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1.
Nat Commun ; 11(1): 6352, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33311518

RESUMO

Immunosuppressive molecules are extremely valuable prognostic biomarkers across different cancer types. However, the diversity of different immunosuppressive molecules makes it very difficult to accurately predict clinical outcomes based only on a single immunosuppressive molecule. Here, we establish a comprehensive immune scoring system (ISSGC) based on 6 immunosuppressive ligands (NECTIN2, CEACAM1, HMGB1, SIGLEC6, CD44, and CD155) using the LASSO method to improve prognostic accuracy and provide an additional selection strategy for adjuvant chemotherapy of gastric cancer (GC). The results show that ISSGC is an independent prognostic factor and a supplement of TNM stage for GC patients, and it can improve their prognosis prediction accuracy; in addition, it can distinguish GC patients with better prognosis from those with high prognostic nutritional index score; furthermore, ISSGC can also be used as a tool to select GC patients who would benefit from adjuvant chemotherapy independent of their TNM stages, MSI status and EBV status.


Assuntos
Biomarcadores Tumorais/metabolismo , Quimioterapia Adjuvante/métodos , Proteína HMGB1/metabolismo , Neoplasias Gástricas/imunologia , Idoso , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Moléculas de Adesão Celular/metabolismo , Feminino , Humanos , Receptores de Hialuronatos/metabolismo , Lectinas/metabolismo , Masculino , Pessoa de Meia-Idade , Nectinas/metabolismo , Estadiamento de Neoplasias , Prognóstico , Receptores Virais/metabolismo , Neoplasias Gástricas/patologia , Fatores de Tempo
2.
Proc Natl Acad Sci U S A ; 117(41): 25759-25770, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32994342

RESUMO

Human coronaviruses OC43 and HKU1 are respiratory pathogens of zoonotic origin that have gained worldwide distribution. OC43 apparently emerged from a bovine coronavirus (BCoV) spillover. All three viruses attach to 9-O-acetylated sialoglycans via spike protein S with hemagglutinin-esterase (HE) acting as a receptor-destroying enzyme. In BCoV, an HE lectin domain promotes esterase activity toward clustered substrates. OC43 and HKU1, however, lost HE lectin function as an adaptation to humans. Replaying OC43 evolution, we knocked out BCoV HE lectin function and performed forced evolution-population dynamics analysis. Loss of HE receptor binding selected for second-site mutations in S, decreasing S binding affinity by orders of magnitude. Irreversible HE mutations led to cooperativity in virus swarms with low-affinity S minority variants sustaining propagation of high-affinity majority phenotypes. Salvageable HE mutations induced successive second-site substitutions in both S and HE. Apparently, S and HE are functionally interdependent and coevolve to optimize the balance between attachment and release. This mechanism of glycan-based receptor usage, entailing a concerted, fine-tuned activity of two envelope protein species, is unique among CoVs, but reminiscent of that of influenza A viruses. Apparently, general principles fundamental to virion-sialoglycan interactions prompted convergent evolution of two important groups of human and animal pathogens.


Assuntos
Coronavirus/fisiologia , Hemaglutininas Virais/genética , Glicoproteína da Espícula de Coronavírus/genética , Proteínas Virais de Fusão/genética , Vírion/metabolismo , Animais , Evolução Biológica , Linhagem Celular , Coronavirus/genética , Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Coronavirus Humano OC43/genética , Coronavirus Humano OC43/metabolismo , Coronavirus Humano OC43/fisiologia , Coronavirus Bovino/genética , Coronavirus Bovino/metabolismo , Coronavirus Bovino/fisiologia , Hemaglutininas Virais/química , Hemaglutininas Virais/metabolismo , Humanos , Lectinas/genética , Lectinas/metabolismo , Camundongos , Mutação , Ligação Proteica , Domínios Proteicos , Receptores Virais/metabolismo , Seleção Genética , Ácidos Siálicos/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/metabolismo , Vírion/genética , Ligação Viral , Liberação de Vírus
3.
Nat Commun ; 11(1): 4646, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938911

RESUMO

The human betacoronaviruses HKU1 and OC43 (subgenus Embecovirus) arose from separate zoonotic introductions, OC43 relatively recently and HKU1 apparently much longer ago. Embecovirus particles contain two surface projections called spike (S) and haemagglutinin-esterase (HE), with S mediating receptor binding and membrane fusion, and HE acting as a receptor-destroying enzyme. Together, they promote dynamic virion attachment to glycan-based receptors, specifically 9-O-acetylated sialic acid. Here we present the cryo-EM structure of the ~80 kDa, heavily glycosylated HKU1 HE at 3.4 Å resolution. Comparison with existing HE structures reveals a drastically truncated lectin domain, incompatible with sialic acid binding, but with the structure and function of the esterase domain left intact. Cryo-EM and mass spectrometry analysis reveals a putative glycan shield on the now redundant lectin domain. The findings further our insight into the evolution and host adaptation of human embecoviruses, and demonstrate the utility of cryo-EM for studying small, heavily glycosylated proteins.


Assuntos
Betacoronavirus/química , Betacoronavirus/fisiologia , Infecções por Coronavirus/virologia , Hemaglutininas Virais/química , Proteínas Virais de Fusão/química , Betacoronavirus/classificação , Sítios de Ligação , Domínio Catalítico , Microscopia Crioeletrônica , Glicosilação , Células HEK293 , Hemaglutininas Virais/metabolismo , Hemaglutininas Virais/ultraestrutura , Humanos , Lectinas/química , Lectinas/metabolismo , Espectrometria de Massas , Modelos Moleculares , Ácido N-Acetilneuramínico/metabolismo , Polissacarídeos/química , Domínios Proteicos , Proteínas Virais de Fusão/metabolismo , Proteínas Virais de Fusão/ultraestrutura
4.
PLoS One ; 15(9): e0238347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32870938

RESUMO

Highly exposed seronegative (HESN) individuals present a unique setting to study mechanisms of protection against HIV acquisition. As natural killer (NK) cell activation and function have been implicated as a correlate of protection in HESN individuals, we sought to better understand the features of NK cells that may confer protection. We used mass cytometry to phenotypically profile NK cells from a cohort of Beninese sex workers and healthy controls. We found that NK cells from HESN women had increased expression of NKG2A, NKp30 and LILRB1, as well as the Fc receptor CD16, and decreased expression of DNAM-1, CD94, Siglec-7, and NKp44. Using functional assessments of NK cells from healthy donors against autologous HIV-infected CD4+ T cells, we observed that NKp30+ and Siglec-7+ cells had improved functional activity. Further, we found that NK cells from HESN women trended towards increased antibody-dependent cellular cytotoxicity (ADCC) activity; this activity correlated with increased CD16 expression. Overall, we identify features of NK cells in HESN women that may contribute to protection from HIV infection. Follow up studies with larger cohorts are warranted to confirm these findings.


Assuntos
Infecções por HIV/patologia , Células Matadoras Naturais/metabolismo , Adulto , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antígenos de Diferenciação Mielomonocítica/metabolismo , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Genótipo , Infecções por HIV/imunologia , Humanos , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Lectinas/metabolismo , Modelos Lineares , Receptor 3 Desencadeador da Citotoxicidade Natural/metabolismo , Fenótipo , Receptores de IgG/genética , Receptores de IgG/metabolismo , Profissionais do Sexo
5.
Yonsei Med J ; 61(8): 720-725, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32734736

RESUMO

Lectin-like oxidized low-density lipoprotein (LDL) receptor 1 (LOX1) binds to oxidized LDL, which is associated with inflammation in various vascular disorders. Here, we aimed to investigate the potential of soluble LOX1 (sLOX1) as an indicator of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) activity. Serum levels of sLOX1 in frozen samples from patients with AAV enrolled in a prospective observational cohort study at the Severance Hospital were measured using enzyme-linked immunosorbent assay. Clinical and laboratory data were collected on the date when the blood sampling was performed. The association between sLOX1 and clinical and laboratory data was assessed using Pearson's correlation analysis. The median age of the recruited 79 patients was 62.0 years, and 27 (34.2%) patients were men. The median Birmingham vasculitis activity score (BVAS), five-factor score, vasculitis damage index, and sLOX1 level were 6, 1, 3, and 911.9 pg/mL, respectively. Correlation analysis based on BVAS revealed that sLOX1 and total cholesterol were significantly inversely correlated with BVAS (r=-0.224, p=0.047 and r=-0.424, p<0.001, respectively). No significant correlations were observed between continuous variables and sLOX1 except for BVAS, although total cholesterol tended to correlate with sLOX1 (r=0.190, p=0.093). Additionally, sLOX1 was not influenced by sex, hypertension, diabetes mellitus, or the presence of pulmonary, cardiovascular, and renal involvement of AAV. In summary, sLOX1 was inversely correlated with BVAS in AAV patients, which is different from other vascular diseases or inflammatory diseases.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/sangue , Lectinas/metabolismo , Receptores Depuradores Classe E/sangue , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Solubilidade
6.
Nat Commun ; 11(1): 3546, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669559

RESUMO

Advanced ovarian cancer usually spreads to the omentum. However, the omental cell-derived molecular determinants modulating its progression have not been thoroughly characterized. Here, we show that circulating ITLN1 has prognostic significance in patients with advanced ovarian cancer. Further studies demonstrate that ITLN1 suppresses lactotransferrin's effect on ovarian cancer cell invasion potential and proliferation by decreasing MMP1 expression and inducing a metabolic shift in metastatic ovarian cancer cells. Additionally, ovarian cancer-bearing mice treated with ITLN1 demonstrate marked decrease in tumor growth rates. These data suggest that downregulation of mesothelial cell-derived ITLN1 in the omental tumor microenvironment facilitates ovarian cancer progression.


Assuntos
Carcinoma Epitelial do Ovário/secundário , Citocinas/metabolismo , Lectinas/metabolismo , Omento/patologia , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/secundário , Animais , Carcinoma Epitelial do Ovário/sangue , Carcinoma Epitelial do Ovário/mortalidade , Carcinoma Epitelial do Ovário/terapia , Linhagem Celular Tumoral/transplante , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Citocinas/administração & dosagem , Citocinas/sangue , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Proteínas Ligadas por GPI/administração & dosagem , Proteínas Ligadas por GPI/sangue , Proteínas Ligadas por GPI/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Lactoferrina/metabolismo , Lectinas/administração & dosagem , Lectinas/sangue , Metaloproteinase 1 da Matriz/metabolismo , Camundongos , Invasividade Neoplásica/patologia , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/terapia , Ovário , Proteínas Recombinantes/administração & dosagem , Taxa de Sobrevida , Microambiente Tumoral
7.
Int J Mol Sci ; 21(12)2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32604730

RESUMO

The recently emerged SARS-CoV-2 is the cause of the global health crisis of the coronavirus disease 2019 (COVID-19) pandemic. No evidence is yet available for CoV infection into hosts upon zoonotic disease outbreak, although the CoV epidemy resembles influenza viruses, which use sialic acid (SA). Currently, information on SARS-CoV-2 and its receptors is limited. O-acetylated SAs interact with the lectin-like spike glycoprotein of SARS CoV-2 for the initial attachment of viruses to enter into the host cells. SARS-CoV-2 hemagglutinin-esterase (HE) acts as the classical glycan-binding lectin and receptor-degrading enzyme. Most ß-CoVs recognize 9-O-acetyl-SAs but switched to recognizing the 4-O-acetyl-SA form during evolution of CoVs. Type I HE is specific for the 9-O-Ac-SAs and type II HE is specific for 4-O-Ac-SAs. The SA-binding shift proceeds through quasi-synchronous adaptations of the SA-recognition sites of the lectin and esterase domains. The molecular switching of HE acquisition of 4-O-acetyl binding from 9-O-acetyl SA binding is caused by protein-carbohydrate interaction (PCI) or lectin-carbohydrate interaction (LCI). The HE gene was transmitted to a ß-CoV lineage A progenitor by horizontal gene transfer from a 9-O-Ac-SA-specific HEF, as in influenza virus C/D. HE acquisition, and expansion takes place by cross-species transmission over HE evolution. This reflects viral evolutionary adaptation to host SA-containing glycans. Therefore, CoV HE receptor switching precedes virus evolution driven by the SA-glycan diversity of the hosts. The PCI or LCI stereochemistry potentiates the SA-ligand switch by a simple conformational shift of the lectin and esterase domains. Therefore, examination of new emerging viruses can lead to better understanding of virus evolution toward transitional host tropism. A clear example of HE gene transfer is found in the BCoV HE, which prefers 7,9-di-O-Ac-SAs, which is also known to be a target of the bovine torovirus HE. A more exciting case of such a switching event occurs in the murine CoVs, with the example of the ß-CoV lineage A type binding with two different subtypes of the typical 9-O-Ac-SA (type I) and the exclusive 4-O-Ac-SA (type II) attachment factors. The protein structure data for type II HE also imply the virus switching to binding 4-O acetyl SA from 9-O acetyl SA. Principles of the protein-glycan interaction and PCI stereochemistry potentiate the SA-ligand switch via simple conformational shifts of the lectin and esterase domains. Thus, our understanding of natural adaptation can be specified to how carbohydrate/glycan-recognizing proteins/molecules contribute to virus evolution toward host tropism. Under the current circumstances where reliable antiviral therapeutics or vaccination tools are lacking, several trials are underway to examine viral agents. As expected, structural and non-structural proteins of SARS-CoV-2 are currently being targeted for viral therapeutic designation and development. However, the modern global society needs SARS-CoV-2 preventive and therapeutic drugs for infected patients. In this review, the structure and sialobiology of SARS-CoV-2 are discussed in order to encourage and activate public research on glycan-specific interaction-based drug creation in the near future.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/virologia , Evolução Molecular , Interações entre Hospedeiro e Microrganismos/fisiologia , Pneumonia Viral/virologia , Receptores Virais/metabolismo , Internalização do Vírus , Acetilesterase/metabolismo , Animais , Betacoronavirus/genética , Sítios de Ligação , Linhagem Celular , Coronavirus/genética , Esterases , Transferência Genética Horizontal , Glicosaminoglicanos/metabolismo , Hemaglutininas Virais/genética , Humanos , Lectinas/metabolismo , Pandemias , Polissacarídeos , Receptores Virais/química , Ácidos Siálicos/química , Ácidos Siálicos/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/fisiologia , Torovirus , Proteínas Virais de Fusão/genética
8.
Int J Mol Sci ; 21(11)2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32503354

RESUMO

Monoclonal antibodies, engineered antibodies, and antibody fragments have become important biological therapeutic platforms. The IgG format with bivalent binding sites has a modular structure with different biological roles, i.e., effector and binding functions, in different domains. We demonstrated the reconstruction of an IgG-like domain structure in vitro by protein ligation using protein trans-splicing. We produced various binding domains to replace the binding domain of IgG from Escherichia coli and the Fc domain of human IgG from Brevibacillus choshinensis as split-intein fusions. We showed that in vitro protein ligation could produce various Fc-fusions at the N-terminus in vitro from the independently produced domains from different organisms. We thus propose an off-the-shelf approach for the combinatorial production of Fc fusions in vitro with several distinct binding domains, particularly from naturally occurring binding domains. Antiviral lectins from algae are known to inhibit virus entry of HIV and SARS coronavirus. We demonstrated that a lectin could be fused with the Fc-domain in vitro by protein ligation, producing an IgG-like molecule as a "lectibody". Such an Fc-fusion could be produced in vitro by this approach, which could be an attractive method for developing potential therapeutic agents against rapidly emerging infectious diseases like SARS coronavirus without any genetic fusion and expression optimization.


Assuntos
Fragmentos Fc das Imunoglobulinas/metabolismo , Lectinas/metabolismo , Trans-Splicing , Brevibacillus/imunologia , Clorófitas/metabolismo , HIV/fisiologia , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Imunoglobulina G/química , Imunoglobulina G/metabolismo , Lectinas/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Vírus da SARS/fisiologia , Internalização do Vírus/efeitos dos fármacos
9.
Food Chem ; 329: 127183, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32521427

RESUMO

Combined effects of pH and thermal treatments on black kidney bean lectin (BKBL) were investigated by response surface methodology (RSM). Low-pH (1.0, 2.0, 3.0) incubation decreased hemagglutination activity (HA) and IgE-binding capacity, but the activities would be restored when the lectin was treated by pH shifting to 7.2. Conformational structure analyses indicated that low-pH induced protein unfolding and pH-shifting treatment resulted in a limited structural rearrangement. Mild heating, such as 60 °C for 3 min, slightly increased the HA and IgE-binding activities of pH shifted BKBL, but no obvious effects in the pH 1.0 incubated BKBL. High-temperature and long-time treatment might induce the protein aggregation, further decreased HA and IgE-binding capacities. RSM results showed both IgE-binding capacity and HA were the lowest under the combination of pH 1.0 incubation with 80 °C heating for 15 min or pH shifting from 1.0 to 7.2 with 100 °C heating for 10 min.


Assuntos
Imunoglobulina E/metabolismo , Lectinas/química , Phaseolus/metabolismo , Dicroísmo Circular , Temperatura Alta , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lectinas/metabolismo , Agregados Proteicos , Conformação Proteica em alfa-Hélice , Estrutura Terciária de Proteína , Espectrometria de Fluorescência
10.
Mol Carcinog ; 59(7): 713-723, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32391973

RESUMO

Chimeric antigen receptor (CAR) T-cells treatment demonstrate the increasing and powerful potential of immunotherapeutic strategies, as seen mainly for hematological malignancies. Still, efficient CAR-T cell approaches for the treatment of a broader spectrum of tumors are needed. It has been shown that cancer cells can implement strategies to evade immune response that include the expression of inhibitory ligands, such as hypersialylated proteins (sialoglycans) on their surface. These may be recognized by sialic acid-binding immunoglobulin-type lectins (siglecs) which are surface receptors found primarily on immune cells. In this regard, siglec-7 and -9 are found on immune cells, such as natural killer cells, T-cells, and dendritic cells and they can promote immune suppression when binding to sialic acids expressed on target cells. In the present study, we hypothesized that it is possible to use genetically engineered T-cells expressing siglec-based CARs, enabling them to recognize and eliminate tumor cells, in a non-histocompatibility complex molecule restricted way. Thus, we genetically modified human T-cells with different chimeric receptors based on the exodomain of human siglec-7 and -9 molecules and selected optimal receptors. We then assessed their antitumor activity in vitro demonstrating the recognition of cell lines from different histologies. These results were confirmed in a tumor xenograft model exemplifying the potential of the present approach. Overall, this study demonstrates the benefit of targeting cancer-associated glycosylation patterns using CAR based on native immune receptors and expressed in human primary T-cells.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Lectinas/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Linfócitos T/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Glicosilação , Células HEK293 , Células HeLa , Xenoenxertos/metabolismo , Humanos , Células Jurkat , Células K562 , Leucócitos Mononucleares/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID
11.
BMC Cardiovasc Disord ; 20(1): 214, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375640

RESUMO

BACKGROUND: Epicardial adipose tissue (EAT) remodeling and adipocytokines are associated with structural remodeling in atrial fibrillation (AF). However, the role of omentin-1, a novel adipocytokine, in structural remodeling remains unknown. METHODS: Hematoxylin and eosin (H&E) and Masson's trichrome stains were used to investigate the histology of EAT and right atrial appendages. The expression levels of adipocytokines in these human samples were determined by immunohistochemical assay and western blotting. Models of transforming growth factor (TGF)-ß1-induced activation of cardiac fibroblasts (CFs) and TGF-ß1-induced endothelial-mesenchymal transition (EndMT) of human umbilical vein endothelial cell (HUVEC) were established to explore roles of omentin-1 in these processes. To determine changes in adipocytokines secretion under hypoxia conditions, adipocytes were treated with 5% O2 and 95% N2, and then CFs and HUVECs were co-cultured with the conditioned medium of adipocytes to determine the effects of hypoxia-treated adipocytes on these cells. RESULTS: Expression of omentin-1 was downregulated in the EAT and right atrial appendages from patients with AF compared to samples from patients without AF, while the TGF-ß1 level was upregulated in EAT from patients with AF. EAT from patients with AF exhibited adipocyte hypertrophy and severe interstitial fibrosis. Omentin-1 inhibited TGF-ß1-induced CF activation and reversed TGF-ß1-induced HUVEC EndMT. Adipocytes treated with hypoxia exhibited downregulation of omentin-1 and partly activated CFs. CONCLUSIONS: This study demonstrated that omentin-1 was an antifibrotic adipocytokine and was downregulated in patients with AF, which was partly mediated by hypoxia.


Assuntos
Adipócitos/metabolismo , Fibrilação Atrial/metabolismo , Citocinas/metabolismo , Doenças das Valvas Cardíacas/metabolismo , Lectinas/metabolismo , Comunicação Parácrina , Células 3T3-L1 , Adipócitos/patologia , Adulto , Idoso , Animais , Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Hipóxia Celular , Técnicas de Cocultura , Transição Epitelial-Mesenquimal , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Proteínas Ligadas por GPI/metabolismo , Doenças das Valvas Cardíacas/patologia , Doenças das Valvas Cardíacas/fisiopatologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Ratos , Transdução de Sinais , Fator de Crescimento Transformador beta1/metabolismo , Função Ventricular Esquerda , Remodelação Ventricular
12.
Nat Commun ; 11(1): 2265, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32404934

RESUMO

The mucosal epithelium secretes a host of protective disulfide-rich peptides, including the trefoil factors (TFFs). The TFFs increase the viscoelasticity of the mucosa and promote cell migration, though the molecular mechanisms underlying these functions have remained poorly defined. Here, we demonstrate that all TFFs are divalent lectins that recognise the GlcNAc-α-1,4-Gal disaccharide, which terminates some mucin-like O-glycans. Degradation of this disaccharide by a glycoside hydrolase abrogates TFF binding to mucins. Structural, mutagenic and biophysical data provide insights into how the TFFs recognise this disaccharide and rationalise their ability to modulate the physical properties of mucus across different pH ranges. These data reveal that TFF activity is dependent on the glycosylation state of mucosal glycoproteins and alludes to a lectin function for trefoil domains in other human proteins.


Assuntos
Lectinas/metabolismo , Muco/metabolismo , Fator Trefoil-1/metabolismo , Fator Trefoil-3/metabolismo , Cristalografia por Raios X , Dissacarídeos/metabolismo , Glicosídeo Hidrolases/metabolismo , Humanos , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Espectrometria de Massas , Mucinas/metabolismo , Filogenia , Polissacarídeos/metabolismo , Fator Trefoil-1/química , Fator Trefoil-1/genética , Fator Trefoil-3/química , Fator Trefoil-3/genética
13.
Proc Natl Acad Sci U S A ; 117(22): 11931-11939, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32424105

RESUMO

Cell surfaces are often decorated with glycoconjugates that contain linear and more complex symmetrically and asymmetrically branched carbohydrates essential for cellular recognition and communication processes. Mannose is one of the fundamental building blocks of glycans in many biological membranes. Moreover, oligomannoses are commonly found on the surface of pathogens such as bacteria and viruses as both glycolipids and glycoproteins. However, their mechanism of action is not well understood, even though this is of great potential interest for translational medicine. Sequence-defined amphiphilic Janus glycodendrimers containing simple mono- and disaccharides that mimic glycolipids are known to self-assemble into glycodendrimersomes, which in turn resemble the surface of a cell by encoding carbohydrate activity via supramolecular multivalency. The synthetic challenge of preparing Janus glycodendrimers containing more complex linear and branched glycans has so far prevented access to more realistic cell mimics. However, the present work reports the use of an isothiocyanate-amine "click"-like reaction between isothiocyanate-containing sequence-defined amphiphilic Janus dendrimers and either linear or branched oligosaccharides containing up to six monosaccharide units attached to a hydrophobic amino-pentyl linker, a construct not expected to assemble into glycodendrimersomes. Unexpectedly, these oligoMan-containing dendrimers, which have their hydrophobic linker connected via a thiourea group to the amphiphilic part of Janus glycodendrimers, self-organize into nanoscale glycodendrimersomes. Specifically, the mannose-binding lectins that best agglutinate glycodendrimersomes are those displaying hexamannose. Lamellar "raft-like" nanomorphologies on the surface of glycodendrimersomes, self-organized from these sequence-defined glycans, endow these membrane mimics with high biological activity.


Assuntos
Biomimética/métodos , Dendrímeros/síntese química , Glicoconjugados/síntese química , Nanopartículas/química , Membrana Celular/química , Glicolipídeos/química , Interações Hidrofóbicas e Hidrofílicas , Isotiocianatos/metabolismo , Lectinas/metabolismo , Manose/metabolismo , Oligossacarídeos/metabolismo , Polissacarídeos/metabolismo , Pesquisa Médica Translacional/métodos
14.
Am J Pathol ; 190(7): 1530-1544, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32246920

RESUMO

HIV-associated sensory neuropathy is a common neurologic comorbidity of HIV infection and prevails in the post-antiretroviral therapy (ART) era. HIV infection drives pathologic changes in the dorsal root ganglia (DRG) through inflammation, altered metabolism, and neuronal dysfunction. Herein, we characterized specific neuronal populations in an SIV-infected macaque model with or without ART. DRG neuronal populations were identified by neurofilament H-chain 200, I-B4 isolectin (IB4), or tropomyosin receptor kinase A expression and assessed for cell body diameter, population size, apoptotic markers, and regeneration signaling. IB4+ and tropomyosin receptor kinase A-positive neurons showed a reduced cell body size (atrophy) and decreased population size (cell death) in the DRG of SIV-infected animals compared with uninfected animals. IB4+ nonpeptidergic neurons were less affected in the presence of ART. DRG neurons showed accumulation of cleaved caspase 3 (apoptosis) and nuclear-localized activating transcription factor 3 (regeneration) in SIV infection, which was significantly lower in uninfected animals and SIV-infected animals receiving ART. Nonpeptidergic neurons predominantly colocalized with cleaved caspase 3 staining. Nonpeptidergic and peptidergic neurons colocalized with nuclear-accumulated activating transcription factor 3, showing active regeneration in sensory neurons. These data suggest that nonpeptidergic and peptidergic neurons are susceptible to pathologic changes from SIV infection, and intervention with ART did not fully ameliorate damage to the DRG, specifically to peptidergic neurons.


Assuntos
Atrofia/patologia , Nociceptores/patologia , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Animais , Antirretrovirais/farmacologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/patologia , Lectinas/metabolismo , Macaca mulatta , Masculino , Nociceptores/efeitos dos fármacos , Nociceptores/metabolismo , Polineuropatias/patologia , Polineuropatias/virologia , Receptor trkA/metabolismo , Vírus da Imunodeficiência Símia
15.
Scand J Immunol ; 92(1): e12882, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32243627

RESUMO

Intelectin (ITLN) is a new type of glycan-binding lectin. It has been demonstrated to agglutinate bacteria probably due to its carbohydrate-binding capacity, suggesting its role in an innate immune response. It is involved not only in many physiological processes but also in some human diseases such as asthma, heart disease, inflammatory bowel disease, chronic obstructive pulmonary disease and cancer. Up to now, intelectin orthologs have been identified in placozoans, urochordatas, cephalochordates and several vertebrates, such as cyclostomata, fish, amphibians and mammals. Although the sequences of intelectins in different species are conserved, their expression patterns, quaternary structures and functions differ considerably among and within species. We summarize the evolution of the intelectin gene family, the tissue distribution, structure and functions of intelectins. We conclude that intelectin plays a role in innate immune response and there are still potential functions of intelectin awaiting discovery.


Assuntos
Bactérias/imunologia , Citocinas/genética , Citocinas/metabolismo , Imunidade Inata/imunologia , Lectinas/genética , Lectinas/metabolismo , Reconhecimento Fisiológico de Modelo/fisiologia , Sequência de Aminoácidos , Animais , Citocinas/farmacocinética , Evolução Molecular , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Proteínas Ligadas por GPI/farmacocinética , Humanos , Lectinas/farmacocinética , Estrutura Secundária de Proteína , Alinhamento de Sequência , Distribuição Tecidual/fisiologia
16.
PLoS One ; 15(4): e0230411, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32267878

RESUMO

BACKGROUND: Cancer patients who undergo tumor removal, and reconstructive surgery by transfer of a free tissue flap, are at high risk of surgical site infection and ischemia-reperfusion injury. Complement activation through the lectin pathway (LP) may contribute to ischemia-reperfusion injury. Remote ischemic preconditioning (RIPC) is a recent experimental treatment targeting ischemia-reperfusion injury. The study aims were to investigate LP protein plasma levels in head and neck cancer patients compared with healthy individuals, to explore whether RIPC affects LP protein levels in head and neck cancer surgery, and finally to examine the association between postoperative LP protein levels and the risk of surgical site infection. METHODS: Head and neck cancer patients (n = 60) undergoing tumor resection and reconstructive surgery were randomized 1:1 to RIPC or sham intervention administered intraoperatively. Blood samples were obtained preoperatively, 6 hours after RIPC/sham, and on the first postoperative day. LP protein plasma levels were measured utilizing time-resolved immunofluorometric assays. RESULTS: H-ficolin and M-ficolin levels were significantly increased in cancer patients compared with healthy individuals (both P ≤ 0.02). Conversely, mannan-binding lectin (MBL)-associated serine protease (MASP)-1, MASP-3, collectin liver-1 (CL-L1), and MBL-associated protein of 44 kilodalton (MAp44) levels were decreased in cancer patients compared with healthy individuals (all P ≤ 0.04). A significant reduction in all LP protein levels was observed after surgery (all P < 0.001); however, RIPC did not affect LP protein levels. No difference was demonstrated in postoperative LP protein levels between patients who developed surgical site infection and patients who did not (all P > 0.13). CONCLUSIONS: The LP was altered in head and neck cancer patients. LP protein levels were reduced after surgery, but intraoperative RIPC did not influence the LP. Postoperative LP protein levels were not associated with surgical site infection.


Assuntos
Neoplasias de Cabeça e Pescoço , Precondicionamento Isquêmico , Lectinas/metabolismo , Serina Proteases Associadas a Proteína de Ligação a Manose/metabolismo , Infecção da Ferida Cirúrgica/complicações , Feminino , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Traumatismo por Reperfusão/patologia
17.
Sci Rep ; 10(1): 6652, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313043

RESUMO

The role of Mesenchymal-endothelial transition (MEndoT) in cardiac hypertrophy is unclear. To determine the difference between MEndoT-derived and coronary endothelial cells is essential for understanding the revascularizing strategy in cardiac repair. Using lineage tracing we demonstrated that MEndoT-derived cells exhibit highly heterogeneous which were characterized with highly expression of endothelial markers such as vascular endothelial cadherin(VECAD) and occludin but low expression of Tek receptor tyrosine kinase(Tek), isolectin B4, endothelial nitric oxide synthase(eNOS), von Willebrand factor(vWF), and CD31 after cardiac hypertrophy. RNA-sequencing showed altered expression of fibroblast lineage commitment genes in fibroblasts undergoing MEndoT. Compared with fibroblasts, the expression of p53 and most endothelial lineage commitment genes were upregulated in MEndoT-derived cells; however, the further analysis indicated that MEndoT-derived cells may represent an endothelial-like cell sub-population. Loss and gain function study demonstrated that MEndoT-derived cells are substantial sources of neovascularization, which can be manipulated to attenuate cardiac hypertrophy and preserve cardiac function by improving the expression of endothelial markers in MEndoT-derived cells. Moreover, fibroblasts undergoing MEndoT showed significantly upregulated anti-hypertrophic factors and downregulated pro-hypertrophic factors. Therefore MEndoT-derived cells are an endothelial-like cell population that can be regulated to treat cardiac hypertrophy by improving neovascularization and altering the paracrine effect of fibroblasts.


Assuntos
Cardiomegalia/genética , Células Endoteliais/metabolismo , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Células-Tronco Mesenquimais/metabolismo , Neovascularização Fisiológica/genética , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/genética , Caderinas/metabolismo , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Linhagem da Célula/genética , Rastreamento de Células , Transdiferenciação Celular/genética , Modelos Animais de Doenças , Células Endoteliais/patologia , Fibroblastos/patologia , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Lectinas/genética , Lectinas/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Ocludina/genética , Ocludina/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Receptor TIE-2/genética , Receptor TIE-2/metabolismo , Transdução de Sinais , Fator de von Willebrand/genética , Fator de von Willebrand/metabolismo
18.
Lab Invest ; 100(7): 1014-1025, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32205858

RESUMO

Glycodelin is a major glycoprotein expressed in reproductive tissues, like secretory and decidualized endometrium. It has several reproduction related functions that are dependent on specific glycosylation, but it has also been found to drive differentiation of endometrial carcinoma cells toward a less malignant phenotype. Here we aimed to elucidate whether the glycosylation and function of glycodelin is altered in endometrial carcinoma as compared with a normal endometrium. We carried out glycan structure analysis of glycodelin expressed in HEC-1B human endometrial carcinoma cells (HEC-1B Gd) by mass spectrometry glycomics strategies. Glycans of HEC-1B Gd were found to comprise a typical mixture of high-mannose, hybrid, and complex-type N-glycans, often containing undecorated LacNAc (Galß1-4GlcNAc) antennae. However, several differences, as compared with previously reported glycan structures of normal human decidualized endometrium-derived glycodelin isoform, glycodelin-A (GdA), were also found. These included a lower level of sialylation and more abundant poly-LacNAc antennae, some of which are fucosylated. This allowed us to select lectins that showed different binding to these classes of glycodelin. Despite the differences in glycosylation between HEC-1B Gd and GdA, both showed similar inhibitory activity on trophoblast cell invasion and peripheral blood mononuclear cell proliferation. For the detection of cancer associated glycodelin, we established a novel in situ proximity-ligation based histochemical staining method using a specific glycodelin antibody and UEAI lectin. We found that the UEAI reactive glycodelin was abundant in endometrial carcinoma, but virtually absent in normal endometrial tissue even when glycodelin was strongly expressed. In conclusion, we established a histochemical staining method for the detection of endometrial carcinoma-associated glycodelin and showed that this specific glycodelin is exclusively expressed in cancer, not in normal endometrium. Similar methods can be used for studies of other glycoproteins.


Assuntos
Neoplasias do Endométrio , Glicodelina , Neoplasias Uterinas , Sequência de Carboidratos , Linhagem Celular Tumoral , Neoplasias do Endométrio/química , Neoplasias do Endométrio/metabolismo , Feminino , Glicodelina/análise , Glicodelina/química , Glicodelina/metabolismo , Glicômica , Glicosilação , Humanos , Lectinas/metabolismo , Espectrometria de Massas , Placenta/química , Gravidez , Neoplasias Uterinas/química , Neoplasias Uterinas/metabolismo
19.
Int J Mol Sci ; 21(5)2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32121292

RESUMO

Stress granules are cytoplasmic compartments, which serve as mRNA storage units during stress, therefore regulating translation. The Arabidopsis thaliana lectin ArathEULS3 has been widely described as a stress inducible gene. This study aimed to examine in detail the localization of ArathEULS3 lectin in normal and stressed cells. Colocalization experiments revealed that the nucleo-cytoplasmic lectin ArathEULS3 relocates to stress granules after stress. The ArathEULS3 sequence encodes a protein with a EUL lectin domain and an N-terminal domain with unknown structure and function. Bioinformatics analyses showed that the N-terminal domain sequence contains intrinsically disordered regions and likely does not exhibit a stable protein fold. Plasmolysis experiments indicated that ArathEULS3 also localizes to the apoplast, suggesting that this protein might follow an unconventional route for secretion. As part of our efforts we also investigated the interactome of ArathEULS3 and identified several putative interaction partners important for the protein translation process.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Grânulos Citoplasmáticos/metabolismo , Lectinas/metabolismo , Estresse Fisiológico , Sequência de Aminoácidos , Proteínas de Arabidopsis/química , Núcleo Celular/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Lectinas/química , Ligação Proteica
20.
Hum Immunol ; 81(2-3): 101-104, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32046870

RESUMO

Most sialic acid-binding immunoglobulin-like lectins (Siglecs) suppress immune cell function but are expressed at low levels on human T cells. We found that soluble CD52 inhibited T cell signalling by ligating Siglec-10, but the presence of Siglec-10 on human T cells has been questioned. To address this concern, we examined the expression of Siglec-10 at the RNA and protein level in human CD4+ T cells. Analysis by RNAseq, qPCR and flow cytometry demonstrated that, in contrast to other Siglecs, after activation of CD4+ T cells Siglec-10 was selectively upregulated in a subset of cells also high for CD52 expression. This observation is consistent with a homeostatic role for Siglec-10 in human CD4+ T cells.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Lectinas/metabolismo , Receptores de Superfície Celular/metabolismo , Linfócitos T CD4-Positivos/imunologia , Antígeno CD52/imunologia , Antígeno CD52/metabolismo , Humanos , Lectinas/imunologia , Ativação Linfocitária/imunologia , Receptores de Superfície Celular/imunologia , Regulação para Cima
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