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1.
Nat Commun ; 11(1): 1794, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286285

RESUMO

Although group 3 innate lymphoid cells (ILC3s) are efficient inducers of T cell responses in the spleen, they fail to induce CD4+ T cell proliferation in the gut. The signals regulating ILC3-T cell responses remain unknown. Here, we show that transcripts associated with MHC II antigen presentation are down-modulated in intestinal natural cytotoxicity receptor (NCR)- ILC3s. Further data implicate microbiota-induced IL-23 as a crucial signal for reversible silencing of MHC II in ILC3s, thereby reducing the capacity of ILC3s to present antigen to T cells in the intestinal mucosa. Moreover, IL-23-mediated MHC II suppression is dependent on mTORC1 and STAT3 phosphorylation in NCR- ILC3s. By contrast, splenic interferon-γ induces MHC II expression and CD4+ T cell stimulation by NCR- ILC3s. Our results thus identify biological circuits for tissue-specific regulation of ILC3-dependent T cell responses. These pathways may have implications for inducing or silencing T cell responses in human diseases.


Assuntos
Apresentação do Antígeno/imunologia , Imunidade Inata , Linfócitos/imunologia , Microbiota , Baço/citologia , Animais , Células Apresentadoras de Antígenos/citologia , Células Apresentadoras de Antígenos/imunologia , Antígenos CD/metabolismo , Polaridade Celular , Regulação para Baixo , Antígenos de Histocompatibilidade Classe II/metabolismo , Interferon gama/metabolismo , Interleucina-23/metabolismo , Ativação Linfocitária/imunologia , Linfócitos/citologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Microbiota/genética , Microbiota/imunologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenótipo , Fosforilação , Análise de Componente Principal , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT3/metabolismo , Linfócitos T/imunologia , Transativadores/genética , Transativadores/metabolismo , Transcrição Genética
2.
Nat Commun ; 11(1): 1110, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111828

RESUMO

Targeted delivery of a nanovaccine loaded with a tumor antigen and adjuvant to the lymph nodes (LNs) is an attractive approach for improving cancer immunotherapy outcomes. However, the application of this technique is restricted by the paucity of suitable tumor-associated antigens (TAAs) and the sophisticated technology required to identify tumor neoantigens. Here, we demonstrate that a self-assembling melittin-lipid nanoparticle (α-melittin-NP) that is not loaded with extra tumor antigens promotes whole tumor antigen release in situ and results in the activation of antigen-presenting cells (APCs) in LNs. Compared with free melittin, α-melittin-NPs markedly enhance LN accumulation and activation of APCs, leading to a 3.6-fold increase in antigen-specific CD8+ T cell responses. Furthermore, in a bilateral flank B16F10 tumor model, primary and distant tumor growth are significantly inhibited by α-melittin-NPs, with an inhibition rate of 95% and 92%, respectively. Thus, α-melittin-NPs induce a systemic anti-tumor response serving as an effective LN-targeted whole-cell nanovaccine.


Assuntos
Vacinas Anticâncer/imunologia , Sistemas de Liberação de Medicamentos , Linfonodos/imunologia , Meliteno/administração & dosagem , Nanopartículas/administração & dosagem , Neoplasias/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/química , Vacinas Anticâncer/metabolismo , Linhagem Celular Tumoral , Citocinas/imunologia , Feminino , Imunoterapia , Lipídeos/administração & dosagem , Lipídeos/química , Linfonodos/metabolismo , Meliteno/química , Meliteno/imunologia , Meliteno/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Nanopartículas/metabolismo , Neoplasias/terapia , Linfócitos T/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
3.
PLoS Biol ; 18(2): e3000590, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069316

RESUMO

DO (HLA-DO, in human; murine H2-O) is a highly conserved nonclassical major histocompatibility complex class II (MHC II) accessory molecule mainly expressed in the thymic medulla and B cells. Previous reports have suggested possible links between DO and autoimmunity, Hepatitis C (HCV) infection, and cancer, but the mechanism of how DO contributes to these diseases remains unclear. Here, using a combination of various in vivo approaches, including peptide elution, mixed lymphocyte reaction, T-cell receptor (TCR) deep sequencing, tetramer-guided naïve CD4 T-cell precursor enumeration, and whole-body imaging, we report that DO affects the repertoire of presented self-peptides by B cells and thymic epithelium. DO induces differential effects on epitope presentation and thymic selection, thereby altering CD4 T-cell precursor frequencies. Our findings were validated in two autoimmune disease models by demonstrating that lack of DO increases autoreactivity and susceptibility to autoimmune disease development.


Assuntos
Doenças Autoimunes/genética , Predisposição Genética para Doença/genética , Antígenos de Histocompatibilidade Classe II/genética , Animais , Células Apresentadoras de Antígenos/imunologia , Doenças Autoimunes/imunologia , Autoimunidade/genética , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Colágeno/administração & dosagem , Colágeno/imunologia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Glicoproteína Mielina-Oligodendrócito/imunologia , Peptídeos/imunologia , Células Precursoras de Linfócitos T/imunologia , Timo/imunologia
4.
Nat Protoc ; 15(3): 773-798, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31932772

RESUMO

Synthetic antigen-presenting cells (APCs) are used to mediate scalable ex vivo T-cell expansion for adoptive cell therapy. Recently, we developed APC-mimetic scaffolds (APC-ms), which present signals to T cells in a physiological manner to mediate rapid and controlled T-cell expansion. APC-ms are composed of individual high-aspect-ratio silica microrods loaded with soluble mitogenic cues and coated with liposomes of defined compositions, to form supported lipid bilayers. Membrane-bound ligands for stimulation and co-stimulation of T-cell receptors are presented via the fluid, synthetic membranes, while mitogenic cues are released slowly from the microrods. In culture, interacting T cells assemble the individual APC-ms microrods into a biodegradable 3D matrix. Compared to conventional methods, APC-ms facilitates several-fold greater polyclonal T-cell expansion and improved antigen-specific enrichment of rare T-cell subpopulations. Here we provide a detailed protocol for APC-ms synthesis and use for human T-cell activation, and discuss important considerations for material design and T-cell co-culture. This protocol describes the facile assembly of APC-ms in ~4 h and rapid expansion or enrichment of relevant T-cell clones in <2 weeks, and is applicable for T-cell manufacturing and assay development.


Assuntos
Células Apresentadoras de Antígenos , Linfócitos T , Linhagem da Célula , Clonagem Molecular , Regulação da Expressão Gênica , Humanos
5.
PLoS One ; 15(1): e0227047, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929548

RESUMO

Enterotoxin-based proteins are powerful manipulators of mucosal immunity. The A1 domain of heat-labile enterotoxin from E. coli, or LTA1, is a newer adjuvant from this family under investigation for intranasal vaccines. Although LTA1 has been examined in mouse vaccination studies, its ability to directly stimulate immune cells compared to related adjuvant proteins has not been well explored. Here, we perform the first rigorous examination of LTA1's effect on antigen presenting cells (APC) using a human monocyte cell line THP-1. To better understand LTA1's stimulatory effects, we compared it to dmLT, or LT-R192G/L211A, a related AB5 adjuvant in clinical trials for oral or parenteral vaccines. LTA1 and dmLT both activated APCs to upregulate MHC-II (HLA-DR), CD86, cytokine secretion (e.g., IL-1ß) and inflammasome activation. The effect of LTA1 on surface marker changes (e.g., MHC-II) was highly dose-dependent whereas dmLT exhibited high MHC-II expression regardless of dose. In contrast, cytokine secretion profiles were similar and dose-dependent after both LTA1 and dmLT treatment. Cellular activation by LTA1 was independent of ganglioside binding, as pre-treatment with purified GM1 blocked the effect of dmLT but not LTA1. Unexpectedly, while activation of the inflammasome and cytokine secretion by LTA1 or dmLT was blocked by the protein kinase A inhibitor H89 (similar to previous reports), these responses were not inhibited by a more specific PKA peptide inhibitor or antagonist; thus Indicating that a novel and unknown mechanism is responsible for inflammasome activation and cytokine secretion by LT proteins. Lastly, LTA1 stimulated a similar cytokine profile in primary human monocytes as it did in THP1 cells, including IL-1ß, IL-6, IL-8, MIP-1α, MIP-1ß, and TNFα. Thus, we report that LTA1 protein programs a dendritic cell-like phenotype in APCs similar to dmLT in a mechanism that is independent of PKA activation and GM1 binding and entry.


Assuntos
Células Apresentadoras de Antígenos/metabolismo , Enterotoxinas/farmacologia , Lipopolissacarídeos/farmacologia , Ácidos Teicoicos/farmacologia , Adjuvantes Imunológicos , Células Apresentadoras de Antígenos/efeitos dos fármacos , Linhagem Celular , Permeabilidade da Membrana Celular , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico , Citocinas/efeitos dos fármacos , Citocinas/metabolismo , Enterotoxinas/imunologia , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Lipopolissacarídeos/imunologia , Monócitos/patologia , Células THP-1 , Ácidos Teicoicos/imunologia
6.
Am J Pathol ; 190(1): 125-133, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669306

RESUMO

Neuroinflammation plays an important role in the pathogenesis of ocular surface disease, including dry eye disease (DED), but little is known about the contribution of substance P (SP) to DED. In this study, we investigated the expression of SP at the ocular surface and evaluated its effect on maturation of antigen-presenting cells (APCs), the key cell component involved in the induction of type 17 helper T-cell (Th17) response in DED. The effect of topical blockade of SP signaling was further investigated using neurokinin-1 receptor (NK1R) inhibitors on APC maturation, Th17 cell activation, and disease severity in a mouse model of DED. The results demonstrate that SP is constitutively expressed at the ocular surface, and trigeminal ganglion neurons are the major source of SP in DED. SP derived from trigeminal ganglion enhanced the expression of major histocompatibility complex class II maturation marker by bone marrow-derived dendritic cells, an effect that is abrogated by blockade of SP signaling using NK1R antagonist spantide. Finally, using a well-established murine model of DED, topical treatment of DED mice with NK1R antagonists CP-99,994 and L-733,060 suppressed APC acquisition of major histocompatibility complex class II, reduced Th17 cell activity, and ameliorated DED severity. These findings are of translational value, as they suggest that antagonizing NK1R-mediated SP signaling may be an effective strategy in suppressing Th17-mediated ocular surface disease.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Modelos Animais de Doenças , Síndromes do Olho Seco/prevenção & controle , Antagonistas do Receptor de Neuroquinina-1/farmacologia , Receptores da Neurocinina-1/química , Células Th17/imunologia , Animais , Células Apresentadoras de Antígenos/efeitos dos fármacos , Córnea/efeitos dos fármacos , Córnea/imunologia , Síndromes do Olho Seco/imunologia , Síndromes do Olho Seco/metabolismo , Síndromes do Olho Seco/patologia , Feminino , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Células Th17/efeitos dos fármacos
7.
Am J Pathol ; 190(1): 25-32, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669415

RESUMO

The major histocompatibility complex class II (MHC II)-CD4 immunologic synapse is classically described between the T-cell receptor of CD4-positive lymphocytes and MHC II on antigen-presenting cells. This interaction and others between surrounding costimulatory and checkpoint molecules promote differentiation of naïve CD4 T lymphocytes into helper T cells subtypes, including types 1, 2, and 17 helper T cells, that have more tailored immunologic responses. Although MHC II is mainly produced by professional antigen-presenting cells, it can be aberrantly produced by other cell types, including hepatocytes in various liver pathologies, such as autoimmune hepatitis and alcoholic hepatitis. This can lead to direct targeting of hepatocytes by CD4-positive lymphocytes, which form an immunologic synapse with the hepatocyte. The lymphocytes internalize the MHC II-CD4 complexes in a phagocytosis-like mechanism and in the process eat the hepatocyte piece by piece. We review the evidence for this mechanism and the role of these autoimmune responses in various liver diseases, including alcoholic hepatitis, autoimmune hepatitis, and primary biliary cirrhosis. The role of aberrant MHC II in malignancy, including hepatocellular carcinoma, is also reviewed. Further understanding of this mechanism can lead to better understanding of the immune mechanisms involved in these liver pathologies, with potential diagnostic and therapeutic applications.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Doenças Autoimunes/imunologia , Linfócitos T CD4-Positivos/imunologia , Hepatite Alcoólica/imunologia , Hepatócitos/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Animais , Doenças Autoimunes/patologia , Hepatite Alcoólica/patologia , Humanos
8.
Biomed Pharmacother ; 121: 109157, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31731195

RESUMO

INTRODUCTION: Bone marrow mesenchymal stem cells (BMSCs) have been extensively investigated from a perspective on cardiac regeneration therapy. The current study aimed to investigate the protective effect conferred by BMSCs in subacute myocardial injury, and to identify an appropriate BMSC reinfusion time. METHODS: BMSCs were isolated from human bone marrow blood. Daunorubicin (DNR)-induced subacute myocardial models were subsequently established. The rats with DNR-induced subacute myocardial injury were injected with dexrazoxane (DZR) and/or BMSCs at varying time points, after which cardiac function was evaluated by assessing left ventricular ejection fraction (LVEF) and fraction shortening (FS). The myocardial structural changes were analyzed, after which the levels of CD3 and human leukocyte antigen DR (HLA-DR) were examined to further validate the mechanism by which BMSCs could influence subacute myocardial injury. RESULTS: BMSCs combined with DZR treatment enhanced the cardiac function of rats with DNR-induced myocardial injury, as reflected by increased LVEF and FS. DNR-induced myocardial injuries were mitigated via the application of BMSCs combined with treatment of DZR, accompanied by diminished infiltration or vacuolization. Moreover, BMSCs were observed to alleviate infiltration of T lymphocyte and antigen-presenting cells, as evidenced by reduced expression of CD3 and HLA-DR. CONCLUSION: Taken together, this study demonstrates that BMSCs could protect against DNR-induced myocardial injury, especially in the first three days of DNR administration. BMSCs combined with DZR exert a better therapeutic effect, but there are individual differences.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Daunorrubicina/farmacologia , Células-Tronco Mesenquimais/imunologia , Infarto do Miocárdio/induzido quimicamente , Infarto do Miocárdio/imunologia , Miocárdio/imunologia , Linfócitos T/imunologia , Animais , Células da Medula Óssea/imunologia , Humanos , Masculino , Transplante de Células-Tronco Mesenquimais/métodos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/imunologia , Ratos , Ratos Sprague-Dawley
9.
Elife ; 82019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31815664

RESUMO

Antibody production depends on B cell internalization and presentation of antigens to helper T cells. To acquire antigens displayed by antigen-presenting cells, B cells form immune synapses and extract antigens by the mechanical activity of the acto-myosin cytoskeleton. While cytoskeleton organization driving the initial formation of the B cell synapse has been studied, how the cytoskeleton supports antigen extraction remains poorly understood. Here we show that after initial cell spreading, F-actin in synapses of primary mouse B cells and human B cell lines forms a highly dynamic pattern composed of actin foci interspersed with linear filaments and myosin IIa. The foci are generated by Arp2/3-mediated branched-actin polymerization and stochastically associate with antigen clusters to mediate internalization. However, antigen extraction also requires the activity of formins, which reside near the foci and produce the interspersed filaments. Thus, a cooperation of branched-actin foci supported by linear filaments underlies B cell mechanics during antigen extraction.


Assuntos
Citoesqueleto de Actina/imunologia , Complexo 2-3 de Proteínas Relacionadas à Actina/imunologia , Actinas/imunologia , Antígenos/imunologia , Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Citoesqueleto de Actina/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Actinas/metabolismo , Animais , Formação de Anticorpos/imunologia , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Antígenos/metabolismo , Linfócitos B/metabolismo , Linhagem Celular Tumoral , Células HEK293 , Humanos , Sinapses Imunológicas/imunologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos B/metabolismo
10.
Immunohorizons ; 3(12): 559-572, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31791977

RESUMO

Use of recombinant viral vectors encoding nonnative Ags is an attractive mechanism for the generation of protective Ab, CD4+ T cell (TCD4+), and CD8+ T cell (TCD8+) responses in vivo following immunization. However, the life cycle and tropism of the viral vector, and its interactions with various components of the immune system, must be fully understood to maximize the efficacy of any vaccination strategies. Ab and TCD4+ responses typically target native Ags driven by late promoters in vaccinia virus (VACV)-based vectors. However, it has been demonstrated that model Ags driven by late promoters in recombinant VACV vectors do not stimulate TCD8+ responses, whereas identical Ags driven by early promoters stimulate strong responses. Conversely, TCD8+ can be generated against some natural late VACV Ags. We explored this dichotomy by investigating the Ag presentation pathways responsible for presentation of natural late VACV Ags in mice. We found that all of the late VACV Ags we examined could be cross-primed (i.e., presented by uninfected professional APC), as well as directly presented by infected dendritic cell populations. However, one Ag was only presented by professional APC populations and was not the target of a protective TCD8+ response. Therefore, there is no generalized blockade in Ag presentation of late VACV Ags, and expression of nonnative Ags driven by a late promoter allows production of large quantities of Ag that may allow simultaneous targeting of both TCD4+ and Ab responses, as well as TCD8+ responses, in the future.


Assuntos
Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Vírus Vaccinia/imunologia , Vaccinia/metabolismo , Proteínas Virais/metabolismo , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos Virais/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Epitopos de Linfócito T/imunologia , Vetores Genéticos , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Regiões Promotoras Genéticas/imunologia , Vaccinia/virologia
11.
Virol J ; 16(1): 154, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31831027

RESUMO

BACKGROUND: Porcine circovirus (PCV) disease caused by PCV type 2 (PCV2) is mainly attributed to immunosuppression and immune damage. PCV2 can infect vascular endothelial cells and induce high expression of endothelial IL-8. Dendritic cells (DCs), as professional antigen-presenting cells, can not only present antigens but also activate naïve T-cells, causing an immune response. METHODS: To demonstrate whether endothelial IL-8 is the main factor inhibiting the maturation and related functions of dendritic cells during PCV2 infection, monocyte-derived DCs (MoDCs) and porcine iliac artery endothelial cells (PIECs) processed by different methods were co-cultured in two ways. Flow cytometry, molecular probe labeling, fluorescence quantitative PCR, and the MTS assay were used to detect the changes in related functions and molecules of MoDCs. RESULTS: Compared to those in the PIEC-DC group, the endothelial IL-8 upregulation co-culture group showed significantly lower double-positive rates for CD80/86 and MHC-II of MoDCs and significantly increased endocytosis of MoDCs. Meanwhile, the adhesion rate and average fluorescence intensity of MoDCs were significantly downregulated in migration and adhesion experiments. Furthermore, the MHC-I and LAMP7 mRNA levels in MoDCs and the proliferation of MoDC-stimulated T-cells were markedly reduced. However, the changes in MoDCs of the endothelial IL-8 downregulation co-culture group were the opposite. CONCLUSIONS: PCV2-induced endothelial IL-8 reduces the adhesion and migration ability of MoDCs, resulting in a decreased maturation rate of MoDCs, and further inhibits antigen presentation by DCs. These results may explain the immunosuppressive mechanism of PCV2 from the perspective of the interaction between endothelial cells and DCs in vitro.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Diferenciação Celular , Circovirus/imunologia , Células Dendríticas/imunologia , Células Endoteliais/virologia , Fatores Imunológicos/metabolismo , Interleucina-8/metabolismo , Animais , Células Apresentadoras de Antígenos/fisiologia , Células Cultivadas , Circovirus/crescimento & desenvolvimento , Técnicas de Cocultura , Células Dendríticas/fisiologia , Células Endoteliais/metabolismo , Suínos
12.
BMC Cancer ; 19(1): 1246, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31870332

RESUMO

BACKGROUND: Myeloma cells retain B cell functions, considered to be potential antigen presenting cells, yet there is little information regarding promoting Th2 cell proliferation or the direct effects to myeloma on the Th2 cells stimulated by microbial antigens-loaded myeloma cells. METHODS: Mixed lymphocyte reaction was used colorimetric assays via CCK8-kit. Surface molecular expression was performed by flow cytometry, cells sorting using microbeads. The concentrations of cytokines in serum were assessed using an ELISA kit. Clonogenic assay were performed in a methylcellulose culture system. Statistical analysis was assessed using the Student's t-test or one-way analysis of variance for multiple comparisons test. RESULTS: The expression of HLA-DR, CD80 and CD40 on RPMI8266 cell membrane surface was upregulated by interaction with interferon-γ and/or Bacillus Calmette-Guerin Vaccine (BCGV). RPMI8266 cells were able to induce the mixed lymphocyte reaction in a dose-dependent fashion. The Th2 ratio induced by RPMI8266 treated by BCGV and interferon-γ (treated-RPMI8266) cells was only slightly greater than by untreated-tumor cells, but the serum IL-4 level secreted by Th2 cells was markedly higher in treated-RPMI8266 cells group. Th2 cells stimulated by treated-myeloma cells could directly promote treated-myeloma cell clonogenicity in a dose-dependent manner. Anti-HLADR IgG2b completely blocked increased of IL-4 secretion by Th2 cells stimulated by treated-myeloma cells, while also blocked enhancing the clonogenicity of treated tumor cells stimulated by MM-Th2 cells. CONCLUSIONS: These results indicate that a novel mechanism of myeloma pathogenesis in myeloma cells could act as an APC to present microbial Ags to Th2 cells, promoting Th2 cell proliferation, consequently facilitating tumor development by close interaction between Th2 myeloma cells. Taken together, the microbial Ag presenting course of MM-Th2-MM interactions-restricted by MHC class-II-may result in tumor development such that all factors involved in the system could have a potential for myeloma therapeutic intervention.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Antígenos de Bactérias/imunologia , Mieloma Múltiplo/imunologia , Células Th2/imunologia , Comunicação Celular/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Células Cultivadas , Citocinas/imunologia , Humanos , Ativação Linfocitária/imunologia , Teste de Cultura Mista de Linfócitos , Mieloma Múltiplo/patologia
13.
Nat Commun ; 10(1): 4987, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31676770

RESUMO

Bystander activation of memory T cells occurs in the absence of cognate antigen during infections that elicit strong systemic inflammatory responses, which subsequently affect host immune responses. Here we report that memory T cell bystander activation is not limited to induction by systemic inflammation. We initially observe potential T cell bystander activation in a cohort of human vaccine recipients. Using a mouse model system, we then find that memory CD8+ T cells are specifically recruited to sites with activated antigen-presenting cells (APCs) in a CXCR3-dependent manner. In addition, CXCR3 is also necessary for T cell clustering around APCs and T cell bystander activation, which temporospatially overlaps with the subsequent antigen-specific T cell response. Our data thus suggest that bystander activation is part of the initial localized immune response, and is mediated by a site-specific recruitment process of memory T cells.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Efeito Espectador/imunologia , Linfócitos T CD8-Positivos/imunologia , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Receptores CXCR3/imunologia , Animais , Antígenos/imunologia , Feminino , Humanos , Imunização , Inflamação/imunologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores CXCR3/genética , Receptores CXCR3/metabolismo
14.
Nutrients ; 11(11)2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683517

RESUMO

Bioactive peptides secreted by probiotic Bifidobacterium longum (peptide B7) and opportunistic pathogen Bacteroides fragilis (peptide B12) modulate the intestinal cytokine milieu in health. Here, we characterized their capacity to modulate both the mucosal cytokine production and the phenotype of circulating antigen presenting cells (APCs) in active inflammatory bowel disease (IBD). The IBD mucosa produced higher levels of pro-inflammatory cytokines referred to healthy controls (HCs). Peptides B7 and B12, however, did not ameliorate the mucosal cytokine milieu in IBD. Human circulating APCs (B-cells, monocytes, plasmacytoid dendritic cells (pDCs), and conventional dendritic cells (cDCs)) were characterized by flow cytometry in presence/absence of the peptides. Circulating B-cells, monocytes, and cDCs from IBD patients were more activated than those from HCs. Peptide B7, but not B12, decreased CCR2 expression on all APC subsets from HC, but not IBD patients. Moreover, both peptides tend to further increase their pro-inflammatory profile in IBD. In summary, IBD patients display mucosal and circulating APC pro-inflammatory properties. Peptide B7 immunomodulatory capacity elicited over circulating APCs from HC, but not IBD patients, suggests the presence of disrupted modulatory mechanisms for this peptide in IBD. Future studies should address the effect of bacteria-derived immunomodulatory peptides in non-inflamed (quiescent) IBD patients.


Assuntos
Células Apresentadoras de Antígenos , Proteínas de Bactérias/farmacologia , Citocinas , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Produtos Biológicos/farmacologia , Células Cultivadas , Citocinas/efeitos dos fármacos , Citocinas/metabolismo , Humanos , Imunomodulação/efeitos dos fármacos , Imunomodulação/imunologia , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Peptídeos/farmacologia
15.
Proc Natl Acad Sci U S A ; 116(47): 23671-23681, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31690657

RESUMO

Invariant NKT (iNKT) cells have the unique ability to shape immunity during antitumor immune responses and other forms of sterile and nonsterile inflammation. Recent studies have highlighted a variety of classes of endogenous and pathogen-derived lipid antigens that can trigger iNKT cell activation under sterile and nonsterile conditions. However, the context and mechanisms that drive the presentation of self-lipid antigens in sterile inflammation remain unclear. Here we report that endoplasmic reticulum (ER)-stressed myeloid cells, via signaling events modulated by the protein kinase RNA-like ER kinase (PERK) pathway, increase CD1d-mediated presentation of immunogenic endogenous lipid species, which results in enhanced iNKT cell activation both in vitro and in vivo. In addition, we demonstrate that actin cytoskeletal reorganization during ER stress results in an altered distribution of CD1d on the cell surface, which contributes to enhanced iNKT cell activation. These results define a previously unidentified mechanism that controls iNKT cell activation during sterile inflammation.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Células Dendríticas/imunologia , Estresse do Retículo Endoplasmático/imunologia , Ativação Linfocitária , Células T Matadoras Naturais/imunologia , Animais , Apresentação do Antígeno , Antígenos CD1d/biossíntese , Antígenos CD1d/imunologia , Autoantígenos/imunologia , Carcinoma Pulmonar de Lewis/patologia , Linhagem Celular Tumoral , Técnicas de Cocultura , Citoesqueleto/ultraestrutura , Endossomos/imunologia , Glicoesfingolipídeos/imunologia , Glicoesfingolipídeos/metabolismo , Humanos , Subunidade alfa de Receptor de Interleucina-2/biossíntese , Lipídeos/imunologia , Lisossomos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Células THP-1 , Tapsigargina/farmacologia , Resposta a Proteínas não Dobradas/imunologia , eIF-2 Quinase/deficiência , eIF-2 Quinase/fisiologia
16.
Nat Commun ; 10(1): 5108, 2019 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-31704921

RESUMO

Mounting evidence suggests that the tumor microenvironment is profoundly immunosuppressive. Thus, mitigating tumor immunosuppression is crucial for inducing sustained antitumor immunity. Whereas previous studies involved intratumoral injection, we report here an inhalable nanoparticle-immunotherapy system targeting pulmonary antigen presenting cells (APCs) to enhance anticancer immunity against lung metastases. Inhalation of phosphatidylserine coated liposome loaded with STING agonist cyclic guanosine monophosphate-adenosine monophosphate (NP-cGAMP) in mouse models of lung metastases enables rapid distribution of NP-cGAMP to both lungs and subsequent uptake by APCs without causing immunopathology. NP-cGAMP designed for enhanced cytosolic release of cGAMP stimulates STING signaling and type I interferons production in APCs, resulting in the pro-inflammatory tumor microenvironment in multifocal lung metastases. Furthermore, fractionated radiation delivered to one tumor-bearing lung synergizes with inhaled NP-cGAMP, eliciting systemic anticancer immunity, controlling metastases in both lungs, and conferring long-term survival in mice with lung metastases and with repeated tumor challenge.


Assuntos
Células Apresentadoras de Antígenos/efeitos dos fármacos , Imunoterapia , Neoplasias Pulmonares/secundário , Pulmão/efeitos dos fármacos , Melanoma Experimental/secundário , Proteínas de Membrana/agonistas , Nanopartículas , Nucleotídeos Cíclicos/farmacologia , Radioterapia , Administração por Inalação , Animais , Células Apresentadoras de Antígenos/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Interferon Tipo I/efeitos dos fármacos , Interferon Tipo I/imunologia , Lipossomos , Pulmão/imunologia , Pulmão/efeitos da radiação , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Nucleotídeos Cíclicos/administração & dosagem , Fosfatidilserinas
17.
Blood ; 134(24): 2139-2148, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31697827

RESUMO

Allogeneic stem cell transplantation is a cornerstone of curative therapy for high-risk and/or advanced hematological malignancies but remains limited by graft-versus-host disease (GVHD). GVHD is initiated by the interaction between recipient antigen-presenting cells (APCs) and donor T cells, culminating in T-cell differentiation along pathogenic type-1 and type-17 paradigms at the expense of tolerogenic regulatory T-cell patterns. Type-1 and type-17 T cells secrete cytokines (eg, granulocyte-macrophage colony-stimulating factor and interferon-γ) critical to the cytokine storm that amplifies expansion of donor APCs and their alloantigen presentation. It has become increasingly clear that pathogenic donor T-cell differentiation is initiated by both professional recipient APCs (eg, dendritic cells [DCs]) and nonprofessional APCs (eg, epithelial and mesenchymal cells), particularly within the gastrointestinal (GI) tract. In the immediate peritransplantation period, these APCs are profoundly modified by pathogen-associated molecular pattern (PAMP)/damage-associated molecular pattern (DAMP) signals derived from conditioning and intestinal microbiota. Subsequently, donor DCs in the GI tract are activated by DAMP/PAMP signals in the colon that gain access to the lamina propria once the mucosal barrier mucosa is compromised by GVHD. This results in donor DC expansion and alloantigen presentation in the colon and subsequent migration into the mesenteric lymph nodes. Here, new donor T cells are primed, expanded, differentiated, and imprinted with gut-homing integrins permissive of migration into the damaged GI tract, resulting in the lethal feed-forward cascade of GVHD. These new insights into our understanding of the cellular and molecular factors initiating GVHD, both spatially and temporally, give rise to a number of logical therapeutic targets, focusing on the inhibition of APC function in the GI tract.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Suscetibilidade a Doenças , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/metabolismo , Animais , Apresentação do Antígeno/imunologia , Transplante de Medula Óssea , Trato Gastrointestinal/patologia , Estudos de Associação Genética , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Isoantígenos/imunologia , Ativação Linfocitária , Microbiota
18.
Proc Natl Acad Sci U S A ; 116(50): 25229-25235, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31767744

RESUMO

Responses of solid tumors to chimeric antigen receptor (CAR) T cell therapy are often minimal. This is potentially due to a lack of sustained activation and proliferation of CAR T cells when encountering antigen in a profoundly immunosuppressive tumor microenvironment. In this study, we investigate if inducing an interaction between CAR T cells and antigen-presenting cells (APCs) in lymphoid tissue, away from an immunosuppressive microenvironment, could enhance solid-tumor responses. We combined CAR T cell transfer with the bacterial enterotoxin staphylococcal enterotoxin-B (SEB), which naturally links a proportion of T cell receptor (TCR) Vß subtypes to MHC-II, present on APCs. CAR T cell proliferation and function was significantly enhanced by SEB. Solid tumor-growth inhibition in mice was increased when CAR T cells were administered in combination with SEB. CAR T cell expansion in lymphoid tissue was demonstrated, and inhibition of lymphocyte egress from lymph nodes using FTY720 abrogated the benefit of SEB. We also demonstrate that a bispecific antibody, targeting a c-Myc tag on CAR T cells and cluster of differentiation 40 (CD40), could also enhance CAR T cell activity and mediate increased antitumor activity of CAR T cells. These model systems serve as proof-of-principle that facilitating the interaction of CAR T cells with APCs can enhance their ability to mediate antitumor activity.


Assuntos
Enterotoxinas/farmacologia , Neoplasias/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/imunologia , Antígenos CD40/imunologia , Proliferação de Células/efeitos dos fármacos , Humanos , Imunoterapia Adotiva , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/genética , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/citologia
19.
Elife ; 82019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31663508

RESUMO

Supramolecular signaling assemblies are of interest for their unique signaling properties. A µm scale signaling assembly, the central supramolecular signaling cluster (cSMAC), forms at the center of the interface of T cells activated by antigen-presenting cells. We have determined that it is composed of multiple complexes of a supramolecular volume of up to 0.5 µm3 and associated with extensive membrane undulations. To determine cSMAC function, we have systematically manipulated the localization of three adaptor proteins, LAT, SLP-76, and Grb2. cSMAC localization varied between the adaptors and was diminished upon blockade of the costimulatory receptor CD28 and deficiency of the signal amplifying kinase Itk. Reconstitution of cSMAC localization restored IL-2 secretion which is a key T cell effector function as dependent on reconstitution dynamics. Our data suggest that the cSMAC enhances early signaling by facilitating signaling interactions and attenuates signaling thereafter through sequestration of a more limited set of signaling intermediates.


Assuntos
Células Apresentadoras de Antígenos/fisiologia , Comunicação Celular , Interleucina-2/metabolismo , Linfócitos T/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antígenos CD28/metabolismo , Células Cultivadas , Proteína Adaptadora GRB2/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Fosfoproteínas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo
20.
PLoS One ; 14(10): e0223901, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31622420

RESUMO

Human semen contains trillions of extracellular vesicles (SEV) similar in size to sexually transmitted viruses and loaded with potentially bioactive miRNAs, proteins and lipids. SEV were shown to inhibit HIV and Zika virus infectivity, but whether SEV are able also to affect subsequent immune responses is unknown. We found that SEV efficiently bound to and entered antigen-presenting cells (APC) and thus we set out to further dissect the impact of SEV on APC function and the impact on downstream T cell responses. In an APC-T cell co-culture system, SEV exposure to APC alone markedly reduced antigen-specific cytokine production, degranulation and cytotoxicity by antigen-specific memory CD8+ T cells. In contrast, inhibition of CD4+ T cell responses required both APC and T cell exposure to SEV. Surprisingly, SEV did not alter MHC or co-stimulatory receptor expression on APCs, but caused APCs to upregulate indoleamine 2,3 deoxygenase, an enzyme known to indirectly inhibit T cells. Thus, SEV reduce the ability of APCs to activate T cells. We propose here that these immune-inhibitory properties of SEV may be intended to prevent immune responses against semen-derived antigens, but can be hi-jacked by genitally acquired viral infections to compromise adaptive cellular immunity.


Assuntos
Células Apresentadoras de Antígenos/citologia , Citocinas/metabolismo , Vesículas Extracelulares/imunologia , Sêmen/citologia , Linfócitos T/citologia , Adulto , Células Apresentadoras de Antígenos/imunologia , Linfócitos T CD8-Positivos , Células Cultivadas , Técnicas de Cocultura , Voluntários Saudáveis , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Sêmen/imunologia , Linfócitos T/imunologia , Adulto Jovem
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