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1.
Malar J ; 20(1): 376, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34551786

RESUMO

BACKGROUND: The FcγRs genotypes have been reported to play a key role in the defence against malaria parasites through both cellular and humoral immunity. This study aimed to investigate the possible correlation between FcγR (IIa, IIIa, and IIIb) genes polymorphism and the clinical outcome for anti-malarial antibody response of Plasmodium falciparum infection among Saudi children. METHODS: A total of 600 volunteers were enrolled in this study, including 200 malaria-free control (MFC) subjects, 218 patients with uncomplicated malaria (UM) and 182 patients with severe malaria (SM). The FcγR genotypes were analysed using PCR amplification methods, and measurements of immunoglobulin were determined using enzyme-linked immunosorbent assay (ELISA) technique. RESULTS: The data revealed that the FcγRIIa-R/R131 showed a statistically significant association with SM patients when compared to UM patients. Furthermore, higher levels of IgG1, IgG2, and IgG4 were associated with the FcγRIIa-H/H131 genotype among UM patients. Although the FcγRIIa-F/V176 genotype was not associated with UM, it showed a significant association with severe malaria. Interestingly, the FcγRIIIa-V/V176 genotype offered protection against SM. Moreover, SM patients carrying the FcγRIIIa-F/F genotype showed higher levels of AMA-1-specific IgG2 and IgG4 antibodies. The FcγRIIIb-NA1/NA1 and FcγRIIIb-NA2/NA2 genotypes did not show significant differences between the UM and the MFC groups. However, the genotype FcγRIIIb-NA2/NA2 was statistically significantly associated with SM patients. CONCLUSIONS: The data presented in this study suggest that the influence of the FcγRIIa-R/R131, FcγRIIIa-F/F176 and FcγRIIIb-NA2/NA2 genotypes are statistically significantly associated with SM patients. However, the FcγRIIa-H/H13 and FcγRIIIa-V/V176 genotypes have demonstrated a protective effect against SM when compared to UM patients. The impact of the FcyR (IIa, IIIa and IIIb) gene variants and anti-malaria IgG subclasses play an important role in susceptibility to malaria infection and disease outcome in Saudi children.


Assuntos
Malária Falciparum/genética , Polimorfismo Genético , Receptores de IgG/genética , Criança , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Humanos , Imunoglobulina G , Masculino , Receptores de IgG/metabolismo , Arábia Saudita
2.
mBio ; 12(5): e0198721, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34579572

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic has raised concerns about the detrimental effects of antibodies. Antibody-dependent enhancement (ADE) of infection is one of the biggest concerns in terms of not only the antibody reaction to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) upon reinfection with the virus but also the reaction to COVID-19 vaccines. In this study, we evaluated ADE of infection by using COVID-19 convalescent-phase plasma and BHK cells expressing human Fcγ receptors (FcγRs). We found that FcγRIIA and FcγRIIIA mediated modest ADE of infection against SARS-CoV-2. Although ADE of infection was observed in monocyte-derived macrophages infected with SARS-CoV-2, including its variants, proinflammatory cytokine/chemokine expression was not upregulated in macrophages. SARS-CoV-2 infection thus produces antibodies that elicit ADE of infection, but these antibodies do not contribute to excess cytokine production by macrophages. IMPORTANCE Viruses infect cells mainly via specific receptors at the cell surface. Antibody-dependent enhancement (ADE) of infection is an alternative mechanism of infection for viruses to infect immune cells that is mediated by antibodies and IgG receptors (FcγRs). Because ADE of infection contributes to the pathogenesis of some viruses, such as dengue virus and feline coronavirus, it is important to evaluate the precise mechanism of ADE and its contribution to the pathogenesis of SARS-CoV-2. Here, using convalescent-phase plasma from COVID-19 patients, we found that two types of FcγRs, FcγRIIA and FcγRIIIA, mediate ADE of SARS-CoV-2 infection. Although ADE of infection was observed for SARS-CoV-2 and its recent variants, proinflammatory cytokine production in monocyte-derived macrophages was not upregulated. These observations suggest that SARS-CoV-2 infection produces antibodies that elicit ADE of infection, but these antibodies may not be involved in aberrant cytokine release by macrophages during SARS-CoV-2 infection.


Assuntos
Citocinas/metabolismo , Macrófagos/metabolismo , Receptores de IgG/metabolismo , SARS-CoV-2/patogenicidade , Animais , Anticorpos Facilitadores/fisiologia , Linhagem Celular , Cricetinae , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Receptores de IgG/genética
3.
Nature ; 597(7875): 250-255, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34497389

RESUMO

The cellular landscape of the human intestinal tract is dynamic throughout life, developing in utero and changing in response to functional requirements and environmental exposures. Here, to comprehensively map cell lineages, we use single-cell RNA sequencing and antigen receptor analysis of almost half a million cells from up to 5 anatomical regions in the developing and up to 11 distinct anatomical regions in the healthy paediatric and adult human gut. This reveals the existence of transcriptionally distinct BEST4 epithelial cells throughout the human intestinal tract. Furthermore, we implicate IgG sensing as a function of intestinal tuft cells. We describe neural cell populations in the developing enteric nervous system, and predict cell-type-specific expression of genes associated with Hirschsprung's disease. Finally, using a systems approach, we identify key cell players that drive the formation of secondary lymphoid tissue in early human development. We show that these programs are adopted in inflammatory bowel disease to recruit and retain immune cells at the site of inflammation. This catalogue of intestinal cells will provide new insights into cellular programs in development, homeostasis and disease.


Assuntos
Envelhecimento , Sistema Nervoso Entérico/citologia , Feto/citologia , Saúde , Intestinos/citologia , Intestinos/crescimento & desenvolvimento , Linfonodos/citologia , Linfonodos/crescimento & desenvolvimento , Adulto , Animais , Criança , Doença de Crohn/patologia , Conjuntos de Dados como Assunto , Sistema Nervoso Entérico/anatomia & histologia , Sistema Nervoso Entérico/embriologia , Sistema Nervoso Entérico/crescimento & desenvolvimento , Células Epiteliais/citologia , Feminino , Feto/anatomia & histologia , Feto/embriologia , Humanos , Intestinos/embriologia , Intestinos/inervação , Linfonodos/embriologia , Linfonodos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Organogênese , Receptores de IgG/metabolismo , Transdução de Sinais , Análise Espaço-Temporal , Fatores de Tempo
4.
Cell Rep ; 37(1): 109798, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34587481

RESUMO

Despite the worldwide effect of the coronavirus disease 2019 (COVID-19) pandemic, the underlying mechanisms of fatal viral pneumonia remain elusive. Here, we show that critical COVID-19 is associated with enhanced eosinophil-mediated inflammation when compared to non-critical cases. In addition, we confirm increased T helper (Th)2-biased adaptive immune responses, accompanying overt complement activation, in the critical group. Moreover, enhanced antibody responses and complement activation are associated with disease pathogenesis as evidenced by formation of immune complexes and membrane attack complexes in airways and vasculature of lung biopsies from six fatal cases, as well as by enhanced hallmark gene set signatures of Fcγ receptor (FcγR) signaling and complement activation in myeloid cells of respiratory specimens from critical COVID-19 patients. These results suggest that SARS-CoV-2 infection may drive specific innate immune responses, including eosinophil-mediated inflammation, and subsequent pulmonary pathogenesis via enhanced Th2-biased immune responses, which might be crucial drivers of critical disease in COVID-19 patients.


Assuntos
Anticorpos Antivirais/imunologia , COVID-19/imunologia , Proteínas do Sistema Complemento/imunologia , Eosinófilos/imunologia , Inflamação/imunologia , Pneumonia Viral/imunologia , SARS-CoV-2/imunologia , Imunidade Adaptativa , Adulto , Idoso , Idoso de 80 Anos ou mais , Complexo Antígeno-Anticorpo/metabolismo , COVID-19/metabolismo , COVID-19/virologia , Ativação do Complemento , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Eosinófilos/virologia , Feminino , Humanos , Inflamação/metabolismo , Inflamação/virologia , Lesão Pulmonar/imunologia , Lesão Pulmonar/patologia , Lesão Pulmonar/virologia , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/metabolismo , Receptores de IgG/imunologia , Receptores de IgG/metabolismo , Índice de Gravidade de Doença , Transdução de Sinais , Células Th2/imunologia , Carga Viral , Adulto Jovem
5.
Int J Mol Sci ; 22(16)2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34445732

RESUMO

Infection with viruses, such as the lactate dehydrogenase-elevating virus (LDV), is known to trigger the onset of autoimmune anemia through the enhancement of the phagocytosis of autoantibody-opsonized erythrocytes by activated macrophages. Type I interferon receptor-deficient mice show enhanced anemia, which suggests a protective effect of these cytokines, partly through the control of type II interferon production. The development of anemia requires the expression of Fcγ receptors (FcγR) I, III, and IV. Whereas LDV infection decreases FcγR III expression, it enhances FcγR I and IV expression in wild-type animals. The LDV-associated increase in the expression of FcγR I and IV is largely reduced in type I interferon receptor-deficient mice, through both type II interferon-dependent and -independent mechanisms. Thus, the regulation of the expression of FcγR I and IV, but not III, by interferons may partly explain the exacerbating effect of LDV infection on anemia that results from the enhanced phagocytosis of IgG autoantibody-opsonized erythrocytes.


Assuntos
Anemia Hemolítica Autoimune/imunologia , Infecções por Arterivirus/imunologia , Interferons/metabolismo , Vírus Elevador do Lactato Desidrogenase/imunologia , Receptores de IgG/metabolismo , Anemia Hemolítica Autoimune/virologia , Animais , Infecções por Arterivirus/virologia , Interações Hospedeiro-Patógeno , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fagocitose
6.
ACS Chem Biol ; 16(8): 1526-1537, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34369155

RESUMO

The globo-series glycosphingolipids (SSEA3, SSEA4, and Globo H) were shown to express in many cancers selectively, and a combination of anti-SSEA4 and anti-Globo H antibodies was able to suppress tumor growth in mice inoculated with breast cancer cell lines. To further understand the effect, we focused on the combined effect of the two antibodies in target binding and antibody-dependent cellular cytotoxicity (ADCC) in vitro. Here, we report that the binding of anti-Globo H antibody (VK9) to MDA-MB231 breast cancer cells was influenced by anti-SSEA4 antibody (MC813-70), and a combination of both antibodies induced a similar effect as did anti-SSEA4 antibodies alone in a reporter-based ADCC assay, indicating that SSEA4 is a major target in breast cancer due to its higher expression than Globo H. Furthermore, we showed that a homogeneous anti-SSEA4 antibody (chMC813-70-SCT) designed to maximize the ADCC activity can be used to isolate a subpopulation of natural killer (NK) cells that exhibit an ∼23% increase in killing the target cells as compared to the unseparated NK cells. These findings can be used to predict a therapy outcome based on the expression levels of antigens and evaluate therapeutic antibody development.


Assuntos
Anticorpos/imunologia , Antígenos Glicosídicos Associados a Tumores/imunologia , Neoplasias da Mama/metabolismo , Antígenos Embrionários Estágio-Específicos/imunologia , Animais , Antígenos Glicosídicos Associados a Tumores/metabolismo , Linhagem Celular Tumoral , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Camundongos , Receptores de IgG/metabolismo , Antígenos Embrionários Estágio-Específicos/metabolismo
7.
J Exp Med ; 218(9)2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34269788

RESUMO

Necrotizing enterocolitis (NEC) is a severe gastrointestinal complication of prematurity. Using suspension and imaging mass cytometry coupled with single-cell RNA sequencing, we demonstrate severe inflammation in patients with NEC. NEC mucosa could be subtyped by an influx of three distinct neutrophil phenotypes (immature, newly emigrated, and aged). Furthermore, CD16+CD163+ monocytes/Mϕ, correlated with newly emigrated neutrophils, were specifically enriched in NEC mucosa, found adjacent to the blood vessels, and increased in circulation of infants with surgical NEC, suggesting trafficking from the periphery to areas of inflammation. NEC-specific monocytes/Mϕ transcribed inflammatory genes, including TREM1, IL1A, IL1B, and calprotectin, and neutrophil recruitment genes IL8, CXCL1, CXCL2, CXCL5 and had enrichment of gene sets in pathways involved in chemotaxis, migration, phagocytosis, and reactive oxygen species generation. In summary, we identify a novel subtype of inflammatory monocytes/Mϕ associated with NEC that should be further evaluated as a potential biomarker of surgical NEC and a target for the development of NEC-specific therapeutics.


Assuntos
Antígenos CD , Antígenos de Diferenciação Mielomonocítica , Enterocolite Necrosante/patologia , Mucosa Gástrica/patologia , Monócitos/patologia , Receptores de Superfície Celular , Receptores de IgG , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/genética , Antígenos de Diferenciação Mielomonocítica/metabolismo , Vasos Sanguíneos/patologia , Estudos de Casos e Controles , Quimiotaxia , Enterocolite Necrosante/cirurgia , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Humanos , Lactente , Recém-Nascido , Intestino Delgado/irrigação sanguínea , Intestino Delgado/patologia , Monócitos/imunologia , Neutropenia/etiologia , Neutropenia/patologia , Neutrófilos/patologia , Fagocitose/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores de IgG/genética , Receptores de IgG/metabolismo , Análise de Sequência de RNA , Análise de Célula Única
8.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201498

RESUMO

In ischemic stroke patients, a higher monocyte count is associated with disease severity and worse prognosis. The complex correlation between subset phenotypes and functions underscores the importance of clarifying the role of monocyte subpopulations. We examined the subtype-specific distribution of the CD163+ and CD80+ circulating monocytes and evaluated their association with the inflammatory status in 26 ischemic stroke patients and 16 healthy controls. An increased percentage of CD163+/CD16+ and CD163+/CD14++ events occurred 24 and 48 h after a stroke compared to the controls. CD163+ expression was more pronounced in CD16+ non-classical and intermediate monocytes, as compared to CD14+ classical subtype, 24 h after stroke. Conversely, the percentage of CD80+/CD16+ events was unaffected in patients; meanwhile, the percentage of CD80+/CD14+ events significantly increased only 24 h after stroke. Interleukin (IL)-1beta, TNF-alpha, and IL-4 mRNA levels were higher, while IL-10 mRNA levels were reduced in total monocytes from patients versus controls, at either 24 h or 48 h after stroke. The percentage of CD163+/CD16+ events 24 h after stroke was positively associated with NIHSS score and mRS at admission, suggesting that stroke severity and disability are relevant triggers for CD163+ expression in circulating CD16+ monocytes.


Assuntos
Antígenos CD/sangue , Antígenos de Diferenciação Mielomonocítica/sangue , Biomarcadores/sangue , AVC Isquêmico/sangue , Monócitos/metabolismo , Receptores de Superfície Celular/sangue , Idoso , Idoso de 80 Anos ou mais , Antígeno B7-1/metabolismo , Biomarcadores/metabolismo , Estudos de Casos e Controles , Estudos Transversais , Citocinas/genética , Feminino , Proteínas Ligadas por GPI/metabolismo , Humanos , AVC Isquêmico/etiologia , Masculino , Pessoa de Meia-Idade , Receptores de IgG/metabolismo , Índice de Gravidade de Doença
9.
Int J Mol Sci ; 22(12)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205578

RESUMO

Surface plasmon resonance (SPR)-based optical biosensors offer real-time and label-free analysis of protein interactions, which has extensively contributed to the discovery and development of therapeutic monoclonal antibodies (mAbs). As the biopharmaceutical market for these biologics and their biosimilars is rapidly growing, the role of SPR biosensors in drug discovery and quality assessment is becoming increasingly prominent. One of the critical quality attributes of mAbs is the N-glycosylation of their Fc region. Other than providing stability to the antibody, the Fc N-glycosylation influences immunoglobulin G (IgG) interactions with the Fcγ receptors (FcγRs), modulating the immune response. Over the past two decades, several studies have relied on SPR-based assays to characterize the influence of N-glycosylation upon the IgG-FcγR interactions. While these studies have unveiled key information, many conclusions are still debated in the literature. These discrepancies can be, in part, attributed to the design of the reported SPR-based assays as well as the methodology applied to SPR data analysis. In fact, the SPR biosensor best practices have evolved over the years, and several biases have been pointed out in the development of experimental SPR protocols. In parallel, newly developed algorithms and data analysis methods now allow taking into consideration complex biomolecular kinetics. In this review, we detail the use of different SPR biosensing approaches for characterizing the IgG-FcγR interactions, highlighting their merit and inherent experimental complexity. Furthermore, we review the latest SPR-derived conclusions on the influence of the N-glycosylation upon the IgG-FcγR interactions and underline the differences and similarities across the literature. Finally, we explore new avenues taking advantage of novel computational analysis of SPR results as well as the latest strategies to control the glycoprofile of mAbs during production, which could lead to a better understanding and modelling of the IgG-FcγRs interactions.


Assuntos
Imunoglobulina G/metabolismo , Receptores de IgG/metabolismo , Ressonância de Plasmônio de Superfície
10.
Front Immunol ; 12: 674079, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248955

RESUMO

At homeostasis the vast majority of neutrophils in the circulation expresses CD16 and CD62L within a narrow expression range, but this quickly changes in disease. Little is known regarding the changes in kinetics of neutrophils phenotypes in inflammatory conditions. During acute inflammation more heterogeneity was found, characterized by an increase in CD16dim banded neutrophils. These cells were probably released from the bone marrow (left shift). Acute inflammation induced by human experimental endotoxemia (LPS model) was additionally accompanied by an immediate increase in a CD62Llow neutrophil population, which was not as explicit after injury/trauma induced acute inflammation. The situation in sub-acute inflammation was more complex. CD62Llow neutrophils appeared in the peripheral blood several days (>3 days) after trauma with a peak after 10 days. A similar situation was found in the blood of COVID-19 patients returning from the ICU. Sorted CD16low and CD62Llow subsets from trauma and COVID-19 patients displayed the same nuclear characteristics as found after experimental endotoxemia. In diseases associated with chronic inflammation (stable COPD and treatment naive HIV) no increases in CD16low or CD62Llow neutrophils were found in the peripheral blood. All neutrophil subsets were present in the bone marrow during homeostasis. After LPS rechallenge, these subsets failed to appear in the circulation, but continued to be present in the bone marrow, suggesting the absence of recruitment signals. Because the subsets were reported to have different functionalities, these results on the kinetics of neutrophil subsets in a range of inflammatory conditions contribute to our understanding on the role of neutrophils in health and disease.


Assuntos
COVID-19/imunologia , Endotoxemia/imunologia , Inflamação/imunologia , Neutrófilos/imunologia , SARS-CoV-2/fisiologia , Ferimentos e Lesões/imunologia , Doença Aguda , Adulto , Idoso , Movimento Celular , Células Cultivadas , Doença Crônica , Feminino , Humanos , Selectina L/metabolismo , Lipopolissacarídeos/imunologia , Masculino , Pessoa de Meia-Idade , Receptores de IgG/metabolismo , Adulto Jovem
11.
Biomed Res Int ; 2021: 8874578, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34285919

RESUMO

Objective: We aim to investigate the correlation between FCGR2A mRNA level and prognosis of head and neck squamous cancer (HNSC) in public databases. In addition, we investigated the correlation between FCGR2A expression and clinicopathological characteristics and tumor-infiltrating immune cells in HNSC patients. Methods: FCGR2A mRNA expression in multiple cancers was analyzed based on Gene Expression Profiling Interactive Analysis. A protein-protein interaction network was obtained based on the STRING database. The 10 proteins most closely related to FCGR2A (i.e., CD3G, PLCG2, LAT, LYN, SYK, FCGR3A, PIK3R1, HCK, ITGAM, and ITGB2) were screened, followed by establishing the protein-protein interaction network. The correlation between FCGR2A expression and immunocytes was investigated, together with the effects of FCGR2A on the metastasis, recurrence, and survival of HNSC. Results: FCGR2A expression in several carcinoma tissues was significantly higher than that of adjacent tissues. Significant differences were noticed in the HNSC samples and the adjacent tissue samples except the seven samples of grade 4. There were statistical differences between the FCGR2A expression in tissues of grade 1, grade 2, and grade 3 (P < 0.05). In the tissues of grade 4, the expression of FCGR2A was the lowest. The FCGR2A protein was a type of II-a receptor in γFc of the low-affinity immunoglobulin, which could bind with the Fc region of the immunoglobulin γ. There was a correlation between the FCGR2A gene and the distal HNSC metastasis. FCGR2A gene expression was correlated with the survival and prognosis. The GSE65858 dataset was selected for the validation. The FCGR2A expression was significantly correlated with total survival (P = 0.0107) and progression-free survival (P = 0.0362). Conclusions: Our findings shed light on the importance of FCGR2A in HNSC and illustrated a potential relationship between FCGR2A and tumor-immune interactions.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias de Cabeça e Pescoço/imunologia , Linfócitos do Interstício Tumoral/imunologia , Receptores de IgG/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Membrana Celular/metabolismo , Variações do Número de Cópias de DNA/genética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Complexo de Golgi/metabolismo , Neoplasias de Cabeça e Pescoço/sangue , Neoplasias de Cabeça e Pescoço/genética , Humanos , Metástase Neoplásica , Recidiva Local de Neoplasia/patologia , Prognóstico , Mapas de Interação de Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de IgG/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/sangue , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Análise de Sobrevida , Transcrição Genética
12.
Cell ; 184(16): 4203-4219.e32, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34242577

RESUMO

SARS-CoV-2-neutralizing antibodies (NAbs) protect against COVID-19. A concern regarding SARS-CoV-2 antibodies is whether they mediate disease enhancement. Here, we isolated NAbs against the receptor-binding domain (RBD) or the N-terminal domain (NTD) of SARS-CoV-2 spike from individuals with acute or convalescent SARS-CoV-2 or a history of SARS-CoV infection. Cryo-electron microscopy of RBD and NTD antibodies demonstrated function-specific modes of binding. Select RBD NAbs also demonstrated Fc receptor-γ (FcγR)-mediated enhancement of virus infection in vitro, while five non-neutralizing NTD antibodies mediated FcγR-independent in vitro infection enhancement. However, both types of infection-enhancing antibodies protected from SARS-CoV-2 replication in monkeys and mice. Three of 46 monkeys infused with enhancing antibodies had higher lung inflammation scores compared to controls. One monkey had alveolar edema and elevated bronchoalveolar lavage inflammatory cytokines. Thus, while in vitro antibody-enhanced infection does not necessarily herald enhanced infection in vivo, increased lung inflammation can rarely occur in SARS-CoV-2 antibody-infused macaques.


Assuntos
Anticorpos Neutralizantes/imunologia , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Anticorpos Antivirais/imunologia , Líquido da Lavagem Broncoalveolar/química , COVID-19/patologia , COVID-19/virologia , Citocinas/metabolismo , Feminino , Haplorrinos , Humanos , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Domínios Proteicos , RNA Guia/metabolismo , Receptores de IgG/metabolismo , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/química , Carga Viral , Replicação Viral
13.
Front Immunol ; 12: 688201, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248975

RESUMO

Bone erosion is one of the primary features of inflammatory arthritis and is caused by excessive differentiation and activation of osteoclasts. Fc gamma receptors (FcγRs) have been implicated in osteoclastogenesis. Our recent studies demonstrate that joint-deposited lupus IgG inhibited RANKL-induced osteoclastogenesis. FcγRI is required for RANKL-induced osteoclastogenesis and lupus IgG-induced signaling transduction. We reviewed the results of studies that analyzed the association between FcγRs and bone erosion in inflammatory arthritis. The analysis revealed the dual roles of FcγRs in bone destruction in inflammatory arthritis. Thus, IgG/FcγR signaling molecules may serve as potential therapeutic targets against bone erosion.


Assuntos
Artrite/metabolismo , Remodelação Óssea , Osso e Ossos/metabolismo , Osteoclastos/metabolismo , Osteogênese , Receptores de IgG/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Artrite/tratamento farmacológico , Artrite/imunologia , Artrite/patologia , Remodelação Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/imunologia , Osso e Ossos/patologia , Humanos , Imunoglobulina G/metabolismo , Imunoterapia , Osteoclastos/efeitos dos fármacos , Osteoclastos/imunologia , Osteoclastos/patologia , Osteogênese/efeitos dos fármacos , Ligante RANK/metabolismo , Receptores de IgG/antagonistas & inibidores , Receptores de IgG/imunologia , Transdução de Sinais
14.
Elife ; 102021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34080973

RESUMO

Macrophages destroy pathogens and diseased cells through Fcγ receptor (FcγR)-driven phagocytosis of antibody-opsonized targets. Phagocytosis requires activation of multiple FcγRs, but the mechanism controlling the threshold for response is unclear. We developed a DNA origami-based engulfment system that allows precise nanoscale control of the number and spacing of ligands. When the number of ligands remains constant, reducing ligand spacing from 17.5 nm to 7 nm potently enhances engulfment, primarily by increasing efficiency of the engulfment-initiation process. Tighter ligand clustering increases receptor phosphorylation, as well as proximal downstream signals. Increasing the number of signaling domains recruited to a single ligand-receptor complex was not sufficient to recapitulate this effect, indicating that clustering of multiple receptors is required. Our results suggest that macrophages use information about local ligand densities to make critical engulfment decisions, which has implications for the mechanism of antibody-mediated phagocytosis and the design of immunotherapies.


Assuntos
DNA/metabolismo , Ativação de Macrófagos , Macrófagos/metabolismo , Nanotecnologia , Fagocitose , Receptores de Antígenos Quiméricos/metabolismo , Receptores de IgG/metabolismo , Animais , DNA/genética , Células HEK293 , Humanos , Cinética , Ligantes , Macrófagos/imunologia , Camundongos , Conformação de Ácido Nucleico , Fosforilação , Células RAW 264.7 , Receptores de Antígenos Quiméricos/genética , Receptores de IgG/genética , Transdução de Sinais , Células THP-1
15.
Immunology ; 164(3): 494-506, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34110622

RESUMO

An exclusive feature of dendritic cells (DCs) is their capacity to present exogenous antigens by MHC class I molecules, called cross-presentation. Here, we show that protein antigen can be conserved in mature murine DCs for several days in a lysosome-like storage compartment, distinct from MHC class II and early endosomal compartments, as an internal source for the supply of MHC class I ligands. Using two different uptake routes via Fcγ receptors and C-type lectin receptors, we could show that antigens were routed towards the same endolysosomal compartments after 48 h. The antigen-containing compartments lacked co-expression of molecules involved in MHC class I processing and presentation including TAP and proteasome subunits as shown by single-cell imaging flow cytometry. Moreover, we observed the absence of cathepsin S but selective co-localization of active cathepsin X with protein antigen in the storage compartments. This indicates cathepsin S-independent antigen degradation and a novel but yet undefined role for cathepsin X in antigen processing and cross-presentation by DCs. In summary, our data suggest that these antigen-containing compartments in DCs can conserve protein antigens from different uptake routes and contribute to long-lasting antigen cross-presentation.


Assuntos
Antígenos/metabolismo , Apresentação Cruzada , Células Dendríticas/imunologia , Lectinas Tipo C/metabolismo , Receptores de IgG/metabolismo , Animais , Apresentação do Antígeno , Antígenos/imunologia , Catepsinas/metabolismo , Células Dendríticas/metabolismo , Células Dendríticas/ultraestrutura , Endossomos/imunologia , Endossomos/metabolismo , Endossomos/ultraestrutura , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Lisossomos/imunologia , Lisossomos/metabolismo , Lisossomos/ultraestrutura , Camundongos , Microscopia Eletrônica de Transmissão , Modelos Animais , Células NIH 3T3 , Cultura Primária de Células
17.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070506

RESUMO

Concentration of hyaluronic acid (HA) in the lungs increases in idiopathic pulmonary fibrosis (IPF). HA is involved in the organization of fibrin, fibronectin, and collagen. HA has been proposed to be a biomarker of fibrosis and a potential target for antifibrotic therapy. Hyaluronidase (HD) breaks down HA into fragments, but is a subject of rapid hydrolysis. A conjugate of poloxamer hyaluronidase (pHD) was prepared using protein immobilization with ionizing radiation. In a model of bleomycin-induced pulmonary fibrosis, pHD decreased the level of tissue IL-1ß and TGF-ß, prevented the infiltration of the lung parenchyma by CD16+ cells, and reduced perivascular and peribronchial inflammation. Simultaneously, a decrease in the concentrations of HA, hydroxyproline, collagen 1, total soluble collagen, and the area of connective tissue in the lungs was observed. The effects of pHD were significantly stronger compared to native HD which can be attributed to the higher stability of pHD. Additional spiperone administration increased the anti-inflammatory and antifibrotic effects of pHD and accelerated the regeneration of the damaged lung. The potentiating effects of spiperone can be explained by the disruption of the dopamine-induced mobilization and migration of fibroblast progenitor cells into the lungs and differentiation of lung mesenchymal stem cells (MSC) into cells of stromal lines. Thus, a combination of pHD and spiperone may represent a promising approach for the treatment of IPF and lung regeneration.


Assuntos
Ácido Hialurônico/metabolismo , Hialuronoglucosaminidase/farmacologia , Fibrose Pulmonar Idiopática/tratamento farmacológico , Fibrose Pulmonar Idiopática/metabolismo , Pulmão/efeitos dos fármacos , Espiperona/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Colágeno Tipo I/metabolismo , Hialuronoglucosaminidase/administração & dosagem , Hialuronoglucosaminidase/farmacocinética , Hidroxiprolina/metabolismo , Fibrose Pulmonar Idiopática/induzido quimicamente , Fibrose Pulmonar Idiopática/enzimologia , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Queratinas/metabolismo , Pulmão/enzimologia , Pulmão/metabolismo , Pulmão/patologia , Masculino , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Poloxâmero/química , Receptores de IgG/metabolismo , Espiperona/administração & dosagem , Fator de Crescimento Transformador beta/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
18.
Front Immunol ; 12: 700429, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34177967

RESUMO

The rapid spread of SARS-CoV-2 has induced a global pandemic. Severe forms of COVID-19 are characterized by dysregulated immune response and "cytokine storm". The role of IgG and IgM antibodies in COVID-19 pathology is reasonably well studied, whereas IgA is neglected. To improve clinical outcome of patients, immune modulatory drugs appear to be beneficial. Such drugs include intravenous immunoglobulin preparations, which were successfully tested in severe COVID-19 patients. Here we established a versatile in vitro model to study inflammatory as well as anti-inflammatory processes by therapeutic human immunoglobulins. We dissect the inflammatory activation on neutrophil-like HL60 cells, using an immune complex consisting of latex beads coated with spike protein of SARS-CoV-2 and opsonized with specific immunoglobulins from convalescent plasma. Our data clarifies the role of Fc-receptor-dependent phagocytosis via IgA-FcαRI and IgG-FcγR for COVID-19 disease followed by cytokine release. We show that COVID-19 associated inflammation could be reduced by addition of human immunoglobulin preparations (IVIG and trimodulin), while trimodulin elicits stronger immune modulation by more powerful ITAMi signaling. Besides IgG, the IgA component of trimodulin in particular, is of functional relevance for immune modulation in this assay setup, highlighting the need to study IgA mediated immune response.


Assuntos
Anti-Inflamatórios/farmacologia , Antígenos CD/metabolismo , COVID-19/terapia , Síndrome da Liberação de Citocina/terapia , Imunoglobulinas Intravenosas/farmacologia , Neutrófilos/imunologia , Receptores Fc/metabolismo , Receptores de IgG/metabolismo , SARS-CoV-2/fisiologia , Anticorpos Antivirais/metabolismo , Complexo Antígeno-Anticorpo , Linhagem Celular , Humanos , Imunização Passiva , Imunomodulação , Fagocitose , Transdução de Sinais , Glicoproteína da Espícula de Coronavírus/metabolismo
19.
Nat Commun ; 12(1): 3451, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103486

RESUMO

Several cell-surface receptors for neurotoxic forms of amyloid-ß (Aß) have been described, but their molecular interactions with Aß assemblies and their relative contributions to mediating Alzheimer's disease pathology have remained uncertain. Here, we used super-resolution microscopy to directly visualize Aß-receptor interactions at the nanometer scale. We report that one documented Aß receptor, PrPC, specifically inhibits the polymerization of Aß fibrils by binding to the rapidly growing end of each fibril, thereby blocking polarized elongation at that end. PrPC binds neurotoxic oligomers and protofibrils in a similar fashion, suggesting that it may recognize a common, end-specific, structural motif on all of these assemblies. Finally, two other Aß receptors, FcγRIIb and LilrB2, affect Aß fibril growth in a manner similar to PrPC. Our results suggest that receptors may trap Aß oligomers and protofibrils on the neuronal surface by binding to a common molecular determinant on these assemblies, thereby initiating a neurotoxic signal.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Amiloide/metabolismo , Neurotoxinas/química , Multimerização Proteica , Receptores de Superfície Celular/metabolismo , Animais , Benzotiazóis/metabolismo , Calmodulina/metabolismo , Humanos , Cinética , Camundongos , Modelos Biológicos , Polimerização , Príons/metabolismo , Ligação Proteica , Receptores de IgG/metabolismo , Receptores Imunológicos/metabolismo
20.
Artigo em Inglês | MEDLINE | ID: mdl-34098178

RESUMO

Commercially approved conventional antibody-drug conjugates (ADCs) are produced as heterogeneous mixtures containing a stochastic distribution of payloads decorating the antibody molecules resulting in decreased efficacy and thus lowering their therapeutic index. Control of the DAR and conjugation site in the development of next-generation ADCs is believed to assist in increasing the therapeutic index of these targeted biologics leading to overall enhanced clinical efficacy and reduced toxicity. A chemical site-specific conjugation technology termed AJICAP® allows ADC developers to control both the location and quantity of the payload conjugation to an antibody. Furthermore, this simplified ADC composition enables a streamlined chemical analysis. Here we report the chromatographic separation of site-specific ADCs produced by AJICAP® technology using an analytical affinity chromatography HPLC column containing a recombinant FcγIIIa receptor-ligand immobilized on a non-porous polymer resin (NPR). These HPLC analyses provided visually clear chromatogram results reflecting the heterogeneity of each ADC. The affinity strength was also measured by biolayer interferometry (BLI) and predicted by molecular structure analysis. The results indicate that AJICAP® technology is a promising solution to link hydrophobic payloads to antibodies without compromising antibody receptor function. This study also shows that FcγIIIa-NPR column can be used to characterize site-specific conjugated ADCs compared to ADCs synthesized using conventional methods.


Assuntos
Cromatografia de Afinidade/métodos , Imunoconjugados , Receptores de IgG , Proteínas Recombinantes , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Imunoconjugados/análise , Imunoconjugados/química , Imunoconjugados/metabolismo , Modelos Moleculares , Porosidade , Receptores de IgG/análise , Receptores de IgG/química , Receptores de IgG/metabolismo , Proteínas Recombinantes/análise , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
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