Phagocytosis: A Practical Approach for Evaluating Neutrophil Function in Health and Disease

Neutrophils, crucial players in the effector phase of the immune response, are recognized as important mediators of both innate and adaptive immune responses. Through the production of pro- and anti-inflammatory cytokines, they modulate the function of T and other lymphoid cells. Countless reports have highlighted the importance of these cells as efficient antimicrobial agents and annotated their involvement in the pathology of infectious and noninfectious diseases. The development of modern, sophisticated technologies has allowed the study of the functions of these cells in clinical settings. These advanced technologies include fluorescence-activated cell sorters, confocal microscopy, automated cell image analyzers, and live cell analysis instruments. Unfortunately, the cost of these modern instruments, maintenance, reagents, and the need for qualified technicians prohibit their use in low-income laboratories and universities in developing countries. With this in mind, we propose a series of basic tests that can be used in low-input clinical laboratories and universities to evaluate the function of neutrophils in health and disease. Our methodology allows us to assess in a practical and low-cost manner the functions of neutrophils in the phagocytic process, including opsonization, ingestion, ROI production (NBT reduction), myeloperoxidase content, phagosome-lysosome fusion, microbicidal activity, and NET production. Thus, under a disadvantageous ambiance, this may guide physicians in deciding whether a patient’s illness involves phagocytic defects without imposing a heavy financial burden.Graphical Abstract[-rId13-]

MyD88-independent activation of a novel actin-Cdc42/Rac pathway is required for Toll-like receptor-stimulated phagocytosis

Phagocytosis and subsequent degradation of pathogens by macrophages play a pivotal role in host innate immune responses to microbial infection. Recent studies have shown that Toll-like receptors （TLRs） play an important role in promoting the clearance of bacteria by up-regulating the phagocytic activity of macrophages. However, information regarding the signaling mechanism of TLR-mediated phagocytosis is still limited. Here, we provide evidence that the stimulation of TLR4 with LPS leads to activation of multiple signaling pathways including MAP kinases, phosphatidylinositide 3-kinase （PI3K）, and small GTPases in the murine macrophage-like cell line RAW264.7. Specific inhibition of Cdc42/Rac or p38 MAP kinase, but not PI3K, reduced TLR4-induced phagocytosis of bacteria. Moreover, we have found that either inhibition of actin polymerization by cytochalasin D or the knockdown of actin by RNAi markedly reduced the activation of Cdc42 and Rac by LPS. TLR4-induced activation of Cdc42 and Rac appears to be independent of MyD88. Taken together, our results described a novel actin-Cdc42/Rac pathway through which TLRs can specifically provoke phagocytosis.

Specific function and modulation of teleost monocytes/macrophages: polarization and phagocytosis

Macrophages exist in most tissues and play a variety of functions in vertebrates.Teleost fish species are found in most aquatic environments throughout the world and are quite diverse for a group of vertebrate animals.Due to whole genome duplication and en vironme ntal adaptati on,teleost monocytes/macrophages possess a variety of different functions and modulations compared with those of mammals.A deeper understanding of teleost monocytes/macrophages in the immune system will not only help develop teleost-specific methods of disease prevention but will also help improve our understanding of the various immune mechanisms in mammals.In this review,we summarize the differences in polarizati on and phagocytosis of teleost and mammalian macrophages to improve our understanding of the various immune mechanisms in vertebrates.

Regulation of cytokine production during phagocytosis of apoptotic cells

Loss of self-tolerance and expansion of auto-reactive lymphocytes are the basis for autoimmunity. Apoptosis and the rapid clearance of apoptotic cells by phagocytes usually occur as coordinated processes that ensure regulated cellularity and stress response with non-pathological outcomes. Defects in clearance of apoptotic ceils would contribute to the generation of self-reactive lymphocytes, which drive autoimmune disorders such as rheumatoid arthritis （RA） and systemic lupus erythematosus （SLE）. The IL-12 family of cytokines （IL-12, IL-23, and IL-27） and IL-10 are produced by phagocytic macrophages and play critical roles in the regulation of antigen-presenting cells （APCs） and effector lymphocytes during an immune response to pathogens. Inappropriate expression of these cytokines and their dysregulated activities have been strongly implicated in the pathogenesis of several autoimmune diseases. The production of pro- and anti-inflammatory cytokines by phagocytic APCs is delicately regulated during the ingestion of apoptotic cells as part of an intrinsic mechanism to prevent inflammatory autoimmune reactions. How apoptotic cell-derived signals regulate cytokine production is poorly understood. A recent study by our group demonstrated that phagocytosis of apoptotic cells by activated macrophages results in strong inhibition of IL-12 p35 gene expression by activating a novel transcription repressor, which we named GC-binding protein （GC-BP）, through tyrosine dephosphorylation. We are also beginning to understand the molecular mechanisms underlying apoptotic cell-triggered production of IL-10 by phagocytes. These studies will help to elucidate some novel immune regulatory mechanisms and explore the regulation of immune responses to autoantigens with potentials to discover new therapeutic targets for the treatment of autoimmune disorders.

Clearing the corpses： regulatory mechanisms, novel tools, and therapeutic potential of harnessing microglial phagocytosis in the diseased brain

Apoptosis is a widespread phenomenon that occurs in the brain in both physiological and pathological conditions. Dead ceils must be quickly removed to avoid the further toxic effects they exert in the pa- renchyma, a process executed by microglia, the brain professional phagocytes. Although phagocytosis is critical to maintain tissue homeostasis, it has long been either overlooked or indirectly assessed based on microglial morphology, expression of classical activation markers, or engulfment of artificial phagocytic targets in vitro. Nevertheless, these indirect methods present several limitations and, thus, direct obser- vation and quantification of microglial phagocytosis is still necessary to fully grasp its relevance in the diseased brain. To overcome these caveats and obtain a comprehensive, quantitative picture of microglial phagocytosis we have developed a novel set of parameters. These parameters have allowed us to identify the different strategies utilized by microglia to cope with apoptotic challenges induced by excitotoxicity or inflammation. In contrast, we discovered that in mouse and human epilepsy microglia failed to find and engulf apoptotic ceils, resulting in accumulation of debris and inflammation. Herein, we advocate that the efficiency of microglial phagocytosis should be routinely tested in neurodegenerative and neuro- logical disorders, in order to determine the extent to which it contributes to apoptosis and inflammation found in these conditions. Finally, our findings point towards enhancing microglial phagocytosis as a novel therapeutic strategy to control tissue damage and inflammation, and accelerate recovery in brain diseases.

Effects of glycine on phagocytosis and secretion by Kupffer cells in vitro

AIM:To investigate the effects and mechanisms of action of glycine on phagocytosis and tumor necrosis factor(TNF)-α secretion by Kupffer cells in vitro. METHODS:Kupffer cells were isolated from normal rats by collagenase digestion and Percoll density gradient differential centrifugation.After culture for 24 h,Kupffer cells were incubated in fresh Dulbecco's Modification of Eagle's Medium containing glycine (G1:1 mmol/L,G2:10 mmol/L,G3:100 mmol/L and G4:300 mmol/L)for 3 h,then used to measure phagocytosis by a bead test,TNF-α secretion after lipopolysaccharide stimulation by radioactive immunoassay,and microfilament and microtubule expression by staining with phalloidin-fluorescein isothiocyanate (FITC)or a monoclonal anti-α tubulin-FITC antibody, respectively,and evaluated under a ultraviolet fluorescence microscope. RESULTS:Glycine decreased the phagocytosis of Kupffer cells at both 30 min and 60 min(P<0.01,P< 0.05).The numbers of beads phagocytosed by Kupffer cells in 30 min were 16.9±4.0(control),9.6±4.1(G1), 12.1±5.7(G2),8.1±3.2(G3)and 7.5±2.0(G4),and were 22.5±7.9(control),20.1±5.8(G1),19.3±4.8 (G2),13.5±4.7(G3)and 9.2±3.1(G4)after 60 min. TNF-α secretion by Kupffer cells in G1(0.19±0.03),G2 (0.16±0.04),G3(0.14±0.03)and G4(0.13±0.05) was significantly less than that in controls(0.26±0.03, P<0.01),and the decrease in secretion was dose-dependent(P<0.05).Microfilaments of Kupffer cells in G2, G3 and G4 groups were arranged in a disorderly manner. The fluorescence densities of microtubules in G1(53.4± 10.5),G2(54.1±14.6),G3(64.9±12.1)and G4(52.1 ±14.2)were all lower than those in the controls(102.2 ±23.7,P<0.01),but the decrease in microtubule fluorescence density was not dose-dependant. CONCLUSION:Glycine can decrease the phagocytosis and secretion by Kupffer cells in vitro,which may be related to the changes in the expression of microfilaments and microtubules induced by Kupffer cells.

ATG16L1 and NOD2 polymorphisms enhance phagocytosis in monocytes of Crohn's disease patients

AIM: To investigate if the presence of relevant genetic polymorphisms has effect on the effectual clearance of bacteria by monocytes and granulocytes in patients with Crohn&#x02019;s disease (CD).

ROCK Inhibition with Fasudil Promotes Early Functional Recovery of Spinal Cord Injury in Rats by Enhancing Microglia Phagocytosis

Emerging evidence indicates that microglia activation plays an important role in spinal cord injury（SCI） caused by trauma. Studies have found that inhibiting the Rho/Rho-associated protein kinase（ROCK） signaling pathway can reduce inflammatory cytokine production by microglia. In this study, Western blotting was conducted to detect ROCK2 expression after the SCI; the ROCK Activity Assay kit was used for assay of ROCK pathway activity; microglia morphology was examined using the CD11 b antibody; electron microscopy was used to detect microglia phagocytosis; TUNEL was used to detect tissue cell apoptosis; myelin staining was performed using an antibody against myelin basic protein（MBP）; behavioral outcomes were evaluated according to the methods of Basso, Beattie, and Bresnahan（BBB）. We observed an increase in ROCK activity and microglial activation after SCI. The microglia became larger and rounder and contained myelin-like substances. Furthermore, treatment with fasudil inhibited neuronal cells apoptosis, alleviated demyelination and the formation of cavities, and improved motor recovery. The experimental evidence reveals that the ROCK inhibitor fasudil can regulate microglial activation, promote cell phagocytosis, and improve the SCI microenvironment to promote SCI repair. Thus, fasudil may be useful for the treatment of SCI.

Age-related maculopathy susceptibility 2 participates in the phagocytosis functions of the retinal pigment epithelium

AIM: Age-related macular degeneration (AMD) is a multifactorial disease and a prevalent cause of visual impairment in developed countries. Many studies suggest that age-related maculopathy susceptibility 2 (ARMS2) is a second major susceptibility gene for AMD. At present, there is no functional information on this gene. Therefore, the purpose of the present study was to detect the expression of ARMS2 in retinal pigment epithelium (RPE) cells and to investigate the effect of ARMS2 on the phagocytosis function of RPE cells. METHODS: Immunofluorescence and reverse transcriptase PCR were used to demonstrate the presence and location of ARMS2 in ARPE-19 (human retinal pigment epithelial cell line, ATCC, catalog No.CRL-2302) cells. siRNA was used to knock down ARMS2 mRNA, and the effects of the knockdown on the phagocytosis function of the ARPE-19 cells were evaluated via Fluorescence Activated Cell Sorting (FACS). RESULTS: ARMS2 was present in ARPE-19 cells, localized in the cytosol of the perinuclear region. The expression of ARMS2 mRNA (messenger RNA) in ARPE-19 cells transfected with ARMS2-siRNA (small interfering RNA, 0.73+/- 0.08) was decreased compared with normal cells (1.00+/- 0.00) or with cells transfected with scrambled siRNA (0.95+/- 0.13) (P<0.05). After incubation of RPE cells with a latex beads medium for 12, 18, or 24 hours, the fluorescence intensities were 38.04 +/- 1.02, 68.92 +/- 0.92, and 78.00 +/- 0.12 in the ARMS2-siRNA-transfected groups, respectively, and 77.98 +/- 5.43, 94.87 +/- 0.60, and 98.30 +/- 0.11 in the scrambled siRNA-transfected groups, respectively. The fluorescent intensities of the same time points in the two groups were compared using Student's t-test, and the p values were all less than 0.001 at the three different time points. CONCLUSION: There is endogenous expression of ARMS2 in ARPE-19 cells. ARMS2 plays a role in the phagocytosis function of RPE cells, and this role may be one of the mechanisms that participates in the development of AMD.

Regulation of Migration, Phagocytosis and Apoptosis of Human Neutrophils by Recombinant Human Intestinal Alkaline Phosphatase

The purpose of this study was to explore the effects of recombinant human intestinal alkaline phosphatase(recIAP) on human neutrophils in vitro, and the migration, phagocytosis, apoptosis in presence and absence of LPS. In this study, freshly extracted human neutrophils were used to establish an inflammatory cell model, and the control group, recIAP group, LPS group and recIAP +LPS group were set up to stimulate the model. The migration of neutrophils was detected by agarose gel drop method. Fluorescent particles and fluorescent probes were added to different treatment groups, and the phagocytic rate of neutrophils and the release of reactive oxygen species(ROS) from neutrophils were detected by flow cytometry. The apoptosis rate of neutrophils was detected by flow cytometry according to Annexin V-FITC apoptosis detection kit. The results showed that regardless of the presence or absence of LPS, recIAP could inhibit the migration of neutrophils, phagocytosis and the release of ROS. In addition, recIAP could weaken the inhibitory effect of LPS on neutrophils apoptosis.

Proposal for a new evaluation of phagocytosis using different sizes of fluorescent polystyrene microspheres

To investigate phagocytosis, peritoneal-resident and J774.1 macrophages were incubated with fluorescent polystyrene microspheres measuring 1.0 μm in diamter at 200 particles per cell. The amount of phagocytized microspheres increased with incubation time, and both cell types had similar phagocytic activity. Further, we investigated the phagocytosis of different sizes of microspheres by J774.1 macrophages. To adequately evaluate phagocytosis, varying amounts of different sizes of microspheres were added to J774.1 cells, and their phagocytic activities were evaluated. When the microspheres were added at a density of 20 particles per cell, few small microspheres (<1.0 μm in diameter) were phagocytized. This result suggested that their low amount caused difficulty in evaluating phagocytosis. In contrast, when the same variety of microspheres was added at a density of 200 particles per cell, phagocytosis of large microspheres (>3 μm in diameter) could not be evaluated because of cytotoxicity. Thus, the amount of different sizes of microspheres added is important for precisely evaluating phagocytic activity. When the amount of different sizes of microspheres added was standardized to provide a set amount of total surface area, phagocytosis of these microspheres could be adequately evaluated and compared. To determine the effects of phagocytosis on cell viability and proliferation, cells incubated with different sizes of microspheres were assayed using a cell counting kit. We found that phagocytosis had no effect on cell viability or proliferation and was independent of particle size. Furthermore, cells already phagocytized microspheres retained their phagocytic activity.

Immunomodulatory effects of selected Malaysian plants on the CD18/11a expression and phagocytosis activities of leukocytes

Objective:To investigate the effects of 20 methanolic extracts from Malaysian selected plants on CD18/11 a expression and phagocytosis activity of leukocytes using flow cytometry analysis.Methods:The effects of methanolic extracts on CD18/11 a expression and phagocytosis of leukocytes were measured by labelling the cells with CD18-fluorescein isolhiocyanaie and ingestion labelled with Escherichia coli-fluorescein isothiocyanate and then analyzed using flow cytometer.Results:About 12 out of 20 methanolic extracts of selected Malaysian medicinal plants significantly(P≤0.05) inhibited the CD18/1 la expression of leukocytes at both concentrations of 6.25 μg/mL and 100 μg/mL in dose dependent manner.The most active inhibitory was shown in Citrus aurantifolia(Christm.) Swingle and Alpinia galangal(L.) Willd.at dosage 100ug/mL.Moreover,the Orthosiphon aristatus(Blume) Miq(O.aristatus).showed the highest stimulatory activity at the concentration of 100 μg/mL.Other than that,four plant extracts significantly(P<0.05) rose the phagocytosis activities of leukocytes in dose dependent manner.However,Annona muricata L.and O.aristatus showed the highest stimulated activities at the 100 pg/mL concentration.Conclusions:The results suggest that methanolic extracts of Cirrus aurantifolia.Alpinia gaiangal,O.aristatus and Annona muricata are able to modulate innate immune system and can potentially be recognized as therapeutic agents for modulating immune system.

Interferon-γ acts as a regulator in the trade-off between phagocytosis and production performance in dwarf chickens

Background: Interferon-γ(IFN-γ) is critical for innate and adaptive immunity against viral and bacterial infections. IFN-γ reportedly affects the phagocytic ability of monocytes and macrophages as well as regulates pituitary function in humans and mice. The present study analyzed the impact of IFN-γ on monocyte and macrophage phagocytosis, production performance, and pituitary function in vivo and in vitro(in dwarf chickens). IFN-γ was injected into dwarf chickens through a vein, and then, the laying rate, average egg weight, and levels of follicle-stimulating hormone(FSH) and IFN-γ were measured in treatment and control groups. For the in vitro experiment, the pituitary tissues were supplemented with IFN-γ, and the m RNA expression levels of follicle-stimulating hormone beta subunit(FSH-β), interferon gamma receptor 1(IFNGR1),and interferon gamma receptor 2(IFNGR2) in the pituitary were assessed.Results: Monocyte and macrophage phagocytosis product(PP) was decreased by IFN-γ treatment in a dose-dependent manner in vitro. In the in vivo experiment, the level of IFN-γ in the treatment group was higher than that in the control group at 7 d(P < 0.05), 14 d(P < 0.01), and 21 d(P < 0.01) post-injection.Compared with the control group, monocyte and macrophage PP was lower in the treatment group after injection(P < 0.01). The laying rate was higher in the treatment group than in the control group at 2 and3 wk post-injection(P < 0.05). There was a significant difference between the treatment and control groups in the levels of FSH at 1, 3, 7, and 14 d post-injection(P < 0.01). In the in vitro experiment, increased m RNA expression levels of FSH-β, IFNGR1, and IFNGR2 were observed in the treatment group after stimulation with100 U/m L IFN-γ for 24 h compared to those in the control group(P < 0.05).Conclusions: IFN-γ inhibited the phagocytosis of monocytes and macrophages; up-regulated the m RNA expression levels of the FSH-β, IFNGR1, and IFNGR2; enhanced the secretion of FSH; and improved the laying rate. IFN-γ might be an important regulator in the trade-off between the immune effect and production performance in dwarf chickens.

Effects of LPLI on microglial phagocytosis in LPS-induced neuroinflammation model

Microglial activation plays an important role in neurodegenerative diseases.Once activated,they have macrophage-like capabilities,which can be beneficial by phagocytosis and harmful by se-cretion of neurotoxins.However,the resident microglia always fail to trigger an effective pha-gocytic response to clear dead cells or Aβdeposits during the progression of neurodegeneration.Therefore,the regulation of microglial phagocytosis is considered a useful strategy in searchingfor neuroprotective treatments.In this study,our results showed that low-power laser iradiation(LPLI)(20 J/cm²)could enhance microglial phagocytic function in LPS-activated microglia.Wefound that LPLI-mediated microglial phagocytosis is a Rac-1-dependent actin-based process,that a constitutively activated form of Rac1(RaclQ61L)induced a higher level of actin pol-ymerization than cells transfected with wild-type Racl,whereas a dominant negative form ofRacl(RaclT17N)markedly suppressed actin polymerization.In addition,the involvement of Racl activation after LPLI treatment was also observed by using a Raichu fluorescence resonance energy transfer(FRET)-based biosensor.We also found that PI3K/Akt pathway was required inthe LPLI-induced Raci activation.Our research may provide a feasible therapeutic approach tocontrol the progression of neurodegenerative diseases.

CD47 decline in pancreatic islet cells promotes macrophage-mediated phagocytosis in type Ⅰ diabetes

BACKGROUND Type Ⅰ diabetes(T1D)is characterized by insulin loss caused by inflammatory cells that excessively infiltrate and destroy the pancreas,resulting in dysregulation of tissue homeostasis,mechanobiological properties,and the immune response.The streptozotocin(STZ)-induced mouse model exhibits multiple features of human T1D and enables mechanistic analysis of disease progression.However,the relationship between the mechanochemical signaling regulation of STZ-induced T1D and macrophage migration and phagocytosis is unclear.AIM To study the mechanochemical regulation of STZ-induced macrophage response on pancreatic beta islet cells to gain a clearer understanding of T1D.METHODS We performed experiments using different methods.We stimulated isolated pancreatic beta islet cells with STZ and then tested the macrophage migration and phagocytosis.RESULTS In this study,we discovered that the integrin-associated surface factor CD47 played a critical role in immune defense in the STZ-induced T1D model by preventing pancreatic beta islet inflammation.In comparison with healthy mice,STZ-treated mice showed decreased levels of CD47 on islet cells and reduced interaction of CD47 with signal regulatory proteinα(SIRPα),which negatively regulates macrophage-mediated phagocytosis.This resulted in weakened islet cell immune defense and promoted macrophage migration and phagocytosis of target inflammatory cells.Moreover,lipopolysaccharide-activated human acute monocytic leukemia THP-1 cells also exhibited enhanced phagocytosis in the STZ-treated islets,and the aggressive attack of the inflammatory islets correlated with impaired CD47-SIRPαinteractions.In addition,CD47 overexpression rescued the pre-labeled targeted cells.CONCLUSION This study indicates that CD47 deficiency promotes the migration and phagocytosis of macrophages and provides mechanistic insights into T1D by associating the interactions between membrane structures and inflammatory disease progression.

Effect of Transforming Growth Factor-β_2 on Phagocytosis in Cultured Bovine Trabecular Meshwork Cells

The effect of transforming growth factor β 2 (TGF β 2) on phagocytosis in bovine trabecular meshwork cells in vitro was investigated. After the cultured bovine trabecular meshwork cells were treated with 0 ng/ml, 0.32 ng/ml, 1 ng/ml, 3.2 ng/ml TGF β 2 for 24 h, latex beads were added into the incubation medium, and the numbers of the latex beads in 20 adjacent cells were counted under a microscope 24 h later, after treatment with Wright's stain. Our results showed that the average numbers of the latex beads in the trabecular meshwork cells treated with TGF β 2 of different concentrations were 53.1±1.7 beads/cell, 56.4±2.9 beads/cell and 77.9±6.5 beads/cell respectinvely, in comparison with 45.5±3.3 beads/cell of the control group. TGF β 2 significantly increased the number of the latex beads phagocytosed by cultured bovine trabecular meshwork cells in a dose dependent manner. TGF β 2 could promote the phagocytosis of bovine trabecular meshwork cells in vitro . It may be involved in the cellularity decrease of the trabecular meshwork in the patients of primary open angle glaucoma through promoting the phagocytosis of trabecular meshwork cells.

A digital cmos sequential circuit model for bio-cellular adaptive immune response pathway using phagolysosomic digestion: a digital phagocytosis engine

Living systems have to constantly counter micro-or- ganisms which seek parasitic existence by extracting nutrition (amino acids) from the host. Phagocytosis is the ingestion of micro-creatures by certain cells of living systems for counter nutrition (breakdown of the micro-creature into basic components) as part of cellular adaptive immune response. These particular cells are called phagocytes, all of which are different types of white blood cells or their derivatives. Phagocytes are activated by certain components of the micro-creatures which act as an antigen, generating an- tibody secretion by the phagocyte. This paper develops a digital CMOS circuit model of phagocytosis: the immune response biochemical pathway of a pha- gocyte. A micro-sequenced model has been developed where the different stages in phagocytosis are modeled as different states clocked by circadian time intervals. The model converts the bio-chemical immune system digestive pathway into a cascade of CMOS multi-step logical transformations from micro-crea- ture ingestion to the secretion of indigestible residuals. This modeling technique leads to the understanding of cellular immune deficiency diseases of living systems in the form of logical (electrical) faults in a circuit.

Stimulation of Phagocytosis and Production of Antibodies against Canine Herpesvirus Type 1 by Pidotimod (Adimod^TM)

Neutrophils are the most important circulating phagocytes. Circulating mono-cytes and precursors of tissue macrophages also have the ability to phagocytize. Pidotimod (ADIMODTM) exerts immunostimulatory and immunoregulatory effects through the stimulation and regulation of cellular immune responses by lymphocytes Canine herpesvirus (CHV) mainly affect puppies between the first and second weeks of age, causing high morbidity in the litter. To date, there is only one commercial vaccine in Europe to prevent disease. In this work, inactivated CHV cultures were inoculated in rabbits, adsorbed and not adsorbed to chitosan nanoparticles. Phagocytosis in the presence or absence of specific antibodies was measured. Response of virus neutralizing antibodies was also evaluated. AdimodTM enhanced the nonspecific and specific phagocytotic response. The association of the virus to the nanoparticles increased the phagocytic ability of blood cells;however, AdimodTM alone had a greater effect on phagocytic activity and generated a stronger immune response that corresponded to the increased phagocytosis (p TM was used.

PKC Is a Target to Modulate the Expression of Receptor Mediated Endocytosis (RME) Mice Macrophages BALB/c for Optimizing the Phagocytosis toward Candida albicans

Introduction: The existence of receptor-mediated endocytosis (RME) means that selectivity and selectivity occurs in capturing macromolecules. Protein kinase C (PKC) which can be expressed by almost all cells are proteins important in signal transduction groove that plays a role in a number of cell activity, e.g. phagocytosis. Aims: The purpose of this study is to determine the expression of RME after modulating the PKC which is characterized by the number of Candida albicans cells attached to the surface of macrophages. Methods: Peritoneal macrophages cultured BALB/c mice are treated with PMA and/or bisindolylmaleimides of providing levels of 5 ng/ml to 100 ng/ml for 10 minutes. Then immediately insert Candida albicans and observe every 30 minutes for 120 minutes. The research design used the same subject. Data collected in the form of number of Candida albicans cells attached to the surface of macrophages are analyzed with ANOVA statistical test (one way) to show the differences between treatments. Results: The test shows statistically significant difference in the number of Candida albicans cells attached to the surface of macrophages after administration of various levels of PMA (p 0.001). The higher level of PMA is given, the more active the PKC is, the more RME are formed, the more Candida albicans cells attached to the surface of macrophages. Another result shows statistically significant difference in the number of Candida albicans cells attached to the surface of macrophages after administration of various levels of bisindolylmaleimides (p 0.001). The higher level of bisindolylmaleimide is given, the less active PKC is, and the less RME are formed, the less Candida albicans cells attached to the surface of macrophages. Conclusion: Research shows that activator PKC (PMA) can increase the expression of RME on macrophages. Another research shows that inhibitor PKC (bisindolylmaleimides) can decrease the expression of RME on macrophages.

Antimicrobial roles of phagocytosis in teleost fish:Phagocytic B cells vs professional phagocytes

The defense system of teleost fish organized on innate and adaptive immunity protects them against a wide variety of pathogenic microorganisms in the aquatic environment.Phagocytosis is one of the most effective defense strategies against microbial challenge mainly performed by classical‘professional’phagocytes(including monocytes,macrophages and granulocytes).They contain,kill and process the internalized pathogens for antigen presentation by providing antigenic ligands to initiate activation and clonal expansion of T and B cells,which bridge the innate and adaptive immunity.The discovery of phagocytic B cells in teleost fish has broken the paradigm that primary vertebrate B cells are lack of phagocytosis of particulates,as well as led to the investigation of phagocytic activity of mammalian B-1 B cells.The active phagocytic,microbicidal capabilities and antigen presentation in teleost phagocytic B cell have demonstrated to be similar as professional phagocytes,providing a potential impact on development of new vaccination strategies to prevent and control infectious diseases.In this review,we aim to address current progress on the antimicrobial role of phagocytic B cells in teleost fish by comparing it with other professional phagocytes and mammalian B-1 B cells,and provide the application prospect of phagocytic B cells in developing vaccines as well as the prevention of fish diseases.