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1.
Int J Mol Sci ; 25(11)2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38891893

RESUMO

Skin macrophages are critical to maintain and restore skin homeostasis. They serve as major producers of cytokines and chemokines in the skin, participating in diverse biological processes such as wound healing and psoriasis. The heterogeneity and functional diversity of macrophage subpopulations endow them with multifaceted roles in psoriasis development. A distinct subpopulation of skin macrophages, characterized by high expression of CD169, has been reported to exist in both mouse and human skin. However, its role in psoriasis remains unknown. Here, we report that CD169+ macrophages exhibit increased abundance in imiquimod (IMQ) induced psoriasis-like skin lesions. Specific depletion of CD169+ macrophages in CD169-ditheria toxin receptor (CD169-DTR) mice inhibits IMQ-induced psoriasis, resulting in milder symptoms, diminished proinflammatory cytokine levels and reduced proportion of Th17 cells within the skin lesions. Furthermore, transcriptomic analysis uncovers enhanced activity in CD169+ macrophages when compared with CD169- macrophages, characterized by upregulated genes that are associated with cell activation and cell metabolism. Mechanistically, CD169+ macrophages isolated from IMQ-induced skin lesions produce more proinflammatory cytokines and exhibit enhanced ability to promote Th17 cell differentiation in vitro. Collectively, our findings highlight the crucial involvement of CD169+ macrophages in psoriasis development and offer novel insights into the heterogeneity of skin macrophages in the context of psoriasis.


Assuntos
Imiquimode , Macrófagos , Psoríase , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Pele , Animais , Psoríase/imunologia , Psoríase/metabolismo , Psoríase/patologia , Psoríase/induzido quimicamente , Psoríase/genética , Macrófagos/metabolismo , Macrófagos/imunologia , Camundongos , Pele/metabolismo , Pele/patologia , Pele/imunologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Células Th17/imunologia , Células Th17/metabolismo , Diferenciação Celular , Camundongos Endogâmicos C57BL
2.
J Clin Exp Hematop ; 64(2): 71-78, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38925976

RESUMO

Lymph nodes are secondary lymphoid organs localized throughout the body that typically appear as bean-like nodules. Numerous antigen-presenting cells, including dendritic cells and macrophages, that mediate host defense responses against pathogens, such as bacteria and viruses, reside within lymph nodes. To react to cancer cell-derived antigens in a variety of cancers, antigen-presenting cells induce cytotoxic T lymphocytes (CTLs). In relation to anticancer immune responses, macrophages in the lymph node sinus have been of particular interest because a number of studies involving both human specimens and animal models have reported that lymph node macrophages expressing CD169 play a key role in activating anticancer CTLs. Recent studies have indicated that dysfunction of lymph node macrophages potentially contributes to immune suppression in elderly patients and immunological "cold" tumors. Therefore, in anticancer therapy, the regulation of lymph node macrophages is a potentially promising approach.


Assuntos
Linfonodos , Macrófagos , Neoplasias , Humanos , Linfonodos/imunologia , Linfonodos/patologia , Animais , Macrófagos/imunologia , Neoplasias/imunologia , Neoplasias/patologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Linfócitos T Citotóxicos/imunologia
3.
J Autoimmun ; 147: 103243, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38788537

RESUMO

OBJECTIVES: Autoreactive B cells and interferon (IFN) signature are hallmarks of primary sjögren's syndrome (pSS), but how IFN signaling pathways influence autoantibody production and clinical manifestations remain unclear. More detailed studies hold promise for improved diagnostic methodologies and personalized treatment. METHODS: We analyzed peripheral blood T and B cell subsets from 34 pSS patients and 38 healthy donors (HDs) at baseline and upon stimulation regarding their expression levels of type I and II IFN signaling molecules (STAT1/2, IRF1, IRF9). Additionally, we investigated how the levels of these molecules correlated with serological and clinical characteristics and performed ROC analysis. RESULTS: Patients showed elevated IFN pathway molecules, including STAT1, STAT2 and IRF9 among most T and B cell subsets. We found a reduced ratio of phosphorylated STAT1 and STAT2 in patients in comparison to HDs, although B cells from patients were highly responsive by increased phosphorylation upon IFN stimulation. Correlation matrices showed further interrelations between STAT1, IRF1 and IRF9 in pSS. Levels of STAT1 and IRF9 in T and B cells correlated with the IFN type I marker Siglec-1 (CD169) on monocytes. High levels of STAT1 and IRF9 within pSS B cells were significantly associated with hypergammaglobulinemia as well as anti-SSA/anti-SSB autoantibodies. Elevated STAT1 levels were found in patients with extraglandular disease and could serve as a biomarker for this subgroup (p < 0.01). Notably, IRF9 levels in T and B cells correlated with EULAR Sjögren's syndrome disease activity index (ESSDAI). CONCLUSION: Here, we provide evidence that in active pSS patients, enhanced IFN signaling incl. unphosphorylated STAT1 and STAT2 with IRFs entertain chronic T and B cell activation. Furthermore, increased STAT1 levels candidate as biomarker of extraglandular disease, while IRF9 levels can serve as biomarker for disease activity.


Assuntos
Biomarcadores , Fator Gênico 3 Estimulado por Interferon, Subunidade gama , Fator de Transcrição STAT1 , Síndrome de Sjogren , Humanos , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/diagnóstico , Síndrome de Sjogren/metabolismo , Fator de Transcrição STAT1/metabolismo , Feminino , Fosforilação , Pessoa de Meia-Idade , Masculino , Fator Gênico 3 Estimulado por Interferon, Subunidade gama/metabolismo , Idoso , Adulto , Linfócitos B/imunologia , Linfócitos B/metabolismo , Autoanticorpos/imunologia , Autoanticorpos/sangue , Transdução de Sinais , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo
4.
Immunohorizons ; 8(5): 384-396, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38809232

RESUMO

The mammalian Siglec receptor sialoadhesin (Siglec1, CD169) confers innate immunity against the encapsulated pathogen group B Streptococcus (GBS). Newborn lung macrophages have lower expression levels of sialoadhesin at birth compared with the postnatal period, increasing their susceptibility to GBS infection. In this study, we investigate the mechanisms regulating sialoadhesin expression in the newborn mouse lung. In both neonatal and adult mice, GBS lung infection reduced Siglec1 expression, potentially delaying acquisition of immunity in neonates. Suppression of Siglec1 expression required interactions between sialic acid on the GBS capsule and the inhibitory host receptor Siglec-E. The Siglec1 gene contains multiple STAT binding motifs, which could regulate expression of sialoadhesin downstream of innate immune signals. Although GBS infection reduced STAT1 expression in the lungs of wild-type newborn mice, we observed increased numbers of STAT1+ cells in Siglece-/- lungs. To test if innate immune activation could increase sialoadhesin at birth, we first demonstrated that treatment of neonatal lung macrophages ex vivo with inflammatory activators increased sialoadhesin expression. However, overcoming the low sialoadhesin expression at birth using in vivo prenatal exposures or treatments with inflammatory stimuli were not successful. The suppression of sialoadhesin expression by GBS-Siglec-E engagement may therefore contribute to disease pathogenesis in newborns and represent a challenging but potentially appealing therapeutic opportunity to augment immunity at birth.


Assuntos
Animais Recém-Nascidos , Camundongos Knockout , Ácido N-Acetilneuramínico , Fator de Transcrição STAT1 , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Infecções Estreptocócicas , Streptococcus agalactiae , Animais , Camundongos , Streptococcus agalactiae/imunologia , Ácido N-Acetilneuramínico/metabolismo , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT1/genética , Imunidade Inata , Camundongos Endogâmicos C57BL , Pulmão/imunologia , Pulmão/microbiologia , Pulmão/metabolismo , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/metabolismo , Feminino , Macrófagos/imunologia , Macrófagos/metabolismo , Lectinas/metabolismo , Lectinas/genética , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/genética , Antígenos CD/metabolismo , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos B
5.
Biomed Pharmacother ; 175: 116726, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38754263

RESUMO

New therapies to treat or prevent viral infections are essential, as recently observed during the COVID-19 pandemic. Here, we propose a therapeutic strategy based on monoclonal antibodies that block the specific interaction between the host receptor Siglec-1/CD169 and gangliosides embedded in the viral envelope. Antibodies are an excellent option for treating infectious diseases based on their high specificity, strong targeting affinity, and relatively low toxicity. Through a process of humanization, we optimized monoclonal antibodies to eliminate sequence liabilities and performed biophysical characterization. We demonstrated that they maintain their ability to block viral entry into myeloid cells. These molecular improvements during the discovery stage are key if we are to maximize efforts to develop new therapeutic strategies. Humanized monoclonal antibodies targeting CD169 provide new opportunities in the treatment of infections caused by ganglioside-containing enveloped viruses, which pose a constant threat to human health. In contrast with current neutralizing antibodies that bind antigens on the infectious particle, our antibodies can prevent several types of enveloped viruses interacting with host cells because they target the host CD169 protein, thus becoming a potential pan-antiviral therapy.


Assuntos
Anticorpos Monoclonais Humanizados , Antivirais , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Humanos , Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/imunologia , Antivirais/farmacologia , Antivirais/uso terapêutico , Animais , Tratamento Farmacológico da COVID-19 , Internalização do Vírus/efeitos dos fármacos , SARS-CoV-2/imunologia , SARS-CoV-2/efeitos dos fármacos
6.
Int J Mol Sci ; 25(7)2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38612832

RESUMO

A murine colorectal carcinoma (CRC) model was established. CT26 colon carcinoma cells were injected into BALB/c mice's spleen to study the primary tumor and the mechanisms of cell spread of colon cancer to the liver. The CRC was verified by the immunohistochemistry of Pan Cytokeratin and Vimentin expression. Immunophenotyping of leukocytes isolated from CRC-bearing BALB/c mice or healthy controls, such as CD19+ B cells, CD11+ myeloid cells, and CD3+ T cells, was carried out using fluorochrome-labeled lectins. The binding of six lectins to white blood cells, such as galectin-1 (Gal1), siglec-1 (Sig1), Sambucus nigra lectin (SNA), Aleuria aurantia lectin (AAL), Phytolacca americana lectin (PWM), and galectin-3 (Gal3), was assayed. Flow cytometric analysis of the splenocytes revealed the increased binding of SNA, and AAL to CD3 + T cells and CD11b myeloid cells; and increased siglec-1 and AAL binding to CD19 B cells of the tumor-bearing mice. The whole proteomic analysis of the established CRC-bearing liver and spleen versus healthy tissues identified differentially expressed proteins, characteristic of the primary or secondary CRC tissues. KEGG Gene Ontology bioinformatic analysis delineated the established murine CRC characteristic protein interaction networks, biological pathways, and cellular processes involved in CRC. Galectin-1 and S100A4 were identified as upregulated proteins in the primary and secondary CT26 tumor tissues, and these were previously reported to contribute to the poor prognosis of CRC patients. Modelling the development of liver colonization of CRC by the injection of CT26 cells into the spleen may facilitate the understanding of carcinogenesis in human CRC and contribute to the development of novel therapeutic strategies.


Assuntos
Carcinoma , Neoplasias do Colo , Neoplasias Colorretais , Humanos , Animais , Camundongos , Galectina 1 , Modelos Animais de Doenças , Imunofenotipagem , Proteômica , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Tomografia Computadorizada por Raios X
7.
Am J Physiol Lung Cell Mol Physiol ; 326(6): L672-L686, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38530936

RESUMO

Alveolar macrophages (AMs) in patients with chronic obstructive pulmonary disease (COPD) orchestrate persistent inflammation in the airway. However, subpopulations of AMs participating in chronic inflammation have been poorly characterized. We previously reported that Siglec-1 expression on AMs, which is important for bacteria engulfment, was decreased in COPD. Here, we show that Siglec-1-negative AMs isolated from COPD lung tissues exhibit a proinflammatory phenotype and are associated with poor clinical outcomes in patients with COPD. Using flow cytometry, we segregated three subsets of AMs based on the expression of Siglec-1 and their side scattergram (SSC) and forward scattergram (FSC) properties: Siglec-1+SSChiFSChi, Siglec-1-SSChiFSChi, and Siglec-1-SSCloFSClo subsets. The Siglec-1-SSCloFSClo subset number was increased in COPD. RNA sequencing revealed upregulation of multiple proinflammatory signaling pathways and emphysema-associated matrix metalloproteases in the Siglec-1-SSCloFSClo subset. Gene set enrichment analysis indicated that the Siglec-1-SSCloFSClo subset adopted intermediate phenotypes between monocytes and mature alveolar macrophages. Functionally, these cells produced TNF-α, IL-6, and IL-8 at baseline, and these cytokines were significantly increased in response to viral RNA. The increase in Siglec-1-negative AMs in induced sputum is associated with future exacerbation risk and lung function decline in patients with COPD. Collectively, the novel Siglec-1-SSCloFSClo subset of AMs displays proinflammatory properties, and their emergence in COPD airways may be associated with poor clinical outcomes.NEW & NOTEWORTHY Alveolar macrophages (AMs) in patients with chronic obstructive pulmonary disease (COPD) orchestrate persistent inflammation in the airway. We find that Siglec-1-negative alveolar macrophages have a wide range of proinflammatory landscapes and a protease-expressing phenotype. Moreover, this subset is associated with the pathogenesis of COPD and responds to viral stimuli.


Assuntos
Macrófagos Alveolares , Doença Pulmonar Obstrutiva Crônica , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Citocinas/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patologia , Macrófagos Alveolares/imunologia , Fenótipo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/patologia , Doença Pulmonar Obstrutiva Crônica/imunologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo
8.
Diabetologia ; 67(4): 623-640, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38349399

RESUMO

AIMS/HYPOTHESIS: Type 1 diabetes is a T cell-mediated autoimmune disease characterised by pancreatic beta cell destruction. In this study, we explored the pathogenic immune responses in initiation of type 1 diabetes and new immunological targets for type 1 diabetes prevention and treatment. METHODS: We obtained peripheral blood samples from four individuals with newly diagnosed latent autoimmune diabetes in adults (LADA) and from four healthy control participants. Single-cell RNA-sequencing (scRNA-seq) was performed on peripheral blood mononuclear cells to uncover transcriptomic profiles of early LADA. Validation was performed through flow cytometry in a cohort comprising 54 LADA, 17 adult-onset type 2 diabetes, and 26 healthy adults, matched using propensity score matching (PSM) based on age and sex. A similar PSM method matched 15 paediatric type 1 diabetes patients with 15 healthy children. Further flow cytometry analysis was performed in both peripheral blood and pancreatic tissues of non-obese diabetic (NOD) mice. Additionally, cell adoptive transfer and clearance assays were performed in NOD mice to explore the role of this monocyte subset in islet inflammation and onset of type 1 diabetes. RESULTS: The scRNA-seq data showed that upregulated genes in peripheral T cells and monocytes from early-onset LADA patients were primarily enriched in the IFN signalling pathway. A new cluster of classical monocytes (cluster 4) was identified, and the proportion of this cluster was significantly increased in individuals with LADA compared with healthy control individuals (11.93% vs 5.93%, p=0.017) and that exhibited a strong IFN signature marked by SIGLEC-1 (encoding sialoadhesin). These SIGLEC-1+ monocytes expressed high levels of genes encoding C-C chemokine receptors 1 or 2, as well as genes for chemoattractants for T cells and natural killer cells. They also showed relatively low levels of genes for co-stimulatory and HLA molecules. Flow cytometry analysis verified the elevated levels of SIGLEC-1+ monocytes in the peripheral blood of participants with LADA and paediatric type 1 diabetes compared with healthy control participants and those with type 2 diabetes. Interestingly, the proportion of SIGLEC-1+ monocytes positively correlated with disease activity and negatively with disease duration in the LADA patients. In NOD mice, the proportion of SIGLEC-1+ monocytes in the peripheral blood was highest at the age of 6 weeks (16.88%), while the peak occurred at 12 weeks in pancreatic tissues (23.65%). Adoptive transfer experiments revealed a significant acceleration in diabetes onset in the SIGLEC-1+ group compared with the SIGLEC-1- or saline control group. CONCLUSIONS/INTERPRETATION: Our study identified a novel group of SIGLEC-1+ monocytes that may serve as an important indicator for early diagnosis, activity assessment and monitoring of therapeutic efficacy in type 1 diabetes, and may also be a novel target for preventing and treating type 1 diabetes. DATA AVAILABILITY: RNA-seq data have been deposited in the GSA human database ( https://ngdc.cncb.ac.cn/gsa-human/ ) under accession number HRA003649.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Adulto , Animais , Criança , Humanos , Lactente , Camundongos , Diabetes Mellitus Tipo 2/metabolismo , Interferons/metabolismo , Leucócitos Mononucleares/metabolismo , Camundongos Endogâmicos NOD , Monócitos/metabolismo , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo
9.
Drug Deliv Transl Res ; 14(7): 1794-1809, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38165530

RESUMO

Mice as a crucial tool for preclinical assessment of antineoplastic agents. The impact of physiological differences among mouse strains on the in vivo efficacy of antitumor drugs, however, has been significantly overlooked. Mononuclear phagocyte system (MPS) is the major player in clearance in vivo, and differences in MPS among different strains may potentially impact the effectiveness of antitumor preparations. Therefore, in this study, we employed conventional liposomes (CL-EPI) and SA-ODA modified liposomes (SAL-EPI) as model preparations to investigate the comprehensive tumor therapeutic effects of CL-EPI and SAL-EPI in KM, BALB/c, and C57BL/6 tumor-bearing mice. The results demonstrated significant variability in the efficacy of CL-EPI for tumor treatment across different mouse strains. Therefore, we should pay attention to the selection of animal models in the study of antitumor agents. SAL-EPI effectively targeted tumor sites by binding to Siglec-1 on the surface of peripheral blood monocytes (PBMs), and achieved good therapeutic effect in different mouse strains with little difference in treatment. The SA modified preparation is therefore expected to achieve a favorable therapeutic effect in tumor patients with different immune states through PBMs delivery (Siglec-1 was expressed in both mice and humans), thereby possessing clinical translational value and promising development prospects.


Assuntos
Antineoplásicos , Lipossomos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Ácido N-Acetilneuramínico/química , Ácido N-Acetilneuramínico/administração & dosagem , Camundongos , Linhagem Celular Tumoral , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Feminino , Modelos Animais de Doenças , Especificidade da Espécie
10.
Biomater Adv ; 154: 213606, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37678087

RESUMO

Tumor-associated macrophages (TAMs) in the tumor microenvironment potentially enhance tumor growth and invasion through various mechanisms and are thus an essential factor in tumor immunity. The highly expressed siglec-1 receptors on the surfaces of TAMs are potential targets for cancer drug delivery systems. Sialic acid (SA) is a specific ligand for siglec-1. In this study, the sialic acid-polyethylene glycol conjugate (DSPE-PEG2000-SA) was synthesized to modify the surface of liposomes and target TAMs by interacting with the siglec-1 receptor. Three docetaxel (DTX)-loaded liposomes, conventional (DTX-CL), DSPE-PEG2000-coated (DTX-PL), and DSPE-PEG2000-SA-coated (DTX-SAPL) liposomes, were prepared, with a particle size of <100 nm, uniform polydispersity index (PDI) values, negative zeta potential, and % encapsulation efficiency (EE) exceeding 95 %. Liposomes showed high stability after 3 months of storage at 4 °C without significant changes in particle size, PDI, zeta potential, or % EE. DTX was released from liposomes according to the Weibull model, and DTX-SAPL exhibited more rapid drug release than other liposomes. In vitro studies demonstrated that DTX-SAPL liposome exhibited a higher uptake and cytotoxicity on RAW 264.7 cells (TAM model) and lower toxicity on NIH3T3 cells (normal cell model) than other formulations. The high cell uptake ability was demonstrated by the role of the SA-SA receptor. Biodistribution studies indicated a high tumor accumulation of surface-modified liposomal formulations, particularly SA-modified liposomes, showing high signal accumulation at the tumor periphery, where TAMs were highly concentrated. Ex vivo imaging showed a significantly higher accumulation of SA-modified liposomes in the tumor, kidney, and heart than conventional liposomes. In the anti-cancer efficacy study, DTX-SAPL liposomes showed effective inhibition of tumor growth and relatively low systemic toxicity, as evidenced by the tumor volume, tumor weight, body weight values, and histopathological analysis. Therefore, DSPE-PEG2000-SA-coated liposomes could be promising carriers for DTX delivery targeting TAMs in cancer therapy.


Assuntos
Lipossomos , Neoplasias , Camundongos , Animais , Docetaxel/farmacologia , Lipossomos/uso terapêutico , Ácido N-Acetilneuramínico/uso terapêutico , Macrófagos Associados a Tumor , Células NIH 3T3 , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Distribuição Tecidual , Neoplasias/tratamento farmacológico , Microambiente Tumoral
11.
Elife ; 122023 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-36940134

RESUMO

The immunoglobulin-like lectin receptor CD169 (Siglec-1) mediates the capture of HIV-1 by activated dendritic cells (DCs) through binding to sialylated ligands. These interactions result in a more efficient virus capture as compared to resting DCs, although the underlying mechanisms are poorly understood. Using a combination of super-resolution microscopy, single-particle tracking and biochemical perturbations we studied the nanoscale organization of Siglec-1 on activated DCs and its impact on viral capture and its trafficking to a single viral-containing compartment. We found that activation of DCs leads to Siglec-1 basal nanoclustering at specific plasma membrane regions where receptor diffusion is constrained by Rho-ROCK activation and formin-dependent actin polymerization. Using liposomes with varying ganglioside concentrations, we further demonstrate that Siglec-1 nanoclustering enhances the receptor avidity to limiting concentrations of gangliosides carrying sialic ligands. Binding to either HIV-1 particles or ganglioside-bearing liposomes lead to enhanced Siglec-1 nanoclustering and global actin rearrangements characterized by a drop in RhoA activity, facilitating the final accumulation of viral particles in a single sac-like compartment. Overall, our work provides new insights on the role of the actin machinery of activated DCs in regulating the formation of basal Siglec-1 nanoclustering, being decisive for the capture and actin-dependent trafficking of HIV-1 into the virus-containing compartment.


Assuntos
Infecções por HIV , HIV-1 , Humanos , Células Dendríticas/metabolismo , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , HIV-1/fisiologia , Actinas/metabolismo , Lipossomos/metabolismo , Ligantes , Gangliosídeos/metabolismo
12.
Glycoconj J ; 40(2): 213-223, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36738392

RESUMO

Sialoadhesin (CD169/Siglec-1, Sn) is a macrophage receptor that interacts with sialic acids on both host cells and pathogens. It is a type 1 membrane protein with an unusually large number of 17 extracellular immunoglobulin (Ig)-like domains, made up of an N-terminal V-set domain that binds sialic acid and 16 adjacent C2-set domains. The potential importance of 17 Ig domains in Sn for mediating cellular interactions has not been investigated experimentally. In the present study, Chinese Hamster Ovary (CHO) cells were stably transfected with full-length or truncated forms of Sn. Using human red blood cells (RBC) as a model system, CHO cells expressing truncated forms of Sn with 4 or less Ig domains were unable to bind RBC in comparison to the full-length protein. Immunoelectron microscopy of the CHO cells indicated that full-length Sn extends ~ 33 nm from the plasma membrane compared with ~ 14 nm for a truncated form with 6 N-terminal Ig domains. Co-expresssion of Sn-expressing CHO cells with heavily glycosylated membrane proteins of differing predicted lengths resulted in selective modulation of Sn-dependent binding to RBC and supported the hypothesis that Sn has evolved 17 Ig domains to escape inhibitory cis-interactions. The functional significance of the extended length of Sn was demonstrated in experiments with macrophages showing that Sn synergizes with phagocytic receptors FcR and TIM-4 to strongly promote uptake of IgG-opsonized and eryptotic RBC respectively.


Assuntos
Macrófagos , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Animais , Cricetinae , Humanos , Células CHO , Cricetulus , Macrófagos/metabolismo , Fagocitose , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo
13.
Glycobiology ; 33(3): 215-224, 2023 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-36651496

RESUMO

The monocyte adhesion to endothelial cells is an early step in chronic inflammation. Interferon-γ (IFN-γ) is regarded as a master regulator of inflammation development. However, the significance and mechanisms of IFN-γ in the monocyte adhesion to endothelial cells remains largely unknown. IFN-γ up-regulates PD-L1 on various types of cells. Here, we performed flow cytometry to examine the contribution of IFN-γ-induced PD-L1 expression on monocyte adhesion to endothelial cells. Up-regulation of PD-L1 by IFN-γ enhanced the adhesion of monocytes to endothelial cells. By immunoprecipitation and lectin blot, PD-L1 in endothelial cells interacted with CD169/Siglec 1 in monocytes depending on the α2,3-sialylation of PD-L1. ST3Gal family (ST3ß-galactoside α-2,3-sialyltransferase) was the major glycosyltransferase responsible for the α2,3-sialylation of membrane proteins. Down-regulation of ST3Gal4 by RNAinterference partially reduced the α2,3-sialylation of PD-L1 and the PD-L1-CD169 interaction. Finally, purified PD-L1 protein with α2,3-sialylation, but not PD-L1 protein without α2,3-sialylation, partially reduced IFN-γ-induced monocyte adhesion to endothelial cells. These findings provide evidence that the interaction between PD-L1 and CD169 promoted monocyte adhesion to endothelial cells and might elucidate a new mechanism of monocyte adhesion to endothelial cells.


Assuntos
Células Endoteliais , Monócitos , Humanos , Células Endoteliais/metabolismo , Inflamação , Interferon gama/farmacologia , Interferon gama/metabolismo , Monócitos/metabolismo , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Antígeno B7-H1/metabolismo
14.
Int Rev Immunol ; 42(2): 113-138, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34494938

RESUMO

Siglec-1, also known as Sialoadhesin (Sn) and CD169 is highly conserved among vertebrates and with 17 immunoglobulin-like domains is Siglec-1 the largest member of the Siglec family. Expression of Siglec-1 is found primarily on dendritic cells (DCs), macrophages and interferon induced monocyte. The structure of Siglec-1 is unique among siglecs and its function as a receptor is also different compared to other receptors in this class as it contains the most extracellular domains out of all the siglecs. However, the ability of Siglec-1 to internalize antigens and to pass them on to lymphocytes by allowing dendritic cells and macrophages to act as antigen presenting cells, is the main reason that has granted Siglec-1's key role in multiple human disease states including atherosclerosis, coronary artery disease, autoimmune diseases, cell-cell signaling, immunology, and more importantly bacterial and viral infections. Enveloped viruses for example have been shown to manipulate Siglec-1 to increase their virulence by binding to sialic acids present on the virus glycoproteins allowing them to spread or evade immune response. Siglec-1 mediates dissemination of HIV-1 in activated tissues enhancing viral spread via infection of DC/T-cell synapses. Overall, the ability of Siglec-1 to bind a variety of target cells within the immune system such as erythrocytes, B-cells, CD8+ granulocytes and NK cells, highlights that Siglec-1 is a unique player in these essential processes.


Assuntos
Doenças Transmissíveis , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Animais , Humanos , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Ácidos Siálicos , Imunoglobulinas
15.
AAPS PharmSciTech ; 23(8): 285, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36258152

RESUMO

Breast cancer metastasis is an important cause of death in patients with breast cancer and is closely related to circulating tumor cells (CTCs) and the metastatic microenvironment. As the most infiltrating immune cells in the tumor microenvironment (TME), tumor-associated macrophages (TAMs), which highly express sialic acid (SA) receptor (Siglec-1), are closely linked to tumor progression and metastasis. Furthermore, the surface of CTCs also highly expressed receptor (Selectin) for SA. A targeting ligand (SA-CH), composed of SA and cholesterol, was synthesized and modified on the surface of epirubicin (EPI)-loaded liposomes (EPI-SL) as an effective targeting delivery system. Liposomes were evaluated for characteristics, stability, in vitro release, cytotoxicity, cellular uptake, pharmacokinetics, tumor targeting, and pharmacodynamics. In vivo and in vitro experiments showed that EPI-SL enhanced EPI uptake by TAMs. In addition, cellular experiments showed that EPI-SL could also enhance the uptake of EPI by 4T1 cells, resulting in cytotoxicity second only to that of EPI solution. Pharmacodynamic experiments have shown that EPI-SL has optimal tumor inhibition with minimal toxicity, which can be ascribed to the fact that EPI-SL can deliver drugs to tumor based on TAMs and regulate TME through the depletion of TAMs. Our study demonstrated the significant potential of SA-modified liposomes in antitumor metastasis. Schematic diagram of the role of SA-CH modified EPI-loaded liposomes in the model of breast cancer metastasis.


Assuntos
Neoplasias da Mama , Lipossomos , Humanos , Feminino , Epirubicina/farmacocinética , Ácido N-Acetilneuramínico , Neoplasias da Mama/tratamento farmacológico , Macrófagos Associados a Tumor , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Ligantes , Linhagem Celular Tumoral , Imunoterapia , Colesterol , Microambiente Tumoral , Melanoma Maligno Cutâneo
16.
Xenotransplantation ; 29(6): e12780, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36125388

RESUMO

The phenomenon of diminishing hematocrit after in vivo liver and lung xenotransplantation and during ex vivo liver xenoperfusion has largely been attributed to action by resident liver porcine macrophages, which bind and destroy human erythrocytes. Porcine sialoadhesin (siglec-1) was implicated previously in this interaction. This study examines the effect of porcine genetic modifications, including knockout of the CMAH gene responsible for expression of Neu5Gc sialic acid, on the adhesion of human red blood cells (RBCs) to porcine macrophages. Wild-type (WT) porcine macrophages and macrophages from several strains of genetically engineered pigs, including CMAH gene knockout and several human transgenes (TKO+hTg), were incubated with human RBCs and "rosettes" (≥3 erythrocytes bound to one macrophage) were quantified by microscopy. Our results show that TKO+hTg genetic modifications significantly reduced rosette formation. The monoclonal antibody 1F1, which blocks porcine sialoadhesin, significantly reduced rosette formation by WT and TKO+hTg macrophages compared with an isotype control antibody. Further, desialation of human RBCs with neuraminidase before addition to WT or TKO+hTg macrophages resulted in near-complete abrogation of rosette formation, to a level not significantly different from porcine RBC rosette formation on porcine macrophages. These observations are consistent with rosette formation being mediated by binding of sialic acid on human RBCs to sialoadhesin on porcine macrophages. In conclusion, the data predict that TKO+hTg genetic modifications, coupled with targeting of porcine sialoadhesin by the 1F1 mAb, will attenuate erythrocyte sequestration and anemia during ex vivo xenoperfusion and following in vivo liver, lung, and potentially other organ xenotransplantation.


Assuntos
Ácido N-Acetilneuramínico , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Humanos , Suínos , Animais , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Transplante Heterólogo/métodos , Ácido N-Acetilneuramínico/metabolismo , Macrófagos , Eritrócitos/metabolismo
17.
PLoS One ; 17(7): e0269932, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35802715

RESUMO

Dendritic cells (DCs) promote HIV-1 transmission by acting as Trojan horses, capturing viral particles, facilitating the infection of CD4+ T-cells. Vitamin D (VitD) has shown to decrease T cell activation, reducing susceptibility to HIV-1 infection of CD4+ T-cells in vitro; however, if VitD decreases viral transfer from DCs to CD4+ T-cells is unknown. In this study, we co-cultured HIV-1-pulsed immature and LPS mature monocytes-derived DCs (iDCs and LmDCs, respectively), differentiated in presence or absence of calcitriol (VitD active form), with PHA-activated autologous CD4+ T-cells from 16 healthy donors. In co-cultures of iDCs and LmDCs treated with calcitriol, there was a significant decrease in frequency of infected CD4+ T-cells, evaluated by flow cytometry. However, p24 levels evaluated by ELISA were not significantly reduced in culture supernatants. Moreover, calcitriol-treated iDCs exhibited decreased expression of genes involved in HIV-1 transfer compared to the control. Both, calcitriol-treated iDCs and LmDCs exhibit a similar gene expression profile, probably related to a transcriptional balance achieved after long treatment with calcitriol. Since calcitriol-differentiated DCs express on their surface a lower amount of DC-SIGN and SIGLEC-1 molecules, widely associated with HIV-1 transfer, suggesting that this mechanism contributes to a lower transfer of viral particles by the DCs.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Linfócitos T CD4-Positivos , Calcitriol/farmacologia , Moléculas de Adesão Celular , Células Cultivadas , Células Dendríticas , Infecções por HIV/prevenção & controle , HIV-1/fisiologia , Humanos , Lectinas Tipo C , Monócitos , Receptores de Superfície Celular , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico
18.
Front Cell Infect Microbiol ; 12: 919097, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35865810

RESUMO

Immunotherapy is a promising therapeutic area in cancer and chronic viral infections. An important component of immunotherapy in these contexts is the activation of innate immunity. Here we investigate the potential for CD169 (Siglec 1) expression on monocytes to serve as a robust biomarker for activation of innate immunity and, particular, as a proxy for IFN-α production. Specifically, we investigated the effects of Toll-like receptor 9 agonism with MGN1703 (lefitolimod) across experimental conditions ex vivo, in humanized mice, and in clinical trial participants. Ex vivo we observed that the percentage of classical monocytes expressing CD169 increased dramatically from 10% pre-stimulation to 97% 24 hrs after MGN1703 stimulation (p<0.0001). In humanized NOG mice, we observed prominent upregulation of the proportions of monocytes expressing CD169 after two doses of MGN1703 where 73% of classical monocytes were CD169 positive in bone marrow following MGN1703 treatment vs 19% in vehicle treated mice (p=0.0159). Finally, in a clinical trial in HIV-infected individuals receiving immunotherapy treatment with MGN1703, we observed a uniform upregulation of CD169 on monocytes after dosing with 97% of classical monocytes positive for CD169 (p=0.002). Hence, in this comprehensive evaluation ex vivo, in an animal model, and in a clinical trial, we find increases in the percentage of CD169 positive monocytes to be a reliable and robust biomarker of immune activation following TLR9 agonist treatment.


Assuntos
Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Receptor Toll-Like 9 , Adjuvantes Imunológicos , Animais , Biomarcadores , Humanos , Fatores Imunológicos/uso terapêutico , Imunoterapia , Camundongos , Receptor Toll-Like 9/agonistas , Receptor Toll-Like 9/metabolismo
19.
Front Immunol ; 13: 799598, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35757750

RESUMO

Microbiota is essential to the development and functional maturation of the immune system. The effects of the gut microbiota on myeloid cells remote from the gut, especially the skin remain unclear. Transcriptomic analysis revealed that type I interferon (IFN) signaling was down-regulated in the skin of germ-free mice compared to that in specific pathogen-free mice. The decrease in type I IFN signaling was closely related to the presence of microbiota and macrophage-specific marker CD169. The absence of CD169+ macrophages resulted in increased bacterial burden and impaired immune responses against Staphylococcus aureus skin infection. CD169+ macrophages mediated the recruitment of γδ T cells as well as the activation of γδ T cells via interleukin (IL)-23. Our findings demonstrate the role of the microbiota in establishment of a specific myeloid cell subset expressing CD169 in the skin and provide evidence of a specific mechanism by which this subset protects against bacterial skin infection.


Assuntos
Microbiota , Dermatopatias Bacterianas , Infecções Estafilocócicas , Animais , Macrófagos , Camundongos , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Pele/microbiologia
20.
Gut Microbes ; 14(1): 2064706, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35442154

RESUMO

Campylobacter jejuni is a leading cause of gastroenteritis that has been causally linked with development of the autoimmune peripheral neuropathy Guillain Barré Syndrome (GBS). Previously, we showed that C. jejuni isolates from human enteritis patients induced Type1/17-cytokine dependent colitis in interleukin-10 (IL-10)-/- mice, while isolates from GBS patients colonized these mice without colitis but instead induced autoantibodies that cross-reacted with the sialylated oligosaccharide motifs on the LOS of GBS-associated C. jejuni and the peripheral nerve gangliosides. We show here that infection of IL-10-/- mice with the GBS but not the colitis isolate led to sciatic nerve inflammation and abnormal gait and hind limb movements, with character and timing consistent with this syndrome in humans. Autoantibody responses and associated nerve histologic changes were dependent on IL-4 production by CD4 T cells. We further show that Siglec-1 served as a central antigen presenting cell receptor mediating the uptake of the GBS isolates via interaction with the sialylated oligosaccharide motifs found specifically on the LOS of GBS-associated C. jejuni, and the ensuing T cell differentiation and autoantibody elicitation. Sialylated oligosaccharide motifs on the LOS of GBS-associated C. jejuni therefore acted as both the Siglec-1-ligand for phagocytosis, as well as the epitope for autoimmunity. Overall, we present a mouse model of an autoimmune disease induced directly by a bacterium that is dependent upon Siglec-1 and IL-4. We also demonstrate the negative regulatory role of IL-10 in C. jejuni induced autoimmunity and provide IL-4 and Siglec-1 blockade as potential therapeutic interventions against GBS.


Assuntos
Infecções por Campylobacter , Campylobacter jejuni , Colite , Microbioma Gastrointestinal , Síndrome de Guillain-Barré , Animais , Autoanticorpos , Infecções por Campylobacter/microbiologia , Campylobacter jejuni/genética , Colite/microbiologia , Síndrome de Guillain-Barré/etiologia , Síndrome de Guillain-Barré/patologia , Humanos , Interleucina-10/genética , Interleucina-4 , Lipopolissacarídeos , Camundongos , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico
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