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1.
Nat Commun ; 12(1): 5218, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471125

RESUMO

CD47 is the only 5-transmembrane (5-TM) spanning receptor of the immune system. Its extracellular domain (ECD) is a cell surface marker of self that binds SIRPα and inhibits macrophage phagocytosis, and cancer immuno-therapy approaches in clinical trials are focused on blocking CD47/SIRPα interaction. We present the crystal structure of full length CD47 bound to the function-blocking antibody B6H12. CD47 ECD is tethered to the TM domain via a six-residue peptide linker (114RVVSWF119) that forms an extended loop (SWF loop), with the fundamental role of inserting the side chains of W118 and F119 into the core of CD47 extracellular loop region (ECLR). Using hydrogen-deuterium exchange and molecular dynamics simulations we show that CD47's ECLR architecture, comprised of two extracellular loops and the SWF loop, creates a molecular environment stabilizing the ECD for presentation on the cell surface. These findings provide insights into CD47 immune recognition, signaling and therapeutic intervention.


Assuntos
Biomarcadores , Antígeno CD47/química , Antígeno CD47/metabolismo , Proteínas de Transporte/metabolismo , Receptores Imunológicos/metabolismo , Anticorpos Bloqueadores/química , Anticorpos Bloqueadores/farmacologia , Antígenos de Diferenciação/imunologia , Sítios de Ligação , Antígeno CD47/efeitos dos fármacos , Antígeno CD47/genética , Humanos , Macrófagos/metabolismo , Modelos Moleculares , Fagocitose/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
2.
J Immunol ; 207(5): 1357-1370, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34380651

RESUMO

Zinc (Zn) is required for proper immune function and host defense. Zn homeostasis is tightly regulated by Zn transporters that coordinate biological processes through Zn mobilization. Zn deficiency is associated with increased susceptibility to bacterial infections, including Streptococcus pneumoniae, the most commonly identified cause of community-acquired pneumonia. Myeloid cells, including macrophages and dendritic cells (DCs), are at the front line of host defense against invading bacterial pathogens in the lung and play a critical role early on in shaping the immune response. Expression of the Zn transporter ZIP8 is rapidly induced following bacterial infection and regulates myeloid cell function in a Zn-dependent manner. To what extent ZIP8 is instrumental in myeloid cell function requires further study. Using a novel, myeloid-specific, Zip8 knockout model, we identified vital roles of ZIP8 in macrophage and DC function upon pneumococcal infection. Administration of S. pneumoniae into the lung resulted in increased inflammation, morbidity, and mortality in Zip8 knockout mice compared with wild-type counterparts. This was associated with increased numbers of myeloid cells, cytokine production, and cell death. In vitro analysis of macrophage and DC function revealed deficits in phagocytosis and increased cytokine production upon bacterial stimulation that was, in part, due to increased NF-κB signaling. Strikingly, alteration of myeloid cell function resulted in an imbalance of Th17/Th2 responses, which is potentially detrimental to host defense. These results (for the first time, to our knowledge) reveal a vital ZIP8- and Zn-mediated axis that alters the lung myeloid cell landscape and the host response against pneumococcus.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Células Dendríticas/imunologia , Macrófagos/imunologia , Células Mieloides/imunologia , Pneumonia Pneumocócica/imunologia , Streptococcus pneumoniae/fisiologia , Células Th17/imunologia , Células Th2/imunologia , Animais , Proteínas de Transporte de Cátions/genética , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Imunidade Inata , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismo , Fagocitose/genética , Transdução de Sinais
3.
Int J Mol Sci ; 22(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34445160

RESUMO

Throughout life, macrophages are located in every tissue of the body, where their main roles are to phagocytose cellular debris and recycle aging red blood cells. In the tissue niche, they promote homeostasis through trophic, regulatory, and repair functions by responding to internal and external stimuli. This in turn polarizes macrophages into a broad spectrum of functional activation states, also reflected in their iron-regulated gene profile. The fast adaptation to the environment in which they are located helps to maintain tissue homeostasis under physiological conditions.


Assuntos
Ferro/imunologia , Ativação de Macrófagos , Macrófagos/imunologia , Animais , Homeostase , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Ferro/metabolismo , Macrófagos/metabolismo , Fagocitose
4.
Am J Physiol Cell Physiol ; 321(3): C607-C614, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34378992

RESUMO

Bovine milk exosomes (BMEs) are being explored in drug delivery despite their rapid elimination by macrophages. We aimed at identifying the BME transporter in murine bone marrow-derived macrophages (BMDMs). Fluorophore-labeled BMEs were used in transport studies in BMDMs from C57BL/6J and class A scavenger receptor type 1/2 (CASR-1/2) knockout mice and tissue accumulation in macrophage-depleted C57BL/6J mice. Parametric and nonparametric statistics tests for pairwise and multiple comparisons were used. Chemical inhibitors of phagocytosis by cytochalasin D led to a 69 ± 18% decrease in BME uptake compared with controls (P < 0.05), whereas inhibitors of endocytic pathways other than phagocytosis had a modest effect on uptake (P > 0.05). Inhibitors of class A scavenger receptors (CASRs) including CASR-1/2 caused a 70% decrease in BME uptake (P < 0.05). The uptake of BMEs by BMDMs from CASR-1/2 knockout mice was smaller by 58 ± 23% compared with wild-type controls (P < 0.05). Macrophage depletion by clodronate caused a more than 44% decrease in BME uptake in the spleen and lungs (P < 0.05), whereas the decrease observed in liver was not statistically significant. In conclusion, CASR-1/2 facilitates the uptake of BMEs in BMDMs and C57BL/6J mice.


Assuntos
Exossomos/metabolismo , Macrófagos/metabolismo , Leite/química , Receptores Depuradores Classe A/genética , Animais , Bovinos , Ácido Clodrônico/farmacologia , Citocalasina D/farmacologia , Endocitose/efeitos dos fármacos , Exossomos/química , Feminino , Corantes Fluorescentes/química , Expressão Gênica , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fagocitose/efeitos dos fármacos , Isoformas de Proteínas/deficiência , Isoformas de Proteínas/genética , Receptores Depuradores Classe A/deficiência , Baço/efeitos dos fármacos , Baço/metabolismo , Coloração e Rotulagem/métodos
5.
Rev Soc Bras Med Trop ; 54: e07562020, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34431955

RESUMO

INTRODUCTION: This study aimed to determine the number of macrophages and apoptotic cells and perform annexin-A1 detection in patients with leishmaniasis. METHODS: Patients with Leishmania infection were admitted to Júlio Müller University Hospital. RESULTS: The number of apoptotic cells was higher in the exudative granulomatous reaction. The exudative cellular reaction displayed higher levels of annexin-A1 detection in macrophages and apoptotic cells. The correlation between annexin-A1 detection in apoptotic cells and macrophages was observed in exudative necrotic reaction and exudative necrotic-granulomatous reaction. CONCLUSIONS: Our data demonstrate the relevance of annexin-A1 in the regulation of apoptosis and phagocytosis in leishmaniasis.


Assuntos
Anexina A1 , Leishmaniose Cutânea , Apoptose , Humanos , Macrófagos , Fagocitose
6.
J Med Case Rep ; 15(1): 438, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34452644

RESUMO

BACKGROUND: Spindle cell squamous cell carcinoma is an uncommon variant of squamous cell carcinoma; its diagnosis is sometimes challenging because it histopathologically resembles neoplastic or reactive spindle cell lesions of mesenchymal origins. Here, we report a rare case of spindle cell squamous cell carcinoma exhibiting prominent neutrophil phagocytosis. CASE PRESENTATION: A 69-year-old Japanese man presented with pain and a polypoid mass on the lower left gingiva. He had received chemoradiotherapy for squamous cell carcinoma of the buccal mucosa 15 years prior to this consultation. In addition, he was treated for mandibular osteonecrosis 6 years after chemoradiotherapy without evidence of cancer recurrence. A biopsy revealed atypical spindle or pleomorphic cells scattered in the edematous and fibrin-rich stroma; however, no malignant squamous components were apparent. These atypical cells frequently contained neutrophils within their cytoplasm that formed cell-in-cell figures. Immunohistochemically, the atypical cells were negative for cytokeratins, epithelial membrane antigen, and E-cadherin, but positive for p63, vimentin, and p53. Although these findings suggested spindle cell squamous cell carcinoma, it was difficult to reach a definitive diagnosis. Based on a clinical diagnosis of a malignant tumor, the patient underwent a hemimandibulectomy. The surgically resected specimen had a typical spindle cell squamous cell carcinoma histology consisting of biphasic spindle cells and conventional squamous cell carcinoma components. Moreover, the surgical specimen also exhibited spindle tumor cells that frequently included neutrophils, around which intense staining for lysosomal-associated membrane protein 1 and cathepsin B was observed. This suggested that the cell-in-cell figures represent active neutrophil phagocytosis by tumor cells, and not emperipolesis. CONCLUSION: The presence of neutrophil phagocytosis may be a potent indicator of malignancy.


Assuntos
Carcinoma de Células Escamosas , Neutrófilos , Idoso , Carcinoma de Células Escamosas/terapia , Humanos , Masculino , Recidiva Local de Neoplasia , Fagocitose , Vimentina
7.
Cell Host Microbe ; 29(8): 1216-1217, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34384524

RESUMO

Engagement of LC3-associated phagocytosis (LAP) in response to the uptake of certain particles modulates innate immune responses. Now in Cell Host and Microbe, Akoumianaki et al. (2021) show how a regulatory role of IL-6 on LAP may be at the core of susceptibility to secondary infection during severe sepsis.


Assuntos
Autofagia , Fagossomos , Humanos , Imunidade Inata , Proteínas Associadas aos Microtúbulos , Fagocitose
8.
Biomaterials ; 276: 121062, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34418816

RESUMO

Adenovirus (Ad) has been extensively developed as a gene delivery vector, but the potential side effect caused by systematic immunization remains one major obstacle for its clinical application. Needle-free mucosal immunization with Ad-based vaccine shows advantages but still faces poor mucosal responses. We herein report that the chemical engineering of single live viral-based vaccine effectively modulated the location and pattern of the subsequently elicited immunity. Through precisely assembly of functional materials onto single live Ad particle, the modified virus entered host cell in a phagocytosis-dependent manner, which is completely distinct from the receptor-mediated entry of native Ad. RNA-Seq data further demonstrated that the modified Ad-induced innate immunity was sharply reshaped via phagocytosis-related pathway, therefore promoting the activation and mature of antigen presentation cells (APC). Moreover, the functional shell enabled the modified Ad-based vector with enhanced muco-adhesion to nasal tissues in mice, and then prolonged resident time onto mucosal surface, leading to the robust mucosal IgA production and T cell immunity at local and even remote mucosal-associated lymphoid tissues. This study demonstrated that vaccine-induced immunity can be well modulated by chemistry engineering, and this method provides the rational design for needle-free mucosa-targeting vaccine against a variety of emerging infectious diseases.


Assuntos
Vacinas Virais , Adenoviridae/genética , Animais , Vetores Genéticos , Imunidade nas Mucosas , Camundongos , Fagocitose
9.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360986

RESUMO

Human Cytomegalovirus (HCMV) may cause severe infections in transplant recipients. HCMV-replication can be limited by HCMV-specific antibody responses. The impact of the antibody-dependent cellular phagocytosis (ADCP) on inhibition of HCMV-replication in natural infections has not been clarified. Therefore, we investigated the HCMV-specific ADCP response in a study cohort of lung-transplant recipients (LTRs) with different donor (D) and recipient (R) HCMV-serostatus. Follow-up plasma samples from 39 non/low-viremic and 36 highly viremic (>1000 HCMV copies/mL plasma) LTRs were collected for one (R+ LTRs) or two (D+/R- LTRs) years post-transplantation. The HCMV-specific ADCP responses were assessed by focal expansion assays (FEA) and flow-cytometry. In all LTRs, ADCP responses were detected against HCMV-infected cells and cell-free virions. When measured in fibroblasts as well as with cell-free virus, the HCMV-specific ADPC response was higher in LTRs than in HCMV-seropositive healthy controls. In D+/R- LTRs, a significant ADCP response developed over time after the receipt of an HCMV positive lung, and a level of <19 IE+ cells/focus in the FEA on fibroblasts was associated with further protection from high-level viremia. Taken together, a strong HCMV-specific ADCP response is elicited in transplant recipients, which may contribute to protection from high-level viremia in primary HCMV infection.


Assuntos
Infecções por Citomegalovirus/imunologia , Imunoglobulina G/imunologia , Transplante de Pulmão/efeitos adversos , Fagocitose , Infecção dos Ferimentos/imunologia , Células Cultivadas , Citomegalovirus/imunologia , Infecções por Citomegalovirus/etiologia , Infecções por Citomegalovirus/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Células THP-1 , Carga Viral , Infecção dos Ferimentos/etiologia , Infecção dos Ferimentos/virologia
10.
Int J Mol Sci ; 22(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34445642

RESUMO

Endocytosis provides the cellular nutrition and homeostasis of organisms, but pathogens often take advantage of this entry point to infect host cells. This is counteracted by phagocytosis that plays a key role in the protection against invading microbes both during the initial engulfment of pathogens and in the clearance of infected cells. Phagocytic cells balance two vital functions: preventing the accumulation of cell corpses to avoid pathological inflammation and autoimmunity, whilst maintaining host defence. In this review, we compare elements of phagocytosis in mammals and the nematode Caenorhabditis elegans. Initial recognition of infection requires different mechanisms. In mammals, pattern recognition receptors bind pathogens directly, whereas activation of the innate immune response in the nematode rather relies on the detection of cellular damage. In contrast, molecules involved in efferocytosis-the engulfment and elimination of dying cells and cell debris-are highly conserved between the two species. Therefore, C. elegans is a powerful model to research mechanisms of the phagocytic machinery. Finally, we show that both mammalian and worm studies help to understand how the two phagocytic functions are interconnected: emerging data suggest the activation of innate immunity as a consequence of defective apoptotic cell clearance.


Assuntos
Apoptose , Imunidade Inata/imunologia , Fagócitos/fisiologia , Fagocitose , Animais , Caenorhabditis elegans , Humanos , Transdução de Sinais
11.
Viruses ; 13(7)2021 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-34372538

RESUMO

Bacterial surface structures of a proteinic nature and glycoconjugates contribute to biofilm formation and provide shields to host defense mechanisms (e.g., the complement system and phagocytosis). A loss or alteration of these molecules, leading to phage resistance, could result in fewer virulent bacteria. In this study, we evaluate the biology and phenotype changes in Pseudomonas aeruginosa PAO1 phage-resistant clones, which emerge in phage-treated biofilms. We characterize these clones for phage-typing patterns, antibiotic resistance, biofilm formation, pathogenicity, and interactions with the innate immune system. Another important question that we address is whether phage-resistant mutants are also generated incidentally, despite the phage treatment-selective pressure, as the natural adaptation of the living biofilm population. It is found that the application of different phages targeting a particular receptor selects similar phage resistance patterns. Nevertheless, this results in a dramatic increase in the population heterogeneity, giving over a dozen phage-typing patterns, compared to one of the untreated PAO1 sessile forms. We also confirm the hypothesis that "phage-resistant bacteria are more susceptible to antibiotics and host-clearance mechanisms by the immune system". These findings support phage application in therapy, although the overall statement that phage treatment selects the less virulent bacterial population should be further verified using a bigger collection of clinical strains.


Assuntos
Resistência Microbiana a Medicamentos/genética , Fagos de Pseudomonas/genética , Pseudomonas aeruginosa/virologia , Antibacterianos/farmacologia , Bacteriófagos/genética , Biofilmes/crescimento & desenvolvimento , Resistência Microbiana a Medicamentos/fisiologia , Humanos , Terapia por Fagos/métodos , Fagocitose/genética , Fenótipo , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Virulência
12.
Front Cell Infect Microbiol ; 11: 622491, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34350128

RESUMO

The metabolite-rich environment that is the intestinal lumen contains metabolic by-products deriving from microbial fermentation and host cell metabolism, with resident macrophages being constantly exposed to this metabolic flux. Succinate, lactate and itaconate are three metabolites secreted by primed macrophages due to a fragmented tri-carboxylic acid (TCA) cycle. Additionally, succinate and lactate are known by-products of microbial fermentation. How these metabolites impact biological functioning of resident macrophages particularly in response to bacterial infection remains poorly understood. We have investigated the potential influence of these metabolites on macrophage phagocytosis and clearance of Escherichia coli (E. coli) infection. Treatment of murine bone-marrow-derived macrophages (BMDMs) with succinate reduced numbers of intracellular E. coli early during infection, while lactate-treated BMDMs displayed no difference throughout the course of infection. Treatment of BMDMs with itaconate lead to higher levels of intracellular E. coli early in the infection with bacterial burden subsequently reduced at later time-points compared to untreated macrophages, indicative of enhanced engulfment and killing capabilities of macrophages in response to itaconate. Expression of engulfment mediators MARCKS, RhoB, and CDC42 were reduced or unchanged following succinate or lactate treatment and increased in itaconate-treated macrophages following E. coli infection. Nitric oxide (NO) levels varied while pro- and anti-inflammatory cytokines differed in secretory levels in all metabolite-treated macrophages post-infection with E. coli or in response to lipopolysaccharide (LPS) stimulation. Finally, the basal phenotypic profile of metabolite-treated macrophages was altered according to marker gene expression, describing how fluid macrophage phenotype can be in response to the microenvironment. Collectively, our data suggests that microbe- and host-derived metabolites can drive distinct macrophage functional phenotypes in response to infection, whereby succinate and itaconate regulate phagocytosis and bactericidal mechanisms, limiting the intracellular bacterial niche and impeding the pathogenesis of infection.


Assuntos
Infecções Bacterianas , Escherichia coli , Animais , Lipopolissacarídeos , Macrófagos , Camundongos , Fagocitose
13.
Front Immunol ; 12: 669103, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367135

RESUMO

Targeted therapeutics for the treatment of coronavirus disease 2019 (COVID-19), especially severe cases, are currently lacking. As macrophages have unique effector functions as a first-line defense against invading pathogens, we genetically armed human macrophages with chimeric antigen receptors (CARs) to reprogram their phagocytic activity against SARS-CoV-2. After investigation of CAR constructs with different intracellular receptor domains, we found that although cytosolic domains from MERTK (CARMERTK) did not trigger antigen-specific cellular phagocytosis or killing effects, unlike those from MEGF10, FcRγ and CD3ζ did, these CARs all mediated similar SARS-CoV-2 clearance in vitro. Notably, we showed that CARMERTK macrophages reduced the virion load without upregulation of proinflammatory cytokine expression. These results suggest that CARMERTK drives an 'immunologically silent' scavenger effect in macrophages and pave the way for further investigation of CARs for the treatment of individuals with COVID-19, particularly those with severe cases at a high risk of hyperinflammation.


Assuntos
COVID-19/tratamento farmacológico , COVID-19/imunologia , Imunoterapia Adotiva , Macrófagos/imunologia , SARS-CoV-2/imunologia , Vírion/imunologia , Animais , COVID-19/genética , Chlorocebus aethiops , Humanos , Fagocitose , SARS-CoV-2/genética , Células THP-1 , Células Vero , Vírion/genética
14.
Immunity ; 54(7): 1377-1391, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34260886

RESUMO

Neutrophils are immune cells with unusual biological features that furnish potent antimicrobial properties. These cells phagocytose and subsequently kill prokaryotic and eukaryotic organisms very efficiently. Importantly, it is not only their ability to attack microbes within a constrained intracellular compartment that endows neutrophils with antimicrobial function. They can unleash their effectors into the extracellular space, where, even post-mortem, their killing machinery can endure and remain functional. The antimicrobial activity of neutrophils must not be misconstrued as being microbe specific and should be viewed more generally as biotoxic. Outside of fighting infections, neutrophils can harness their noxious machinery in other contexts, like cancer. Inappropriate or dysregulated neutrophil activation damages the host and contributes to autoimmune and inflammatory disease. Here we review a number of topics related to neutrophil biology based on contemporary findings.


Assuntos
Neutrófilos/imunologia , Animais , Espaço Extracelular/imunologia , Humanos , Inflamação/imunologia , Ativação de Neutrófilo/imunologia , Fagocitose/imunologia
15.
Anticancer Res ; 41(8): 4089-4092, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34281879

RESUMO

BACKGROUND/AIM: Serum-derived macrophage activating factor (serum-MAF) is expected to have adjuvant effects through rapid phagocytic activation, which depends on F-actin accumulation in multi-layered membrane ruffles induced within 5 min after serum-MAF addition. This study aimed to elucidate the importance of annexin A2, which is a multifunctional Ca2+-binding protein related to cytoskeletal membrane dynamics, in serum-MAF signalling. MATERIALS AND METHODS: Annexin A2 and F-actin localizations were analyzed via immunostaining and confocal microscopy. Using EGTA as chelator, the role of Ca2+ in serum-MAF signalling was examined. RESULTS: Annexin A2 was found to translocate from the cytosol to the cell cortex within 30 s of serum-MAF stimulation. Ca2+ chelation inhibited the translocation of annexin A2, frill-like structure formation, and phagocytic activation by serum-MAF. CONCLUSION: Annexin A2 and Ca2+ were responsible for the rapid phagocytic activation by serum-MAF. This study provides an understanding of phagocytic activation in macrophages, which could be beneficial for cancer immunotherapy.


Assuntos
Anexina A2/metabolismo , Ativação de Macrófagos , Fatores Ativadores de Macrófagos/sangue , Macrófagos/fisiologia , Actinas/metabolismo , Humanos , Fagocitose , Células THP-1
16.
Am J Physiol Lung Cell Mol Physiol ; 321(3): L555-L565, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34261337

RESUMO

Patients with cystic fibrosis (CF) have defective macrophage phagocytosis and efferocytosis. Several reports demonstrate that neutrophil elastase (NE), a major inflammatory protease in the CF airway, impairs macrophage phagocytic function. To date, NE-impaired macrophage phagocytic function has been attributed to cleavage of cell surface receptors or opsonins. We applied an unbiased proteomic approach to identify other potential macrophage targets of NE protease activity that may regulate phagocytic function. Using the murine macrophage cell line, RAW 264.7, human blood monocyte-derived macrophages, and primary alveolar macrophages from Cftr-null and wild-type littermate mice, we demonstrated that NE exposure blocked phagocytosis of Escherichia coli bio-particles. We performed liquid chromatography-tandem mass spectroscopy (LC-MS/MS) proteomic analysis of the conditioned media from RAW264.7 treated either with active NE or inactive (boiled) NE as a control. Out of 840 proteins identified in the conditioned media, active NE upregulated 142 proteins and downregulated 211 proteins. NE released not only cell surface proteins into the media but also cytoskeletal, mitochondrial, cytosolic, and nuclear proteins that were detected in the conditioned media. At least 32 proteins were associated with the process of phagocytosis including 11 phagocytic receptors [including lipoprotein receptor-related protein 1 (LRP1)], 7 proteins associated with phagocytic cup formation, and 14 proteins involved in phagocytic maturation (including calpain-2) and phagolysosome formation. NE had a broad effect on the proteome required for regulation of all stages of phagocytosis and phagolysosome formation. Furthermore, the NE sheddome/secretome included proteins from other macrophage cellular domains, suggesting that NE may globally regulate macrophage structure and function.


Assuntos
Elastase de Leucócito/metabolismo , Lisossomos/metabolismo , Macrófagos/metabolismo , Fagocitose , Fagossomos/metabolismo , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Feminino , Humanos , Elastase de Leucócito/genética , Lisossomos/genética , Lisossomos/patologia , Macrófagos/fisiologia , Masculino , Camundongos , Camundongos Mutantes , Fagossomos/genética , Fagossomos/patologia , Células RAW 264.7
17.
Fish Shellfish Immunol ; 116: 107-114, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34256133

RESUMO

An eight-week investigation was conducted to access the potential impact of dietary watermelon rind powder (WMRP) and L. plantarum CR1T5 (LP) administered individually or in combination on immunity, disease resistance, and growth rate of Nile tilapia fingerlings cultured in a biofloc system. Three hundred twenty fish (average weight 16.57 ± 0.14 g) were distributed into 16 tanks at a rate of 20 fish per tank. The fish were fed different diets: Diet 1 (0 g kg-1 WMRP and 0 CFU g-1 L. plantarum) (control), Diet 2 (40 g kg-1 WMRP), Diet 3 (108 CFU g-1 LP), and Diet 4 (40 g kg-1 WMRP + 108 CFU g-1 LP) for eight weeks. A completely randomized design (CRD) with four replications was applied. Skin mucus, serum immunity, and growth parameters were analyzed every 4 weeks, and a challenge study against S. agalactiae was conducted at the end of the experiment. The findings showed that the inclusion of WMRP + LP, administrated individually or in a mixture, significantly (P<0.05) stimulated growth, skin mucus, and serum immune parameters of Nile tilapia fingerlings compared with the control. The highest values were detected in fish fed the combination of WMRP and LP, as opposed to individual administration of either WMRP or LP, in which no significant differences were detected. Within the challenge study, the relative percent survival (RPS) in Diet 2, Diet 3, and Diet 4 was 48.0%, 52.0%, and 68.0%, respectively. Fish fed 40 g kg-1 WMRP + LP produced significantly higher RPS and protection against S. agalactiae than the other treated groups. Current results suggest that the dual administration of WMRP and LP maybe an effective feed additive for Nile tilapia grown in an indoor biofloc system, capable of improving growth parameters and increasing resistance to S. agalactiae infection.


Assuntos
Citrullus , Lactobacillus plantarum , Preparações de Plantas/farmacologia , Prebióticos , Simbióticos , Ração Animal , Animais , Aquicultura , Ciclídeos/sangue , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/imunologia , Dieta/veterinária , Resistência à Doença , Contagem de Leucócitos , Micrococcus , Muco/enzimologia , Muco/imunologia , Muramidase/imunologia , Peroxidase/imunologia , Fagocitose , Pós , Explosão Respiratória , Pele/imunologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae
18.
Free Radic Biol Med ; 172: 550-561, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34245858

RESUMO

The small GTPase Arf6 regulates many cellular processes, including cytoskeletal remodeling, receptor endocytosis, and pathogen phagocytosis. Arf6 silencing in neutrophil (PMN)-like cells is well-known to inhibit chemotactic peptide-mediated activation of phospholipase D, the oxidative burst, and ß2 integrin-dependent adhesion. In conditional knockout (cKO) mice, the migration to inflammatory sites of Arf6-deficient PMNs was diminished and associated with reduced cell surface expression of ß2 integrins. In this study we assessed the impact of Arf6 depletion on the functions and gene expression profile of PMNs isolated from the mouse air pouch. Numerous genes involved in response to oxygen levels, erythrocyte and myeloid differentiation, macrophage chemotaxis, response to chemicals, apoptosis, RNA destabilization, endosome organization, and vesicle transport were differentially expressed in PMNs cKO for Arf6. Lpar6 and Lacc-1 were the most up-regulated and down-regulated genes, respectively. The deletion of Arf6 also decreased Lacc-1 protein level in PMNs, and silencing of Arf6 in THP-1 monocytic cells delayed LPS-mediated Lacc-1 expression. We report that fMLP or zymosan-induced glycolysis and oxygen consumption rate were both decreased in air pouch PMNs but not in bone marrow PMNs of Arf6 cKO mice. Reduced oxygen consumption correlated with a decrease in superoxide and ROS production. Deletion of Arf6 in PMNs also reduced phagocytosis and interfered with apoptosis. The data suggest that Arf6 regulates energy metabolism, which may contribute to impaired phagocytosis, ROS production, and apoptosis in PMN-Arf6 cKO. This study provides new information on the functions and the inflammatory pathways influenced by Arf6 in PMNs.


Assuntos
Neutrófilos , Explosão Respiratória , Animais , Metabolismo Energético/genética , Camundongos , Fagocitose , Superóxidos
19.
Int J Mol Sci ; 22(14)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34298979

RESUMO

Platelet extravasation during inflammation is under-appreciated. In wild-type (WT) mice, a central corneal epithelial abrasion initiates neutrophil (PMN) and platelet extravasation from peripheral limbal venules. The same injury in mice expressing low levels of the ß2-integrin, CD18 (CD18hypo mice) shows reduced platelet extravasation with PMN extravasation apparently unaffected. To better define the role of CD18 on platelet extravasation, we focused on two relevant cell types expressing CD18: PMNs and mast cells. Following corneal abrasion in WT mice, we observed not only extravasated PMNs and platelets but also extravasated erythrocytes (RBCs). Ultrastructural observations of engorged limbal venules showed platelets and RBCs passing through endothelial pores. In contrast, injured CD18hypo mice showed significantly less venule engorgement and markedly reduced platelet and RBC extravasation; mast cell degranulation was also reduced compared to WT mice. Corneal abrasion in mast cell-deficient (KitW-sh/W-sh) mice showed less venule engorgement, delayed PMN extravasation, reduced platelet and RBC extravasation and delayed wound healing compared to WT mice. Finally, antibody-induced depletion of circulating PMNs prior to corneal abrasion reduced mast cell degranulation, venule engorgement, and extravasation of PMNs, platelets, and RBCs. In summary, in the injured cornea, platelet and RBC extravasation depends on CD18, PMNs, and mast cell degranulation.


Assuntos
Plaquetas/fisiologia , Antígenos CD18/fisiologia , Degranulação Celular , Córnea/irrigação sanguínea , Eritrócitos/fisiologia , Hiperemia/fisiopatologia , Mastócitos/fisiologia , Neutrófilos/fisiologia , Migração Transendotelial e Transepitelial/fisiologia , Vasculite/imunologia , Vênulas/metabolismo , Animais , Antígenos CD18/deficiência , Movimento Celular , Quimiotaxia de Leucócito , Lesões da Córnea/metabolismo , Lesões da Córnea/patologia , Epitélio Corneano/fisiologia , Feminino , Hiperemia/sangue , Macrófagos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microcirculação , Microscopia Eletrônica , Modelos Animais , Fagocitose , Regeneração/fisiologia , Vasculite/sangue , Vênulas/patologia , Cicatrização/fisiologia
20.
J Immunol ; 207(3): 777-783, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34272233

RESUMO

Bactericidal/permeability-increasing protein (BPI) plays a major role in innate immunity through the ability of the N-terminal domain (NTD) to bind LPS, mediate cytotoxicity, and block LPS-induced inflammation. The C-terminal domain mediates phagocytosis of bacteria bound to the NTD. These two domains are linked by a surface-exposed loop at amino acids 231-249 for human BPI, known as the "hinge region." Autoantibodies to human BPI are prevalent in many chronic lung diseases; their presence is strongly correlated with Pseudomonas aeruginosa and with worse lung function in patients with cystic fibrosis and bronchiectasis. Although prior literature has reported BPI neutralization effect with autoantibodies targeting either NTD or C-terminal domain, the functionality of BPI Ab to the hinge region has never been investigated. Here, we report that Ab responses to the BPI hinge region mediate a remarkably selective potentiation of BPI-dependent phagocytosis of P. aeruginosa with both human and murine neutrophils in vitro and in vivo. These findings indicate that autoantibodies to the BPI hinge region might enhance bacterial clearance.


Assuntos
Fibrose Cística , Neutrófilos , Animais , Autoanticorpos , Proteínas Sanguíneas , Humanos , Proteínas de Membrana , Camundongos , Permeabilidade , Fagocitose
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