Displaying publications 41 - 60 of 89 in total

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  1. Kampan NC, Madondo MT, McNally OM, Stephens AN, Quinn MA, Plebanski M
    Front Immunol, 2017;8:1482.
    PMID: 29163543 DOI: 10.3389/fimmu.2017.01482
    Background: Epithelial ovarian cancer (EOC) remains a highly lethal gynecological malignancy. Ascites, an accumulation of peritoneal fluid present in one-third of patients at presentation, is linked to poor prognosis. High levels of regulatory T cells (Tregs) in ascites are correlated with tumor progression and reduced survival. Malignant ascites harbors high levels of Tregs expressing the tumor necrosis factor receptor 2 (TNFR2), as well as pro-inflammatory factors such as interleukin 6 (IL-6) and tumor necrosis factor (TNF). IL-6 is also associated with poor prognosis. Herein, we study the effect of IL-6 and TNF present in ascites on the modulation of TNFR2 expression on T cells, and specifically Tregs.

    Methods: Ascites and respective peripheral blood sera were collected from 18 patients with advanced EOC and soluble biomarkers, including IL-6, sTNFR2, IL-10, TGF-β, and TNF, were quantified using multiplexed bead-based immunoassay. Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated with cell-free ascites for 48 h (or media as a negative control). In some experiments, IL-6 or TNF within the ascites were neutralized by using monoclonal antibodies. The phenotype of TNFR2(+) Tregs and TNFR2(-) Tregs were characterized post incubation in ascites. In some experiments, cell sorted Tregs were utilized instead of PBMC.

    Results: High levels of immunosuppressive (sTNFR2, IL-10, and TGF-β) and pro-inflammatory cytokines (IL-6 and TNF) were present in malignant ascites. TNFR2 expression on all T cell subsets was higher in post culture in ascites and highest on CD4(+)CD25(hi)FoxP3(+) Tregs, resulting in an increased TNFR2(+) Treg/effector T cell ratio. Furthermore, TNFR2(+) Tregs conditioned in ascites expressed higher levels of the functional immunosuppressive molecules programmed cell death ligand-1, CTLA-4, and GARP. Functionally, TNFR2(+) Treg frequency was inversely correlated with interferon-gamma (IFN-γ) production by effector T cells, and was uniquely able to suppress TNFR2(+) T effectors. Blockade of IL-6, but not TNF, within ascites decreased TNFR2(+) Treg frequency. Results indicating malignant ascites promotes TNFR2 expression, and increased suppressive Treg activity using PBMC were confirmed using purified Treg subsets.

    Conclusion: IL-6 present in malignant ovarian cancer ascites promotes increased TNFR2 expression and frequency of highly suppressive Tregs.

    Matched MeSH terms: Leukocytes, Mononuclear
  2. Kozielewicz P, Alomar H, Yusof S, Grafton G, Cooper AJ, Curnow SJ, et al.
    FEBS Open Bio, 2017 12;7(12):1982-1993.
    PMID: 29226084 DOI: 10.1002/2211-5463.12339
    A number of members of the G protein-coupled receptor class of cell surface receptors are 'orphans' with no known endogenous ligand. One of these orphan receptors is GPR61; there are little data about its expression in human cells and tissues. In this study, we investigated the post-translational modification of GPR61 by N-glycosylation at an identified consensus N-glycosylation site (N12) and the impact of this modification upon the subcellular expression of the protein. The N-glycosylation inhibitor tunicamycin reduced the apparent molecular weight of immunoreactivity associated with myc-tagged GPR61 by 1-2 kDa, which was comparable to the evident molecular weight of the myc-tagged N12S GPR61 mutant with disrupted consensus N-glycosylation site. Analysis of GPR61 expression demonstrated that tunicamycin treatment reduced considerably heterologous expression of GPR61 in the cell membrane despite the N12S GPR61 mutant being readily expressed at the cell surface. These results demonstrate that GPR61 is subject to N-glycosylation but suggest this is not a prerequisite for cell surface expression, although N-glycosylation of other proteins may be important for cell membrane expression of GPR61. Expression of GPR61 protein was demonstrated at the cellular level in human hippocampus and human peripheral blood mononuclear cells. In the latter, there was a significantly higher expression of GPR61 in the Th17 cell subset in comparison with resting CD4+ cells, which may point toward a potential role for the GPR61 receptor in autoimmune diseases. This is the first report that GPR61 protein is subject to post-translational modification and is expressed in immune cell subsets and the hippocampus. These findings will help guide studies to investigate the function of GPR61.
    Matched MeSH terms: Leukocytes, Mononuclear
  3. Kuppusamy UR, Chong YL, Mahmood AA, Indran M, Abdullah N, Vikineswary S
    Indian J. Biochem. Biophys., 2009 Apr;46(2):161-5.
    PMID: 19517993
    Lentinula edodes (Berk) Pegler, commonly known as Shiitake mushroom has been used as medicinal food in Asian countries, especially in China and Japan and is believed to possess strong immunomodulatory property. In the present study, the methanolic extract of the fruit bodies of L. edodes was investigated for cytoprotective effect against H2O2-induced cytotoxicity in human peripheral blood mononuclear cells (PBMCs) by measuring the activities of xanthine oxidase (XO) and glutathione peroxidase (GPx) . H2O2 at a concentration of 5 microM caused 50% inhibition of PBMCs viability. The extract improved the PBMC viability and exerted a dose-dependent protection against H2O2-induced cytotoxicity. At 100 microg/ml of extract concentration, the cell viability increased by 60% compared with the PBMCs incubated with H2O2 alone. The extract also inhibited XO activity in PBMC, while showing moderate stimulatory effect on GPx. However, in the presence of H2O2 alone, both the enzyme activities were increased significantly. The GPx activity increased, possibly in response to the increased availability of H2O2 in the cell. When the cells were pretreated with the extract and washed (to remove the extract) prior to the addition of H2O2, the GPx and XO activities as well as the cell viability were comparable to those when incubated with the extract alone. Thus, it is suggested that one of the possible mechanisms via which L. edodes methanolic extract confers protection against H2O2-induced oxidative stress in PBMC is by inhibiting the superoxide-producing XO and increasing GPx activity which could rapidly inactivate H2O2.
    Matched MeSH terms: Leukocytes, Mononuclear/cytology; Leukocytes, Mononuclear/drug effects*; Leukocytes, Mononuclear/enzymology
  4. Kuppusamy UR, Dharmani M, Kanthimathi MS, Indran M
    Biol Trace Elem Res, 2005 Jul;106(1):29-40.
    PMID: 16037608
    The trace elements copper, zinc, and selenium are important immune modulators and essential cofactors of the antioxidant enzymes. In the present study, the proliferative effect of human peripheral mononuclear cells (PBMCs) that have been exposed to copper, zinc, and selenium and the corresponding activities of antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase, were determined. Zinc and copper stimulated the PBMC proliferation in a dose-dependent manner within the dose range 25-200 micromol/L. SOD and GPx activities in PBMCs exposed to zinc were inhibited, whereas catalase activity was unaffected. All the three antioxidant enzymes in the cells exposed to copper were inhibited. Selenium exerted more potent inhibition of the cell proliferation while causing stimulation of the antioxidant enzymes at the lowest dose (25 micromol/L) than at the highest dose (200 micromol/L) tested. A significant negative correlation was observed between proliferation and antioxidant enzyme (SOD and GPx) activities in trace-element-exposed PBMC. The present findings substantiate the importance of trace elements as immune modulators and the involvement of enzymatic antioxidant system in the immune cell regulation.
    Matched MeSH terms: Leukocytes, Mononuclear/cytology*; Leukocytes, Mononuclear/drug effects*
  5. Lai JY, Lim TS
    Methods Mol Biol, 2023;2702:39-58.
    PMID: 37679614 DOI: 10.1007/978-1-0716-3381-6_3
    Phage display has been applied successfully for the rapid isolation of monoclonal antibodies against various targets including infectious diseases, autoantigens, cancer markers, and even small molecules. The main component in any phage display experiment is the availability of an antibody library to carry out the selection process of target-specific antibodies through an iterative process termed as biopanning. To generate human antibody libraries, the antibody repertoire can be obtained from human peripheral blood mononuclear cell (PBMC) or directly from cell-sorted B-cell populations. The choice of antibody isotype is dictated by the nature of the library. Naïve libraries would utilize IgM repertoires, whereas the IgG repertoire is commonly used for immune libraries. Antibody genes are amplified through polymerase chain reaction (PCR) and paired in a combinatorial fashion to expand the diversity of the cloned library repertoire. The protocol here describes the use of a two-step cloning method that can be applied for the construction of either a naïve or immune human antibody library in Fab format followed by the subsequent panning.
    Matched MeSH terms: Leukocytes, Mononuclear*
  6. Lam HY, Yusoff K, Yeap SK, Subramani T, Abd-Aziz S, Omar AR, et al.
    Int J Med Sci, 2014;11(12):1240-7.
    PMID: 25317070 DOI: 10.7150/ijms.8170
    Immunotherapy has raised the attention of many scientists because it hold promise to be an attractive therapeutic strategy to treat a number of disorders. In this study, the immunomodulatory effects of low titers of Newcastle disease virus (NDV) AF2240 on human peripheral blood mononuclear cells (PBMC) were analyzed. We evaluated cytokine secretion and PBMC activation by cell proliferation assay, immunophenotyping and enzyme linked immunosorbent assay. The proliferation of the human PBMC was measured to be 28.5% and 36.5% upon treatment with 8 hemaglutinin unit (HAU) and 2 HAU of NDV respectively. Interestingly, the percentage of cells with activating markers CD16 and CD56 were increased significantly. Furthermore, the intracellular perforin and granzyme levels were also increased upon virus infection. Human PBMC treated with NDV titer 8 HAU was found to stimulate the highest level of cytokine production including interferon-γ, interleukin-2 and interleukin-12. The release of these proteins contributes to the antitumor effect of PBMC against MCF-7 breast cancer cells. Based on the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay, activated human PBMC showed high cytolytic efficiency towards human breast tumor cells. In summary, NDV was able to stimulate PBMC proliferation, cytokine secretion and cytolytic activity.
    Matched MeSH terms: Leukocytes, Mononuclear/cytology; Leukocytes, Mononuclear/immunology*; Leukocytes, Mononuclear/virology
  7. Lau KA, Wang B, Miranda-Saksena M, Boadle R, Kamarulzaman A, Ng KP, et al.
    Curr. HIV Res., 2010 Apr;8(3):259-71.
    PMID: 20214658
    In Malaysia, co-circulation of CRF01_AE and subtype B has resulted in the emergence of the second generation derivative; CRF33_01B in approximately 20% of its HIV-1 infected individuals. Our objective was to identify possible biological advantages that CRF33_01B possesses over its progenitors. Biological and molecular comparisons of CRF33_01B against its parental subtypes clearly show that CRF33_01B replicated better in activated whole peripheral blood mononuclear cells (PBMCs) and CD4+ T-lymphocytes, but not monocyte-derived macrophages (MDMs). Also, its acquired fitness was greater than CRF01_AE but not subtype B. Moreover, CRF33_01B has higher rate of apoptotic cell death and syncytia induction compared to subtype B. These adaptive and survival abilities could have been acquired by CRF33_01B due to the incorporation of subtype B fragments into the gag-RT region of its full-length genome. Our studies confirm the previously held belief that HIV-1 strains may harbor enhanced biological fitness upon recombination. We therefore estimate a possible gradual replacement of the current predominance of CRF01_AE, as well as wider dissemination of CRF33_01B, together with the identification of other new CRF01_AE/B inter-subtype recombinants in Malaysia.
    Matched MeSH terms: Leukocytes, Mononuclear/virology
  8. Lau YL, Thiruvengadam G, Lee WW, Fong MY
    Parasitol Res, 2011 Sep;109(3):871-8.
    PMID: 21455621 DOI: 10.1007/s00436-011-2315-6
    In this study, we successfully expressed a chimerical surface antigen 1 and 2 (SAG1/2) of Toxoplasma gondii in Pichia pastoris. Eighty human serum samples, including 60 from confirmed cases of toxoplasmosis, were tested against the purified recombinant SAG1/2 in Western blots. Results of Western blots targeted at Toxoplasma IgG and IgM showed that the recombinant SAG1/2 reacted with all sera from the toxoplasmosis cases but none with the Toxoplasma-negative serum samples. These results showed that the P. pastoris-derived recombinant SAG1/2 was sensitive and specific and suitable for use as antigen for detecting anti-Toxoplasma antibodies. To further investigate the immunological characteristic of the recombinant protein, the recombinant SAG1/2 was injected subcutaneously into BALB/c mice, and their serum was tested against total protein lysate of T. gondii. Mice immunized with the recombinant SAG1/2 reacted specifically with the native SAG1 and SAG2 of T. gondii. Significant proliferation of splenocytes stimulated with tachyzoite total protein lysate was observed in vaccinated BALB/c mice but not in those from negative control mice. Specific production of IFN-γ, the Th1-type cytokines, was also found in stimulated splenocytes from vaccinated mice. These results show that the chimeric protein recombinant SAG1/2 can elicit a Th1-associated protection against T. gondii infections in mice. Finally, vaccinated mice were significantly protected against lethal challenge with live T. gondii RH strain tachyzoites (P 
    Matched MeSH terms: Leukocytes, Mononuclear/immunology
  9. Leng CY, Low HC, Chua LL, Chong ML, Sulaiman H, Azwa I, et al.
    HIV Med, 2017 05;18(5):321-331.
    PMID: 27649852 DOI: 10.1111/hiv.12432
    OBJECTIVES: Human papillomavirus (HPV)-associated cancers disproportionately affect those infected with HIV despite effective combination antiretroviral therapy (cART). The primary aim of this study was to quantify HPV16 and HPV52 E6-specific interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) T-cell responses, a correlate of protective immunity, in the first year following cART initiation and subsequently in those patients with suboptimal (sIR) and optimal (oIR) immune reconstitution.

    METHODS: Ninety-four HIV-infected patients were recruited to the study; a longitudinal cohort of patients recruited just prior to commencing cART and followed up for 48 weeks (n = 27), and a cross-sectional cohort (n = 67) consisting of patients with sIR (CD4 T-cell count < 350 cells/μL) and oIR (CD4 T-cell count > 500 cells/μL) after a minimum of 2 years on cART. Controls (n = 29) consisted of HIV-negative individuals. IFN-γ ELISPOT responses against HPV16 and HPV52 E6 were correlated to clinical characteristics, anal and oral HPV carriage, T-cell maturational subsets, markers of activation, senescence and T-regulatory cells.

    RESULTS: HPV16 and HPV52 E6-specific T-cell responses were detected in only one of 27 patients (3.7%) during the initial phase of immune recovery. After at least 2 years of cART, those who achieved oIR had significantly higher E6-specific responses (9 of 34; 26.5%) compared with those with sIR (2 of 32; 6.3%) (P = 0.029). Apart from higher CD4 T-cell counts and lower CD4 T-cell activation, no other immunological correlates were associated with the detection of HPV16 and HPV52 E6-specific responses.

    CONCLUSIONS: HPV16 and HPV52 E6-specific IFN-γ T-cell responses, a correlate of protective immunity, were detected more frequently among HIV-infected patients who achieved optimal immune recovery on cART (26.5%) compared with those with suboptimal recovery (6.3%).

    Matched MeSH terms: Leukocytes, Mononuclear/immunology
  10. Leong KF, Sato R, Oh GGK, Surana U, Pramono ZAD
    Indian J Dermatol, 2019 9 24;64(5):400-403.
    PMID: 31543536 DOI: 10.4103/ijd.IJD_44_18
    Blau syndrome (BS) is a very rare autosomal dominant juvenile inflammatory disorder caused by mutation in nucleotide-binding oligomerization domain containing 2 (NOD2). Usually, dermatitis is the first symptom that appears in the 1st year of life. About 220 BS cases with confirmed NOD2 mutation have been reported. However, the rarity and lack of awareness of the disease, especially in the regions where genetic tests are very limited, often result in late diagnosis and misdiagnosis. Here, we report a de novo BS case from Malaysia, which may be the first report from southeast Asia. PCR and DNA sequencing of peripheral blood mononuclear cells were performed to screen the entire coding region of NOD2 gene. A heterozygous c.1000C>T transition in exon 4, p. R334W, of the NOD2 gene was identified in the patient. This report further reaffirms the ubiquitousness of the disease and recurrency of p. R334W mutation.
    Matched MeSH terms: Leukocytes, Mononuclear
  11. Lim KP, Chun NA, Ismail SM, Abraham MT, Yusoff MN, Zain RB, et al.
    PLoS One, 2014;9(8):e103975.
    PMID: 25153698 DOI: 10.1371/journal.pone.0103975
    Regulatory T cells (Tregs), a subset of CD4+ T cells plays a pivotal role in regulating the immune system. An increase in Treg numbers enables cancer progression by dampening the immune system and allowing tumor cells to evade immune detection and destruction. An increase in Treg numbers and expression of inhibitory cytokines including TGF-β and IL-10 are mechanisms by which Tregs exert their immune suppressive function. However, the presence of Tregs and inhibitory cytokines in oral cancer patients is still unclear. In this study, the presence of circulating Tregs in 39 oral cancer patients and 24 healthy donors was examined by studying the presence of the CD4+CD25hiCD127low cell population in their peripheral blood mononuclear cells using flow cytometry. Serum levels of TGF-β and IL-10 were measured by ELISA. T cell subsets of OSCC patients were found to differ significantly from healthy donors where a decrease in CD8+ cytotoxic T cells and an increase in Tregs (CD4+CD25hiCD127low) were observed. Further, the ratio of CD8+ T cells/Tregs was also decreased in patients compared to healthy donors. The presence of Tregs was accompanied by a decrease in IL-10 but not TGF-β secretion in OSCC patients when compared to donors; in addition, the analysis also revealed that an increased presence of Tregs was accompanied by better patient survival. Amongst OSCC patients, smokers had significantly higher levels of TGF-β. It is apparent that the immune system is compromised in OSCC patients and the characterization of the Treg subpopulation could form a basis for improving our understanding of the perturbations in the immune system that occur during OSCC tumorigenesis.
    Matched MeSH terms: Leukocytes, Mononuclear/immunology; Leukocytes, Mononuclear/metabolism
  12. Lindsay A, Othman MI, Prebble H, Davies S, Gieseg SP
    Exp Physiol, 2016 07 01;101(7):851-65.
    PMID: 27094349 DOI: 10.1113/EP085795
    What is the central question of this study? Acute and repetitive cryotherapy are routinely used to accelerate postexercise recovery, although the effect on resident immune cells and repetitive exposure has largely been unexplored and neglected. What is the main finding and its importance? Using blood-derived mononuclear cells and semi-professional mixed martial artists, we show that acute and repetitive cryotherapy reduces the in vitro and in vivo T-cell and monocyte activation response whilst remaining independent of the physical performance of elite athletes. We investigated the effect of repetitive cryotherapy on the in vitro (cold exposure) and in vivo (cold water immersion) activation of blood-derived mononuclear cells following high-intensity exercise. Single and repeated cold exposure (5°C) of a mixed cell culture (T cells and monocytes) was investigated using in vitro tissue culture experimentation for total neopterin production (neopterin plus 7,8-dihydroneopterin). Fourteen elite mixed martial art fighters were also randomly assigned to either a cold water immersion (15 min at 10°C) or passive recovery protocol, which they completed three times per week during a 6 week training camp. Urine was collected and analysed for neopterin and total neopterin three times per week, and perceived soreness, fatigue, physical performance (broad jump, push-ups and pull-ups) and training performance were also assessed. Single and repetitive cold exposure significantly (P 
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism; Leukocytes, Mononuclear/physiology*
  13. Lithanatudom P, Chawansuntati K, Saenjum C, Chaowasku T, Rattanathammethee K, Wungsintaweekul B, et al.
    BMC Res Notes, 2023 Dec 22;16(1):381.
    PMID: 38135870 DOI: 10.1186/s13104-023-06664-w
    OBJECTIVE: Plants in the Annonaceae family are known for having abundant biologically active secondary metabolites. They have been used in alternative drugs for various diseases in several countries, for instance, the bark of Cananga odorata (Lam.) Hook and Thomson is used for Ophthalmic inflammation and wound healing in Malaysia. Extracts from the leaves and stems of four Annonaceae plants, namely Uvaria longipes (Craib) L.L.Zhou, Y.C.F.Su & R.M.K.Saunders, Dasymaschalon sp., Artabotrys burmanicus A.DC, and Marsypopetalum modestum (Pierre) B.Xue & R.M.K.Saunders were investigated for growth inhibitory activity against blood-stage Plasmodium falciparum growth in vitro and for non-specific cytotoxicity against normal peripheral blood mononuclear cells (PBMCs). Antimalarial activity was assessed by invasion inhibition assay and the percentage of infected red blood cells on blood smears were determined. Cytotoxicity was tested by culturing PBMCs with the extracts, and viabilities were determined by Annexin V/propidium iodide staining.

    RESULTS: A. burmanicus stem extract and M. modestum leaf extract were capable of inhibiting growth of P. falciparum when used at 200 µg/mL compared to chloroquine. The extracts at effective concentrations, did not affect the viability of PBMCs. These results support further need for characterization of active compounds from specific Annonaceae plants in order to exploit their components for potential malaria treatment.

    Matched MeSH terms: Leukocytes, Mononuclear
  14. Maniam P, Nurul Aiezzah Z, Mohamed R, Embi N, Hasidah MS
    Trop Biomed, 2015 Mar;32(1):36-48.
    PMID: 25801253
    Increased susceptibility of diabetics to melioidosis, a disease caused by the Burkholderia pseudomallei bacterium is believed to be attributed to dysfunction of the innate immune system. However, the underlying mechanism of the innate susceptibility is not well-understood. Glycogen synthase kinase-3β (GSK3β) plays an important role in the innate inflammatory response caused by bacterial pathogens. The present study was conducted to investigate the effects of GSK3β inhibition by LiCl on levels of pro- and anti-inflammatory cytokines; and the activity of transcription factor NF-κB in B. pseudomallei-infected peripheral blood mononuclear cells (PBMC) derived from diabetic-induced and normal Sprague Dawley rats. In addition, the effects of LiCl on intracellular bacterial counts were also investigated. Infection of PBMC from diabetic and normal rats with B. pseudomallei resulted in elevated levels of cytokines (TNF-α, IL-12 and IL-10) and phosphorylation of NF-κB in both cell types. Intracellular bacterial counts decreased with time in both cell types during infection. However bacterial clearance was less prominent in diabetic PBMC. Burkholderia pseudomallei infection also caused inactivation (Ser9 phosphorylation) of GSK3β in normal PBMC, an effect absent in infected diabetic PBMC. Inhibition of GSK3β by LiCl lowered the levels of pro-inflammatory cytokines (TNF-α and IL-12) in both normal and diabetic PBMC. Similarly, phosphorylated NF- κB (pNF-κB) levels in both cell types were decreased with LiCl treatment. Also, LiCl was able to significantly decrease the intracellular bacterial count in normal as well as diabetic PBMC. Interestingly, the levels of anti-inflammatory cytokine IL-10 in both normal and diabetic PBMC were further elevated with GSK3β inhibition. More importantly, GSK3β in infected diabetic PBMC was inactivated as in their non-diabetic counterparts upon LiCl treatment. Taken together, our results suggest that inhibition of dysregulated GSK3β in diabetic PBMC resulted in the inactivation of NF-κB and modulation of inflammatory cytokine levels. This is evidence that dysregulation of GSK3β is a contributing factor in the molecular basis of innate dysfunction and susceptibility of diabetic host to melioidosis infection.
    Matched MeSH terms: Leukocytes, Mononuclear/immunology*
  15. Menon N, Mariappan V, Vellasamy KM, Samudi C, See JX, Ganesh PS, et al.
    Access Microbiol, 2020;2(5):acmi000110.
    PMID: 32974575 DOI: 10.1099/acmi.0.000110
    Burkholderia pseudomallei is the causative agent for melioidosis. Because of its intracellular nature, the bacterium is capable of replicating within a plethora of eukaryotic cell lines. B. pseudomallei can remain dormant within host cells without symptoms for years, causing recrudescent infections. Here, we investigated the pathogenesis mechanism behind the suppression of T cell responses by B. pseudomallei . Peripheral blood mononuclear cells (1×106 cells/well) isolated by Ficoll Paque (Sigma-Aldrich) density gradient centrifugation were incubated with optimized concentrations of bacterial crude culture filtrate antigens (CFAs) (10 ug ml-1) and heat-killed bacteria [1 : 10 multiplicity of infection (m.o.i.)]. Following incubation, cells were investigated for surface expression of coinhibitory molecules by flow cytometry. We found that B. pseudomallei induced the upregulation of programmed death 1 (PD-1), a molecule responsible for T cell exhaustion, on T cells in vitro following exposure to crude CFAs of B. pseudomallei . This upregulation of PD-1 probably contributes to poor immune surveillance and disease pathogenesis.
    Matched MeSH terms: Leukocytes, Mononuclear
  16. Mirsafian H, Ripen AM, Leong WM, Manaharan T, Mohamad SB, Merican AF
    Genomics, 2017 Oct;109(5-6):463-470.
    PMID: 28733102 DOI: 10.1016/j.ygeno.2017.07.003
    Differential gene and transcript expression pattern of human primary monocytes from healthy young subjects were profiled under different sequencing depths (50M, 100M, and 200M reads). The raw data consisted of 1.3 billion reads generated from RNA sequencing (RNA-Seq) experiments. A total of 17,657 genes and 75,392 transcripts were obtained at sequencing depth of 200M. Total splice junction reads showed an even more significant increase. Comparative analysis of the expression patterns of immune-related genes revealed a total of 217 differentially expressed (DE) protein-coding genes and 50 DE novel transcripts, in which 40 DE protein-coding genes were related to the immune system. At higher sequencing depth, more genes, known and novel transcripts were identified and larger proportion of reads were allowed to map across splice junctions. The results also showed that increase in sequencing depth has no effect on the sequence alignment.
    Matched MeSH terms: Leukocytes, Mononuclear/chemistry*
  17. 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: Leukocytes, Mononuclear/drug effects; Leukocytes, Mononuclear/immunology
  18. Munisvaradass R, Ding SSL, Ee AHK, Syahril Abdullah, Mok PL, Kumar S, et al.
    Sains Malaysiana, 2017;46:1831-1838.
    Breast cancer is one of the most common malignancies among woman. Decades of scientific study have linked the
    overexpression of ERBB2 antigen to aggressive tumors. To target aggressive breast cancer, chimeric antigen receptor
    (CAR) technology can be utilized. For this, human T-cells are transduced with a gene sequence encoding a CAR that is
    specific for tumor-associated antigens (TAAs). These genetically-engineered CAR transduced T-cells (CAR-T cells) are
    able to target the tumor antigen without the need for major histocompatibility complex (MHC) recognition, rendering
    it a potentially universal immunotherapeutic option. However, efficient transduction of therapeutic gene into human
    T-cells and further cell expansion are challenging. In this study, we reported a successful optimization of a transduction
    protocol using spinoculation on CD3+ T-cells with different concentrations of lentiviral plasmid encoding the CAR gene.
    CD3+T-cells were isolated from the peripheral blood mononuclear cells (PBMCs). The constructed CAR gene was inserted
    into a lentiviral plasmid containing the green fluorescent protein (GFP) tag and lentiviral particles were produced. These
    lentiviral particles were used to transduce activated T-cells by spinoculation. T-cells were activated using Dynabeadconjugated
    CD3/CD28 human T-cell activator and interleukin-2 (IL-2) before transduction. CD3+ T-cells were selected
    and GFP expression, which indicated transduction, was observed. Future studies will focus on in vitro and in vivo models
    to determine the efficiency of CAR-T cells in specifically targeting ERBB2-expressing cells.
    Matched MeSH terms: Leukocytes, Mononuclear
  19. Nathan SA, Puthucheary SD
    Malays J Pathol, 2005 Jun;27(1):3-7.
    PMID: 16676686
    B. pseudomallei has been shown to persist intracellularly in melioidosis patients until reactivated by decreasing immunocompetence. We have shown by transmission electron microscopy the internalization of B. pseudomallei by human macrophages via conventional phagocytosis enclosed within membrane-bound vacuoles or phagosomes. Ferritin labeled lysosomes provided evidence of phagosome-lysosome fusion. Ingested bacilli were designated as "intact" or "damaged" on the basis of their ultrastructural features. An intact bacterium was seen with low electron opaque central nuclear region surrounded by dense bacterial cytoplasm, bounded externally by bacterial plasma membrane and cell wall. In contrast, B. pseudomallei were considered damaged when seen with cavitation within the central nuclear region, separation of bacterial cytoplasm from the cell wall, herniation of cytoplasmic contents and lamination of bacterial cell wall and its surrounding electron transparent zone. Our observations indicate that the microbicidal mechanism(s) in B. pseudomallei-infected macrophages failed to ensure complete clearance of the organism and this failure probably facilitates intracellular persistence and proliferation, and this may be one of the survival strategies adopted by this organism.
    Matched MeSH terms: Leukocytes, Mononuclear/physiology*; Leukocytes, Mononuclear/ultrastructure*
  20. Nor Hazwani Ahmad, Rohanizah Abdul Rahim, Ishak Mat
    Trop Life Sci Res, 2010;21(2):-.
    MyJurnal
    Research on natural products has been widely used as a strategy to discover new drugs with potential for applications in complementary medicines because they have fewer side effects than conventional drugs. The aim of the present study was to evaluate the in vitro cytotoxic effects of crude aqueous Catharanthus roseus extract on Jurkat cells and normal peripheral blood mononuclear cells (PBMCs). The aqueous extract was
    standardised to vinblastine by high performance liquid chromatography (HPLC) and was used to determine cytotoxicity by the MTS [3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. DNA fragmentation assay was employed to determine if cell death was due to apoptosis. The results showed that the aqueous extract induced cell death of Jurkat cells at 24, 48 and 72 hours posttreatment in a time- and dose-dependent manner. However, cells treated at 48 and 72 hours produced higher cytotoxic effects with half maximal inhibitory concentration (IC50)values of 2.55 µg/ml and 2.38 µg/ml, respectively. In contrast, the extract induced normal PBMC proliferation, especially after 24 hours treatment with 1000 µg/ml. This result indicates that the C. roseus crude aqueous extract showed differential effects of inhibiting the proliferation of the Jurkat cell line and promoting the growth of PBMCs. These data suggest that the extract may be applicable for modulating the normal and transformed immune cells in leukaemia patients.
    Matched MeSH terms: Leukocytes, Mononuclear
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