Displaying publications 41 - 52 of 52 in total

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  1. Hot water extract of Pleurotus pulmonarius stalk waste enhances innate immune response and immune-related gene expression in red hybrid tilapia Oreochromis sp. following challenge with pathogen-associated molecular patterns
    Ching JJ, Shuib AS, Abdullah N, Majid NA, Taufek NM, Sutra J, et al.
    Fish Shellfish Immunol, 2021 Sep;116:61-73.
    PMID: 34157396 DOI: 10.1016/j.fsi.2021.06.005
    In aquaculture, commercial fish such as red hybrid tilapia are usually raised at high density to boost the production within a short period of time. This overcrowded environment, however, may cause stress to the cultured fish and increase susceptibility to infectious diseases. Antibiotics and chemotherapeutics are used by fish farmers to overcome these challenges, but this may increase the production cost. Studies have reported on the potential of mushroom polysaccharides that can act as immunostimulants to enhance the immune response and disease resistance in fish. In the current study, hot water extract (HWE) from mushroom stalk waste (MSW) was used to formulate fish feed and hence administered to red hybrid tilapia to observe the activation of immune system. Upon 30 days of feeding, the fish were challenged with pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharides (LPS) and polyinosinic:polycytidylic acid (poly (I:C)) to mimic bacterial and viral infection, respectively. HWE supplementation promoted better feed utilisation in red hybrid tilapia although it did not increase the body weight gain and specific growth rate compared to the control diet. The innate immunological parameters such as phagocytic activity and respiratory burst activity were significantly higher in HWE-supplemented group than that of the control group following PAMPs challenges. HWE-supplemented diet also resulted in higher mRNA transcription of il1b and tnfa in midgut, spleen and head kidney at 1-day post PAMPs injection. Tlr3 exhibited the highest upregulation in the HWE fed fish injected with poly (I:C). At 3-days post PAMPs injection, both ighm and tcrb expression were upregulated significantly in the spleen and head kidney. Results showed that HWE supplementation enhances the immune responses of red hybrid tilapia and induced a higher serum bactericidal activity against S. agalactiae.
    Matched MeSH terms: Phagocytosis/drug effects
  2. Umbilical Cord Mesenchymal Stem Cells Conditioned Medium Promotes Aβ25-35 phagocytosis by Modulating Autophagy and Aβ-Degrading Enzymes in BV2 Cells
    Xu Z, Nan W, Zhang X, Sun Y, Yang J, Lu K, et al.
    J Mol Neurosci, 2018 Jun;65(2):222-233.
    PMID: 29845511 DOI: 10.1007/s12031-018-1075-5
    Mesenchymal stem cell (MSC) therapy is a promising prospect for the treatment of Alzheimer's disease (AD); however, the underlying mechanisms by which MSCs mediate positive effects are still unclear. We speculated that MSCs mediate microglial autophagy and enhance the clearance of Aβ. To test this hypothesis, we cultured BV2 microglial cells with umbilical cord mesenchymal stem cells conditioned medium (ucMSCs-CM) in the presence or absence of Aβ25-35 oligomers. We investigated BV2 cell proliferation, cell death, and Aβ25-35 phagocytosis as well as protein expression levels of LC3, Beclin-1, p62, insulin-degrading enzyme (IDE), and neprilysin (Nep) with western blotting. The results showed that ucMSCs-CM inhibited the proliferation and decreased cell death of BV2 cells induced by Aβ25-35. ucMSCs-CM also promoted the phagocytosis of Aβ25-35 by BV2 cells and changed the expression of autophagy-related proteins LC3, Beclin-1, and p62. Treatment also upregulated the expression of Aβ-degrading enzymes IDE and Nep. Furthermore, the culture medium in BV2 cells with Aβ25-35 and ucMSCs-CM prevented neuronal cell SH-SY5Y from cell death compared to control medium without ucMSCs-CM. Altogether, these data suggested that ucMSCs-CM protect microglial and neuronal cells from Aβ25-35-induced cell death and promote Aβ phagocytosis by modulating autophagy and enhancing the expression of Aβ-degrading enzymes in microglia.
    Matched MeSH terms: Phagocytosis*
  3. Fulltext Dendritic cells pulsed with generated tumor cell lysate from Phyllanthus amarus Schum. & Thonn. induces anti-tumor immune response
    Mohamed SIA, Jantan I, Nafiah MA, Seyed MA, Chan KM
    BMC Complement Altern Med, 2018 Aug 06;18(1):232.
    PMID: 30081891 DOI: 10.1186/s12906-018-2296-4
    BACKGROUND: Dendritic cells (DCs) are unique antigen presenting cells (APC) which play a pivotal role in immunotherapy and induction of an effective immune response against tumors. In the present study, 80% ethanol extract of Phyllanthus amarus was used to generate tumor lysate (TLY) derived from HCT 116 and MCF-7 cancer cell lines via induction of apoptosis. Monocyte-derived DCs were generated ex vivo from the adherent population of peripheral blood mononuclear cells (PBMCs). The generated TLY were used to impulse DCs to investigate its effect on their cellular immune functions including antigen presentation capacity, phagocytic activity, chemotaxis capacity, T-cell proliferation and cytokines release.

    METHODS: The effect of P. amarus-generated TLY on DCs maturation was evaluated by determination of MHC class I, II and CD 11c expression as well as the co-stimulatory molecules CD 83 and 86 by using flow cytometry. The phagocytic capacity of TLY-pulsed DCs was investigated through FITC-dextran uptake by using flow cytometry. The effect on the cytokines release including IL-12, IL-6 and IL-10 was elucidated by using ELISA. The migration capacity and T cell proliferation activity of pulsed DCs were measured. The relative gene expression levels of cytokines were determined by using qRT-PCR. The major constituents of P. amarus extract were qualitatively and quantitatively analyzed by using validated reversed-phase high performance liquid chromatography (HPLC) methods.

    RESULTS: P. amarus-generated TLY significantly up-regulated the expression levels of MHC class I, CD 11 c, CD 83 and 86 in pulsed DCs. The release of interleukin IL-12 and IL-6 was enhanced by TLY-DCs at a ratio of 1 DC: 3 tumor apoptotic bodies (APO), however, the release of IL-10 was suppressed. The migration ability as well as allogeneic T-cell proliferation activities of loaded DCs were significantly enhanced, but their phagocytic capacity was highly attenuated. The gene expression profiles for IL-12 and IL-6 of DCs showed increase in their mRNA gene expression in TLY pulsed DCs versus unloaded and LPS-treated only DCs.

    CONCLUSION: The effect of P. amarus-generated TLY on the immune effector mechanisms of DCs verified its potential to induce an in vitro anti-tumor immune response against the recognized tumor antigen.

    Matched MeSH terms: Phagocytosis/drug effects
  4. 1'-Acetoxychavicol acetate inhibits NLRP3-dependent inflammasome activation via mitochondrial ROS suppression
    Sok SPM, Ori D, Wada A, Okude H, Kawasaki T, Momota M, et al.
    Int Immunol, 2021 06 18;33(7):373-386.
    PMID: 33830232 DOI: 10.1093/intimm/dxab016
    The nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing (NLRP) 3 inflammasome is a multiprotein complex that triggers Caspase-1-mediated IL-1β production and pyroptosis, and its dysregulation is associated with the pathogenesis of inflammatory diseases. 1'-Acetoxychavicol acetate (ACA) is a natural compound in the rhizome of tropical ginger Alpinia species with anti-microbial, anti-allergic and anti-cancer properties. In this study, we found that ACA suppressed NLRP3 inflammasome activation in mouse bone marrow-derived macrophages and human THP-1 monocytes. ACA inhibited Caspase-1 activation and IL-1β production by NLRP3 agonists such as nigericin, monosodium urate (MSU) crystals, and ATP. Moreover, it suppressed oligomerization of the adapter molecule, apoptosis-associated speck-like protein containing a CARD (ASC), and Caspase-1-mediated cleavage of pyroptosis executor Gasdermin D. Mechanistically, ACA inhibited generation of mitochondrial reactive oxygen species (ROS) and prevented release of oxidized mitochondrial DNA, which trigger NLRP3 inflammasome activation. ACA also prevented NLRP3 inflammasome activation in vivo, as evidenced in the MSU crystal-induced peritonitis and dextran sodium sulfate-induced colitis mouse models accompanied by decreased Caspase-1 activation. Thus, ACA is a potent inhibitor of the NLRP3 inflammasome for prevention of NLRP3-associated inflammatory diseases.
    Matched MeSH terms: Phagocytosis/drug effects
  5. Immunization with the recombinant Burkholderia pseudomallei outer membrane protein Omp85 induces protective immunity in mice
    Su YC, Wan KL, Mohamed R, Nathan S
    Vaccine, 2010 Jul 12;28(31):5005-11.
    PMID: 20546831 DOI: 10.1016/j.vaccine.2010.05.022
    Burkholderia pseudomallei is resistant to a wide range of antibiotics, leading to relapse and recrudescence of melioidosis after cessation of antibiotic therapy. More effective immunotherapies are needed for better management of melioidosis. We evaluated the prophylactic potential of the immunogenic outer membrane protein Omp85 as a vaccine against murine melioidosis. Immunization of BALB/c mice with recombinant Omp85 (rOmp85) triggered a Th2-type immune response. Up to 70% of the immunized animals were protected against infectious challenge of B. pseudomallei with reduced bacterial load in extrapulmonary organs. Mouse anti-rOmp85 promoted complement-mediated killing and opsonophagocytosis of B. pseudomallei by human polymorphonuclear cells. In conclusion, we demonstrated that B. pseudomallei Omp85 is potentially able to induce protective immunity against melioidosis.
    Matched MeSH terms: Phagocytosis
  6. Changes in cellular immunity during chemotherapy for primary breast cancer with anthracycline regimens
    Wijayahadi N, Haron MR, Stanslas J, Yusuf Z
    J Chemother, 2007 Dec;19(6):716-23.
    PMID: 18230556
    Anthracyclines are the most widely used anticancer agents for breast cancer, of which doxorubicin and epirubicin have been reported to have equal efficacy. Unfortunately, the integrity of the immune system of breast cancer patients is severely affected by chemotherapy. This study compared the effect of combination chemotherapy with epirubicin (5-fluorouracil, epirubicin, cyclophosphamide (FEC)) and doxorubicin (5-fluorouracil, doxorubicin, cyclophosphamide (FDC)) regimens on subsets of the immune cells of patients with primary malignant breast tumors. Our aim was to determine the best regimen that produces the least degree of myelosuppression. Blood from 80 breast cancer patients undergoing chemotherapy (40 FEC and 40 FDC) was taken before chemotherapy and after every cycle (3 weeks) for 6 cycles. Blood was also taken from 40 normal healthy donors who served as normal control. Subsets of lymphocytes T-helper cells (CD3(+)CD4(+)), T-cytotoxic cells (CD3(+) CD8(+)), B-cells (CD19(+) CD20(+)) and NK cells (CD16(+)/CD56(+)CD3(-)) were analyzed by flow cytometry (FacsCalibur, BD) using monoclonal antibodies (Multitest, BD). All patients in the FEC and FDC groups suffered from myelosuppressive side effects. Both regimens led to an increase in the counts of monocytes but decreased polymorphonuclear cells (PMNs) and lymphocytes. Percentages of T-cytotoxic cells and NK cells were increased, but the percentage of B-cells was dramatically decreased. The phagocytic and intracellular killing ability of PMNs were also suppressed (p<0.01). No significant difference was found between the epirubicin-based regimen and doxorubicin-based regimen with regard to numbers of immune cells, percentages of lymphocytes subsets, Th/CTL ratio, engulfment and killing abilities of PMNs. In conclusion, we found that the epirubicin-based regimen is not superior to the doxorubicin-based regimen with respect to their toxicity of the immune cells, Th/CTL ratio and PMN count and functions. Moreover, both FEC and FDC regimens appear to conserve the cell-mediated immunity response needed for fighting against cancer cells.
    Matched MeSH terms: Phagocytosis
  7. Chediak-Higashi syndrome: a case report
    Jayaranee S, Menaka N
    Malays J Pathol, 2004 Jun;26(1):53-7.
    PMID: 16190108
    A 5-month-old Chinese male infant was referred to the University Hospital, Kuala Lumpur for persistent fever, generalised rash and abdominal distension. Clinically he was suspected to have haemophagocytic lymphohistiocytosis. Haematological findings including the presence of several abnormal giant granules in neutrophils and single large azurophilic granules in many lymphocytes and monocytes in the peripheral blood established the diagnosis of Chediak-Higashi syndrome. The patient responded to allogeneic bone marrow transplant. This paper discusses the characteristic features, clinical course and management of this rare disorder. We suggest that peripheral blood film examination for the abnormal giant granules in granulocytes is an essential investigation in all young children with frequent recurrent infections or who are suspected to have virus-associated haemophagocytic syndrome or familial haemophagocytic lymphohistiocytosis.
    Matched MeSH terms: Phagocytosis
  8. The effect of Pasteurella haemolytica A2 infection on phagocytosis efficiency of caprine broncho-alveolar macrophages
    Zamri-Saad M, Mera HR
    J. Vet. Med. B Infect. Dis. Vet. Public Health, 2001 Sep;48(7):513-8.
    PMID: 11666033
    An experiment was designed to study the in vivo effect of Pasteurella haemolytica A2 infection on the phagocytosis activity of caprine broncho-alveolar macrophages and the extent of pneumonic lesions. Twelve healthy local Kacang goats, about 7 months of age, were divided into two groups of six. Goats in group 1 were inoculated intratracheally with 4 ml inoculum containing 2.8 x 10(9) colony-forming units (CFU)/ml of Staphylococcus aureus. Goats in group 2 were inoculated intratracheally with 4 ml of inoculum containing 9.5 x 10(8) CFU/ml of Pasteurella haemolytica A2 isolated earlier from pneumonic lungs of goat. At intervals of 3 and 7 days post-challenge five goats from each group were killed and the lungs were washed with sterile phosphate-buffered saline. Smears were prepared from the lung washing fluid and the number of macrophages with phagocytic activity was determined. At day 3 post-infection, goats of both groups showed a similar pattern of pneumonic lesion. The lung washing fluid of goats in group 2 was found to contain numerous neutrophils and macrophages. Goats in group 2 showed significantly (P < 0.05) higher extent of lung lesions than group 1. Similarly, the average extent of lung lesions was significantly (P < 0.05) more severe in group 2 at day 7 post-infection. The lung washing fluid contained mostly macrophages. The phagocytic activity following S. aureus infection was more efficient and significantly (P < 0.01) higher compared with infection by P. haemolytica A2. There were weak correlations between the extent of pneumonic lesion and the phagocytic activity. Thus, goats with poor phagocytic activity were likely to develop more extensive lung lesions.
    Matched MeSH terms: Phagocytosis
  9. Induction of cell death and modulation of Annexin A1 by phytoestrogens in human leukemic cell lines
    Sabran A, Kumolosasi E, Jantan I, Jamal JA, Azmi N, Jasamai M
    Saudi Pharm J, 2021 Jan;29(1):73-84.
    PMID: 33603542 DOI: 10.1016/j.jsps.2020.12.011
    Background: Phytoestrogens are polyphenolic plant compounds which are structurally similar to the endogenous mammalian estrogen, 17β-estradiol. Annexin A1 (ANXA1) is an endogenous protein which inhibits cyclo-oxygenase 2 (COX-2) and phospholipase A2, signal transduction, DNA replication, cell transformation, and mediation of apoptosis.

    Objective: This study aimed to determine the effects of selected phytoestrogens on annexin A1 (ANXA1) expression, mode of cell death and cell cycle arrest in different human leukemic cell lines.

    Methods: Cells viability were examined by MTT assay and ANXA1 quantification via Enzyme-linked Immunosorbent Assay. Cell cycle and apoptosis were examined by flow cytometer and phagocytosis effect was evaluated using haematoxylin-eosin staining.

    Results: Coumestrol significantly (p 

    Matched MeSH terms: Phagocytosis
  10. Fulltext Human mesenchymal stem cells inhibit the differentiation and effector functions of monocytes
    Maqbool M, Algraittee SJR, Boroojerdi MH, Sarmadi VH, John CM, Vidyadaran S, et al.
    Innate Immun, 2020 07;26(5):424-434.
    PMID: 32635840 DOI: 10.1177/1753425919899132
    Although monocytes represent an essential part of the host defence system, their accumulation and prolonged stimulation could be detrimental and may aggravate chronic inflammatory diseases. The present study has explored the less-understood immunomodulatory effects of mesenchymal stem cells on monocyte functions. Isolated purified human monocytes were co-cultured with human umbilical cord-derived mesenchymal stem cells under appropriate culture conditions to assess monocytes' vital functions. Based on the surface marker analysis, mesenchymal stem cells halted monocyte differentiation into dendritic cells and macrophages and reduced their phagocytosis functions, which rendered an inability to stimulate T-cell proliferation. The present study confers that mesenchymal stem cells exerted potent immunosuppressive activity on monocyte functions such as differentiation, phagocytosis and Ag presentation; hence, they promise a potential therapeutic role in down-regulating the unwanted monocyte-mediated immune responses in the context of chronic inflammatory diseases.
    Matched MeSH terms: Phagocytosis
  11. Fulltext Differential polarization and the expression of efferocytosis receptor MerTK on M1 and M2 macrophages isolated from coronary artery disease patients
    Mohd Idrus FN, Ahmad NS, Hoe CH, Azlan M, Norfuad FA, Yusof Z, et al.
    BMC Immunol, 2021 03 24;22(1):21.
    PMID: 33761885 DOI: 10.1186/s12865-021-00410-2
    BACKGROUND: Differential polarization of macrophage into M1 and M2 mediates atherosclerotic plaque clearance through efferocytosis. Higher expression of Mer proto-oncogene tyrosine kinase (MerTK) on M2 macrophage helps in maintaining macrophage efferocytic efficiency. In healthy individuals, macrophage polarization into M1 and M2 occurs in tissues in concomitance with the acquisition of functional phenotypes depending on specific microenvironment stimuli. However, whether the macrophage differential polarization and MerTK expression vary in coronary artery disease (CAD) patients remain unknown.

    OBJECTIVE: This study aimed to elucidate the polarization of M1 and M2 macrophage from CAD patients as well as to investigate the expression of MerTK in these macrophage phenotypes.

    METHODS: A total of 14 (n) CAD patients were recruited and subsequently grouped into "no apparent CAD", "non-obstructive CAD" and "obstructive CAD" according to the degree of stenosis. Thirty ml of venous blood was withdrawn to obtain monocyte from the patients. The M1 macrophage was generated by treating the monocyte with GMCSF, LPS and IFN-γ while MCSF, IL-4 and IL-13 were employed to differentiate monocyte into M2 macrophage. After 7 days of polarization, analysis of cell surface differentiation markers (CD86+/CD80+ for M1 and CD206+/CD200R+ for M2) and measurement of MerTK expression were performed using flow cytometry.

    RESULTS: Both M1 and M2 macrophage expressed similar level of CD86, CD80 and CD206 in all groups of CAD patients. MerTK expression in no apparent CAD patients was significantly higher in M2 macrophage compared to M1 macrophage [12.58 ± 4.40 vs. 6.58 ± 1.37, p = 0.040].

    CONCLUSION: Differential polarization of macrophage into M1 and M2 was highly dynamic and can be varied due to the microenvironment stimuli in atherosclerotic plaque. Besides, higher expression of MerTK in patients with the least coronary obstructive suggest its vital involvement in efferocytosis.

    Matched MeSH terms: Phagocytosis
  12. Fulltext Modulation of Human Macrophage Responses to Mycobacterium tuberculosis by Silver Nanoparticles of Different Size and Surface Modification
    Sarkar S, Leo BF, Carranza C, Chen S, Rivas-Santiago C, Porter AE, et al.
    PLoS One, 2015;10(11):e0143077.
    PMID: 26580078 DOI: 10.1371/journal.pone.0143077
    Exposure to silver nanoparticles (AgNP) used in consumer products carries potential health risks including increased susceptibility to infectious pathogens. Systematic assessments of antimicrobial macrophage immune responses in the context of AgNP exposure are important because uptake of AgNP by macrophages may lead to alterations of innate immune cell functions. In this study we examined the effects of exposure to AgNP with different particle sizes (20 and 110 nm diameters) and surface chemistry (citrate or polyvinlypyrrolidone capping) on cellular toxicity and innate immune responses against Mycobacterium tuberculosis (M.tb) by human monocyte-derived macrophages (MDM). Exposures of MDM to AgNP significantly reduced cellular viability, increased IL8 and decreased IL10 mRNA expression. Exposure of M.tb-infected MDM to AgNP suppressed M.tb-induced expression of IL1B, IL10, and TNFA mRNA. Furthermore, M.tb-induced IL-1β, a cytokine critical for host resistance to M.tb, was inhibited by AgNP but not by carbon black particles indicating that the observed immunosuppressive effects of AgNP are particle specific. Suppressive effects of AgNP on the M.tb-induced host immune responses were in part due to AgNP-mediated interferences with the TLR signaling pathways that culminate in the activation of the transcription factor NF-κB. AgNP exposure suppressed M.tb-induced expression of a subset of NF-κB mediated genes (CSF2, CSF3, IFNG, IL1A, IL1B, IL6, IL10, TNFA, NFKB1A). In addition, AgNP exposure increased the expression of HSPA1A mRNA and the corresponding stress-induced Hsp72 protein. Up-regulation of Hsp72 by AgNP can suppress M.tb-induced NF-κB activation and host immune responses. The observed ability of AgNP to modulate infectious pathogen-induced immune responses has important public health implications.
    Matched MeSH terms: Phagocytosis/drug effects*
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