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1.
Front Immunol ; 12: 765330, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777382

RESUMO

Aims: Although the exact factors promoting disease progression in COVID-19 are not fully elucidated, unregulated activation of the complement system (CS) seems to play a crucial role in the pathogenesis of acute lung injury (ALI) induced by SARS-CoV-2. In particular, the lectin pathway (LP) has been implicated in previous autopsy studies. The primary purpose of our study is to investigate the role of the CS in hospitalized COVID-19 patients with varying degrees of disease severity. Methods: In a single-center prospective observational study, 154 hospitalized patients with PCR-confirmed SARS-CoV-2 infection were included. Serum samples on admission to the COVID-19 ward were collected for analysis of CS pathway activities and concentrations of LP proteins [mannose-binding lectin (MBL) and ficolin-3 (FCN-3)] & C1 esterase inhibitor (C1IHN). The primary outcome was mechanical ventilation or in-hospital death. Results: The patients were predominately male and had multiple comorbidities. ICU admission was required in 16% of the patients and death (3%) or mechanical ventilation occurred in 23 patients (15%). There was no significant difference in LP activity, MBL and FCN-3 concentrations according to different peak disease severities. The median alternative pathway (AP) activity was significantly lower (65%, IQR 50-94) in patients with death/invasive ventilation compared to patients without (87%, IQR 68-102, p=0.026). An optimal threshold of <65.5% for AP activity was derived from a ROC curve resulting in increased odds for death or mechanical ventilation (OR 4,93; 95% CI 1.70-14.33, p=0.003) even after adjustment for confounding factors. Classical pathway (CP) activity was slightly lower in patients with more severe disease (median 101% for death/mechanical ventilation vs 109%, p=0.014). C1INH concentration correlated positively with length of stay, inflammatory markers and disease severity on admission but not during follow-up. Conclusion: Our results point to an overactivated AP in critically ill COVID-19 patients in vivo leading to complement consumption and consequently to a significantly reduced AP activity in vitro. The LP does not seem to play a role in the progression to severe COVID-19. Apart from its acute phase reaction the significance of C1INH in COVID-19 requires further studies.


Assuntos
COVID-19/imunologia , Proteínas do Sistema Complemento/imunologia , SARS-CoV-2 , Adulto , Idoso , COVID-19/sangue , COVID-19/mortalidade , COVID-19/terapia , Proteína Inibidora do Complemento C1/imunologia , Estado Terminal , Feminino , Mortalidade Hospitalar , Hospitalização , Humanos , Lectinas/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Respiração Artificial , Índice de Gravidade de Doença
2.
Nature ; 598(7880): 342-347, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34464958

RESUMO

SARS-CoV-2 infection-which involves both cell attachment and membrane fusion-relies on the angiotensin-converting enzyme 2 (ACE2) receptor, which is paradoxically found at low levels in the respiratory tract1-3, suggesting that there may be additional mechanisms facilitating infection. Here we show that C-type lectin receptors, DC-SIGN, L-SIGN and the sialic acid-binding immunoglobulin-like lectin 1 (SIGLEC1) function as attachment receptors by enhancing ACE2-mediated infection and modulating the neutralizing activity of different classes of spike-specific antibodies. Antibodies to the amino-terminal domain or to the conserved site at the base of the receptor-binding domain, while poorly neutralizing infection of ACE2-overexpressing cells, effectively block lectin-facilitated infection. Conversely, antibodies to the receptor binding motif, while potently neutralizing infection of ACE2-overexpressing cells, poorly neutralize infection of cells expressing DC-SIGN or L-SIGN and trigger fusogenic rearrangement of the spike, promoting cell-to-cell fusion. Collectively, these findings identify a lectin-dependent pathway that enhances ACE2-dependent infection by SARS-CoV-2 and reveal distinct mechanisms of neutralization by different classes of spike-specific antibodies.


Assuntos
Anticorpos Neutralizantes/imunologia , Lectinas/metabolismo , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Moléculas de Adesão Celular/metabolismo , Fusão Celular , Linhagem Celular , Cricetinae , Feminino , Humanos , Lectinas/imunologia , Lectinas Tipo C/metabolismo , Fusão de Membrana , Receptores de Superfície Celular/metabolismo , SARS-CoV-2/imunologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
3.
Life Sci ; 282: 119793, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34242658

RESUMO

Visceral leishmaniasis (VL) is a neglected and highly lethal disease. VL is endemic in South American countries, with Brazil being responsible for 96% of the cases. In this continent, VL is caused by the protozoan Leishmania (Leishmania) infantum (L. infantum), transmitted by the bite of infected female phlebotomine sandflies. Immediately after the inoculation of L.infantum promastigotes into the vertebrate host, the complement, as part of the first line of innate response, becomes activated. L. infantum promastigotes glycocalyx is rich in carbohydrates that can activate the lectin pathway of complement system. In this study, we evaluated whether the lectin pathway collectins [manose binding lectin (MBL) and collectin-11 (CL-11)] and ficolins (-1, -2 and -3) interact with L.infantum promastigotes, using confocal microscopy and flow cytometry. The binding of MBL, CL-11 and ficolins -1 and -3, but not ficolin-2, was observed on the surface of live metacyclic promastigotes after incubation with normal human serum (NHS) or recombinant proteins. C3 and C4 deposition as well as complement mediated lyses was also demonstrated after interaction with NHS. These results highlight a role for collectins and ficolins in the initial immune response to L.infantum.


Assuntos
Proteínas do Sistema Complemento/imunologia , Lectinas/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/imunologia , Ativação do Complemento , Interações Hospedeiro-Parasita , Humanos , Leishmania infantum/fisiologia
5.
JCI Insight ; 6(13)2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34143756

RESUMO

We explored the potential link between chronic inflammatory arthritis and COVID-19 pathogenic and resolving macrophage pathways and their role in COVID-19 pathogenesis. We found that bronchoalveolar lavage fluid (BALF) macrophage clusters FCN1+ and FCN1+SPP1+ predominant in severe COVID-19 were transcriptionally related to synovial tissue macrophage (STM) clusters CD48hiS100A12+ and CD48+SPP1+ that drive rheumatoid arthritis (RA) synovitis. BALF macrophage cluster FABP4+ predominant in healthy lung was transcriptionally related to STM cluster TREM2+ that governs resolution of synovitis in RA remission. Plasma concentrations of SPP1 and S100A12 (key products of macrophage clusters shared with active RA) were high in severe COVID-19 and predicted the need for Intensive Care Unit transfer, and they remained high in the post-COVID-19 stage. High plasma levels of SPP1 were unique to severe COVID-19 when compared with other causes of severe pneumonia, and IHC localized SPP1+ macrophages in the alveoli of COVID-19 lung. Investigation into SPP1 mechanisms of action revealed that it drives proinflammatory activation of CD14+ monocytes and development of PD-L1+ neutrophils, both hallmarks of severe COVID-19. In summary, COVID-19 pneumonitis appears driven by similar pathogenic myeloid cell pathways as those in RA, and their mediators such as SPP1 might be an upstream activator of the aberrant innate response in severe COVID-19 and predictive of disease trajectory including post-COVID-19 pathology.


Assuntos
Artrite Reumatoide/imunologia , COVID-19/imunologia , Monócitos/imunologia , Neutrófilos/imunologia , Osteopontina/imunologia , Artrite Reumatoide/metabolismo , Antígeno B7-H1/imunologia , Líquido da Lavagem Broncoalveolar/imunologia , Antígeno CD48/imunologia , COVID-19/induzido quimicamente , COVID-19/metabolismo , Proteínas de Ligação a Ácido Graxo/imunologia , Humanos , Lectinas/imunologia , Receptores de Lipopolissacarídeos/imunologia , Receptores de Lipopolissacarídeos/metabolismo , Pulmão/diagnóstico por imagem , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Macrófagos/imunologia , Macrófagos/metabolismo , Glicoproteínas de Membrana/imunologia , Monócitos/metabolismo , Neutrófilos/metabolismo , Osteopontina/sangue , Receptores Proteína Tirosina Quinases/metabolismo , Receptores Imunológicos/imunologia , Proteína S100A12/imunologia , Proteína S100A12/metabolismo , Membrana Sinovial/imunologia , Tomografia Computadorizada por Raios X
6.
Chem Commun (Camb) ; 57(50): 6209-6212, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34059855

RESUMO

Toll-like receptor 4 (TLR4) recognizes various protein ligands; however, the protein-TLR4 binding model is unclear. Here we demonstrate a Crenomytilus grayanus lectin (CGL)-TLR4/MD2 model to show that CGL interacts with a TLR4/myeloid differentiation factor 2 (MD2) complex independently of sugar-binding properties. CGL could suppress lipopolysaccharide-induced immune responses significantly, suggesting that TLR4 itself has potential as a therapeutic target.


Assuntos
Carboidratos/química , Lectinas/química , Antígeno 96 de Linfócito/química , Receptor 4 Toll-Like/química , Animais , Sítios de Ligação , Bivalves , Carboidratos/imunologia , Humanos , Lectinas/imunologia , Antígeno 96 de Linfócito/imunologia , Receptor 4 Toll-Like/imunologia
7.
Front Immunol ; 12: 671052, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995410

RESUMO

We do not understand why non-white ethnicity and chronic kidney disease increase susceptibility to COVID-19. The lectin pathway of complement activation is a key contributor to innate immunity and inflammation. Concentrations of plasma lectin pathway proteins influence pathway activity and vary with ethnicity. We measured circulating lectin proteins in a multi-ethnic cohort of chronic kidney disease patients with and without COVID19 infection to determine if lectin pathway activation was contributing to COVID19 severity. We measured 11 lectin proteins in serial samples from a cohort of 33 patients with chronic kidney impairment and COVID19. Controls were single plasma samples from 32 patients on dialysis and 32 healthy individuals. We demonstrated multiple associations between recognition molecules and associated proteases of the lectin pathway and COVID-19, including COVID-19 severity. Some of these associations were unique to patients of Asian and White ethnicity. Our novel findings demonstrate that COVID19 infection alters the concentration of plasma lectin proteins and some of these changes were linked to ethnicity. This suggests a role for the lectin pathway in the host response to COVID-19 and suggest that variability within this pathway may contribute to ethnicity-associated differences in susceptibility to severe COVID-19.


Assuntos
COVID-19/sangue , Lectina de Ligação a Manose da Via do Complemento , Lectinas/sangue , Insuficiência Renal Crônica/sangue , SARS-CoV-2/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/etnologia , COVID-19/imunologia , COVID-19/patologia , Feminino , Humanos , Lectinas/imunologia , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/etnologia , Insuficiência Renal Crônica/imunologia , Insuficiência Renal Crônica/patologia , SARS-CoV-2/imunologia
8.
Methods Mol Biol ; 2227: 121-132, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33847937

RESUMO

Ficolins are recognition proteins of the lectin pathway of the complement system and also play an important role in innate immunity and in the maintenance of tissue homeostasis. They deserve special attention in the context of autoimmunity since they are involved in the uptake of dying cells. Because the monitoring of systemic lupus erythematosus (SLE) patients is particularly difficult, it is crucial to find new relevant serum biomarkers. The ability to detect autoantibodies in the patients' sera provides a diagnostic and prognostic advantage. We describe in this chapter quantitative enzyme linked immunosorbent assays (ELISA) to detect the presence of autoantibodies targeting ficolin-2 and ficolin-3 in human sera. Recombinant ficolins produced in a mammalian expression system are used as coating antigens. The described in-house ELISAs provide a valuable tool to efficiently quantify anti-ficolin autoantibodies in the sera of SLE patients.


Assuntos
Autoanticorpos/análise , Lectinas/imunologia , Animais , Autoanticorpos/sangue , Autoanticorpos/isolamento & purificação , Biomarcadores/análise , Biomarcadores/sangue , Células CHO , Cricetulus , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/imunologia , Nefrite Lúpica/sangue , Nefrite Lúpica/diagnóstico , Nefrite Lúpica/imunologia
9.
J Immunol Res ; 2021: 6697900, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33824880

RESUMO

Entamoeba histolytica is an intestinal parasite that causes dysentery and amebic liver abscess. E. histolytica has the capability to invade host tissue by union of virulence factor Gal/GalNAc lectin; this molecule induces an adherence-inhibitory antibody response as well as to protect against amebic liver abscess (ALA). The present work showed the effect of the immunization with PEΔIII-LC3-KDEL3 recombinant protein. In vitro, this candidate vaccine inhibited adherence of E. histolytica trophozoites to HepG2 cell monolayer, avoiding the cytolysis, and in a hamster model, we observed a vaccine-induced protection against the damage to tissue liver and the inhibition of uncontrolled inflammation. PEΔIII-LC3-KDEL3 reduced the expression of TNF-α, IL-1ß, and NF-κB in all immunized groups at 4- and 7-day postinfection. The levels of IL-10, FOXP3, and IFN-γ were elevated at 7 days. The immunohistochemistry assay confirmed this result, revealing an elevated quantity of +IFN-γ cells in the liver tissue. ALA formation in hamsters immunized was minimal, and few trophozoites were identified. Hence, immunization with PEΔIII-LC3-KDEL3 herein prevented invasive amebiasis, avoided an acute proinflammatory response, and activated a protective response within a short time. Finally, this recombinant protein induced an increase of serum IgG.


Assuntos
Entamoeba histolytica/imunologia , Abscesso Hepático Amebiano/prevenção & controle , Proteínas de Protozoários/administração & dosagem , Vacinas Protozoárias/administração & dosagem , Proteínas Recombinantes de Fusão/administração & dosagem , Animais , Anticorpos Antiprotozoários/sangue , Modelos Animais de Doenças , Entamoeba histolytica/genética , Humanos , Imunogenicidade da Vacina , Lectinas/genética , Lectinas/imunologia , Fígado/imunologia , Fígado/parasitologia , Fígado/patologia , Abscesso Hepático Amebiano/sangue , Abscesso Hepático Amebiano/parasitologia , Abscesso Hepático Amebiano/patologia , Masculino , Mesocricetus , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/genética , Vacinas Protozoárias/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
10.
Am J Respir Cell Mol Biol ; 64(5): 629-640, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33662226

RESUMO

Deficiency of ASM (acid sphingomyelinase) causes the lysosomal storage Niemann-Pick disease (NPD). Patients with NPD type B may develop progressive interstitial lung disease with frequent respiratory infections. Although several investigations using the ASM-deficient (ASMKO) mouse NPD model revealed inflammation and foamy macrophages, there is little insight into the pathogenesis of NPD-associated lung disease. Using ASMKO mice, we report that ASM deficiency is associated with a complex inflammatory phenotype characterized by marked accumulation of monocyte-derived CD11b+ macrophages and expansion of airspace/alveolar CD11c+ CD11b- macrophages, both with increased size, granularity, and foaminess. Both the alternative and classical pathways were activated, with decreased in situ phagocytosis of opsonized (Fc-coated) targets, preserved clearance of apoptotic cells (efferocytosis), secretion of Th2 cytokines, increased CD11c+/CD11b+ cells, and more than a twofold increase in lung and plasma proinflammatory cytokines. Macrophages, neutrophils, eosinophils, and noninflammatory lung cells of ASMKO lungs also exhibited marked accumulation of chitinase-like protein Ym1/2, which formed large eosinophilic polygonal Charcot-Leyden-like crystals. In addition to providing insight into novel features of lung inflammation that may be associated with NPD, our report provides a novel connection between ASM and the development of crystal-associated lung inflammation with alterations in macrophage biology.


Assuntos
Glicoproteínas/imunologia , Lisofosfolipase/imunologia , Macrófagos Alveolares/imunologia , Macrófagos/imunologia , Doença de Niemann-Pick Tipo A/imunologia , Doença de Niemann-Pick Tipo B/imunologia , Pneumonia/imunologia , Esfingomielina Fosfodiesterase/imunologia , Animais , Antígenos CD11/genética , Antígenos CD11/imunologia , Antígeno CD11b/genética , Antígeno CD11b/imunologia , Tamanho Celular , Quitinases/genética , Quitinases/imunologia , Modelos Animais de Doenças , Eosinófilos/imunologia , Eosinófilos/patologia , Feminino , Expressão Gênica , Glicoproteínas/genética , Humanos , Lectinas/genética , Lectinas/imunologia , Pulmão/imunologia , Pulmão/patologia , Lisofosfolipase/genética , Macrófagos/patologia , Macrófagos Alveolares/patologia , Masculino , Camundongos , Camundongos Knockout , Neutrófilos/imunologia , Neutrófilos/patologia , Doença de Niemann-Pick Tipo A/enzimologia , Doença de Niemann-Pick Tipo A/genética , Doença de Niemann-Pick Tipo A/patologia , Doença de Niemann-Pick Tipo B/enzimologia , Doença de Niemann-Pick Tipo B/genética , Doença de Niemann-Pick Tipo B/patologia , Fagocitose , Pneumonia/enzimologia , Pneumonia/genética , Pneumonia/patologia , Esfingomielina Fosfodiesterase/deficiência , Esfingomielina Fosfodiesterase/genética , Equilíbrio Th1-Th2/genética , beta-N-Acetil-Hexosaminidases/genética , beta-N-Acetil-Hexosaminidases/imunologia
11.
Front Immunol ; 12: 603133, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33692781

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is a progressive disorder that can develop into liver fibrosis and hepatocellular carcinoma. Natural killer (NK) cells have been shown to protect against liver fibrosis and tumorigenesis, suggesting that they may also play a role in the pathogenesis of NAFLD. Sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of inhibitory and activating receptors expressed by many cell types, including NK cells. Here, we investigated the phenotypic profiles of peripheral blood and intrahepatic NK cells, including expression of Siglecs and immune checkpoint molecules, and their association with NK cell function in patients with NAFLD. Immune cells in the peripheral blood of 42 patients with biopsy-proven NAFLD and 13 healthy volunteers (HVs) were identified by mass cytometry. The function of various NK cell subpopulations was assessed by flow cytometric detection of intracellular IFN-γ and CD107a/LAMP-1, a degranulation marker, after in vitro stimulation. We found that peripheral blood from NAFLD patients, regardless of fibrosis stage, contained significantly fewer total CD56+ NK cell and CD56dim NK cell populations compared with HVs, and the CD56dim cells from NAFLD patients were functionally impaired. Among the Siglecs examined, NK cells predominantly expressed Siglec-7 and Siglec-9, and both the expression levels of Siglec-7 and Siglec-9 on NK cells and the frequencies of Siglec-7+CD56dim NK cells were reduced in NAFLD patients. Notably, Siglec-7 levels on CD56dim NK cells were inversely correlated with PD-1, CD57, and ILT2 levels and positively correlated with NKp30 and NKp46 levels. Further subtyping of NK cells identified a highly dysfunctional Siglec-7-CD57+PD-1+CD56dim NK cell subset that was increased in patients with NAFLD, even those with mild liver fibrosis. Intrahepatic NK cells from NAFLD patients expressed elevated levels of NKG2D and CD69, suggesting a more activated phenotype than normal liver NK cells. These data identify a close association between NK cell function and expression of Siglec-7, CD57, and PD-1 that could potentially be therapeutically targeted in NAFLD.


Assuntos
Antígenos de Diferenciação Mielomonocítica/imunologia , Antígenos CD57/imunologia , Células Matadoras Naturais/imunologia , Lectinas/imunologia , Hepatopatia Gordurosa não Alcoólica/imunologia , Receptor de Morte Celular Programada 1/imunologia , Adulto , Idoso , Feminino , Citometria de Fluxo , Humanos , Interferon gama/imunologia , Células Matadoras Naturais/patologia , Proteína 1 de Membrana Associada ao Lisossomo/imunologia , Glicoproteínas de Membrana Associadas ao Lisossomo/imunologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/patologia
12.
Front Immunol ; 12: 650331, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777047

RESUMO

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection represents a global health crisis. Immune cell activation via pattern recognition receptors has been implicated as a driver of the hyperinflammatory response seen in COVID-19. However, our understanding of the specific immune responses to SARS-CoV-2 remains limited. Mast cells (MCs) and eosinophils are innate immune cells that play pathogenic roles in many inflammatory responses. Here we report MC-derived proteases and eosinophil-associated mediators are elevated in COVID-19 patient sera and lung tissues. Stimulation of viral-sensing toll-like receptors in vitro and administration of synthetic viral RNA in vivo induced features of hyperinflammation, including cytokine elevation, immune cell airway infiltration, and MC-protease production-effects suppressed by an anti-Siglec-8 monoclonal antibody which selectively inhibits MCs and depletes eosinophils. Similarly, anti-Siglec-8 treatment reduced disease severity and airway inflammation in a respiratory viral infection model. These results suggest that MC and eosinophil activation are associated with COVID-19 inflammation and anti-Siglec-8 antibodies are a potential therapeutic approach for attenuating excessive inflammation during viral infections.


Assuntos
Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos B/imunologia , COVID-19/imunologia , Eosinófilos/imunologia , Lectinas/imunologia , Mastócitos/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , SARS-CoV-2/imunologia , Receptores Toll-Like/imunologia , Animais , Anticorpos Monoclonais/farmacologia , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos B/genética , Antígenos de Diferenciação de Linfócitos B/metabolismo , COVID-19/metabolismo , COVID-19/prevenção & controle , COVID-19/virologia , Estudos de Casos e Controles , Citocinas/metabolismo , Modelos Animais de Doenças , Eosinófilos/efeitos dos fármacos , Eosinófilos/metabolismo , Eosinófilos/virologia , Interações Hospedeiro-Patógeno , Humanos , Lectinas/antagonistas & inibidores , Lectinas/genética , Lectinas/metabolismo , Mastócitos/efeitos dos fármacos , Mastócitos/metabolismo , Mastócitos/virologia , Camundongos Transgênicos , Peptídeo Hidrolases/metabolismo , Infecções por Vírus Respiratório Sincicial/metabolismo , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/virologia , Receptores Toll-Like/metabolismo
13.
Leukemia ; 35(9): 2581-2591, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33633313

RESUMO

The only current curative treatment for chronic lymphocytic leukemia (CLL) is allogenic hematopoietic stem cell transplantation. Chimeric antigen receptor treatment targeting CD19 for CLL achieved some complete responses, suggesting the need for alternative or combinational therapies to achieve a more robust response. In this work, we evaluated CAR-T cells specific for Siglec-6, an antigen expressed in CLL, as a novel CAR-T cell treatment for CLL. We found that detection of SIGLEC6 mRNA and Siglec-6 protein is highly restricted to placenta and immune cells in other tissues and it is not expressed in hematopoietic stem cells. We generated CAR-T cells specific for Siglec-6 based on the sequence of the fully human anti-Siglec-6 antibody (JML1), which was identified in a CLL patient that was cured after allo-hematopoietic stem cell transplantation (alloHSCT), and observed that it specifically targeted CLL cells in vitro and in a xenograft mouse model. Interestingly, a short hinge region increased the activity of CAR-T cells to target cells expressing higher Siglec-6 levels but similarly targeted CLL cells expressing lower Siglec-6 levels in vitro and in vivo. Our results identify a novel CAR-T cell therapy for CLL and establish Siglec-6 as a possible target for immunotherapy.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Imunoterapia Adotiva/métodos , Lectinas/antagonistas & inibidores , Leucemia Linfocítica Crônica de Células B/terapia , Receptores de Antígenos Quiméricos/imunologia , Animais , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Proliferação de Células , Terapia Combinada , Humanos , Lectinas/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
14.
J Biol Chem ; 296: 100375, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33548227

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged during the last months of 2019, spreading throughout the world as a highly transmissible infectious illness designated as COVID-19. Vaccines have now appeared, but the challenges in producing sufficient material and distributing them around the world means that effective treatments to limit infection and improve recovery are still urgently needed. This review focuses on the relevance of different glycobiological molecules that could potentially serve as or inspire therapeutic tools during SARS-CoV-2 infection. As such, we highlight the glycobiology of the SARS-CoV-2 infection process, where glycans on viral proteins and on host glycosaminoglycans have critical roles in efficient infection. We also take notice of the glycan-binding proteins involved in the infective capacity of virus and in human defense. In addition, we critically evaluate the glycobiological contribution of candidate drugs for COVID-19 therapy such as glycans for vaccines, anti-glycan antibodies, recombinant lectins, lectin inhibitors, glycosidase inhibitors, polysaccharides, and numerous glycosides, emphasizing some opportunities to repurpose FDA-approved drugs. For the next-generation drugs suggested here, biotechnological engineering of new probes to block the SARS-CoV-2 infection might be based on the essential glycobiological insight on glycosyltransferases, glycans, glycan-binding proteins, and glycosidases related to this pathology.


Assuntos
Antivirais/uso terapêutico , COVID-19/prevenção & controle , Reposicionamento de Medicamentos , Inibidores de Glicosídeo Hidrolases/uso terapêutico , Glicosiltransferases/antagonistas & inibidores , Proteínas Virais/antagonistas & inibidores , Anticorpos Neutralizantes/uso terapêutico , Antivirais/química , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/virologia , Desenho de Fármacos , Descoberta de Drogas , Expressão Gênica , Glicômica/métodos , Glicosaminoglicanos/química , Glicosaminoglicanos/imunologia , Glicosaminoglicanos/metabolismo , Glicosiltransferases/química , Glicosiltransferases/genética , Glicosiltransferases/imunologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Lectinas/química , Lectinas/imunologia , Lectinas/metabolismo , Polissacarídeos/química , Polissacarídeos/imunologia , Polissacarídeos/metabolismo , SARS-CoV-2/química , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Transdução de Sinais , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/imunologia
15.
J Agric Food Chem ; 69(4): 1379-1390, 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33464885

RESUMO

A high content of potentially allergenic lectin in Phaseolus vulgaris L. beans is of increasing health concerns; however, understanding of the protein allergenicity mechanism on the molecular basis is scarce. In the present study, low-pH treatments were applied to modify black turtle bean lectin allergen, and a sensitization procedure was performed using the BALB/c mice for the allergenicity evaluation, while the conformational changes were monitored by the spectral analyses and the details were explored by the molecular dynamics simulation. Much milder anaphylactic responses were observed in BALB/c mice experiments. At the molecular level, the protein was unfolded in low acidic environments because of protonation, and α-helix was reduced with the exposure of trypsin cleavage sites, especially the improvement of protease accessibility for Lys121, 134, and 157 in the B cell epitope structural alterations. These results indicate that a low-pH treatment might be an efficient method to improve the safety of legume protein consumption.


Assuntos
Alérgenos/química , Lectinas/química , Phaseolus/imunologia , Alérgenos/imunologia , Animais , Linfócitos B/imunologia , Feminino , Manipulação de Alimentos , Hipersensibilidade Alimentar/imunologia , Humanos , Concentração de Íons de Hidrogênio , Lectinas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Phaseolus/genética , Sementes/química , Sementes/imunologia
16.
J Allergy Clin Immunol ; 147(4): 1442-1452, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32791164

RESUMO

BACKGROUND: The immunoinhibitory receptor Siglec-8 on the surface of human eosinophils and mast cells binds to sialic acid-containing ligands in the local milieu, resulting in eosinophil apoptosis, inhibition of mast cell degranulation, and suppression of inflammation. Siglec-8 ligands were found on postmortem human trachea and bronchi and on upper airways in 2 compartments, cartilage and submucosal glands, but they were surprisingly absent from the epithelium. We hypothesized that Siglec-8 ligands in submucosal glands and ducts are normally transported to the airway mucus layer, which is lost during tissue preparation. OBJECTIVE: Our aim was to identify the major Siglec-8 sialoglycan ligand on the mucus layer of human airways. METHODS: Human upper airway mucus layer proteins were recovered during presurgical nasal lavage of patients at a sinus clinic. Proteins were resolved by gel electrophoresis and blotted, and Siglec-8 ligands detected. Ligands were purified by size exclusion and affinity chromatography, identified by proteomic mass spectrometry, and validated by electrophoretic and histochemical colocalization. The affinity of Siglec-8 binding to purified human airway ligand was determined by inhibition of glycan binding. RESULTS: A Siglec-8-ligand with a molecular weight of approximately 1000 kDa was found in all patient nasal lavage samples. Purification and identification revealed deleted in malignant brain tumors 1 (DMBT1) (also known by the aliases GP340 and SALSA), a large glycoprotein with multiple O-glycosylation repeats. Immunoblotting, immunohistochemistry, and enzyme treatments confirmed that Siglec-8 ligand on the human airway mucus layer is an isoform of DMBT1 carrying O-linked sialylated keratan sulfate chains (DMBT1S8). Quantitative inhibition revealed that DMBT1S8 has picomolar affinity for Siglec-8. CONCLUSION: A distinct DMBT1 isoform, DMBT1S8, is the major high-avidity ligand for Siglec-8 on human airways.


Assuntos
Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos B/imunologia , Proteínas de Ligação ao Cálcio/imunologia , Proteínas de Ligação a DNA/imunologia , Lectinas/imunologia , Proteínas Supressoras de Tumor/imunologia , Brônquios/imunologia , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação a DNA/química , Eosinófilos/imunologia , Humanos , Ligantes , Mastócitos/imunologia , Líquido da Lavagem Nasal/imunologia , Proteoglicanas/imunologia , Traqueia/imunologia , Proteínas Supressoras de Tumor/química
17.
J Autoimmun ; 116: 102571, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33223341

RESUMO

Guillain-Barré syndrome (GBS), including its variant Miller Fisher syndrome (MFS), is an acute peripheral neuropathy that involves autoimmune mechanisms leading to the production of autoantibodies to gangliosides; sialic acid-containing glycosphingolipids. Although association with various genetic polymorphisms in the major histocompatibility complex (MHC) is shown in other autoimmune diseases, GBS is an exception, showing no such link. No significant association was found by genome wide association studies, suggesting that GBS is not associated with common variants. To address the involvement of rare variants in GBS, we analyzed Siglec-10, a sialic acid-recognizing inhibitory receptor expressed on B cells. Here we demonstrate that two rare variants encoding R47Q and A108V substitutions in the ligand-binding domain are significantly accumulated in patients with GBS. Because of strong linkage disequilibrium, there was no patient carrying only one of them. Recombinant Siglec-10 protein containing R47Q but not A108V shows impaired binding to gangliosides. Homology modeling revealed that the R47Q substitution causes marked alteration in the ligand-binding site. Thus, GBS is associated with a rare variant of the SIGLEC10 gene that impairs ligand binding of Siglec-10. Because Siglec-10 regulates antibody production to sialylated antigens, our finding suggests that Siglec-10 regulates development of GBS by suppressing antibody production to gangliosides, with defects in its function predisposing to disease.


Assuntos
Gangliosídeos/imunologia , Predisposição Genética para Doença , Síndrome de Guillain-Barré/imunologia , Lectinas/imunologia , Mutação de Sentido Incorreto/imunologia , Polimorfismo de Nucleotídeo Único/imunologia , Receptores de Superfície Celular/imunologia , Alelos , Sequência de Aminoácidos , Autoanticorpos/imunologia , Sítios de Ligação/genética , Feminino , Gangliosídeos/metabolismo , Frequência do Gene , Genótipo , Síndrome de Guillain-Barré/genética , Síndrome de Guillain-Barré/metabolismo , Humanos , Lectinas/genética , Lectinas/metabolismo , Masculino , Pessoa de Meia-Idade , Síndrome de Miller Fisher/genética , Síndrome de Miller Fisher/imunologia , Síndrome de Miller Fisher/metabolismo , Mutação de Sentido Incorreto/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Homologia de Sequência de Aminoácidos
18.
Pharmacol Res ; 163: 105266, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33127557

RESUMO

Ficolins are pattern-recognition molecules (PRMs) that could form complexes with mannose-binding lectin-associated serine proteases (MASPs) to trigger complement activation via the lectin pathway, thereby mediating a series of immune responses including opsonization, phagocytosis and cytokine production. In the past few decades, accumulating evidence have suggested that ficolins play a major role in the onset and development of several autoimmune diseases (ADs), including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), Type 1 diabetes (T1D), inflammatory bowel disease (IBD), etc. In this review, we synthesized previous literatures and recent advances to elucidate the immunological regulations of ficolins and discuss the potential diagnostic ability of ficolins in ADs, as well as giving an insight into the future therapeutic options for ficolins in ADs.


Assuntos
Doenças Autoimunes/imunologia , Lectinas/imunologia , Animais , Doenças Autoimunes/tratamento farmacológico , Humanos , Lectinas/química , Lectinas/genética
19.
Fish Shellfish Immunol ; 108: 32-41, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33249124

RESUMO

Intelectin (ITLN) is a type of glycan-binding lectin involved in many physiological processes and some human diseases. Here we report a common carp intelectin (cITLN). Like other orthologs, cITLN also contains a conserved fibrinogen-related domain (FReD) and a unique intelectin domain, expresses in all the tissues tested with the highest level in the hindgut, and responds to bacterial challenge in the acute phase. We also expressed cITLN in Escherichia coli (E. coli) system, and the purified recombinant cITLN could neither affect the surface of bacteria nor inhibit the growth of bacteria, but it can agglutinate both gram-positive and gram-negative bacteria in a calcium-dependent manner. The cITLN's ability of agglutination of gram-positive bacteria is stronger than that of gram-negative bacteria. This is probably because recombinant cITLN could binding peptidoglycan (PGN) with a higher degree to lipopolysaccharide (LPS). Our results of cITLN provided new insight into the function of intelectin in the intestinal mucosal immunity.


Assuntos
Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Lectinas/genética , Lectinas/imunologia , Perciformes/genética , Perciformes/imunologia , Sequência de Aminoácidos , Animais , Carpas , Citocinas/química , Citocinas/genética , Citocinas/imunologia , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica/veterinária , Lectinas/química , Alinhamento de Sequência/veterinária
20.
J Microbiol Immunol Infect ; 54(3): 420-428, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31706823

RESUMO

BACKGROUND/PURPOSE: SraP is a serine-rich repeat protein (SRRP) from Staphylococcus aureus that binds to sialylated receptors to promote bacterial adhesion to and invasion into host epithelial cells, mediated by the l-lectin module of its ligand-binding region. METHODS: The sequence encoding the L-lectin module of SraP was inserted into pET28a plasmid, and the recombinant protein was purified by His label affinity chromatography. A monoclonal antibody (mAb) against the l-lectin module was obtained and confirmed by enzyme-linked immunosorbent assay and western blotting. The effect of the mAb on S. aureus adhesion and invasion was assessed in A549 cells and mice subjected to S. aureus challenge. RESULTS: We successfully obtained a mAb against the l-lectin module of SraP. Pre-incubation with the mAb dramatically inhibited the bacteria's ability to adhere to and invade A549 cells. Moreover, mice administered mAb through tail vein injection had significantly fewer bacteria in the blood. CONCLUSION: The anti-SraPL-Lectin mAb significantly reduced the adherence and invasion of S. aureus to host cells. This study lays the foundation for the future development of the l-lectin module of SraP as a target for the prevention and treatment of S. aureus infection. Our findings suggest that specific subdomains of SRRPs may represent potential antibacterial drug targets for intervention.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Aderência Bacteriana/imunologia , Proteínas de Bactérias/imunologia , Lectinas/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/química , Staphylococcus aureus/imunologia , Células A549 , Animais , Anticorpos Monoclonais/uso terapêutico , Proteínas de Bactérias/genética , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Infecções Estafilocócicas/prevenção & controle
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