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1.
Electron J Biotechnol ; 49: 5-13, Jan. 2021. ilus, tab, graf
Article in English | LILACS | ID: biblio-1291618

ABSTRACT

BACKGROUND: Opsonization, is the molecular mechanism by which target molecules promote interactions with phagocyte cell surface receptors to remove unwanted cells by induced phagocytosis. We designed an in vitro system to demonstrate that this procedure could be driven to eliminate adipocytes, using peptides mimicking regions of the complement protein C3b to promote opsonization and enhance phagocytosis. Two cell lines were used: (1) THP-1 monocytes differentiated to macrophages, expressing the C3b opsonin receptor CR1 in charge of the removal of unwanted coated complexes; (2) 3T3-L1 fibroblasts differentiated to adipocytes, expressing AQP7, to evaluate the potential of peptides to stimulate opsonization. (3) A co-culture of the two cell lines to demonstrate that phagocytosis could be driven to cell withdrawal with high efficiency and specificity. RESULTS: An array of peptides were designed and chemically synthesized p3691 and p3931 joined bound to the CR1 receptor activating phagocytosis (p < 0.033) while p3727 joined the AQP7 protein (p < 0.001) suggesting that opsonization of adipocytes could occur. In the co-culture system p3980 and p3981 increased lipid uptake to 91.2% and 89.0%, respectively, as an indicator of potential adipocyte phagocytosis. CONCLUSIONS: This in vitro model could help understand the receptor­ligand interaction in the withdrawal of unwanted macromolecules in vivo. The adipocyte-phagocytosis discussed may help to control obesity, since peptides of C3b stimulated the CR1 receptor, promoting opsonisation and phagocytosis of lipidcontaining structures, and recognition of AQP7 in the differentiated adipocytes, favored the phagocytic activity of macrophages, robustly supported by the co-culture strategy.


Subject(s)
Phagocytosis , Complement System Proteins , Adipocytes , In Vitro Techniques , Opsonin Proteins , Coculture Techniques , Foam Cells , Macrophages , Microscopy, Fluorescence
2.
J. appl. oral sci ; 29: e20200770, 2021. graf
Article in English | LILACS | ID: biblio-1180798

ABSTRACT

Abstract Objective Neutrophils are key effector cells of the innate immune system. They recognize antigens through membrane receptors, which are expressed during their maturation and activation. Neutrophils express FcγRII (CD32), FcγRIII (CD16), and FcγRI (CD64) after being activated by different factors such as cytokines and bacterial products. These receptors are involved with phagocytosis of IgG-opsonized microbes and enhance defense mechanisms. Based on that, our study seeks to compare the expression of FcγRII, FcγRIII, FcγRI, and CD11b on neutrophils from elderly and young subjects and their expression after in vitro activation with cytokines and LPS. Methodology Neutrophils were isolated from human peripheral blood and from mice bone marrow by density gradient. After isolation, FCγRs expression was immediately analyzed by flow cytometry or after in vitro stimulation. Results In freshly isolated cells, the percentage of FcγRIIIb+ and CD11b+ neutrophils were higher in samples from young individuals; FcγRIIIa expression was more prominent on aged neutrophils; FcγRIA expression was similar in all samples analyzed. Exposure to CXCL8 and LPS resulted in a higher percentage of FcγRIa+ neutrophils on elderly individuals' samples but lower when compared with neutrophils from young donors. We observed that LPS caused an increase in FcγRIIa expression on aging human neutrophils. In contrast, FcγRIIIb expression in response to CXCL8 and LPS stimulation was not altered in the four groups. CD11b expression was lower in neutrophils from elderly individuals even in response to LPS and CXCL8. In mice, we observed differences only regarding CD11b expression, which was increased on aged neutrophils. LPS exposure caused an increase in all FcγRs. Conclusions Our results suggest that, in humans, the overall pattern of FcγR expression and integrin CD11b are altered during aging and immunosenescence might contribute to age-related infection.


Subject(s)
Animals , Mice , Receptors, IgG , Neutrophils , Phagocytosis , Cell Count , Flow Cytometry
3.
Braz. J. Pharm. Sci. (Online) ; 57: e19139, 2021. graf
Article in English | LILACS | ID: biblio-1350244

ABSTRACT

Dehydroepiandrosterone (DHEA) is a steroid hormone secreted by the adrenal glands, gonads and brain. It is a precursor to sex hormones and also is known to have immune modulatory activity. However, little is known about the relationship between DHEA and neutrophils and thus our study evaluates the influence of DHEA in the effector functions of neutrophils. Human neutrophils were treated in vitro with DHEA and further infected with Salmonella enterica serovar Typhimurium. The treatment of neutrophils with 0.01 µM of DHEA increased the phagocytosis of Salmonella independent of TLR4 as the treatment did not modulate the TLR4 expression. Additionally, DHEA caused a decrease in ROS (reactive oxygen species) production and did not influence the formation of the neutrophil extracellular trap (NET). Steroid treated neutrophils, infected or stimulated with LPS (lipopolysaccharide), showed reduced production of IL-8, compared to untreated cells. Also, the protein levels of p-NFκB were decreased in neutrophils treated with DHEA, and this reduction could explain the reduced levels of IL-8. These results led us to conclude that the steroid hormone DHEA has important modulatory functions in neutrophils


Subject(s)
Humans , Male , Adult , In Vitro Techniques , Dehydroepiandrosterone/analysis , Neutrophils/metabolism , Phagocytosis/genetics , Gonadal Steroid Hormones/pharmacology , Adrenal Glands/metabolism , Salmonella enterica/classification
4.
Pesqui. vet. bras ; 41: e06652, 2021. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1180875

ABSTRACT

Painful procedures can affect the function of innate immune cells, such as neutrophils and macrophages, increasing the risk of infectious diseases. The present work aimed to verify if the analgesics flunixin meglumine or ketoprofen can attenuate the pain/discomfort of newborn lambs submitted by elastration tail docking and thereby avoid the impairment of blood granulocytes function. Twenty-one neonate lambs were divided into three treatments: the control group (n=7), not subjected to caudectomy; the flunixin group (n=7), subjected to caudectomy under local anesthesia and analgesia with two doses of flunixin meglumine; and the ketoprofen group (n=7), subjected to caudectomy under local anesthesia and two doses of ketoprofen. Pain indicators were observed by pain posture score (PS), the number of vocalizations (V), frequency of the movement of the ears (EF), and respiratory rates (RR), observed by a 10 minutes videos for each time points: -15min, 6h, 48h, and 144h. At the same time points, the reactive oxygen species (ROS) production and phagocytosis of blood granulocytes were measured by flow cytometry. At 6h after caudectomy, there was a pain indicator increase (RR, V, and PS), a blood granulocyte percentage increase, and a granulocytes phagocytosis reduction for both groups. At 48h, the ketoprofen group spend more time in pain posture and, at 144h, they exhibited a ROS production granulocyte reduction without signs of pain. We conclude the flunixin meglumine and ketoprofen did not prevent the acute pain/discomfort caused by caudectomy, because the groups showed a pain behavior and impaired of the innate immune response however, the flunixin meglumine was effective in controlling the chronic pain and their effects on blood granulocytes function in compare ketoprofen.(AU)


Procedimentos dolorosos podem afetar a função das células imunes inatas como neutrófilos e macrófagos, aumentando o risco de ocorrer doenças infeciosas. Desta maneira, o presente trabalho pretendeu verificar se os analgésicos flunixin meglumine ou cetoprofeno conseguem atenuar a dor/desconforto de cordeiros neonatos submetidos a caudectomia por elastração, evitando assim o comprometimento da função dos granulócitos sanguíneos. Para tanto 21 cordeiras foram aleatoriamente divididas em três tratamentos: grupo controle (n=7) não submetido a caudectomia, grupo flunixin (n=7) submetido a caudectomia precedida por anestesia local e duas doses de flunixin meglumine, e cetoprofeno (n=7) submetido a caudectomia precedida por anestesia local e duas doses de cetoprofeno. Mensurou-se os indicadores de dor/desconforto após caudectomia por observações de escore de postura de dor (EP), número de vocalizações (V), frequência de movimentar as orelhas (FO) e frequência respiratória (FR), observados em vídeos de 10 minutos nos momentos -15 min e 6, 48 e 144h. Nos mesmos momentos, avaliou-se a as funções de produção de espécies reativas de oxigênio (ERO) e de fagocitose por granulócitos sanguineos em citometria de fluxo. Notou-se aumento dos indicadores de dor (FR, de V e de EP), da porcentagem dos granulócitos sanguíneos e redução da eficiência de fagocitose em ambos os grupos as 6h. As 48h, os animais do grupo cetoprofeno ainda apresentava mais tempo em postura de dor que os demais grupos e as 144h, apresentou redução da produção ERO por granulócitos. Tais achados permitem concluir que tanto o flunexin meglumine como o cetoprofeno não preveniram dor/desconforto agudo promovido pela elastração, pois os dois grupos manifestaram comportamento de dor e redução da resposta imune inata. Ainda, o analgésico flunixin meglumine foi efetivo em controlar a dor mais tardia e seus efeitos na função de granulócitos sanguíneos em comparação ao cetoprofeno.(AU)


Subject(s)
Animals , Female , Phagocytosis , Sheep , Ketoprofen , Analgesia , Neutrophils , Reactive Oxygen Species
5.
J. venom. anim. toxins incl. trop. dis ; 27: e20200147, 2021. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1287092

ABSTRACT

Inflammation has accompanied humans since their first ancestors appeared on Earth. Aulus Cornelius Celsus (25 BC-50 AD), a Roman encyclopedist, offered a still valid statement about inflammation: "Notae vero inflammationis sunt quatuor: rubor et tumor cum calore and dolore", defining the four cardinal signs of inflammation as redness and swelling with heat and pain. While inflammation has long been considered as a morbid phenomenon, John Hunter (18th century) and Elie Metchnikoff (19th century) understood that it was a natural and beneficial event that aims to address a sterile or an infectious insult. Many other famous scientists and some forgotten ones have identified the different cellular and molecular players, and deciphered the different mechanisms of inflammation. This review pays tribute to some of the giants who made major contributions, from Hippocrates to the late 19th and first half of the 20th century. We particularly address the discoveries related to phagocytes, diapedesis, chemotactism, and fever. We also mention the findings of the various inflammatory mediators and the different approaches designed to treat inflammatory disorders.(AU)


Subject(s)
Phagocytosis , Transendothelial and Transepithelial Migration/physiology , Inflammation/classification , Fever
6.
Article in Chinese | WPRIM | ID: wpr-878542

ABSTRACT

Hemocytes play an important role in the immune defense system of animals, especially for invertebrates that have no adaptive immune system. In those animals, hemocytes not only participate in the cellular immunity including phagocytosis, encapsulation, and nodules formation, but also the humoral immunity via storage and release of immune factors. Identification of the components of hemocytes is the basis for understanding the immune mechanism and the function of hemocytes. Despite various researches have been done on distinguishing the composition and function of shrimp hemocytes, no standard is used uniformly until now. So, we analyze and summarize the results on shrimp hemocytes research and offer a three subgroups category in this review. We also introduce the morphological characters and immune function of three subgroups in detail. We hope this work will be beneficial for understanding the function and molecular mechanism of hemocytes in invertebrate, bringing ideas for new separation technology development.


Subject(s)
Animals , Hemocytes , Phagocytosis
7.
Arq. bras. med. vet. zootec. (Online) ; 72(5): 1993-1996, Sept.-Oct. 2020. tab
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1131527

ABSTRACT

This study aimed to evaluate the neutrophil oxidative metabolism and phagocytosis of Zymonsan particles of primiparous and pluriparous Lacaune ewes during the first 30 days after lambing. A total of 20 ewes were evaluated, 10 primiparous (GPR) and 10 pluriparous (GPL). Evaluation of basal oxidative metabolism was performed using the nitroblue tetrazolium (NBT) technique, stimulating neutrophil phagocytosis with Zymosan particles. Blood samples were collected at parturition day (M1) and 1, 3, 7, 15 and 30 days after parturition, corresponding to M2, M3, M4, M5 and M6, respectively. In relation to the groups, GPR presented lower oxidative basal metabolism neutrophils in M1 compared to M4, in M3 with M1, M2, M4 and M5. In M4 and M5 differences were found at all times and in M6 with M4 and M5. Higher percentage of neutrophils than phagocytes were found in M4, M5 and M6 than in M1 and M2 in GPL animals. At all times GPR presented a lower percentage of phagocytosis than GPL. Thus it is concluded that the immune response in pluriparous sheep was more efficient than in primiparous sheep.(AU)


Subject(s)
Animals , Female , Phagocytosis , Sheep/blood , Metabolism , Neutrophils/physiology , Postpartum Period/blood
8.
Infectio ; 24(2): 126-128, abr.-jun. 2020. graf
Article in Spanish | LILACS, COLNAL | ID: biblio-1114852

ABSTRACT

Resumen La linfohistiocitosis hemofagocítica (LHH) por Histoplasma capsulatum, presentación rara de la histoplasmosis diseminada, es causada por la fagocitosis de las células hematopoyéticas por macrófagos tisulares. Presentamos el caso de un paciente masculino de 44 años con trasplante renal que asiste por fiebre sin otra sintomatología. Inicialmente se obtiene una gota gruesa positiva para P. vivax, iniciando manejo antimalárico. A los 2 días de tratamiento, el paciente presenta disfunción multiórganica, se rectifica diagnóstico en centro de referencia reportando en extendido de sangre periférica la presencia de levaduras de H. capsulatum en polimorfonucleares, resultado confirmado con prueba de inmunodifusión. Se ajusta manejo, pero el paciente fallece. El diagnóstico de infecciones por gérmenes inusuales con presentaciones inespecíficas es un reto en pacientes con inmunosupresión.


Abstract Hemophagocytic Lymphohistiocytosis (HLH) induced by Histoplasma capsulatum is a rare entity who is characterized by phagocytosis of hematopoietic cells by tissue macrophages. A 44-year-old male patient with kidney transplantation was admitted to our ambulatory service with fever. Initially, we performed a thick drop test who was positive for P. vivax, so antimalarial therapy was initiated. Patient then progressed to multiple organ dysfunction after 2 days of treatment. Thus, a reference center went back over the blood smear which revealed the presence of yeast cells H. capsulatum within polymorphonuclear cells. This result was confirmed by an immunodifussion assay. Despite of antifungal treatment, patient passed away. The diagnosis for unusual microorganism with unspecific clinical presentation could be a challenge in immunosupressive patients.


Subject(s)
Humans , Male , Adult , Lymphohistiocytosis, Hemophagocytic , Phagocytosis , Hematopoietic Stem Cells , Kidney Transplantation , Histoplasma
9.
Braz. j. biol ; 80(2): 336-344, Apr.-June 2020. graf
Article in English | LILACS | ID: biblio-1132369

ABSTRACT

Abstract Although the potential of surrogate propagation technology for aquaculture and conservation of Neotropical fish, the poor understanding of the host immune system may results in rejection and destruction of the donor material. Thus, it is necessary to study and to develop methods to evaluate the effects of immunosuppressive drugs employment and to evaluate the immunocompatibility between donor and receptor. Thus, the present study aimed to optimize a methodology to assess in vivo phagocytosis in Astyanax altiparanae using Saccharomyces cerevisiae and to evaluate their hematological response resultant from the inflammatory induction. To this, S. cerevisiae were labeled with Congo red and injected in the coelomic cavity of A. altiparanae at the concentration of 2.5 x 106 cells mL-1. A PBS solution and a non-injected group were kept as control. Fish blood was sampled and the phagocytic capacity and index were determined at 1, 2, 3 and 6 h post-injection (hpi). The yeast injection successfully stimulated phagocytosis, with the best result for phagocytosis assessment after 2 hpi. Moreover, it was achieved a high traceability of phagocytized and non-phagocytized yeast under optic microscopy analysis due to the Congo red labeling. The hematological profile was similar to usually observed in early infections, indicating lymphocyte migration to inflammatory site and increase in number of circulating phagocytes due to natural response to inflammatory stimulus. In conclusion, our method was efficient to assess in vivo phagocytosis in A. altiparanae and will be an important tool to evaluate the efficacy of immunosuppressive drugs in this species. Additionally, these results may serve as support for further studies in fish immunocompetence, both in laboratory and in field conditions.


Resumo Apesar do potencial apresentado pela tecnologia de propagação mediada para a aquicultura e conservação de peixes Neotropicais, o pobre entendimento do sistema imune do hospedeiro pode resultar na rejeição e destruição do material do doador. Com isso, se fazem necessários o estudo e o desenvolvimento de métodos para análise tanto dos efeitos de drogas imunossupressoras quanto para a avaliação da imunocompatibilidade entre doadores e receptores. Logo, o presente estudo teve como objetivo aperfeiçoar um método para analisar a fagocitose in vivo em Astyanax altiparanae usando Saccharomyces cerevisiae marcado e avaliar seu perfil hematológico resultante da indução inflamatória. Para isso, S. cerevisiae foram marcados com vermelho Congo e injetados na cavidade celomática dos A. altiparanae na concentração de 2,5 x 106 células.mL-1. Peixes injetados com PBS e peixes não injetados foram mantidos como controle. Sangue foi colhido e a capacidade fagocítica e o índice fagocítico foram determinados após 1, 2, 3 e 6 horas após à injeção (hpi). A injeção de levedura estimulou a fagocitose com sucesso, com o melhor resultado atingido após 2 hpi. Ainda, foi observada uma alta rastreabilidade das leveduras fagocitadas e não fagocitadas sob microscopia óptica devido à marcação com vermelho Congo. O perfil hematológico foi similar ao observado usualmente em infecções recém-induzidas, indicando migração de linfócitos ao sítio inflamatório e aumento no número de fagócitos circulantes devido à resposta natural ao estímulo inflamatório. Como conclusão, nosso método foi eficiente para analisar a fagocitose in vivo em A. altiparanae e será uma ferramenta importante para a avaliação de eficácia de drogas imunossopressoras para esta espécie. Em adição, estes resultados podem contribuir para futuros estudos em imunocompetência em peixes, tanto em âmbito laboratorial quanto a campo.


Subject(s)
Animals , Characidae , Hematology , Phagocytosis , Saccharomyces cerevisiae , Aquaculture
10.
Arq. ciências saúde UNIPAR ; 24(1): 3-7, jan-abr. 2020.
Article in Portuguese | LILACS | ID: biblio-1095737

ABSTRACT

Criptococose é uma doença grave que afeta tanto imunocomprometidos quanto imunocompetentes, com isso analisar a virulência é fundamental para novas terapêuticas. Objetivo: Analisar a capacidade de virulência e susceptibilidade aos antifúngicos de Cryptococcus spp. isolados de líquor de pacientes de hospital do norte do Paraná. Métodos: A partir de dois isolados clínicos C. neoformans e C. gattii, realizou-se a confirmação da identificação. Para a virulência, avaliou-se o tamanho da cápsula, capacidade de sobrevivência após exposição a neutrófilos, produção de melanina e urease. No antifungigrama por difusão em disco utilizou-se: anfotericina B, cetoconazol, voriconazol, itraconazol e miconazol. Resultados: C. gattii destaca-se por maior desenvolvimento da cápsula além da melhor capacidade de sobreviver a fagocitose em relação ao C. neoformans. No antifungigrama, ambos os isolados se apresentam sensíveis às drogas estudadas. Conclusão: Esses achados contribuem para a compreensão das diferentes patogêneses entre C. gattii e C. neoformans.


Cryptococcosis is a serious disease that can affect both immunocompromised and immunocompetent individuals, thus the virulence analysis is fundamental for the development of new treatments. Objective: To analyze the virulence and susceptibility of Cryptococcus spp. isolated from cerebrospinal fluid of patients from a hospital in the north of Paraná. Methods: From two clinical isolates, C. neoformans and C. gattii were confirmed and identified. For virulence, capsule size, survival capacity after exposure to neutrophils, melanin production and urease were evaluated. In the disc-diffusion method, the following antifungals were used: amphotericin B, ketoconazole, voriconazole, itraconazole and miconazole Results: It was observed that C. gattii presents greater results for development of the capsule beside presenting the best ability to survive phagocytosis in relation to C. neoformans. In the disc-diffusion method, both isolates presented sensitivity to the studied drugs. Conclusion: These findings contribute to the understanding of the different pathogens between C. gattii and C. neoformans.


Subject(s)
Cryptococcosis/virology , Virulence Factors/analysis , Antifungal Agents/analysis , Phagocytosis , Urease/urine , Yeasts/virology , Capsules/analysis , Pharmaceutical Preparations , Amphotericin B/analysis , Itraconazole , Cryptococcus neoformans/virology , Agar/analysis , Cryptococcus gattii/virology , Voriconazole , Melanins/analysis , Miconazole , Neutrophils/virology
11.
Mem. Inst. Oswaldo Cruz ; 115: e190408, 2020. graf
Article in English | LILACS | ID: biblio-1101276

ABSTRACT

BACKGROUND The mechanism of resistance to SbIII in Leishmania is complex, multifactorial and involves not only biochemical mechanisms, but also other elements, such as the immune system of the host. OBJECTIVES In this study, putative changes in the immunological profile of human monocytes infected with wild-type (WT) and antimony (SbIII)-resistant Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum lines were evaluated. METHODS Susceptibility assays WT and SbIII-resistant L. braziliensis and L. infantum were performed using lines THP-1 human monocytic lineage. Phagocytic capacity, cytokine profile, intracellular nitric oxide (NO) production and surface carbohydrate residues profile were performed in peripheral blood monocytes by flow cytometry. FINDINGS The phagocytic capacity and intracellular NO production by classical (CD14++CD16-) and proinflammatory (CD14++CD16+) monocytes were higher in the presence of L. infantum lines compared to L. braziliensis lines. The results also highlight proinflammatory monocytes as the cellular subpopulation of major relevance in a phagocytosis event and NO expression. It is important to note that L. infantum induced a proinflammatory cytokine profile characterised by higher levels of TNF-α in culture supernatant than L. braziliensis. Conversely, both Leishmania lines induce high levels of IL-6 in culture supernatant. Analysis of the expression profile of surface carbohydrates showed that L. braziliensis presents 4.3-fold higher expression of galactose(β1,4)N-acetylglucosamine than L. infantum line. Interestingly, the expression level of α-N-acetylgalactosamine residues was 2-fold lower in the SbIII-resistant L. braziliensis line than its counterpart WT line, indicating differences in surface glycoconjugates between these lines. MAIN CONCLUSIONS Our results showed that L. braziliensis and L. infantum induce different innate immune responses and a highly inflammatory profile, which is characteristic of infection by L. infantum, the species associated with visceral disease.


Subject(s)
Humans , Male , Female , Adult , Young Adult , Phagocytosis/immunology , Leishmania braziliensis/immunology , Monocytes/parasitology , Leishmania infantum/immunology , Antimony/pharmacology , Nitric Oxide/biosynthesis , Antiprotozoal Agents/pharmacology , Leishmania braziliensis/drug effects , Drug Resistance , Monocytes/immunology , Leishmania infantum/drug effects , Flow Cytometry , Immunity, Innate
12.
Braz. j. med. biol. res ; 53(7): e9207, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS | ID: biblio-1132533

ABSTRACT

The objective of this study was to investigate the relationship between PI3K/mTOR/RhoA signaling regulated cytoskeletal rearrangements and phagocytic capacity of macrophages. RAW264.7 macrophages were divided into four groups; blank control, negative control, PI3K-RNAi, and mTOR-RNAi. The cytoskeletal changes in the macrophages were observed. Furthermore, the phagocytic capacity of macrophages against Escherichia coli is reported as mean fluorescence intensity (MFI) and percent phagocytosis. Transfection yielded 82.1 and 81.5% gene-silencing efficiencies against PI3K and mTOR, respectively. The PI3K-RNAi group had lower mRNA and protein expression levels of PI3K, mTOR, and RhoA than the blank and negative control groups (Р<0.01). The mTOR-RNAi group had lower mRNA and protein levels of mTOR and RhoA than the blank and the negative control groups (Р<0.01). Macrophages in the PI3K-RNAi group exhibited stiff and inflexible morphology with short, disorganized filopodia and reduced number of stress fibers. Macrophages in the mTOR-RNAi group displayed pronounced cellular deformations with long, dense filopodia and an increased number of stress fibers. The PI3K-RNAi group exhibited lower MFI and percent phagocytosis than blank and negative control groups, whereas the mTOR-RNAi group displayed higher MFI and percent phagocytosis than the blank and negative controls (Р<0.01). Before and after transfection, the mRNA and protein levels of PI3K were both positively correlated with mTOR and RhoA (Р<0.05), but the mRNA and protein levels of mTOR were negatively correlated with those of RhoA (Р<0.05). Changes in the phagocytic capacity of macrophages were associated with cytoskeletal rearrangements and were regulated by the PI3K/mTOR/RhoA signaling pathway.


Subject(s)
Humans , Animals , Rats , Phagocytosis/physiology , Cytoskeleton/metabolism , Phosphatidylinositol 3-Kinases/metabolism , rhoA GTP-Binding Protein/metabolism , TOR Serine-Threonine Kinases/metabolism , Macrophages/metabolism , Transfection , Signal Transduction , Blotting, Western , Gene Silencing , RNA Interference , Real-Time Polymerase Chain Reaction , RAW 264.7 Cells , Genetic Vectors
13.
Chinese Journal of Biotechnology ; (12): 1431-1439, 2020.
Article in Chinese | WPRIM | ID: wpr-826833

ABSTRACT

The purpose of this study is to provide a culture for mouse bone marrow-derived macrophages (BMDM) and peritoneal macrophages (PM) and to characterize their molecular and cellular biology. The cell number and purity from the primary culture were assessed by cell counter and flow cytometry, respectively. Morphological features were evaluated by inverted microscope. Phagocytosis by macrophages was detected by the neutral red dye uptake assay. Phenotypic markers were analyzed by real-time fluorescent quantitative PCR. Our results show that the cell number was much higher from culture of BMDM than PM, while there was no significant difference regarding the percentage of F4/80+CD11b+ cells (98.30%±0.53% vs. 94.83%±1.42%; P>0.05). The proliferation rate of BMDM was significantly higher than PM in the presence of L929 cell conditioned medium, by using CCK-8 assay. However, PM appeared to adhere to the flask wall and extend earlier than BMDM. The phagocytosis capability of un-stimulated BMDM was significantly higher than PM, as well as lipopolysaccharide (LPS)-stimulated BMDM, except the BMDM stimulated by low dose LPS (0.1 μg/mL). Furthermore, Tnfα expression was significantly higher in un-stimulated BMDM than PM, while Arg1 and Ym1 mRNA expression were significantly lower than PM. The expression difference was persistent if stimulated by LPS+IFN-γ or IL-4. Our data indicate that bone marrow can get larger amounts of macrophages than peritoneal cavity. However, it should be aware that the molecular and cellular characteristics were different between these two culture systems.


Subject(s)
Animals , Bone Marrow Cells , Physiology , Cells, Cultured , Culture Media, Conditioned , Lipopolysaccharides , Metabolism , Macrophages , Classification , Physiology , Mice , Phagocytosis
14.
Article in English | WPRIM | ID: wpr-787281

ABSTRACT

Scavenger receptors typically bind to multiple ligands on a cell surface, including endogenous and modified host-derived molecules and microbial pathogens. They promote the elimination of degraded or harmful substances such as non-self or altered-self targets through endocytosis, phagocytosis, and adhesion. Currently, scavenger receptors are subdivided into eight classes based on several variations in their sequences due to alternative splicing. Since recent studies indicate targeting scavenger receptors has been involved in cancer prognosis and carcinogenesis, we will focus on the current knowledge about the emerging role of scavenger receptor classes A to E in cancer progression.


Subject(s)
Alternative Splicing , Carcinogenesis , Endocytosis , Ligands , Macrophages , Phagocytosis , Prognosis , Receptors, Scavenger
15.
Chonnam Medical Journal ; : 12-19, 2020.
Article in English | WPRIM | ID: wpr-787279

ABSTRACT

The macrophage displays functional and phenotypic diversity, which appears, in no small part, to stem from the ability of macrophages to adapt functionally to changes in their tissue microenvironment. Here, we describe the differential activity of peritoneal macrophages with or without the presence of thioglycollate (TG), an inflammatory drug that encouraged the recruitment of macrophages, during aging. The peritoneal-resident macrophages dramatically reduced in phagocytosis and pro-inflammatory cytokines secretion with aging, whereas the functions of macrophages recruited by TG were not significantly changed with aging. These results suggest that macrophages may be changed by their environment in advanced age, and could provide possible explanations for the controversial results regarding differential changes in macrophages in other papers.


Subject(s)
Aging , Cytokines , Inflammation , Macrophages , Macrophages, Peritoneal , Phagocytosis
16.
Arq. bras. med. vet. zootec. (Online) ; 71(3): 939-943, May-June 2019. tab
Article in English | LILACS, VETINDEX | ID: biblio-1011298

ABSTRACT

Alveolar macrophages (AMs) are an essential part of defense mechanisms within the lungs and their phagocytic activity is important for organ homeostasis. The phagocytic ability of AMs obtained from bronchoalveolar lavage from 17 mature mixed-breed pleasure horses (8 healthy and 9 diagnosed with mild equine asthma) was studied through assays with Leishmania (Viannia) braziliensis promastigotes, which enabled the calculation of a phagocytic index (PI) and a survival index (SI). Results indicate that phagocytic activity of AMs in asthma affected horses is similar to healthy horses, while leishmanicidal activity is significantly increased in horses with asthma.(AU)


Os macrófagos alveolares (MAs) são uma parte essencial dos mecanismos de defesa dentro dos pulmões e sua atividade fagocítica é importante para a homeostase desse órgão. A capacidade fagocitária dos MAs obtidos do lavado broncoalveolar de 17 equinos adultos, sem raça definida (oito saudáveis e nove com diagnóstico de asma equina leve), foi estudada por meio de ensaios com promastigotas de Leishmania (Viannia) braziliensis. Foi calculado o índice fagocítico e o índice de sobrevivência. Os resultados indicam que a atividade fagocítica de MAs em cavalos com asma é semelhante a cavalos saudáveis, enquanto a atividade leishmanicida está significativamente aumentada em cavalos com essa enfermidade.(AU)


Subject(s)
Animals , Asthma/veterinary , Leishmania braziliensis , Macrophages, Alveolar/parasitology , Horses/parasitology , Phagocytosis
17.
Mem. Inst. Oswaldo Cruz ; 114: e190158, 2019. graf
Article in English | LILACS | ID: biblio-1040629

ABSTRACT

As phagocytosis is the first line of defense against malaria, we developed a phagocytosis assay with Plasmodium vivax (P. vivax) merozoites that can be applied to evaluate vaccine candidates. Briefly, after leukocyte removal with loosely packed cellulose powder in a syringe, P. vivax trophozoites matured to the merozoite-rich schizont stages in the presence of the E64 protease inhibitor. The Percoll gradient-enriched schizonts were chemically disrupted to release merozoites that were submitted to merozoite opsonin-dependent phagocytosis in two phagocytic lines with human and mouse antibodies against the N- and C-terminus of P. vivax Merozoite Surface Protein-1 (Nterm-PvMSP1 and MSP119). The resulting assay is simple and efficient for use as a routine phagocytic assay for the evaluation of merozoite stage vaccine candidates.


Subject(s)
Animals , Female , Mice , Phagocytosis/physiology , Plasmodium vivax/immunology , Antibodies, Protozoan/immunology , Protozoan Proteins/immunology , Merozoites/immunology , Plasmodium vivax/physiology , Merozoites/cytology , Flow Cytometry , Mice, Inbred BALB C
18.
Rev. Soc. Bras. Med. Trop ; 52: e20190089B, 2019. tab, graf
Article in English | LILACS | ID: biblio-1041519

ABSTRACT

Abstract INTRODUCTION The relationships between phagocytosis, and mucoid phenotype, plasmid profile and virulence, and resistance genetic characteristics of Klebsiella pneumoniae clinical isolates were evaluated. METHODS Thirty isolates were used to determine the mucoid aspect. Four were selected for analysis of phagocytosis by alveolar macrophages. RESULTS Thirty percent of the samples presented the mucoid phenotype. The phagocytosis rate ranged from 21.5% to 43.43%. Phagocytosis was not correlated with the plasmid profile, but was apparently correlated with mucoid phenotype and antibiotic susceptibility. CONCLUSIONS: Several virulence factors act in parallel in K. pneumoniae to impair host defense.


Subject(s)
Humans , Phagocytosis/genetics , Virulence/genetics , Drug Resistance, Microbial/genetics , Virulence Factors/genetics , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology , Phagocytosis/physiology , Phenotype , Plasmids , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/pathogenicity
19.
Article in English | WPRIM | ID: wpr-763148

ABSTRACT

PURPOSE: The purpose of this study was to investigate the efficacy of stereotactic body radiation therapy (SBRT) as a tumor-associated antigen (TAA) presentation method for dendritic cell (DC) sensitization and evaluate its effect in combination with immunotherapy using an intratumoral injection of immature DCs (iDCs). MATERIALS AND METHODS: CT-26 colon carcinoma cell was used as a cancer cell line. Annexin V staining and phagocytosis assays were performed to determine the appropriate radiation dose and incubation time to generate TAAs. BALB/c mice were used for in vivo experiments. Cancer cells were injected into the right legs and left flanks to generate primary and metastatic tumors, respectively. The mice were subjected to radiation therapy (RT) alone, intradermal injection of electroporated DCs alone, or RT in combination with iDC intratumoral injection (RT/iDC). Tumor growth measurement and survival rate analysis were performed. Enzyme-linked immunospot and cytotoxicity assays were performed to observe the effect of different treatments on the immune system. RESULTS: Annexin V staining and phagocytosis assays showed that 15 Gy radiation dose and 48 hours of incubation was appropriate for subsequent experiments. Maximum DC sensitization and T-cell stimulation was observed with RT as compared to other TAA preparation methods. In vivo assays revealed statistically significant delay in the growth of both primary and metastatic tumors in the RT/iDC group. The overall survival rate was the highest in the RT/iDC group. CONCLUSION: The combination of SBRT and iDC vaccination may enhance treatment effects. Clinical trials and further studies are warranted in the future.


Subject(s)
Animals , Annexin A5 , Cell Line , Colon , Dendritic Cells , Immune System , Immunotherapy , Injections, Intradermal , Leg , Methods , Mice , Phagocytosis , Radiation Dosage , Radiosurgery , Survival Rate , T-Lymphocytes , Vaccination
20.
Article in English | WPRIM | ID: wpr-763048

ABSTRACT

Brain aging is an inevitable process characterized by structural and functional changes and is a major risk factor for neurodegenerative diseases. Most brain aging studies are focused on neurons and less on astrocytes which are the most abundant cells in the brain known to be in charge of various functions including the maintenance of brain physical formation, ion homeostasis, and secretion of various extracellular matrix proteins. Altered mitochondrial dynamics, defective mitophagy or mitochondrial damages are causative factors of mitochondrial dysfunction, which is linked to age-related disorders. Etoposide is an anti-cancer reagent which can induce DNA stress and cellular senescence of cancer cell lines. In this study, we investigated whether etoposide induces senescence and functional alterations in cultured rat astrocytes. Senescence-associated β-galactosidase (SA-β-gal) activity was used as a cellular senescence marker. The results indicated that etoposide-treated astrocytes showed cellular senescence phenotypes including increased SA-β-gal-positive cells number, increased nuclear size and increased senescence-associated secretory phenotypes (SASP) such as IL-6. We also observed a decreased expression of cell cycle markers, including Phospho-Histone H3/Histone H3 and CDK2, and dysregulation of cellular functions based on wound-healing, neuronal protection, and phagocytosis assays. Finally, mitochondrial dysfunction was noted through the determination of mitochondrial membrane potential using tetramethylrhodamine methyl ester (TMRM) and the measurement of mitochondrial oxygen consumption rate (OCR). These data suggest that etoposide can induce cellular senescence and mitochondrial dysfunction in astrocytes which may have implications in brain aging and neurodegenerative conditions.


Subject(s)
Aging , Animals , Astrocytes , Brain , Cellular Senescence , Cell Cycle , Cell Line , DNA , Etoposide , Extracellular Matrix Proteins , Homeostasis , Interleukin-6 , Membrane Potential, Mitochondrial , Mitochondria , Mitophagy , Mitochondrial Dynamics , Neurodegenerative Diseases , Neurons , Neuroprotection , Oxygen Consumption , Phagocytosis , Phenotype , Rats , Risk Factors , Wound Healing
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