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1.
Nat Commun ; 14(1): 7922, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38040679

RESUMO

Invariant natural killer T (NKT) cell subsets are defined based on their cytokine-production profiles and transcription factors. Their distribution is different in C57BL/6 (B6) and BALB/c mice, with a bias for NKT1 and NKT2/NKT17 subsets, respectively. Here, we show that the non-classical class I-like major histocompatibility complex CD1 molecules CD1d2, expressed in BALB/c and not in B6 mice, could not account for this difference. We find however that NKT cell subset distribution is intrinsic to bone marrow derived NKT cells, regardless of syngeneic CD1d-ligand recognition, and that multiple intrinsic factors are likely involved. Finally, we find that CD1d expression levels in combination with T cell antigen receptor signal strength could also influence NKT cell distribution and function. Overall, this study indicates that CD1d-mediated TCR signals and other intrinsic signals integrate to influence strain-specific NKT cell differentiation programs and subset distributions.


Assuntos
Células T Matadoras Naturais , Animais , Camundongos , Antígenos CD1/metabolismo , Antígenos CD1d/metabolismo , Diferenciação Celular , Células Matadoras Naturais , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/metabolismo , Subpopulações de Linfócitos T
2.
Bio Protoc ; 12(8): e4390, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35800095

RESUMO

Single molecule tracking (SMT) is a powerful technique to study molecular dynamics, and is particularly adapted to monitor the motion and interactions of cell membrane components. Assessing interactions among two molecular populations is classically performed by several approaches, including dual-color videomicroscopy, which allows monitoring of interactions through colocalization events. Other techniques, such as fluorescence recovery after photobleaching (FRAP), Förster resonance energy transfer (FRET), and fluorescence correlation spectroscopy (FCS), are also utilized to measure molecular dynamics. We developed MTT2col, a set of algorithmic tools extending multi-target tracing (MTT) to dual-color acquisition (https://github.com/arnauldserge1/MTT2col). In this protocol, we used MTT2col to monitor adhesion molecules at the contact between leukemic stem cells and stromal cells, a process involved in cancer resistance to chemotherapy and in relapse. Our dual-color single molecule protocol includes the following steps: (i) labeling molecules of interest with fluorescent probes, (ii) video-acquisition, (iii) analyses using our MTT2col in-house software, to obtain positions and trajectories, followed by (iv) detailed analyses of colocalization, distribution, and dynamic motion modes, according to the issues addressed. MTT2col is a robust and efficient SMT algorithm. Both MTT and MTT2col are open-source software that can be adapted and further developed for specific analyses. Graphical abstract.

3.
Cell Mol Life Sci ; 79(7): 355, 2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35678896

RESUMO

Thymically-derived Foxp3+ regulatory T cells (Treg) critically control immunological tolerance. These cells are generated in the medulla through high affinity interactions with medullary thymic epithelial cells (mTEC) expressing the Autoimmune regulator (Aire). Recent advances have revealed that thymic Treg contain not only developing but also recirculating cells from the periphery. Although Aire is implicated in the generation of Foxp3+ Treg, its role in the biology of recirculating Treg remains elusive. Here, we show that Aire regulates the suppressive signature of recirculating Treg independently of the remodeling of the medullary 3D organization throughout life where Treg reside. Accordingly, the adoptive transfer of peripheral Foxp3+ Treg in AireKO recipients led to an impaired suppressive signature upon their entry into the thymus. Furthermore, recirculating Treg from AireKO mice failed to attenuate the severity of multiorgan autoimmunity, demonstrating that their suppressive function is altered. Using bone marrow chimeras, we reveal that mTEC-specific expression of Aire controls the suppressive signature of recirculating Treg. Finally, mature mTEC lacking Aire were inefficient in stimulating peripheral Treg both in polyclonal and antigen-specific co-culture assays. Overall, this study demonstrates that Aire confers to mTEC the ability to restimulate recirculating Treg, unravelling a novel function for this master regulator in Treg biology.


Assuntos
Tolerância Imunológica , Linfócitos T Reguladores , Animais , Autoimunidade , Células Epiteliais/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Camundongos , Timo
4.
J Cell Sci ; 134(18)2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34435622

RESUMO

Leukemic stem cells (LSCs) adhere to bone niches through adhesion molecules. These interactions, which are deeply reorganized in tumors, contribute to LSC resistance to chemotherapy and leukemia relapse. However, LSC adhesion mechanisms and potential therapeutic disruption using blocking antibodies remain largely unknown. Junctional adhesion molecule C (JAM-C, also known as JAM3) overexpression by LSCs correlates with increased leukemia severity, and thus constitutes a putative therapeutic target. Here, we took advantage of the ability of nanoscopy to detect single molecules with nanometric accuracy to characterize junctional adhesion molecule (JAM) dynamics at leuko-stromal contacts. Videonanoscopy trajectories were reconstructed using our dedicated multi-target tracing algorithm, pipelined with dual-color analyses (MTT2col). JAM-C expressed by LSCs engaged in transient interactions with JAM-B (also known as JAM2) expressed by stromal cells. JAM recruitment and colocalization at cell contacts were proportional to JAM-C level and reduced by a blocking anti-JAM-C antibody. MTT2col revealed, at single-molecule resolution, the ability of blocking antibodies to destabilize LSC binding to their niches, opening opportunities for disrupting LSC resistance mechanisms.


Assuntos
Células-Tronco Mesenquimais , Adesão Celular , Moléculas de Adesão Celular/genética
5.
Elife ; 102021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34402793

RESUMO

Follicular T helper cells (Tfh) are a specialized subset of CD4 effector T cells that are crucial for germinal center (GC) reactions and for selecting B cells to undergo affinity maturation. Despite this central role for humoral immunity, only few data exist about their clonal distribution when multiple lymphoid organs are exposed to the same antigen (Ag) as it is the case in autoimmunity. Here, we used an autoantibody-mediated disease model of the skin and injected one auto-Ag into the two footpads of the same mouse and analyzed the T cell receptor (TCR)ß sequences of Tfh located in GCs of both contralateral draining lymph nodes. We found that over 90% of the dominant GC-Tfh clonotypes were shared in both lymph nodes but only transiently. The initially dominant Tfh clonotypes especially declined after establishment of chronic disease while GC reaction and autoimmune disease continued. Our data demonstrates a dynamic behavior of Tfh clonotypes under autoimmune conditions and emphasizes the importance of the time point for distinguishing auto-Ag-specific Tfh clonotypes from potential bystander activated ones.


Assuntos
Autoanticorpos/imunologia , Autoimunidade/imunologia , Centro Germinativo/imunologia , Linfonodos/imunologia , Células T Auxiliares Foliculares/imunologia , Animais , Antígenos/administração & dosagem , Antígenos/imunologia , Linfócitos B/imunologia , Feminino , Imunidade Humoral , Imunização , Linfonodos/citologia , Camundongos , Camundongos Endogâmicos C57BL
6.
J Immunol ; 204(10): 2685-2696, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32229537

RESUMO

Grasp55 is a ubiquitous Golgi stacking protein involved in autophagy, protein trafficking, and glucose deprivation sensing. The function of Grasp55 in protein trafficking has been attributed to its PDZ-mediated interaction with the C-terminal PDZ-binding motifs of protein cargos. We have recently shown that such an interaction occurs between Grasp55 and the adhesion molecule Jam-C, which plays a central role in stemness maintenance of hematopoietic and spermatogenic cells. Accordingly, we have found that Grasp55-deficient mice suffer from spermatogenesis defects similar to Jam-C knockout mice. However, whether Grasp55 is involved in the maintenance of immunohematopoietic homeostasis through regulation of protein transport and Jam-C expression remains unknown. In this study, we show that Grasp55 deficiency does not affect hematopoietic stem cell differentiation, engraftment, or mobilization, which are known to depend on expression of Grasp55-dependent protein cargos. In contrast, using an Myc-dependent leukemic model addicted to autophagy, we show that knockdown of Grasp55 in leukemic cells reduces spleen and bone marrow tumor burden upon i.v. leukemic engraftment. This is not due to reduced homing of Grasp55-deficient cells to these organs but to increased spontaneous apoptosis of Grasp55-deficient leukemic cells correlated with increased sensitivity of the cells to glucose deprivation. These results show that Grasp55 plays a role in Myc-transformed hematopoietic cells but not in normal hematopoietic cells in vivo.


Assuntos
Complexo de Golgi/patologia , Proteínas da Matriz do Complexo de Golgi/metabolismo , Leucemia/metabolismo , Animais , Apoptose/genética , Autofagia , Carcinogênese , Sobrevivência Celular , Proteínas da Matriz do Complexo de Golgi/genética , Hematopoese/genética , Leucemia/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transporte Proteico , Proteínas Proto-Oncogênicas c-myc/metabolismo , Carga Tumoral
7.
Oncotarget ; 11(8): 759-774, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32165998

RESUMO

Glioblastoma (GBM) are aggressive brain tumors with limited treatment options. Cancer stem-like cells (CSLCs) contribute to GBM invasiveness, representing promising targets. BAL101553, a prodrug of BAL27862, is a novel small molecule tubulin-binding agent, promoting tumor cell death through spindle assembly checkpoint activation, which is currently in Phase 1/2a in advanced solid tumor patients including GBM. This study aimed to evaluate long-term daily oral BAL101553 treatment of mice orthotopically grafted with GBM CSLCs (GBM6) according to EB1 expression-level, and to decipher its mechanism of action on GBM stem cells. Oral treatment with BAL101553 for 100 days provoked a large EB1 expression level-dependent survival benefit, together with a decrease in tumor growth and brain invasion. Formation of vascular structures by the fluorescent GBM6-GFP-sh0 cells, mimicking endothelial vascular networks, was observed in the brains of control grafted mice. Following BAL101553 treatment, vessels were no longer detectable, suggesting inhibition of the endothelial trans-differentiation of GBM stem cells. In vitro, BAL27862 treatment resulted in a switch to the endothelial-like phenotype of GBM6 towards an astrocytic phenotype. Moreover, the drug inhibited secretion of VEGF, thus preventing normal endothelial cell migration activated by CSLCs. The decrease in VEGF secretion was confirmed in a human GBM explant following drug treatment. Altogether, our data first confirm the potential of EB1 expression as a response-predictive biomarker of BAL101553 in GBM we previously published and add new insights in BAL101553 long-term action by counteracting CSLCs mediated tumor angiogenesis. Our results strongly support BAL101553 clinical studies in GBM patients.

8.
J Allergy Clin Immunol ; 145(2): 679-697.e5, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31513879

RESUMO

BACKGROUND: Patients with T-cell immunodeficiencies are generally treated with allogeneic hematopoietic stem cell transplantation, but alternatives are needed for patients without matched donors. An innovative intrathymic gene therapy approach that directly targets the thymus might improve outcomes. OBJECTIVE: We sought to determine the efficacy of intrathymic adeno-associated virus (AAV) serotypes to transduce thymocyte subsets and correct the T-cell immunodeficiency in a zeta-associated protein of 70 kDa (ZAP-70)-deficient murine model. METHODS: AAV serotypes were injected intrathymically into wild-type mice, and gene transfer efficiency was monitored. ZAP-70-/- mice were intrathymically injected with an AAV8 vector harboring the ZAP70 gene. Thymus structure, immunophenotyping, T-cell receptor clonotypes, T-cell function, immune responses to transgenes and autoantibodies, vector copy number, and integration were evaluated. RESULTS: AAV8, AAV9, and AAV10 serotypes all transduced thymocyte subsets after in situ gene transfer, with transduction of up to 5% of cells. Intrathymic injection of an AAV8-ZAP-70 vector into ZAP-70-/- mice resulted in a rapid thymocyte differentiation associated with the development of a thymic medulla. Strikingly, medullary thymic epithelial cells expressing the autoimmune regulator were detected within 10 days of gene transfer, correlating with the presence of functional effector and regulatory T-cell subsets with diverse T-cell receptor clonotypes in the periphery. Although thymocyte reconstitution was transient, gene-corrected peripheral T cells harboring approximately 1 AAV genome per cell persisted for more than 40 weeks, and AAV vector integration was detected. CONCLUSIONS: Intrathymic AAV-transduced progenitors promote a rapid restoration of the thymic architecture, with a single wave of thymopoiesis generating long-term peripheral T-cell function.


Assuntos
Terapia Genética/métodos , Timócitos , Transdução Genética/métodos , Proteína-Tirosina Quinase ZAP-70 , Animais , Dependovirus , Vetores Genéticos , Síndromes de Imunodeficiência/terapia , Camundongos , Camundongos Knockout , Proteína-Tirosina Quinase ZAP-70/administração & dosagem , Proteína-Tirosina Quinase ZAP-70/genética
9.
Nat Commun ; 10(1): 5690, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31857584

RESUMO

In the thymus, the T lymphocyte repertoire is purged of a substantial portion of highly self-reactive cells. This negative selection process relies on the strength of TCR-signaling in response to self-peptide-MHC complexes, both in the cortex and medulla regions. However, whether cytokine-signaling contributes to negative selection remains unclear. Here, we report that, in the absence of Transforming Growth Factor beta (TGF-ß) signaling in thymocytes, negative selection is significantly impaired. Highly autoreactive thymocytes first escape cortical negative selection and acquire a Th1-like-phenotype. They express high levels of CXCR3, aberrantly accumulate at the cortico-medullary junction and subsequently fail to sustain AIRE expression in the medulla, escaping medullary negative selection. Highly autoreactive thymocytes undergo an atypical maturation program, substantially accumulate in the periphery and induce multiple organ-autoimmune-lesions. Thus, these findings reveal TGF-ß in thymocytes as crucial for negative selection with implications for understanding T cell self-tolerance mechanisms.


Assuntos
Transdução de Sinais , Timócitos/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Autoimunidade , Células da Medula Óssea/metabolismo , Diferenciação Celular , Células Epiteliais/metabolismo , Camundongos Knockout , Modelos Biológicos , Ligante RANK/metabolismo , Timócitos/citologia
10.
Cell Rep ; 26(12): 3257-3271.e8, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30893599

RESUMO

In the bone marrow, CXCL12 and IL-7 are essential for B cell differentiation, whereas hematopoietic stem cell (HSC) maintenance requires SCF and CXCL12. Peri-sinusoidal stromal (PSS) cells are the main source of IL-7, but their characterization as a pro-B cell niche remains limited. Here, we characterize pro-B cell supporting stromal cells and decipher the interaction network allowing pro-B cell retention. Preferential contacts are found between pro-B cells and PSS cells, which homogeneously express HSC and B cell niche genes. Furthermore, pro-B cells are frequently located in the vicinity of HSCs in the same niche. Using an interactome bioinformatics pipeline, we identify Nidogen-1 as essential for pro-B cell retention in the peri-sinusoidal niche as confirmed in Nidogen-1-/- mice. Finally, human pro-B cells and hematopoietic progenitors are observed close to similar IL-7+ stromal cells. Thus, a multispecific niche exists in mouse and human supporting both early progenitors and committed hematopoietic lineages.


Assuntos
Células-Tronco Hematopoéticas/imunologia , Glicoproteínas de Membrana/imunologia , Células Precursoras de Linfócitos B/imunologia , Nicho de Células-Tronco/imunologia , Animais , Células-Tronco Hematopoéticas/citologia , Interleucina-7/genética , Interleucina-7/imunologia , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Knockout , Células Precursoras de Linfócitos B/citologia , Células Estromais/citologia , Células Estromais/imunologia
11.
Hum Mol Genet ; 27(19): 3377-3391, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29982567

RESUMO

Skeletal dysplasias are a clinically and genetically heterogeneous group of bone and cartilage disorders. A total of 436 skeletal dysplasias are listed in the 2015 revised version of the nosology and classification of genetic skeletal disorders, of which nearly 20% are still genetically and molecularly uncharacterized. We report the clinical and molecular characterization of a lethal skeletal dysplasia of the short-rib group caused by mutation of the mouse Fop gene. Fop encodes a centrosomal and centriolar satellite (CS) protein. We show that Fop mutation perturbs ciliogenesis in vivo and that this leads to the alteration of the Hedgehog signaling pathway. Fop mutation reduces CSs movements and affects pericentriolar material composition, which probably participates to the ciliogenesis defect. This study highlights the role of a centrosome and CSs protein producing phenotypes in mice that recapitulate a short rib-polydactyly syndrome when mutated.


Assuntos
Ciliopatias/genética , Proteínas Proto-Oncogênicas/genética , Síndrome de Costela Curta e Polidactilia/genética , Fatores de Transcrição/genética , Animais , Centríolos/genética , Centrossomo/metabolismo , Centrossomo/patologia , Cílios/genética , Cílios/patologia , Ciliopatias/fisiopatologia , Humanos , Camundongos , Mutação , Síndrome de Costela Curta e Polidactilia/fisiopatologia
12.
Front Immunol ; 9: 1019, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29867987

RESUMO

CD154 is a transmembrane cytokine expressed transiently on activated CD4 T cells upon T-cell receptor (TCR) stimulation that interacts with CD40 on antigen-presenting cells. The signaling via CD154:CD40 is essential for B-cell maturation and germinal center formation and also for the final differentiation of CD4 T cells during T-dependent humoral immune responses. Recent data demonstrate that CD154 is critically involved in the selection of T-cell clones during the negative selection process in the thymus. Whether CD154 signaling influences the TCR repertoire during peripheral T-dependent humoral immune responses has not yet been elucidated. To find out, we used CD154-deficient mice and assessed the global TCRß repertoire in T-cell zones (TCZ) of spleens by high-throughput sequencing after induction of a Th2 response to the multiepitopic antigen sheep red blood cells. Qualitative and quantitative comparison of the splenic TCZ-specific TCRß repertoires revealed that CD154 deficiency shifts the distribution of Vß-Jß genes after antigen exposure. This data led to the conclusion that costimulation via CD154:CD40 during the interaction of T cells with CD40-matured B cells contributes to the recruitment of T-cell clones into the immune response and thereby shapes the peripheral TCR repertoire.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Ligante de CD40/genética , Ligante de CD40/imunologia , Imunidade Humoral , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos CD40/genética , Antígenos CD40/imunologia , Diferenciação Celular/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Ativação Linfocitária/imunologia , Camundongos , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Transdução de Sinais/imunologia , Baço/anatomia & histologia , Baço/imunologia , Células Th2/enzimologia , Células Th2/imunologia
13.
Nat Commun ; 9(1): 1262, 2018 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-29593265

RESUMO

Medullary thymic epithelial cells (mTEC) purge the T cell repertoire of autoreactive thymocytes. Although dendritic cells (DC) reinforce this process by transporting innocuous peripheral self-antigens, the mechanisms that control their thymic entry remain unclear. Here we show that mTEC-CD4+ thymocyte crosstalk regulates the thymus homing of SHPS-1+ conventional DCs (cDC), plasmacytoid DCs (pDC) and macrophages. This homing process is controlled by lymphotoxin α (LTα), which negatively regulates CCL2, CCL8 and CCL12 chemokines in mTECs. Consequently, Ltα-deficient mice have increased expression of these chemokines that correlates with augmented classical NF-κB subunits and increased thymic recruitment of cDCs, pDCs and macrophages. This enhanced migration depends mainly on the chemokine receptor CCR2, and increases thymic clonal deletion. Altogether, this study identifies a fine-tuning mechanism of T cell repertoire selection and paves the way for therapeutic interventions to treat autoimmune disorders.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Deleção Clonal , Linfotoxina-alfa/metabolismo , Timo/imunologia , Animais , Antígenos/imunologia , Células da Medula Óssea/imunologia , Quimiocinas/imunologia , Técnicas de Cocultura , Células Dendríticas/imunologia , Feminino , Deleção de Genes , Tolerância Imunológica , Ligantes , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Transgênicos , Microscopia Confocal , NF-kappa B/metabolismo , Receptores CCR2/metabolismo , Linfócitos T/imunologia , Timócitos/imunologia
14.
Cancer Res ; 77(23): 6627-6640, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-28972073

RESUMO

Acute myeloid leukemia (AML) originates from hematopoietic stem and progenitor cells that acquire somatic mutations, leading to disease and clonogenic evolution. AML is characterized by accumulation of immature myeloid cells in the bone marrow and phenotypic cellular heterogeneity reflective of normal hematopoietic differentiation. Here, we show that JAM-C expression defines a subset of leukemic cells endowed with leukemia-initiating cell activity (LIC). Stratification of de novo AML patients at diagnosis based on JAM-C-expressing cells frequencies in the blood served as an independent prognostic marker for disease outcome. Using publicly available leukemic stem cell (LSC) gene expression profiles and gene expression data generated from JAM-C-expressing leukemic cells, we defined a single cell core gene expression signature correlated to JAM-C expression that reveals LSC heterogeneity. Finally, we demonstrated that JAM-C controls Src family kinase (SFK) activation in LSC and that LIC with exacerbated SFK activation was uniquely found within the JAM-C-expressing LSC compartment. Cancer Res; 77(23); 6627-40. ©2017 AACR.


Assuntos
Biomarcadores Tumorais/metabolismo , Moléculas de Adesão Celular/metabolismo , Leucemia Mieloide Aguda/patologia , Células-Tronco Neoplásicas/patologia , Quinases da Família src/metabolismo , ADP-Ribosil Ciclase 1/metabolismo , Animais , Antígenos CD34/metabolismo , Biomarcadores Tumorais/genética , Moléculas de Adesão Celular/genética , Linhagem Celular Tumoral , Ativação Enzimática , Feminino , Perfilação da Expressão Gênica , Humanos , Subunidade alfa de Receptor de Interleucina-3/metabolismo , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Transplante de Neoplasias , Células-Tronco Neoplásicas/citologia , Transplante Heterólogo
15.
PLoS Genet ; 13(6): e1006803, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28617811

RESUMO

Spermatogenesis is a dynamic process that is regulated by adhesive interactions between germ and Sertoli cells. Germ cells express the Junctional Adhesion Molecule-C (JAM-C, encoded by Jam3), which localizes to germ/Sertoli cell contacts. JAM-C is involved in germ cell polarity and acrosome formation. Using a proteomic approach, we demonstrated that JAM-C interacted with the Golgi reassembly stacking protein of 55 kDa (GRASP55, encoded by Gorasp2) in developing germ cells. Generation and study of Gorasp2-/- mice revealed that knock-out mice suffered from spermatogenesis defects. Acrosome formation and polarized localization of JAM-C in spermatids were altered in Gorasp2-/- mice. In addition, Golgi morphology of spermatocytes was disturbed in Gorasp2-/- mice. Crystal structures of GRASP55 in complex with JAM-C or JAM-B revealed that GRASP55 interacted via PDZ-mediated interactions with JAMs and induced a conformational change in GRASP55 with respect of its free conformation. An in silico pharmacophore approach identified a chemical compound called Graspin that inhibited PDZ-mediated interactions of GRASP55 with JAMs. Treatment of mice with Graspin hampered the polarized localization of JAM-C in spermatids, induced the premature release of spermatids and affected the Golgi morphology of meiotic spermatocytes.


Assuntos
Proteínas de Transporte/metabolismo , Moléculas de Adesão Celular/metabolismo , Complexo de Golgi/metabolismo , Imunoglobulinas/metabolismo , Proteínas de Membrana/metabolismo , Espermatogênese , Espermatogônias/metabolismo , Animais , Sítios de Ligação , Proteínas de Transporte/química , Proteínas de Transporte/genética , Células Cultivadas , Complexo de Golgi/ultraestrutura , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica , Transporte Proteico , Espermatogônias/citologia
16.
J Clin Invest ; 126(11): 4140-4156, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27701147

RESUMO

The intratumoral microenvironment, or stroma, is of major importance in the pathobiology of pancreatic ductal adenocarcinoma (PDA), and specific conditions in the stroma may promote increased cancer aggressiveness. We hypothesized that this heterogeneous and evolving compartment drastically influences tumor cell abilities, which in turn influences PDA aggressiveness through crosstalk that is mediated by extracellular vesicles (EVs). Here, we have analyzed the PDA proteomic stromal signature and identified a contribution of the annexin A6/LDL receptor-related protein 1/thrombospondin 1 (ANXA6/LRP1/TSP1) complex in tumor cell crosstalk. Formation of the ANXA6/LRP1/TSP1 complex was restricted to cancer-associated fibroblasts (CAFs) and required physiopathologic culture conditions that improved tumor cell survival and migration. Increased PDA aggressiveness was dependent on tumor cell-mediated uptake of CAF-derived ANXA6+ EVs carrying the ANXA6/LRP1/TSP1 complex. Depletion of ANXA6 in CAFs impaired complex formation and subsequently impaired PDA and metastasis occurrence, while injection of CAF-derived ANXA6+ EVs enhanced tumorigenesis. We found that the presence of ANXA6+ EVs in serum was restricted to PDA patients and represents a potential biomarker for PDA grade. These findings suggest that CAF-tumor cell crosstalk supported by ANXA6+ EVs is predictive of PDA aggressiveness, highlighting a therapeutic target and potential biomarker for PDA.


Assuntos
Anexina A6/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Micropartículas Derivadas de Células/metabolismo , Fibroblastos/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Carcinoma Ductal Pancreático/patologia , Comunicação Celular , Micropartículas Derivadas de Células/patologia , Feminino , Fibroblastos/patologia , Humanos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Masculino , Camundongos , Camundongos Nus , Neoplasias Pancreáticas/patologia
17.
Dev Cell ; 37(4): 311-325, 2016 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-27184734

RESUMO

Components of the evolutionarily conserved developmental planar cell polarity (PCP) pathway were recently described to play a prominent role in cancer cell dissemination. However, the molecular mechanisms by which PCP molecules drive the spread of cancer cells remain largely unknown. PRICKLE1 encodes a PCP protein bound to the promigratory serine/threonine kinase MINK1. We identify RICTOR, a member of the mTORC2 complex, as a PRICKLE1-binding partner and show that the integrity of the PRICKLE1-MINK1-RICTOR complex is required for activation of AKT, regulation of focal adhesions, and cancer cell migration. Disruption of the PRICKLE1-RICTOR interaction results in a strong impairment of breast cancer cell dissemination in xenograft assays. Finally, we show that upregulation of PRICKLE1 in basal breast cancers, a subtype characterized by high metastatic potential, is associated with poor metastasis-free survival.


Assuntos
Neoplasias da Mama/patologia , Proteínas com Domínio LIM/metabolismo , Complexos Multiproteicos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Adesões Focais/metabolismo , Genes Dominantes , Humanos , Proteínas com Domínio LIM/química , Alvo Mecanístico do Complexo 2 de Rapamicina , Metástase Neoplásica , Fosforilação , Prognóstico , Ligação Proteica , Domínios Proteicos , Mapeamento de Interação de Proteínas , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina , Proteínas Supressoras de Tumor/química , Regulação para Cima
18.
Front Cell Dev Biol ; 4: 36, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27200348

RESUMO

The plasma membrane delimits the cell, which is the basic unit of living organisms, and is also a privileged site for cell communication with the environment. Cell adhesion can occur through cell-cell and cell-matrix contacts. Adhesion proteins such as integrins and cadherins also constitute receptors for inside-out and outside-in signaling within proteolipidic platforms. Adhesion molecule targeting and stabilization relies on specific features such as preferential segregation by the sub-membrane cytoskeleton meshwork and within membrane proteolipidic microdomains. This review presents an overview of the recent insights brought by the latest developments in microscopy, to unravel the molecular remodeling occurring at cell contacts. The dynamic aspect of cell adhesion was recently highlighted by super-resolution videomicroscopy, also named videonanoscopy. By circumventing the diffraction limit of light, nanoscopy has allowed the monitoring of molecular localization and behavior at the single-molecule level, on fixed and living cells. Accessing molecular-resolution details such as quantitatively monitoring components entering and leaving cell contacts by lateral diffusion and reversible association has revealed an unexpected plasticity. Adhesion structures can be highly specialized, such as focal adhesion in motile cells, as well as immune and neuronal synapses. Spatiotemporal reorganization of adhesion molecules, receptors, and adaptors directly relates to structure/function modulation. Assembly of these supramolecular complexes is continuously balanced by dynamic events, remodeling adhesions on various timescales, notably by molecular conformation switches, lateral diffusion within the membrane and endo/exocytosis. Pathological alterations in cell adhesion are involved in cancer evolution, through cancer stem cell interaction with stromal niches, growth, extravasation, and metastasis.

19.
Front Immunol ; 6: 365, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26257733

RESUMO

The thymus ensures the generation of a functional and highly diverse T-cell repertoire. The thymic medulla, which is mainly composed of medullary thymic epithelial cells (mTECs) and dendritic cells (DCs), provides a specialized microenvironment dedicated to the establishment of T-cell tolerance. mTECs play a privileged role in this pivotal process by their unique capacity to express a broad range of peripheral self-antigens that are presented to developing T cells. Reciprocally, developing T cells control mTEC differentiation and organization. These bidirectional interactions are commonly referred to as thymic crosstalk. This review focuses on the relative contributions of mTEC and DC subsets to the deletion of autoreactive T cells and the generation of natural regulatory T cells. We also summarize current knowledge regarding how hematopoietic cells conversely control the composition and complex three-dimensional organization of the thymic medulla.

20.
J Immunol Methods ; 424: 32-42, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25956038

RESUMO

To decipher the complex topology of lymphoid structures, we developed an automated process called Full Organ Reconstruction in 3D (For3D). A dedicated image-processing pipeline is applied to entire collections of immunolabeled serial sections, acquired with a slide-scanning microscope. This method is automated, flexible and readily applicable in two days to frozen or paraffin-embedded organs stained by fluorescence or brightfield immunohistochemistry. 3D-reconstructed organs can be visualized, rotated and analyzed to quantify substructures of interest. Usefulness of For3D is exemplified here through topological analysis of several mouse lymphoid organs exhibiting a complex organization: (i) the thymus, composed of two compartments, a medulla intricately imbricated into a surrounding cortex, (ii) lymph nodes, also highly compartmentalized into cortex, paracortex and medulla and (iii) the vascularization of an EG7 primary thymoma. This open-source algorithm, based on ImageJ and Matlab scripts, offers a user-friendly interface and is widely applicable to any organ or tissue, hence readily adaptable to a broad range of biomedical samples.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Tecido Linfoide/anatomia & histologia , Animais , Linhagem Celular Tumoral , Linfonodos , Camundongos , Neoplasias/irrigação sanguínea , Neoplasias/patologia , Neovascularização Patológica/patologia , Timo/anatomia & histologia
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