A method for measuring the ADCP potency of anti-CD38 monoclonal antibody / 药学学报

A method to measure the antibody-dependent cell-mediated phagocytosis (ADCP) potency of anti-CD38 mAb was developed based on design of experiment (DoE) with a Jurkat/NFAT/CD32a-FcεRIγ transgenic cell line as the effector cell, the Daudi cell line as the target cells, and luciferase as the detection system. The DoE method was used for optimization of experimental parameters and methodological validation. The results show that anti-CD38 mAb exhibits a dose-response relationship with the following four-parameter equation: y = (A - D) / [1 + (x / C)B] + D. Several experimental parameters were optimized by statistical experimental design and determined as follows: the working concentration of anti-CD38 mAb was 800-20.81 ng·mL-1, the density of the target cells was 7.5×104 per well, and the density of effector cells was 2.5×104 per well, with an induction time of 6 h. The method showed good specificity. The recovery rate for samples from 5 different groups showed that the relative potencies of anti-CD38 mAb were (59.97 ± 4.74) %, (82.44 ± 5.15) %, (110.69 ± 11.71) %, (129.23 ± 5.22)% and (162.15 ± 3.66) %. The recoveries ranged from 103% to 120% and the RSDs of the above results were all less than 11%. The linear detection range was 50%-150%. Based on DoE design, this method for measuring ADCP potency of anti-CD38 mAb was optimized and validated with good specificity, repeatability and accuracy. This method can be used for evaluation of ADCP biological activity of anti-CD38 mAbs.

The disbalance of LRP1 and SIRPα by psychological stress dampens the clearance of tumor cells by macrophages

The relationship between chronic psychological stress and tumorigenesis has been well defined in epidemiological studies; however, the underlying mechanism remains underexplored. In this study, we discovered that impaired macrophage phagocytosis contributed to the psychological stress-evoked tumor susceptibility, and the stress hormone glucocorticoid (GC) was identified as a principal detrimental factor. Mechanistically, GC disturbed the balance of the "eat me" signal receptor (low-density lipoprotein receptor-related protein-1, LRP1) and the "don't eat me" signal receptor (signal regulatory protein alpha, SIRPα). Further analysis revealed that GC led to a direct, glucocorticoid receptor (GR)-dependent trans-repression of LRP1 expression, and the repressed LRP1, in turn, resulted in the elevated gene level of SIRPα by down-regulating miRNA-4695-3p. These data collectively demonstrate that stress induces the imbalance of the LRP1/SIRPα axis and entails the disturbance of tumor cell clearance by macrophages. Our findings provide the mechanistic insight into psychological stress-evoked tumor susceptibility and indicate that the balance of LRP1/SIRPα axis may serve as a potential therapeutic strategy for tumor treatment.

Recent progress of nanoparticle-enabled modulation of macrophages for cancer immunotherapy / 药学学报

Macrophages play an important role in maintaining homeostasis of the body, and they are also one of the most abundant immune cells in the tumor microenvironment (TME). These macrophages are often called tumor-associated macrophages (TAMs), which play an important role in the development of tumor and are an important target for tumor therapy. Studies have shown that tumor growth and metastasis can be inhibited by regulating the function of macrophages, but the therapeutic efficacy was often hampered by the poor performance of the drugs such as lack of targeting, poor solubility, low bioavailability, and severe side effects. After introduction of the background of macrophage and tumor therapy, this review focuses on the research progress of nano-drug delivery systems in the modulation of the function of macrophages to enhance tumor immunotherapy. Nano-drug delivery systems are diverse in structures and functions, and can regulate macrophage functions through a variety of mechanisms. Four important aspects of macrophage modulation, which included TAMs depletion, repolarization of TAMs, promoted phagocytosis of TAMs, and combinational modulation of TAMs were summarized. Each strategy together with typical examples was reviewed and future directions in this field were also prospected.

Immunomodulatory and Antioxidant Activity of Gouqi Chewable Tablets / 中国实验方剂学杂志

ObjectiveTo explore the regulatory effect of Gouqi chewable tablets on innate and adaptive immunity in normal mice and its antioxidant activity in vitro and in vivo. MethodThe effects of low-， medium-， and high-dose groups （0.25， 0.5， 1.5 g·kg-1） on the immune function of normal mice were observed by carbon clearance test， immune organ index test， serum hemolysin test， ConA-induced splenic lymphocyte proliferation test， and natural killer cell （NK cell） activity test. The effects of Gouqi chewable tablets on the antioxidant capacity in vivo were determined by detecting the content of superoxide dismutase （SOD）， glutathione peroxidase （GSH-Px）， and malondialdehyde （MDA） in mice serum. The in vitro antioxidant activity of Gouqi chewable tablets was detected by 2，2'-azino-bis（3-ethylbenzothiazoline-6-sulfonic acid） diammonium salt （ABTS）， 2，2-diphenyl-1-picrylhydrazyl （DPPH）， and hydroxyl radical scavenging tests. ResultCompared with the blank control group， the low-， medium-， and high-dose groups of Gouqi chewable tablets improved the viability of NK cells， the proliferation of splenic lymphocytes， and the level of serum hemolysin antibody in mice （P<0.05）. The high-dose group increased the thymus index， spleen index， and phagocytic function of macrophages （P<0.05， P<0.01）. As compared with the blank control group， the activity of GSH-Px in mice serum in the medium-dose group was increased （P<0.05）， and the content of MDA in mice serum in the high-dose group was decreased （P<0.05）. In in vitro antioxidant tests， the median inhibitory concentration （IC50） values of Gouqi chewable tablets were 1.64±0.20， 2.04±0.03， and 10.27±0.03 g·L-1 by the DPPH， ABTS， and OH- free radical method， respectively. Those results indicated that Gouqi chewable tablets have good antioxidant effects in vitro. ConclusionGouqi chewable tablets can enhance the immune function of mice with good antioxidant effects.

Neutrophils phagocytosing fungal hyphae in urinary sediment / Neutrófilos fagocitando hifas no sedimento urinário

Abstract The Phagocytosis of fungal structures by neutrophils is a well-documented function of these immune cells. However, neutrophil phagocytosis of hyphal structures in the urine sediment is not usually observed during routine sample evaluation. This is a case of hyphal phagocytosis by neutrophils in the urine of a kidney allograft recipient patient.

Resumo A fagocitose de estruturas fúngicas por neutrófilos é uma função bem documentada destas células imunes. No entanto, a fagocitose de hifas por neutrófilos no sedimento urinário não é normalmente observada durante avaliação de rotina de amostras. Este é um caso de fagocitose de hifas por neutrófilos na urina de um paciente receptor de aloenxerto renal.

An in vitro model mimicking the complement system to favor directed phagocytosis of unwanted cells

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.

Methods of macrophages activation and their modulation for the prospection of new antileishmania drugs: a review

Leishmaniasis are a group of parasitic zoonoses provoked by protozoa from Leishmania genus and belonging to the group of neglected tropical diseases. The search and development for new drugs is necessary not only to investigate the activity against only the parasite, but also to investigate the possible synergistic effect of new drugs with the immune response of the host. In the present review, macrophages are pointed out as potential targets of the investigation of new antileishmanial drugs, and some methodologies in order to assess their activation as response to Leishmania-infected cells are presented. Macrophages are an important role in the cellular immune response, since they are cells from mononuclear phagocytic system, the first line of defense of the host, against parasites from Leishmania genus. Phagocytic capacity, lysosomal activity, increase of nitric oxide and intracellular calcium levels are parameters regarding assessment of macrophages activation which allow them to be more hostile in order to solve the infection and lead the patient to cure. In this context, we bring 19 substances already investigated and that activate macrophages, what makes them promising in the antileishmanial treatment. Therefore, assessment of macrophages activation, are important tools for discovery of immunomodulatory compounds which have potential to act in synergism with host immune response. Such compounds might be promising as monotherapy in the treatment of leishmaniasis, as well as being used as adjuvants in vaccines and/or in combination with conventional drugs.

Research progress on trogocytosis of immune cell in transplantation immunity / 器官移植

Trogocytosis is a process of exchanging part of the membrane fragment or cytoplasmic content of cells through direct contact, and it's an interaction mechanism that exists between cells. Immune cell can obtain some characteristics of other cells through trogocytosis, and the new cells generated through trogocytosis may play an important role in the induction of graft immune tolerance. In this article, the origin and development of research on cell trogocytosis, mechanism of cell trogocytosis and biological significance of trogocytosis of immune cell were reviewed.

Effect of flunixin or ketoprofen in caudectomy by elastration in lambs: pain and neutrophil function / Efeito de flunixin ou cetoprofeno em cordeiras submetidas a caudectomia por elastração: dor e função neutrofílica

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)

Once upon a time, inflammation

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)

Role of microglia phagocytosis in acute ischemic stroke / 国际脑血管病杂志

Microglia, as an inherent immune cell in the brain, is an important defense line against central nervous system injury and participates in the pathogenesis of ischemic stroke. Especially the phagocytosis of microglia plays an important role in the pathogenesis of ischemic stroke. This article reviews the important role and phagocytic mechanism of microglia in acute ischemic stroke, and focuses on the dual effects of its phagocytic function on nerve injury and recovery after stroke, hoping to provide new targets and strategies for microglia-targeted acute ischemic stroke treatment.

Pharmacological Activation of RXR-α Promotes Hematoma Absorption via a PPAR-γ-dependent Pathway After Intracerebral Hemorrhage / 神经科学通报·英文版

Endogenously eliminating the hematoma is a favorable strategy in addressing intracerebral hemorrhage (ICH). This study sought to determine the role of retinoid X receptor-α (RXR-α) in the context of hematoma absorption after ICH. Our results showed that pharmacologically activating RXR-α with bexarotene significantly accelerated hematoma clearance and alleviated neurological dysfunction after ICH. RXR-α was expressed in microglia/macrophages, neurons, and astrocytes. Mechanistically, bexarotene promoted the nuclear translocation of RXR-α and PPAR-γ, as well as reducing neuroinflammation by modulating microglia/macrophage reprograming from the M1 into the M2 phenotype. Furthermore, all the beneficial effects of RXR-α in ICH were reversed by the PPAR-γ inhibitor GW9662. In conclusion, the pharmacological activation of RXR-α confers robust neuroprotection against ICH by accelerating hematoma clearance and repolarizing microglia/macrophages towards the M2 phenotype through PPAR-γ-related mechanisms. Our data support the notion that RXR-α might be a promising therapeutic target for ICH.

Photorhabdus virulence cassette promotes bacterial invasion into macrophages by activating NF-κB and MAPK signaling pathway / 生物工程学报

Photorhabdus is a Gram-negative bacterium from the family Enterobacteriaceae that lives in a symbiotic association with nematode or insects. In addition to the role of being insect pathogens, one species called Photorhabdus asymbiotica (Pa) causes human infection around the world. Nevertheless, how does this transkingdom infection occur remains elusive. Here we focus on one pathogenic determinant called Photorhabdus virulence cassette (PVC) that is founded in the Pa genome and many other pathogens. The RNA-seq and qPCR data showed that the NF-κB and MAPK pathways were drastically activated in the PVC-treated mammalian macrophages. Western blotting assays using samples treated with various inhibitors of the affected pathways confirmed the results we have observed for MAPK pathway previously. p65 translocation assays validated the NF-κB activation in the macrophages after PVC treatment. Moreover, the bacterial phagocytosis by macrophage was also promoted by PVC at the early stage, and this phagocytosis was inhibited by cytoskeleton inhibitors. Thus, the results indicated that PVC is involved in the bacterial invasion by activating NF-κB and MAPK signaling pathway, providing a new perspective for analyzing the pathogenicity of Pa in human infections.

Research advances in the effect and utilization of protein corona on the circulation of nanoparticles in vivo / 药学学报

Nanoparticles have better applicability in the detection, treatment of cancer and various difficult diseases, but mononuclear phagocytosis system can seriously shorten the time of nanoparticles in vivo circulation, reduce the drug efficacy. The protein crown formed on the surface of the nanoparticle after entering the body can change its surface properties, interfere with the recognition of phagocytes, and thus affect its circulation time in vivo. This article outlines the general composition and formation process of protein crowns. It also summarizes the influence of the physical and chemical properties of nanoparticles, such as particle size, surface charge, hydrophilicity and surface materials on the formation of protein crowns. The protein crown affects the circulation of nanoparticles in vivo, mainly because the adsorbed opsonic protein promotes cell phagocytosis. Therefore, we also introduce the method of using protein crowns to promote the long circulation of nanoparticles in vivo. By designing appropriate physical and chemical properties, surface modification, and directed design of protein crowns, the adsorption of proteins on the surface of nanoparticles can be reduced. Therefore, it can reduce the clearance of nanoparticles in the mononuclear phagocytic system (mainly the phagocytes of the liver and spleen), and achieve the goal of long circulation of nanoparticles in the body.

Applications of atomic force microscopy in immunology / 医学前沿

Cellular mechanics, a major regulating factor of cellular architecture and biological functions, responds to intrinsic stresses and extrinsic forces exerted by other cells and the extracellular matrix in the microenvironment. Cellular mechanics also acts as a fundamental mediator in complicated immune responses, such as cell migration, immune cell activation, and pathogen clearance. The principle of atomic force microscopy (AFM) and its three running modes are introduced for the mechanical characterization of living cells. The peak force tapping mode provides the most delicate and desirable virtues to collect high-resolution images of morphology and force curves. For a concrete description of AFM capabilities, three AFM applications are discussed. These applications include the dynamic progress of a neutrophil-extracellular-trap release by neutrophils, the immunological functions of macrophages, and the membrane pore formation mediated by perforin, streptolysin O, gasdermin D, or membrane attack complex.

Phagocytic activity of monocytes and neutrophils in patients with periodontitis, whether or not associated to type 2 diabetes / Atividade fagocítica de monócitos e neutrófilos em pacientes com periodontite, associada ou não ao diabetes tipo 2

ABSTRACT Phagocytic functions by neutrophils/ monocytes and biochemical parameters were assessed in peripheral blood of patients with periodontitis, whether or not associated to type 2 diabetes, or patients with type 2 diabetes, or systemically healthy people. Fifty-eight participants were divided into four groups: Control - systemically and periodontally healthy patients (C, n=16), Periodontitis (P, n=14), Type 2 Diabetes (DM, n=11) and Periodontitis associated with type 2 diabetes (DMP, n=17). Blood samples were used to analyze phagocytic activity and the production of superoxide anion using optical microscopy. Significantly lower phagocytic activity of neutrophils was observed in non-opsonized samples (p = 0.008, Kruskal- Wallis) of the periodontitis group and in opsonized samples (p = 0.029, Kruskal-Wallis) of the periodontitis associated with type 2 diabetes group when these groups were compared to the healthy individuals when a 20:1 yeast: phagocyte stimulus was used. Periodontitis patients, whether associated (p = 0.0007, sensitized; Kruskal-Wallis, 20:1) or not with diabetes (p = 0.018 and 0.0007, in the proportions 5:1 and 20:1 yeast: monocyte respectively in sensitized samples; Kruskal-Wallis) also showed lower phagocytic function of monocytes compared to the control group. There was no significant difference in the production of superoxide anion among the evaluated groups. Severe clinical attachment loss was associated with lower levels of HDL in periodontitis patients and a higher percentage of A1C in diabetes with periodontitis patients (p<0.05; Pearson and Spearman correlations, respectively). Patients with both associated diseases had higher levels of triglycerides and CRP (p<0.001, Kruskal-Wallis) compared to patients with diabetes only. The results of the present study suggest that periodontitis negatively interferes with the innate immune response and may represent a major risk of systemic complications such as cardiovascular disease in diabetic patients or even in healthy individuals.

RESUMO As funções fagocíticas de neutrófilos/monócitos e parâmetros bioquímicos foram avaliados no sangue periférico de pacientes com periodontite com ou sem diabetes do tipo 2, ou em pacientes com diabetes tipo 2, ou em pessoas saudáveis sistemicamente. 58 participantes foram divididos em quatro grupos: Controle - pacientes sistemicamente e periodontalmente saudáveis (C, n = 16), Periodontite (P, n = 14), Diabetes Tipo 2 (DM, n = 11) e Periodontite associada a diabetes tipo 2 (DMP, n = 17). Amostras de sangue foram usadas para analisar a atividade fagocítica e a produção de ânion superóxido por microscopia óptica. Observou-se menor atividade fagocítica dos neutrófilos em amostras não opsonizadas (p = 0,008, Kruskal-Wallis) do grupo periodontite e em amostras opsonizadas (p = 0,029, Kruskal-Wallis) do grupo periodontite associada ao diabetes tipo 2 quando esses grupos foram comparados aos indivíduos saudáveis sob um estímulo de levedura:monócito de 20:1. Pacientes com periodontite associada (p = 0,0007, sensibilizados; Kruskal-Wallis, 20: 1) ou não com diabetes (p = 0,018 e 0,0007, nas proporções 5: 1 e 20: 1 de levedura: monócito, respectivamente, em amostras sensibilizadas; Kruskal- Wallis) também demonstraram menor função fagocítica dos monócitos em comparação com o grupo controle. Não houve diferença significativa na produção de ânion superóxido entre os grupos avaliados. A perda de inserção clínica grave foi associada a níveis mais baixos de HDL na periodontite e maior percentual de A1C nos pacientes com periodontite associada ao diabetes (p<0,05; correlações de Person e Spearman, respectivamente). Os pacientes com ambas as doenças associadas apresentaram níveis mais altos de triglicerídeos e PCR (p<0,001, Kruskal- Wallis) em comparação aos pacientes com somente diabetes. Os resultados do presente estudo sugerem que a periodontite interfere negativamente na resposta imune inata e pode representar um risco maior para complicações sistêmicas, como a doença cardiovascular, em pacientes com diabetes ou mesmo em indivíduos saudáveis.

The influence of dehydroepiandrosterone on effector functions of neutrophils

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

Avaliação da atividade funcional dos neutrófilos sanguíneos em ovelhas primíparas e pluríparas da raça Lacaune / [Functional evaluation of blood neutrophils in primiparous and pluriparous Lacaune ewes]

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)

Fatores de virulência e susceptibilidade a antifúngicos de Cryptococcus Spp / Virulence factors and susceptibility to Cryptococcus Spp. antifungals

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.

Relationship between PI3K/mTOR/RhoA pathway-regulated cytoskeletal rearrangements and phagocytic capacity of macrophages

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.