors, as compared to studies that have focused on the general population or disease cohorts. Finally, we highlight sex-bias in the thresholds used for metabolic score determination and recommend a deeper examination of current guidelines. In sum, our clinical design, standardized sample collection strategies, and epidemiological data analyses have established the foundation for defining variability within human immune responses.


Assuntos
Infecções por Citomegalovirus/imunologia , Sistema Imunitário/imunologia , Síndrome Metabólica/imunologia , Fumar/imunologia , Adulto , Fatores Etários , Idoso , Estudos de Coortes , Estudos Transversais , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sexuais , Fatores Socioeconômicos , Adulto Jovem
18.
Methods Mol Biol ; 960: 309-326, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23329496

RESUMO

The tracking of epitope-specific T cells is a useful approach for the study of adaptive immune responses. This protocol describes how Major Histocompatibility Complex Class I (MHC-I) multimers can be used to stain, enrich, and enumerate (rare) populations of CD8(+) T cells specific for a given antigen. It provides the detailed steps for multimer labeling, magnetic enrichment, and cytometric analysis. Additionally, it provides informations for multiplexing experiments in order to achieve simultaneous detection of multiple antigenic specificities, and strategies for coupling the protocol with functional assays (e.g., intracellular cytokine staining). Future developments in cytometric systems (e.g., mass spectroscopy-based cytometry) and gene expression studies (e.g., single cell PCR) will extend these approaches and provide an unprecedented assessment of the immune repertoire.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Antígenos de Histocompatibilidade Classe I/química , Multimerização Proteica , Animais , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Citocinas/metabolismo , Dissecação , Citometria de Fluxo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Espaço Intracelular/metabolismo , Camundongos , Estrutura Quaternária de Proteína
19.
Cancer Res ; 73(1): 128-38, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23135914

RESUMO

Head and neck cancers positive for human papillomavirus (HPV) have a more favorable clinical outcome than HPV-negative cancers, but it is unknown why this is the case. We hypothesized that prognosis was affected by intrinsic features of HPV-infected tumor cells or differences in host immune response. In this study, we focused on a comparison of regulatory Foxp3(+) T cells and programmed death-1 (PD-1)(+) T cells in the microenvironment of tumors that were positive or negative for HPV, in two groups that were matched for various clinical and biologic parameters. HPV-positive head and neck cancers were more heavily infiltrated by regulatory T cells and PD-1(+) T cells and the levels of PD-1(+) cells were positively correlated with a favorable clinical outcome. In explaining this paradoxical result, we showed that these PD-1(+) T cells expressed activation markers and were functional after blockade of the PD-1-PD-L1 axis in vitro. Approximately 50% of PD-1(+) tumor-infiltrating T cells lacked Tim-3 expression and may indeed represent activated T cells. In mice, administration of a cancer vaccine increased PD-1 on T cells with concomitant tumor regression. In this setting, PD-1 blockade synergized with vaccine in eliciting antitumor efficacy. Our findings prompt a need to revisit the significance of PD-1-infiltrating T cells in cancer, where we suggest that PD-1 detection may reflect a previous immune response against tumors that might be reactivated by PD-1/PD-L1 blockade.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/imunologia , Neoplasias de Cabeça e Pescoço/imunologia , Neoplasias de Cabeça e Pescoço/virologia , Linfócitos do Interstício Tumoral/imunologia , Receptor de Morte Celular Programada 1/biossíntese , Linfócitos T/imunologia , Animais , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/virologia , Feminino , Citometria de Fluxo , Imunofluorescência , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Ativação Linfocitária/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/metabolismo , Prognóstico , Receptor de Morte Celular Programada 1/imunologia , Subpopulações de Linfócitos T/imunologia , Microambiente Tumoral/imunologia
20.
Blood ; 115(18): 3718-25, 2010 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-20200354

RESUMO

The number of antigen-specific naive CD8(+) T cells is believed to be important in the shaping of adaptive immune responses, and is predictive for the magnitude of priming responses in mouse models. Because of extremely low precursor frequencies, knowledge about these cells comes from indirect techniques and estimations. Here, we present a strategy based on the combination of tetramer staining, magnetic-bead enrichment, and multiparametric cytometry, which permitted direct detection and analysis of CD8(+) T cells reactive for 6 different naive epitopes (MART-1(26-35), HIV-1 Gag p17(77-85), hepatitis C virus [HCV] NS3(1406-1415), HCV Core(132-140), NY-ESO-1(157-165), and cytomegalovirus [CMV] pp65(495-503)). Interestingly, we detected higher than 100-fold differences in precursor frequency across these epitopes (from 0.6 x 10(-6) to 1.3 x 10(-4)), but conserved frequencies among humans. Development of a procedure for direct assessment of T-cell precursor frequency in humans has important implications, with particular relevance to vaccine development and monitoring of tumor and self-reactive T cells.


Assuntos
Antígenos de Neoplasias/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Proteínas de Neoplasias/imunologia , Fragmentos de Peptídeos/imunologia , Fosfoproteínas/imunologia , Proteínas do Core Viral/imunologia , Proteínas da Matriz Viral/imunologia , Proteínas não Estruturais Virais/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia , Sequência Conservada , Citometria de Fluxo , Antígenos da Hepatite C/imunologia , Humanos , Interferon gama/metabolismo , Antígeno MART-1
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