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1.
Nat Commun ; 12(1): 99, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397934

RESUMO

CD4 and CD8 mark helper and cytotoxic T cell lineages, respectively, and serve as coreceptors for MHC-restricted TCR recognition. How coreceptor expression is matched with TCR specificity is central to understanding CD4/CD8 lineage choice, but visualising coreceptor gene activity in individual selection intermediates has been technically challenging. It therefore remains unclear whether the sequence of coreceptor gene expression in selection intermediates follows a stereotypic pattern, or is responsive to signaling. Here we use single cell RNA sequencing (scRNA-seq) to classify mouse thymocyte selection intermediates by coreceptor gene expression. In the unperturbed thymus, Cd4+Cd8a- selection intermediates appear before Cd4-Cd8a+ selection intermediates, but the timing of these subsets is flexible according to the strength of TCR signals. Our data show that selection intermediates discriminate MHC class prior to the loss of coreceptor expression and suggest a model where signal strength informs the timing of coreceptor gene activity and ultimately CD4/CD8 lineage choice.


Assuntos
Linfócitos T CD4-Positivos/citologia , Linfócitos T CD8-Positivos/citologia , Diferenciação Celular/imunologia , Linhagem da Célula/imunologia , Timo/citologia , Timo/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Subunidade alfa 3 de Fator de Ligação ao Core/metabolismo , Citocinas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Antígenos de Histocompatibilidade/metabolismo , Ativação Linfocitária/genética , Camundongos Endogâmicos C57BL , Análise de Componente Principal , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo
2.
Nat Commun ; 12(1): 635, 2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33504809

RESUMO

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) with the majority of cases characterised by relapsing/remitting (RRMS) attacks of neurologic dysfunction followed by variable resolution. Improving clinical outcomes in RRMS requires both a better understanding of the immunological mechanisms driving recurrent demyelination and better means of predicting future disease course to facilitate early targeted therapy. Here, we apply hypothesis-generating network transcriptomics to CD8+ cells isolated from patients in RRMS, identifying a signature reflecting expansion of a subset of CD8+ natural killer cells (NK8+) associated with favourable outcome. NK8+ are capable of regulating CD4+ T cell activation and proliferation in vitro, with reduced expression of HLA-G binding inhibitory receptors and consequent reduced sensitivity to HLA-G-mediated suppression. We identify surrogate markers of the NK8+ signature in peripheral blood leucocytes and validate their association with clinical outcome in an independent cohort, suggesting their measurement may facilitate early, targeted therapy in RRMS.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Matadoras Naturais/imunologia , Esclerose Múltipla Recidivante-Remitente/genética , Esclerose Múltipla Recidivante-Remitente/imunologia , Transcriptoma/genética , Linfócitos T CD8-Positivos/ultraestrutura , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Antígenos HLA-G/metabolismo , Humanos , Células Matadoras Naturais/ultraestrutura , Ativação Linfocitária/genética , Reprodutibilidade dos Testes , Fatores de Risco , Resultado do Tratamento
3.
Chem Biol Interact ; 335: 109370, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33422520

RESUMO

The aberrant expression level of SARS-CoV-2 cell receptor gene ACE2 was reported in lung adenocarcinoma (LUAD) comorbidity of COVID-19. However, the association of ACE2 expression levels with immunosuppression and metabolic reprogramming in LUAD remains lacking. We investigated the expression level of ACE2, an association of ACE2 expression level with various types of immune signatures, immune ratios, and pathways. We employed a weighted gene co-expression network analysis (WGCNA) R package to identify the gene modules and investigated prognostic roles of hub genes in LUAD. Overexpression of ACE2 level was found in LUAD and ACE2 expression was negatively associated with various types of immune signatures including CD8+ T cells, CD4+ regulatory T cells, NK cells, and T cell activation. Besides, ACE2 upregulation was not only associated with CD8+ T cell/CD4+ regulatory T cell ratios but also linked with downregulation of immune-markers including CD8A, KLRC1, GZMA, GZMB, NKG7, CCL4, and IFNG. Moreover, the ACE2 expression level was found to be associated with the enrichment level of various metabolic pathways and it was also found that the metabolic pathways are directly positively correlated with the increased expression levels of ACE2, indicating that the overexpression of ACE2 is associated with metabolic reprogramming in LUAD. Furthermore, WGCNA based analysis revealed the gene modules in the high-ACE2-expression-level group of LUAD and identified GCLC and SLC7A11 hub genes which are not only highly expressed in lung adenocarcinoma but also correlated with the poor survival prognosis. Our analysis of ACE2 in LUAD tissues suggests that ACE2 is not only a receptor but is also associated with immunosuppression and metabolic reprogramming. This study underlines the clue for understanding the clinical significance of ACE2 in COVID-19 patients with LUAD comorbidity.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Imunidade Celular/genética , Imunidade Inata/genética , Neoplasias Pulmonares/metabolismo , Adenocarcinoma de Pulmão/epidemiologia , Sistema y+ de Transporte de Aminoácidos/genética , /epidemiologia , Comorbidade , Biologia Computacional , Bases de Dados Genéticas/estatística & dados numéricos , Feminino , Regulação Neoplásica da Expressão Gênica , Glutamato-Cisteína Ligase/genética , Humanos , Neoplasias Pulmonares/epidemiologia , Ativação Linfocitária/genética , Masculino , não Fumantes , Mapas de Interação de Proteínas/genética , Fumantes , Linfócitos T/metabolismo , Transcriptoma , Regulação para Cima
4.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 36(8): 680-686, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32958123

RESUMO

Objective To investigate the role of butyrophilin 3A1 (BTN3A1) in the activation and proliferation of human peripheral blood Vγ9Vδ2 T cells induced by M. tuberculosis heat resistant antigen (MTB-HAg). Methods Human peripheral blood mononuclear cells (PBMCs) were treated with BTN3A1 blocking antibody for 3 hours and then stimulated with MTB-HAg or phosphoantigen (PAg). At 24 hours of stimulation, the cells were collected to detect the expression of CD69 in Vγ9Vδ2 T cells by flow cytometry. At 20 hours of stimulation, the cells were collected to detect the proportions of cells producing helper T cell type I (Th1) cytokines IFN-γ and tumor necrosis factor α (TNF-α) in the Vγ9Vδ2 T cells. The PBMCs were also stimulated and cultured in IL-2-containing medium for 10 days, and the expansion and proliferation activity of Vγ9Vδ2 T cells were detected. Results After stimulated with MTB-HAg, the average fluorescence intensity of CD69 and the proportion of CD69 positive cells in Vγ9Vδ2 T cells decreased significantly in BTN3A1 blocked group, being 13.84% and 43.00% of those in the stimulated group, respectively. However, the average fluorescence intensity of CD69 molecules and the proportion of positive cells in PAg blocked group were significantly inhibited (3.10%, 4.47% and 9.53%, 10.91% of those in the stimulated group). The proportions of IFN-γ and TNF-α producing Vγ9Vδ2 T cells stimulated with MTB-HAg decreased significantly in the BTN3A1 blocked group, and the expansion number and cell proliferation activity of Vγ9Vδ2 T cells were also reduced significantly in the BTN3A1 blocked group. The results were similar to those of the PAg blocked group. Conclusion BTN3A1 promotes activation and proliferation of peripheral blood Vγ9Vδ2 T cells induced by MTB-HAg.


Assuntos
Antígenos de Bactérias , Antígenos CD , Butirofilinas , Ativação Linfocitária , Linfócitos T , Antígenos de Bactérias/imunologia , Antígenos CD/genética , Antígenos CD/metabolismo , Butirofilinas/genética , Butirofilinas/metabolismo , Proliferação de Células/genética , Humanos , Ativação Linfocitária/genética , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/citologia , Linfócitos T/imunologia
5.
Proc Natl Acad Sci U S A ; 117(40): 24974-24985, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32958637

RESUMO

The antigen-presenting molecule MR1 (MHC class I-related protein 1) presents metabolite antigens derived from microbial vitamin B2 synthesis to activate mucosal-associated invariant T (MAIT) cells. Key aspects of this evolutionarily conserved pathway remain uncharacterized, including where MR1 acquires ligands and what accessory proteins assist ligand binding. We answer these questions by using a fluorophore-labeled stable MR1 antigen analog, a conformation-specific MR1 mAb, proteomic analysis, and a genome-wide CRISPR/Cas9 library screen. We show that the endoplasmic reticulum (ER) contains a pool of two unliganded MR1 conformers stabilized via interactions with chaperones tapasin and tapasin-related protein. This pool is the primary source of MR1 molecules for the presentation of exogenous metabolite antigens to MAIT cells. Deletion of these chaperones reduces the ER-resident MR1 pool and hampers antigen presentation and MAIT cell activation. The MR1 antigen-presentation pathway thus co-opts ER chaperones to fulfill its unique ability to present exogenous metabolite antigens captured within the ER.


Assuntos
Retículo Endoplasmático/genética , Antígenos de Histocompatibilidade Classe I/genética , Metaboloma/genética , Antígenos de Histocompatibilidade Menor/genética , Proteômica , Apresentação do Antígeno/genética , Antígenos/genética , Antígenos/imunologia , Sistemas CRISPR-Cas/genética , Humanos , Ligantes , Ativação Linfocitária/genética , Proteínas de Membrana Transportadoras/genética , Chaperonas Moleculares/genética , Chaperonas Moleculares/imunologia , Células T Invariáveis Associadas à Mucosa/imunologia , Riboflavina/genética
6.
Nucleic Acids Res ; 48(15): 8724-8739, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32735645

RESUMO

T cell activation is a well-established model for studying cellular responses to exogenous stimulation. Motivated by our previous finding that intron retention (IR) could lead to transcript instability, in this study, we performed BruChase-Seq to experimentally monitor the expression dynamics of nascent transcripts in resting and activated CD4+ T cells. Computational modeling was then applied to quantify the stability of spliced and intron-retained transcripts on a genome-wide scale. Beyond substantiating that intron-retained transcripts were considerably less stable than spliced transcripts, we found a global stabilization of spliced mRNAs upon T cell activation, although the stability of intron-retained transcripts remained relatively constant. In addition, we identified that La-related protein 4 (LARP4), an RNA-binding protein (RBP) known to enhance mRNA stability, was involved in T cell activation-dependent mRNA stabilization. Knocking out Larp4 in mice destabilized Nfκb1 mRNAs and reduced secretion of interleukin-2 (IL2) and interferon-gamma (IFNγ), two factors critical for T cell proliferation and function. We propose that coordination between splicing regulation and mRNA stability may provide a novel paradigm to control spatiotemporal gene expression during T cell activation.


Assuntos
Interferon gama/genética , Interleucina-2/genética , Proteínas/genética , Estabilidade de RNA/genética , Transcriptoma/genética , Processamento Alternativo/genética , Animais , Humanos , Íntrons/genética , Ativação Linfocitária/genética , Camundongos , NF-kappa B/genética , Ligação Proteica/genética , RNA Mensageiro/genética , Linfócitos T/metabolismo
7.
Cells ; 9(9)2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32859121

RESUMO

Natural killer cells are important in the control of viral infections. However, the role of NK cells during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has previously not been identified. Peripheral blood NK cells from SARS-CoV and SARS-CoV-2 naïve subjects were evaluated for their activation, degranulation, and interferon-gamma expression in the presence of SARS-CoV and SARS-CoV-2 spike proteins. K562 and lung epithelial cells were transfected with spike proteins and co-cultured with NK cells. The analysis was performed by flow cytometry and immune fluorescence. SARS-CoV and SARS-CoV-2 spike proteins did not alter NK cell activation in a K562 in vitro model. On the contrary, SARS-CoV-2 spike 1 protein (SP1) intracellular expression by lung epithelial cells resulted in NK cell-reduced degranulation. Further experiments revealed a concomitant induction of HLA-E expression on the surface of lung epithelial cells and the recognition of an SP1-derived HLA-E-binding peptide. Simultaneously, there was increased modulation of the inhibitory receptor NKG2A/CD94 on NK cells when SP1 was expressed in lung epithelial cells. We ruled out the GATA3 transcription factor as being responsible for HLA-E increased levels and HLA-E/NKG2A interaction as implicated in NK cell exhaustion. We show for the first time that NK cells are affected by SP1 expression in lung epithelial cells via HLA-E/NKG2A interaction. The resulting NK cells' exhaustion might contribute to immunopathogenesis in SARS-CoV-2 infection.


Assuntos
Betacoronavirus/química , Infecções por Coronavirus/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Células Matadoras Naturais/imunologia , Ativação Linfocitária/genética , Subfamília C de Receptores Semelhantes a Lectina de Células NK/metabolismo , Pneumonia Viral/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Doadores de Sangue , Brônquios/citologia , Degranulação Celular/genética , Técnicas de Cocultura , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Células Epiteliais/metabolismo , Humanos , Interferon gama/metabolismo , Células K562 , Pandemias , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , RNA Viral/genética , Vírus da SARS/química , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/metabolismo , Síndrome Respiratória Aguda Grave/virologia , Glicoproteína da Espícula de Coronavírus/genética , Transfecção
8.
Int J Hematol ; 112(6): 757-763, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32785818

RESUMO

OBJECTIVE: To investigate the expression of lymphocyte activation gene 3(LAG3) on CD8+T effector cells (Teffs), CD4+ Teffs and regulatory T cells (Tregs) in patients with severe aplastic anemia (SAA). METHODS: We detected the expression of LAG3 on CD8+ Teffs, CD4+ Teffs and Tregs in SAA patients and healthy controls (HC) by flow cytometry, and analyzed its correlation with the immune status and severity of the disease. ELISA was used to detect soluble LAG3(sLAG3). RESULTS: The expression of LAG3 on CD8+ Teffs, CD4+ Teffs and Tregs in untreated SAA patients were significantly lower than those in HC group (P < 0.05). After IST, the LAG3 expression of target cells increased to a level even higher than that in HC group (P < 0.05). LAG3 on T cell subsets was closely related to immune status and severity of the disease. The concentration of sLAG3 in these groups showed similar trends. LAG3 was not a prognostic factor of response. CONCLUSION: The decreased expression of LAG3 on CD8+ Teffs, CD4+ Teffs and Tregs may be involved in the pathogenesis of SAA. LAG3 intervention may have therapeutic potential in treating SAA.


Assuntos
Anemia Aplástica/genética , Anemia Aplástica/imunologia , Antígenos CD/genética , Antígenos CD/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Expressão Gênica , Ativação Linfocitária/genética , Linfócitos T Reguladores/imunologia , Adolescente , Adulto , Idoso , Anemia Aplástica/terapia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Índice de Gravidade de Doença , Adulto Jovem
9.
Science ; 369(6506): 984-988, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32820125

RESUMO

Germinal center (GC) responses potentiate the generation of follicular regulatory T (TFR) cells. However, the molecular cues driving TFR cell formation remain unknown. Here, we show that sclerostin domain-containing protein 1 (SOSTDC1), secreted by a subpopulation of follicular helper T (TFH) cells and T-B cell border-enriched fibroblastic reticular cells, is developmentally required for TFR cell generation. Fate tracking and transcriptome assessment in reporter mice establishes SOSTDC1-expressing TFH cells as a distinct T cell population that develops after SOSTDC1- TFH cells and loses the ability to help B cells for antibody production. Notably, Sostdc1 ablation in TFH cells results in substantially reduced TFR cell numbers and consequently elevated GC responses. Mechanistically, SOSTDC1 blocks the WNT-ß-catenin axis and facilitates TFR cell differentiation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linfócitos B/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Centro Germinativo/imunologia , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Camundongos , Camundongos Mutantes , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
10.
Nat Commun ; 11(1): 3989, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778653

RESUMO

Upon stimulation, B cells assume heterogeneous cell fates, with only a fraction differentiating into antibody-secreting cells (ASC). Here we investigate B cell fate programming and heterogeneity during ASC differentiation using T cell-independent models. We find that maximal ASC induction requires at least eight cell divisions in vivo, with BLIMP-1 being required for differentiation at division eight. Single cell RNA-sequencing of activated B cells and construction of differentiation trajectories reveal an early cell fate bifurcation. The ASC-destined branch requires induction of IRF4, MYC-target genes, and oxidative phosphorylation, with the loss of CD62L expression serving as a potential early marker of ASC fate commitment. Meanwhile, the non-ASC branch expresses an inflammatory signature, and maintains B cell fate programming. Finally, ASC can be further subseted based on their differential responses to ER-stress, indicating multiple development branch points. Our data thus define the cell division kinetics of B cell differentiation in vivo, and identify the molecular trajectories of B cell fate and ASC formation.


Assuntos
Células Produtoras de Anticorpos/metabolismo , Linfócitos B/imunologia , Ativação Linfocitária/fisiologia , Animais , Antígenos CD19/genética , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Imunidade , Fatores Reguladores de Interferon/metabolismo , Selectina L , Ativação Linfocitária/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 1 de Ligação ao Domínio I Regulador Positivo/genética , Fator 1 de Ligação ao Domínio I Regulador Positivo/metabolismo , Transcriptoma
11.
Scand J Immunol ; 92(3): e12929, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32640079

RESUMO

After prolonged extracorporeal multiplication in physiological culture media, there can be curative infusions of a cancer patient's own cytotoxic T cells (adoptive T cell transfer; ACT), which must achieve efficient activation in potentially adverse tumour microenvironments. With spectacular, yet irregular, success, improvements are needed. Developing lymphoid cells are biologically selected, not only for 'near-self' reactivity (positive selection), but also to avoid self-reactivity (negative selection). Thus, success requires harnessing near-self cells while avoiding extreme autoimmune phenomena. Abrupt metabolic changes accompanying T cell activation to leave the G0 stage and enter the G1 stage of the cell cycle (eg enhanced glycolysis) are accompanied by increased transcription of the G0S9 gene that mediates salvage synthesis of NAD+ from nicotinamide; the latter has recently been shown to increase the efficiency of ACT. Despite theoretical and experimental advances, there has not been parallel progress in simulating in vivo conditions with culture media that were initially formulated for their positive benefits for tumour cell lines (cell survival and proliferation). Yet for lymphoid cells, inhibition or death (ie immunological tolerance) is as important as their activation and proliferation (immunological response). Thus, use of media optimized for the latter may mask the former. The resilience of established culture protocols may have been partly politically driven. However, unphysiological conditions have sometimes yielded fortuitous insights. Optimization of culture media for specific tissues must consider the nature of problems addressed in research settings and the need to avoid mishaps in clinical settings.


Assuntos
Metabolismo Energético , Imunoterapia Adotiva , Neoplasias/imunologia , Neoplasias/terapia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Biomarcadores , Reprogramação Celular , Meios de Cultura , Regulação da Expressão Gênica , Humanos , Imunoterapia Adotiva/efeitos adversos , Imunoterapia Adotiva/métodos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Neoplasias/genética , Neoplasias/metabolismo , Cultura Primária de Células , Resultado do Tratamento
12.
Proc Natl Acad Sci U S A ; 117(27): 15809-15817, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571924

RESUMO

Src family kinase Lck plays critical roles during T cell development and activation, as it phosphorylates the TCR/CD3 complex to initiate TCR signaling. Lck is present either in coreceptor-bound or coreceptor-unbound (free) forms, and we here present evidence that the two pools of Lck have different molecular properties. We discovered that the free Lck fraction exhibited higher mobility than CD8α-bound Lck in OT-I T hybridoma cells. The free Lck pool showed more activating Y394 phosphorylation than the coreceptor-bound Lck pool. Consistent with this, free Lck also had higher kinase activity, and free Lck mediated higher T cell activation as compared to coreceptor-bound Lck. Furthermore, the coreceptor-Lck coupling was independent of TCR activation. These findings give insights into the initiation of TCR signaling, suggesting that changes in coreceptor-Lck coupling constitute a mechanism for regulation of T cell sensitivity.


Assuntos
Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T/metabolismo , Quinases da Família src/genética , Animais , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/genética , Hibridomas/imunologia , Ativação Linfocitária/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/imunologia , Camundongos , Fosforilação/genética , Ligação Proteica/genética , Complexo Receptor-CD3 de Antígeno de Linfócitos T/genética , Complexo Receptor-CD3 de Antígeno de Linfócitos T/imunologia , Transdução de Sinais , Linfócitos T/imunologia
13.
PLoS One ; 15(6): e0234548, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32542046

RESUMO

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) are potent suppressors of immune function and may play a key role in the development and progression of metastatic cancers. Aerobic exercise has been shown to have anticancer effects, yet the mechanisms behind this protection are largely unknown. Therefore, we examined the effects of physical activity on MDSC accumulation and function. METHODS: Female BALB/c mice were assigned to one of two primary groups: sedentary tumor (SED+TUM) or wheel run tumor (WR+TUM). After 6 weeks of voluntary wheel running, all animals were randomly subdivided into 4 different timepoint groups; 16, 20, 24, and 28 days post-tumor injection. All mice were inoculated with 4T1 mammary carcinoma cells in the mammary fat pad and WR groups continued to run for the specified time post-injection. Spleen, blood, and tumor samples were analyzed using flow cytometry to assess proportions of MDSCs. RESULTS: Cells expressing MDSC biomarkers were detected in the spleen, blood, and tumor beginning at d16. However, since there was no evidence of immunosuppressive function until d28, we refer to them as immature myeloid cells (IMCs). Compared to SED+TUM, levels of IMCs in the spleen were significantly lower (p < 0.05) in WR+TUM at day 16 (33.0 ± 5.2%; 23.1 ± 10.2% of total cells, respectively) and day 20 (33.9 ± 8.1%; 24.3 ± 5.1% of total cells, respectively). Additionally, there were fewer circulating IMCs in WR+TUM at day 16 and MDSC levels were significantly lower (p < 0.05) in the tumor at day 28 in WR+TUM. Additionally, a non-significant 62% and 26% reduction in metastatic lung nodules was observed at days 24 and 28, respectively. At day 28, MDSCs harvested from SED+TUM significantly suppressed CD3+CD4+ T cell proliferation (3.2 ± 1.3 proliferation index) while proliferation in WR+TUM MDSC co-cultures (5.1 ± 1.7 proliferation index) was not different from controls. CONCLUSIONS: These findings suggest that physical activity may delay the accumulation of immunosuppressive MDSCs providing a broader window of opportunity for interventions with immunotherapies.


Assuntos
Imunossupressão , Neoplasias Mamárias Experimentais/metabolismo , Células Supressoras Mieloides/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Feminino , Imunossupressores/farmacologia , Ativação Linfocitária/genética , Ativação Linfocitária/fisiologia , Neoplasias Mamárias Experimentais/genética , Camundongos , Atividade Motora/genética , Atividade Motora/fisiologia , Células Mieloides/metabolismo , Células Mieloides/patologia , Células Supressoras Mieloides/patologia , Células Supressoras Mieloides/fisiologia
14.
Proc Natl Acad Sci U S A ; 117(21): 11636-11647, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32404419

RESUMO

Micropolymorphisms within human leukocyte antigen (HLA) class I molecules can change the architecture of the peptide-binding cleft, leading to differences in peptide presentation and T cell recognition. The impact of such HLA variation on natural killer (NK) cell recognition remains unclear. Given the differential association of HLA-B*57:01 and HLA-B*57:03 with the control of HIV, recognition of these HLA-B57 allomorphs by the killer cell immunoglobulin-like receptor (KIR) 3DL1 was compared. Despite differing by only two polymorphic residues, both buried within the peptide-binding cleft, HLA-B*57:01 more potently inhibited NK cell activation. Direct-binding studies showed KIR3DL1 to preferentially recognize HLA-B*57:01, particularly when presenting peptides with positively charged position (P)Ω-2 residues. In HLA-B*57:01, charged PΩ-2 residues were oriented toward the peptide-binding cleft and away from KIR3DL1. In HLA-B*57:03, the charged PΩ-2 residues protruded out from the cleft and directly impacted KIR3DL1 engagement. Accordingly, KIR3DL1 recognition of HLA class I ligands is modulated by both the peptide sequence and conformation, as determined by the HLA polymorphic framework, providing a rationale for understanding differences in clinical associations.


Assuntos
Antígenos de Histocompatibilidade Classe I/genética , Células Matadoras Naturais/fisiologia , Polimorfismo Genético/genética , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/fisiologia , Humanos , Ativação Linfocitária/genética , Modelos Moleculares , Polimorfismo Genético/fisiologia , Receptores KIR/genética
15.
Proc Natl Acad Sci U S A ; 117(23): 12969-12979, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32434911

RESUMO

CD5 is characterized as an inhibitory coreceptor with an important regulatory role during T cell development. The molecular mechanism by which CD5 operates has been puzzling and its function in mature T cells suggests promoting rather than repressing effects on immune responses. Here, we combined quantitative mass spectrometry and genetic studies to analyze the components and the activity of the CD5 signaling machinery in primary T cells. We found that T cell receptor (TCR) engagement induces the selective phosphorylation of CD5 tyrosine 429, which serves as a docking site for proteins with adaptor functions (c-Cbl, CIN85, CRKL), connecting CD5 to positive (PI3K) and negative (UBASH3A, SHIP1) regulators of TCR signaling. c-CBL acts as a coordinator in this complex enabling CD5 to synchronize positive and negative feedbacks on TCR signaling through the other components. Disruption of CD5 signalosome in mutant mice reveals that it modulates TCR signal outputs to selectively repress the transactivation of Foxp3 and limit the inopportune induction of peripherally induced regulatory T cells during immune responses against foreign antigen. Our findings bring insights into the paradigm of coreceptor signaling, suggesting that, in addition to providing dualistic enhancing or dampening inputs, coreceptors can engage concomitant stimulatory and inhibitory signaling events, which act together to promote specific functional outcomes.


Assuntos
Antígenos/imunologia , Antígenos CD5/metabolismo , Diferenciação Celular/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T Reguladores/fisiologia , Animais , Antígenos CD5/genética , Diferenciação Celular/genética , Regulação da Expressão Gênica/imunologia , Ativação Linfocitária/genética , Espectrometria de Massas , Camundongos , Camundongos Transgênicos , Cultura Primária de Células , Receptores de Antígenos de Linfócitos T/antagonistas & inibidores , Transdução de Sinais/genética , Transdução de Sinais/imunologia
16.
Sci Rep ; 10(1): 7727, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382026

RESUMO

It is now accepted that red blood cells (RBCs) from healthy individuals regulate T-cell activity through modulating cytokine interactions, and that stored RBCs or RBCs from inflammatory cohorts are dysfunctional. Our study aimed to investigate how changes in RBCs that have been intentionally modified can affect T-cell activity as a mechanistic test of this modification. Exposure to a cancer cell line in culture was used to alter the cytokine profile of intact RBCs and the effect of these modified RBCs (ccRBCs) on T-cells was evaluated using flow cytometry. We used RBCs from healthy volunteers and quantified cytokines in RBC lysates and conditioned media using Luminex technology. During in vitro cancer cell exposure, RBCs sequestered a variety of cytokines including IL-8, bFGF, and VEGF. Although unmodified RBCs (oRBCs) stimulated proliferation of T-cells (Jurkat cells and peripheral blood mononucleated cells), ccRBCs augmented this proliferative response (3.5-fold and 1.9-fold more respectively). Unlike oRBCs, T-cells stimulated with ccRBCs were no longer protected from phytohemagglutinin-P-driven overexpression of GATA-3 and T-bet and these T-cells were induced to secrete a variety of cytokines including IL-17 and MCP-3. This study supports the hypothesis that RBCs are capable of binding and releasing cytokines in blood, and that modification of these cells can then also affect the T-cell response.


Assuntos
Proliferação de Células/genética , Citocinas/genética , Eritrócitos/metabolismo , Linfócitos T/imunologia , Comunicação Celular/genética , Proliferação de Células/efeitos dos fármacos , Citocinas/efeitos dos fármacos , Transfusão de Eritrócitos , Eritrócitos/imunologia , Citometria de Fluxo , Voluntários Saudáveis , Humanos , Células Jurkat , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/genética , Neoplasias/química , Neoplasias/patologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo
17.
Cancer Sci ; 111(7): 2223-2233, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32324315

RESUMO

Invariant natural killer T (iNKT) cells are innate-like CD1d-restricted T cells that express the invariant T cell receptor (TCR) composed of Vα24 and Vß11 in humans. iNKT cells specifically recognize glycolipid antigens such as α-galactosylceramide (αGalCer) presented by CD1d. iNKT cells show direct cytotoxicity toward CD1d-positive tumor cells, especially when CD1d presents glycolipid antigens. However, iNKT cell recognition of CD1d-negative tumor cells is unknown, and direct cytotoxicity of iNKT cells toward CD1d-negative tumor cells remains controversial. Here, we demonstrate that activated iNKT cells recognize leukemia cells in a CD1d-independent manner, however still in a TCR-mediated way. iNKT cells degranulated and released Th1 cytokines toward CD1d-negative leukemia cells (K562, HL-60, REH) as well as αGalCer-loaded CD1d-positive Jurkat cells. The CD1d-independent cytotoxicity was enhanced by natural killer cell-activating receptors such as NKG2D, 2B4, DNAM-1, LFA-1 and CD2, but iNKT cells did not depend on these receptors for the recognition of CD1d-negative leukemia cells. In contrast, TCR was essential for CD1d-independent recognition and cytotoxicity. iNKT cells degranulated toward patient-derived leukemia cells independently of CD1d expression. iNKT cells targeted myeloid malignancies more than acute lymphoblastic leukemia. These findings reveal a novel anti-tumor mechanism of iNKT cells in targeting CD1d-negative tumor cells and indicate the potential of iNKT cells for clinical application to treat leukemia independently of CD1d.


Assuntos
Antígenos CD1d/metabolismo , Leucemia/imunologia , Leucemia/metabolismo , Ativação Linfocitária/imunologia , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Animais , Antígenos CD1d/genética , Biomarcadores , Degranulação Celular , Linhagem Celular Tumoral , Receptores Coestimuladores e Inibidores de Linfócitos T/metabolismo , Citocinas/metabolismo , Citotoxicidade Imunológica , Modelos Animais de Doenças , Feminino , Edição de Genes , Xenoenxertos , Humanos , Imunofenotipagem , Leucemia/genética , Leucemia/patologia , Ativação Linfocitária/genética , Camundongos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores Desencadeadores da Citotoxicidade Natural/metabolismo
18.
Scand J Immunol ; 92(1): e12886, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32243615

RESUMO

This study aimed to investigate the effect of long non-coding RNA XLOC_003810 on the activation of CD4+ T cells and expression of PD-1/PD-L1 in patients with myasthenia gravis-related thymoma (MG-T). Thymus specimens and thymic mononuclear cells were obtained from MG and MG-T patients or cardiac surgery patients undergoing thoracotomy who were selected as negative controls (NC). XLOC_003810 expression was examined using quantitative real-time PCR (qRT-PCR). Frequency of CD4+ T cells and proportion of CD4+ PD-1+ T cells and CD14+ PD-L1+ monocytes were quantified by flow cytometry. The release of inflammatory cytokines was measured by qRT-PCR and enzyme-linked immunosorbent assay. Compared with the NC group, expression of XLOC_003810, frequency of CD4+ T cells and the production of inflammatory cytokines were increased in patients with MG and MG-T. XLOC_003810 overexpression significantly increased the frequency of CD4+ T cells, facilitated the production of inflammatory cytokines and decreased the proportion of CD4+ PD-1+ T cells and CD14+ PD-L1+ monocytes in the thymic mononuclear cells. In contrast, XLOC_003810 knockdown exerted the opposite effect. Together, XLOC_003810 promotes T cell activation and inhibits PD-1/PD-L1 pathway in patients with MG-T.


Assuntos
Antígeno B7-H1/biossíntese , Linfócitos T CD4-Positivos/imunologia , Miastenia Gravis/genética , RNA Longo não Codificante/genética , Timoma/genética , Neoplasias do Timo/genética , Contagem de Linfócito CD4 , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/imunologia , Miastenia Gravis/patologia , Receptores Colinérgicos/imunologia , Timoma/imunologia , Timo/imunologia , Timo/patologia , Neoplasias do Timo/imunologia
19.
Sci Rep ; 10(1): 6351, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286360

RESUMO

Dengue virus (DENV) co-circulation in Brazil represents a challenge for treatment and vaccine development. Despite public health impact, the occurrence of coinfections with other viruses is a common event. Increased T cell activation and altered inflammatory response are found during DENV coinfection with Human Immunodeficiency Virus (HIV) impacting HIV-pathogenesis. Even with Antiretroviral therapy (ART), HIV- treated patients had chronic immune activation and lymphocyte apoptosis. However, apoptotic mechanisms have not been investigated during coinfection with DENV. Our attention was attracted to apoptotic cell markers expressions in PBMCs from DENV and DENV/HIV coinfected patients. We found CD4/CD8 ratio inversion in most coinfected patients. CD4 T and CD8 T-cell subsets from DENV and DENV/HIV groups expressed low levels of anti-apoptotic protein Bcl-2. Furthermore, CD8 CD95 double positive cells frequency expressing low levels of Bcl-2 were significantly higher in these patients. Additionally, the density of Bcl-2 on classical monocytes (CD14++CD16-) was significantly lower during DENV infection. Upregulation of pro-apoptotic proteins and anti-apoptotic proteins were found in DENV and DENV/HIV, while catalase, an antioxidant protein, was upregulated mainly in DENV/HIV coinfection. These findings provide evidence of apoptosis triggering during DENV/HIV coinfection, which may contribute to knowledge of immunological response during DENV acute infection in HIV-patients treated with ART.


Assuntos
Apoptose/genética , Dengue/sangue , Infecções por HIV/sangue , Subpopulações de Linfócitos T/imunologia , Doença Aguda/epidemiologia , Adulto , Idoso , Brasil/epidemiologia , Relação CD4-CD8 , Linfócitos T CD8-Positivos/imunologia , Coinfecção/sangue , Coinfecção/imunologia , Coinfecção/virologia , Dengue/imunologia , Dengue/patologia , Dengue/virologia , Vírus da Dengue/patogenicidade , Feminino , HIV/patogenicidade , Infecções por HIV/imunologia , Infecções por HIV/patologia , Infecções por HIV/virologia , Humanos , Leucócitos Mononucleares/virologia , Ativação Linfocitária/genética , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-bcl-2/genética , Subpopulações de Linfócitos T/patologia , Adulto Jovem
20.
Nat Commun ; 11(1): 1522, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32251280

RESUMO

Foxp3+ regulatory T (Treg) cells are essential for maintaining peripheral tolerance and preventing autoimmunity. While genetic factors may predispose for autoimmunity, additional environmental triggers, such as viral infections, are usually required to initiate the onset of disease. Here, we show that viral infection with LCMV results in type I IFN-dependent Treg cell loss that is rapidly compensated by the conversion and expansion of Vß5+ conventional T cells into iTreg cells. Using Vß5-deficient mice, we show that these Vß5+ iTreg cells are dispensable for limiting anti-viral immunity. Rather, the delayed replenishment of Treg cells in Vß5-deficient mice compromises suppression of microbiota-dependent activation of CD8+ T cells, resulting in colitis. Importantly, recovery from clinical symptoms in IBD patients is marked by expansion of the corresponding Vß2+ Treg population in humans. Collectively, we provide a link between a viral trigger and an impaired Treg cell compartment resulting in the initiation of immune pathology.


Assuntos
Infecções por Arenaviridae/imunologia , Autoimunidade , Linfócitos T CD8-Positivos/imunologia , Colite/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Linfócitos T Reguladores/imunologia , Animais , Infecções por Arenaviridae/complicações , Linhagem Celular , Colite/microbiologia , Colo/imunologia , Colo/microbiologia , Fatores de Transcrição Forkhead/metabolismo , Microbioma Gastrointestinal/imunologia , Voluntários Saudáveis , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Ativação Linfocitária/genética , Masculino , Camundongos , Camundongos Knockout , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Linfócitos T Reguladores/metabolismo
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