Peripheral Blood Mononuclear Cells Cultures Research Articles

Syncytin-1/HERV-W envelope is an early activation marker of leukocytes and is upregulated in multiple sclerosis patients.

Syncytin-1 is the envelope protein of the human endogenous retrovirus W (HERV-W). It has been related to multiple sclerosis (MS) but its role in cellular immunity and its pathogenic mechanism in the autoimmune context are not fully understood. We analyzed syncytin-1 levels in peripheral blood mononuclear cells (PBMC) subsets from healthy donors, MS patients in relapse or remission, and patients with acute infections by flow cytometry. PBMC cultures were also prepared to analyze protein expression kinetics. MS patients had higher levels of syncytin-1 levels than controls. We found that syncytin-1 is elevated in monocytes during MS relapses and infections. Cells expressing syncytin-1, including monocytes, T and B lymphocytes, and NKs presented mainly an activated phenotype and, upon stimulation with LPS, its levels increased rapidly on antigen-presenting cells. Syncytin-1 ligation promoted the activation of monocytes, as demonstrated by the upregulation of CD80 and the nonclassical subset CD14low CD16+ . Our results suggest an important role for syncytin-1 in the activation of leukocytes. Given that the expression of syncytin-1 is upregulated in MS patients, this protein might be contributing to the autoimmune cascade in the disease.

Paroxetine modulates immune responses by activating a JAK2/STAT3 signaling pathway.

Paroxetine, a representative of serotonin reuptake inhibitors, has recently gained attention due to its anti-inflammatory properties. However, underlying mechanisms responsible for its immunosuppressive effects remain to be unveiled. To understand the responsible signaling mechanisms, we examined paroxetine's effect on the Janus kinase 2-signal transducer and activator of transcription 3 (JAK2-STAT3) signaling pathway on lipopolysaccharide + phytohemagglutinin-induced human peripheral blood mononuclear cells culture. We also evaluate the possible dependency of paroxetine immunomodulation effects on the 5-HT system of immune cells. Our results indicated that paroxetine attenuates proinflammatory cytokine production (interleukin-1β [IL-1β], IL-17, and tumor necrosis factor-α) and increases expression of IL-10 and JAK2/STAT3 evidence for macrophages polarization to M2 subset and functional dendritic cells depletion. In conclusion, paroxetine can exert its anti-inflammatory effects via both the 5-HT systems present in immune cells and the JAK2-STAT3 pathway. Our results also suggest that paroxetine exerted its immunosuppressive effects partially via serotonin. Nonetheless, JAK2/STAT3-modulated paroxetine effects were independent of serotonin, hence sufficiently applicable for inflammation repression.

Atorvastatin inhibits IL-17A, TNF, IL-6, and IL-10 in PBMC cultures from patients with severe rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint damage, and it may present with comorbidities at the systemic level. The Th1/Th2/Th17 CD4+ lymphocyte imbalance produces inflammatory cytokines, which begin to act, injuring joint tissue. Atorvastatin is a cholesterol- lowering drug with a range of biological effects including anti-inflammatory potential. Patients with rheumatoid arthritis who used statins exhibited clinical improvement. However, the mechanism is not fully understood. Therefore, we aimed to evaluate the RA immunomodulatory activity of atorvastatin. Peripheral blood mononuclear cells (PBMCs) of RA patients and healthy donors were exposed to atorvastatin in different concentrations following a cytotoxicity assay. Th1, Th2, and Th17 cytokines profiles were evaluated in the culture supernatant by cytometric bead array (CBA). Data were analyzed using the Wilcoxon test, and differences were considered significant when p < 0.05. Atorvastatin showed no toxicity at the tested doses in RA PBMC cultures, and at 10μM, it showed the most significant results, reducing IL-17A (p = 0.002), TNF (p = 0.002), and IL-6 (p = 0.008) supernatant levels. The outcomes also revealed that only patients with more severe disease activity and those sensitive to corticoid treatments were responders to atorvastatin in vitro. These findings suggest the potential immunomodulatory action of atorvastatin as a mechanism in rheumatoid arthritis treatment.

Anti-CD3 Antibody Treatment Reduces Scar Formation in a Rat Model of Myocardial Infarction

Introduction: Antibody treatment with anti-thymocyte globulin (ATG) has been shown to be cardioprotective. We aimed to evaluate which single anti-T-cell epitope antibody alters chemokine expression at a level similar to ATG and identified CD3, which is a T-cell co-receptor mediating T-cell activation. Based on these results, the effects of anti-CD3 antibody treatment on angiogenesis and cardioprotection were tested in vitro and in vivo. Methods: Concentrations of IL-8 and MCP-1 in supernatants of human peripheral blood mononuclear cell (PBMC) cultures following distinct antibody treatments were evaluated by Enzyme-linked Immunosorbent Assay (ELISA). In vivo, anti-CD3 antibodies or vehicle were injected intravenously in rats subjected to acute myocardial infarction (AMI). Chemotaxis and angiogenesis were evaluated using tube and migration assays. Intracellular pathways were assessed using Western blot. Extracellular vesicles (EVs) were quantitatively evaluated using fluorescence-activated cell scanning, exoELISA, and nanoparticle tracking analysis. Also, microRNA profiles were determined by next-generation sequencing. Results: Only PBMC stimulation with anti-CD3 antibody led to IL-8 and MCP-1 changes in secretion, similar to ATG. In a rat model of AMI, systemic treatment with an anti-CD3 antibody markedly reduced infarct scar size (27.8% (Inter-quartile range; IQR 16.2–34.9) vs. 12.6% (IQR 8.3–27.2); p < 0.01). The secretomes of anti-CD3 treated PBMC neither induced cardioprotective pathways in cardiomyocytes nor pro-angiogenic mechanisms in human umbilical vein endothelial cell (HUVECs) in vitro. While EVs quantities remained unchanged, PBMC incubation with an anti-CD3 antibody led to alterations in EVs miRNA expression. Conclusion: Treatment with an anti-CD3 antibody led to decreased scar size in a rat model of AMI. Whereas cardioprotective and pro-angiogenetic pathways were unaltered by anti-CD3 treatment, qualitative changes in the EVs miRNA expression could be observed, which might be causal for the observed cardioprotective phenotype. We provide evidence that EVs are a potential cardioprotective treatment target. Our findings will also provide the basis for a more detailed analysis of putatively relevant miRNA candidates.

Assessment of an Antibody-in-Lymphocyte Supernatant Assay for the Etiological Diagnosis of Pneumococcal Pneumonia in Children.

New diagnostic tests for the etiology of childhood pneumonia are needed. We evaluated the antibody-in-lymphocyte supernatant (ALS) assay to detect immunoglobulin (Ig) G secretion from ex vivo peripheral blood mononuclear cell (PBMC) culture, as a potential diagnostic test for pneumococcal pneumonia. We enrolled 348 children with pneumonia admitted to Patan Hospital, Kathmandu, Nepal between December 2015 and September 2016. PBMCs sampled from participants were incubated for 48 h before harvesting of cell culture supernatant (ALS). We used a fluorescence-based multiplexed immunoassay to measure the concentration of IgG in ALS against five conserved pneumococcal protein antigens. Of children with pneumonia, 68 had a confirmed etiological diagnosis: 12 children had pneumococcal pneumonia (defined as blood or pleural fluid culture-confirmed; or plasma CRP concentration ≥60 mg/l and nasopharyngeal carriage of serotype 1 pneumococci), and 56 children had non-pneumococcal pneumonia. Children with non-pneumococcal pneumonia had either a bacterial pathogen isolated from blood (six children); or C-reactive protein <60 mg/l, absence of radiographic consolidation and detection of a pathogenic virus by multiplex PCR (respiratory syncytial virus, influenza viruses, or parainfluenza viruses; 23 children). Concentrations of ALS IgG to all five pneumococcal proteins were significantly higher in children with pneumococcal pneumonia than in children with non-pneumococcal pneumonia. The concentration of IgG in ALS to the best-performing antigen discriminated between children with pneumococcal and non-pneumococcal pneumonia with a sensitivity of 1.0 (95% CI 0.73–1.0), specificity of 0.66 (95% CI 0.52–0.78) and area under the receiver-operating characteristic curve (AUROCC) 0.85 (95% CI 0.75–0.94). Children with pneumococcal pneumonia were older than children with non-pneumococcal pneumonia (median 5.6 and 2.0 years, respectively, p < 0.001). When the analysis was limited to children ≥2 years of age, assay of IgG ALS to pneumococcal proteins was unable to discriminate between children with pneumococcal pneumonia and non-pneumococcal pneumonia (AUROCC 0.67, 95% CI 0.47–0.88). This method detected spontaneous secretion of IgG to pneumococcal protein antigens from cultured PBMCs. However, when stratified by age group, assay of IgG in ALS to pneumococcal proteins showed limited utility as a test to discriminate between pneumococcal and non-pneumococcal pneumonia in children.

Effects of Gnathostoma spinigerum infective stage larva excretory-secretory products on NK cells in peripheral blood mononuclear cell culture: focused on expressions of IFN-γ and killer cell lectin-like receptors.

Human gnathostomiasis is mainly caused by third-stage larvae of Gnathostoma spinigerum (G. spinigerum L3). Excretory-secretory products (ES) released from infective helminthic larvae are associated with larval migration and host immunity modulation. Natural killer (NK) cells have important immune functions against helminth infection. Currently, the effects of ES from G. spinigerum L3 (G. spinigerum ES) on NK cell activity are unclear. This study investigated whether G. spinigerum ES affected human NK cells. Human normal peripheral blood mononuclear cell (PBMC) cultures were used to mimic immune cells within the circulation. PBMC were co-cultured with G. spinigerum ES (0.01-0.05μg/ml) for 5 or 7days. Levels of IFN-γ in cultured supernatants were measured by enzyme-linked immunosorbent assay. The expressions of mRNA encoding NK cell receptors, especially the C type killer cell lectin-like family (KLR; NKG2A, NKG2C, and NKG2D) and IFN-γ in ES induced PBMC were determined by quantitative reverse transcription-polymerase chain reaction (RT-qPCR). ES induced PBMC markedly decreased the levels of IFN-γ and increased the expressions of NKG2A and NKG2D on NK cells. In conclusion, low amounts of G. spinigerum ES modulated NK cells by downregulating the transcription of IFN-γ and upregulating the expressions of KLR (NKG2A and NKG2D receptors) during the 7-day observation period. These findings indicate more in-depth studies of NK cell function are required to better understand the mechanism involved in immune evasive strategies of human gnathostomiasis.

MicroRNAs in bovine milk exosomes are bioavailable in humans but do not elicit a robust pro-inflammatory cytokine response

BackgroundBovine milk exosomes are studied for their roles as bioactive food compounds and as vehicles for drug delivery. Both lines of investigation converge on immune function, e.g., immune regulation by absorption of microRNAs encapsulated in milk exosomes across species boundaries, and the possibility of exosomes and their cargos triggering an immune response if used in drug delivery. This study assessed the bioavailability of immune-related microRNAs from bovine milk and changes in plasma cytokine concentrations after milk consumption in humans, and the secretion of cytokines by human peripheral blood mononuclear cells (PBMCs) cultured with milk exosomes transfected with immune-relevant microRNAs.ResultsHuman plasma samples were collected before and at timed intervals after a milk meal and analyzed for concentrations of six immune-relevant microRNAs and nine cytokines. The peak plasma concentrations of miR-15b-5p, miR-21-5p, miR-106b-5p, and miR-223-3p were 60 ± 9.80% to 162 ± 31.80% higher after milk consumption (Ct values 23 ± 1.2 to 26 ± 1.1 cycles) compared to baseline values (P < 0.05). Plasma concentrations of TNF-alpha were not significantly different before versus after milk consumption; eight other cytokines were below detection limit. PBMCs were collected before and six hours after milk consumption and cultured with or without concanavalin A (ConA). TNF-alpha, IL-1β, IL-6 and IL-10 were detectable in culture media, but concentrations did not depend on milk consumption prior to PBMC isolation (P > 0.05). When PBMC cultures from fasted subjects were supplemented with milk exosomes that had been transfected with immune-relevant microRNAs, the concentrations of IL-1β, IL-6, IL-10 and TNF-alpha were 29 ± 12% to 220 ± 33% higher than controls cultured with non-transfected exosomes (P < 0.05), but cytokine concentrations were not different compared with control exosomes transfected with scrambled microRNA (P > 0.05).ConclusionsMicroRNAs in bovine milk exosomes are bioavailable. Milk exosomes do not elicit an increase of plasma cytokines following oral administration.Trial registrationISRCTN registry ID: 16329971. Retrospectively registered on February 7th, 2019.

Differentiation plasticity of human monocytes in culture

&amp;lt;p&amp;gt;Introduction. Human monocytes are heterogeneous and plastic cell population with the ability to undergo phenotypic and functional changes as a response to a stimulus from a local microenvironment. Our aim was to determine the potential of human monocytes to differentiate into different cell populations depending on two different cytokines (IL-4 and IL-6) added to cultures as well as to compare their phenotypical and functional characteristics. Methods. Peripheral blood mononuclear cells (PBMNC) were isolated from buffy coats of healthy donors. Monocytes, which were separated from PBMNC by plastic adherence, had been cultivated in Dendritic cell (DC), serum free medium for 5 days, either with granulocyte/macrophage colony-stimulating factor (GM-CSF) alone or with GM-CSF, with addition of interleukin 4 (IL-4) or interleukin 6 (IL-6), respectively. After cultivation, phenotypic characteristics of these cells were analyzed by flow cytometry, whereas the levels of produced cytokines in culture supernatants were quantified by ELISA. The potential of differentiated cells to modulate the proliferation of allogeneic T cells was examined by co-cultivation of these cells with PBMNC. Results. GM-CSF differentiated monocytes into M0/M1 macrophages (M&amp;amp;Oslash;). The combination of GM-CSF and IL-4 favoured differentiation of immature DC, whereas GM-CSF and IL-6 transformed monocytes into monocytic myeloid derived suppressor cells (M-MDSC). All cell populations expressed typical monocyte/macrophage markers such as CD14, CD11b, CD16 and CD33, HLA-DR, CD209 and CD86, a co-stimulatory marker. DC and M-MDSC expressed CD1a and CD11c, in contrast to M0/M1 M&amp;amp;Oslash;. The expression of HLA-DR, CD1a, CD209 and CD86 was highest on DC. The expression of CD33 and CD16 was highest on M-MDSC, followed by lowest expression of HLA-DR. The potential of promoting T-cell proliferation was highest in cultures of PBMNC with DC, whereas M-MDSC had the opposite, suppressive, effect. These differences correlated with highest production of immunosuppressive cytokines such as IL-10, IL-27 and TGF-b by M-MDSC. Conclusion. This study confirmed the differentiation plasticity of human monocytes, which are influenced by cytokines added in cultures. Phenotypic characteristics of these cells correlated with the production of cytokines involved in modulation of T-cell proliferation.&amp;lt;/p&amp;gt;

The Optimum Dose of Beta-Glucan for Stimulating Peripheral Blood Mononuclear Cells (PBMCs) to Produce Cytokines: In Vitro Study

Background: Beta-glucan has been frequently used in laboratory trials as an immunomodulator in both in vivo and in vitro studies, but the ef­fective dose for measuring its performance has not been established. Like other immunomodula­tors, researchers must establish the right dose of beta-glucan in their laboratory experiments for the purpose of testing substances as immuno­modulators without achieving false-positive or –negative results. This study aimed to determine the optimum dose of beta-glucan to induce cyto­kine production by peripheral blood mononu­clear cells (PBMCs) in vitro. Subjects and Method: This was a laboratory experimental study. This study measur­ed the production of two cytokines, including in­terferon gamma (IFN-γ) and interleukin 12 (IL-12), from the isolated PBMCs of healthy subjects. The doses of beta-glucan used as immunomodu­lator in­clu­ded 1, 5, 10, 20, and 50 μg/ml. Beta-glucan was add­ed to the PBMC culture medium, and the PBMCs were cultured for 6 days. On the sixth day, the supernatant was harvested and the cytokine production was analyzed using sandwich enzyme-linked immunosorbent assay (ELISA). Cytokines were also analyzed using the human IFN-γ ELISA kit and the human IL-12 ELISA kit, and data analysis was performed by one-way ANOVA. Results: IFN-γ levels were found to be increased in the group treated with 5 μg/ml beta-glucan. The highest IFN-γ levels (70.0 pg/ml) were observed in the group treated with 10 μg/ml beta-glucan. The production of IL-12 increased sharply in the group treated with5 μg/ml beta-glucan but decreased in the group treated with 10 μg/ml beta-glucan. The mean cytokine levels of the beta-glucan group were found to be significantly different from those of the control group (p=0.001). One-way ANOVA revealed that the highest IL-12 production (77.2 pg/ml) occurred at a dose of 5 μg/ml beta-glucan. This average value was significantly different from the average production of IL-12 in the control group (p=0.001). Conclusion: The optimum dose of beta-glucan for stimulating PBMCs to produce IFN-γ in vitro was 10 μg/ml, while for the production of IL-12, the dose was 5 μg/ml. Both cytokines can be mea­sured within 6 days of cell culture. Keywords: beta-glucan, immunomodulator, cy­to­kines Correspondence: Meira Erawati. Faculty of Medicine, Diponegoro University. Jl. Prof. Soedarto, S.H, Tembalang, Semarang, Indonesia. Email: meira­e­rawati­@­gmail.com. Mobile: +62-81915339685 Indonesian Journal of Medicine (2020), 5(2): 170-177 https://doi.org/10.26911/theijmed.2020.05.02.12

Systemic corticosteroid therapy augments ex vivo release of sCD163 by peripheral blood monocytes of asthmatic patients.

IntroductionThe CD163 is exclusively expressed by mononuclear phagocytes as a transmembrane protein, which synthesis is regulated by anti- and pro-inflammatory signals. After shedding from the cell surface it exists in body fluids as a soluble protein (sCD163) which exerts anti-inflammatory effects.AimTo evaluate serum concentration and ex vivo production of sCD163 by peripheral blood mononuclear cells (PBMC) in asthmatic patients treated with inhaled (ICS) or oral corticosteroids (OCS).Material and methodsThe study was performed on 35 allergic asthma patients (AAs) including 15 treated with ICS (ICS-AAs), 10 with OCS (OCS-AAs), 10 during asthma exacerbation (EX-AAs) before OCS had been started and 13 non-atopic healthy subjects (HCs) as a control group. PBMC were cultured in vitro for up to 144 h. The concentration of sCD163 in serum and the culture supernatants was evaluated with ELISA.ResultsThe greatest serum sCD163 concentration was demonstrated in EX-AAs, which was significantly greater than that in other studied subgroups. The concentration of sCD163 in PBMC culture supernatants was greater in AAs than in HCs (p = 0.006). Among individual asthma subgroups the greatest concentration of sCD163 was demonstrated in PBMC culture supernatants of OCS-AAs, which was significantly greater than in ICS-AAs (p < 0.001) and EX-AAs (p < 0.001), both being significantly greater than in HCs (p < 0.001).ConclusionsIn AAs, enhanced capability of PBMCs to release sCD163 may be at least partially responsible for the anti-inflammatory effects of systemic corticosteroid therapy.

Altered Indoleamine 2,3-Dioxygenase Production and Its Association to Inflammatory Cytokines in Peripheral Blood Mononuclear Cells Culture of Type 2 Diabetes Mellitus.

Aim:To analyze indoleamine 2,3-dioxygenase (IDO) production in the cell culture supernatant of phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs) from type 2 DM (T2DM) patients and investigate IDO’s association to pro- and anti-inflammatory cytokines.Subjects and methods:PBMC samples were collected from 21 T2DM patients and 17 normoglycemic participants, then stimulated with PHA for 3 days. Cytokine and IDO concentrations were measured in the PBMC culture supernatants. In vitro production of TNF-α, IL-6, interferon-γ, and IL-10 were measured using multiplex immunoassay. IDO concentration was assessed using ELISA. To assess how PHA stimulation altered IDO production and to minimize the unstimulated baseline effect of T2DM, we subtracted the PHA-stimulated IDO concentration from the unstimulated one. IBM SPSS version 23 was used for statistical analysis.Results:The IDO concentrations in the PBMC culture supernatants were significantly higher in T2DM patients regardless of whether they were unstimulated (P < .001) or PHA-stimulated (P = .012). Reduced IDO production was observed in 52.8% of T2DM patients and was associated with older age and lower interferon-γ levels. Conversely, 42.8% of T2DM patients showed increased IDO concentrations, which were correlated with the IL-6/IL-10 ratio (r = 0.683, P = .021) and interferon-γ/IL-10 ratio (r = 0.517, P = .077).Conclusion:The interferon-γ level was reduced in the PBMC culture supernatant of T2DM patients with reduced IDO production. Reduced IDO production in T2DM patients following PHA stimulation was associated with older age and, notably, higher baseline IDO concentrations. Since IDO is primarily produced by dendritic cells, reduced IDO production after PHA stimulation may indicate dendritic cell dysfunction.

The Effect of Stabilisation Agents on the Immunomodulatory Properties of Gold Nanoparticles Obtained by Ultrasonic Spray Pyrolysis.

Gold nanoparticles (GNPs) have been investigated extensively as drug carriers in tumour immunotherapy in combination with photothermal therapy. For this purpose, GNPs should be stabilised in biological fluids. The goal of this study was to examine how stabilisation agents influence cytotoxicity and immune response in vitro. Spherical GNPs, 20 nm in size, were prepared by ultrasonic spray pyrolysis (USP). Three types of stabilising agents were used: sodium citrate (SC), polyvinyl-pyrrolidone (PVP), and poly-ethylene glycol (PEG). Pristine, non-stabilised GNPs were used as a control. The culture models were mouse L929 cells, B16F10 melanoma cells and human peripheral blood mononuclear cells (PBMNCs), obtained from healthy donors. Control SC- and PEG-GNPs were non-cytotoxic at concentrations (range 1–100 µg/mL), in contrast to PVP-GNPs, which were cytotoxic at higher concentrations. Control GNPs inhibited the production of IFN-ϒ slightly, and augmented the production of IL-10 by PHA-stimulated PBMNC cultures. PEG-GNPs inhibited the production of pro-inflammatory cytokines (IL-1, IL-6, IL-8, TNF-α) and Th1-related cytokines (IFN-ϒ and IL-12p70), and increased the production of Th2 cytokines (IL-4 and IL-5). SC-PEG inhibited the production of IL-8 and IL-17A. In contrast, PVP-GNPs stimulated the production of pro-inflammatory cytokines, Th1 cytokines, and IL-17A, but also IL-10. When uptake of GNPs by monocytes/macrophages in PBMNC cultures was analysed, the ingestion of PEG- GNPs was significantly lower compared to SC- and PVP-GNPs. In conclusion, stabilisation agents modulate biocompatibility and immune response significantly, so their adequate choice for preparation of GNPs is an important factor when considering the use of GNPs for application in vivo.

T Cell Proliferation Is Induced by Chronically TLR2-Stimulated Gingival Fibroblasts or Monocytes.

During inflammation of the gums, resident cells of the periodontium, gingival fibroblasts (GFs), interact with heterogeneous cell populations of the innate and adaptive immune system that play a crucial role in protecting the host from pathogenic infectious agents. We investigated the effects of chronic inflammation, by exposing peripheral blood mononuclear cells (PBMCs), peripheral blood lymphocyte (PBL) cultures, and GF–PBMC cocultures to Toll-like receptor 2 (TLR2) and TLR4 activators for 21 days and assessed whether this influenced leukocyte retention, survival, and proliferation. Chronic stimulation of PBMC–GF cocultures with TLR2 and TLR4 agonists induced a reduction of NK (CD56+CD3−), T (CD3+), and B (CD19+) cells, whereas the number of TLR-expressing monocytes were unaffected. TLR2 agonists doubled the T cell proliferation, likely of a selective population, given the net decrease of T cells. Subsequent chronic exposure experiments without GF, using PBMC and PBL cultures, showed a significantly (p < 0.0001) increased proinflammatory cytokine production of TNF-α and IL-1β up to 21 days only in TLR2-activated PBMC with concomitant T cell proliferation, suggesting a role for monocytes. In conclusion, chronic TLR activation mediates the shift in cell populations during infection. Particularly, TLR2 activators play an important role in T cell proliferation and proinflammatory cytokine production by monocytes, suggesting that TLR2 activation represents a bridge between innate and adaptive immunity.

Influence of Two Major Toxoplasma Gondii Virulence Factors (ROP16 and ROP18) on the Immune Response of Peripheral Blood Mononuclear Cells to Human Toxoplasmosis Infection.

Toxoplasma gondii ROP16 and ROP18 proteins have been identified as important virulence factors for this parasite. Here, we describe the effect of ROP16 and ROP18 proteins on peripheral blood mononuclear cells (PBMCs) from individuals with different clinical status of infection. We evaluated IFN-γ, IL-10, and IL-1β levels in supernatants from PBMCs cultures infected with tachyzoites of the T. gondii wild-type RH strain or with knock-out mutants of the rop16 and rop18 encoding genes (RHΔrop16 and RHΔrop18). Cytokine secretion was compared between PBMCs obtained from seronegative individuals (n = 10), with those with chronic asymptomatic (n = 8), or ocular infection (n = 12). We also evaluated if polymorphisms in the genes encoding for IFN-γ, IL-10, IL-1β, Toll-like receptor 9 (TLR9), and purinoreceptor P2RX7 influenced the production of the encoded proteins after ex vivo stimulation. In individuals with chronic asymptomatic infection, only a moderate effect on IL-10 levels was observed when PBMCs were infected with RHΔrop16, whereas a significant difference in the levels of inflammatory cytokines IFN-γ and IL-1β was observed in seronegative individuals, but this was also dependent on the host's cytokine gene polymorphisms. Infection with ROP16-deficient parasites had a significant effect on IFN-γ production in previously non-infected individuals, suggesting that ROP16 which is considered as a virulence factor plays a role during the primary infection in humans, but not in the secondary immune response.

The mycelium of the Trametes versicolor (Turkey tail) mushroom and its fermented substrate each show potent and complementary immune activating properties in vitro

BackgroundThe medicinal mushroom Trametes versicolor (Tv, Turkey Tail) is often prepared for consumption as a powder from the fungal mycelium and the fermented substrate on which it grew. The goal for this study was to evaluate the immune-modulating properties of the mycelium versus the fermented substrate, to document whether an important part of the immune-activating effects resides in the metabolically fermented substrate.MethodsTv mycelium was cultured on rice flour. The mycelium and the fermented substrate were mechanically separated, dried, and milled. The initial substrate served as a control. Aqueous fractions were extracted and passed through 0.22-μm filters. The remaining solids were passed through homogenization spin columns without filtration. The aqueous and solid fractions of the initial substrate (IS), the fermented substrate (FS), and the Trametes versicolor mycelium (TvM) were tested for immune-activating and modulating activities on human peripheral blood mononuclear cell cultures, to examine expression of the CD69 activation marker on lymphocytes versus monocytes, and on the T, NKT, and NK lymphocyte subsets. Culture supernatants were tested for cytokines using Luminex arrays.ResultsBoth aqueous and solid fractions of TvM triggered robust induction of CD69 on lymphocytes and monocytes, whereas FS only triggered minor induction of CD69, and IS had no activating effect. The aqueous extract of TvM had stronger activating effects than the solid fraction. In contrast, the solid fraction of IS triggered a reduction in CD69, below levels on untreated cells.Both aqueous and solid fractions of FS triggered large and dose-dependent increases in immune-activating pro-inflammatory cytokines (IL-2, IL-6), anti-inflammatory cytokines Interleukin-1 receptor antagonist (IL-1ra) and Interleukin-10 (IL-10), anti-viral cytokines interferon-gamma (IFN-γ) and Macrophage Inflammatory Protein-alpha (MIP-1α), as well as Granulocyte-Colony Stimulating Factor (G-CSF) and Interleukin-8 (IL-8). TvM triggered more modest cytokine increases. The aqueous extract of IS showed no effects, whereas the solid fraction showed modest effects on induction of cytokines and growth factors.ConclusionThe results demonstrated that the immune-activating bioactivity of a mycelial-based medicinal mushroom preparation is a combination of the mycelium itself (including insoluble beta-glucans, and also water-soluble components), and the highly bioactive, metabolically fermented substrate, not present in the initial substrate.

Endosomal toll-like receptors play a key role in activation of primary human monocytes by cowpea mosaic virus.

The plant virus, cowpea mosaic virus (CPMV), has demonstrated a remarkable capacity to induce anti-tumour immune responses following direct administration into solid tumours. The molecular pathways that account for these effects and the capacity of CPMV to activate human cells are not well defined. Here, we examine the ability of CPMV particles to activate human monocytes, dendritic cells (DCs) and macrophages. Monocytes in peripheral blood mononuclear cell cultures and purified CD14+ monocytes were readily activated by CPMV in vitro, leading to induction of HLA-DR, CD86, PD-L1, IL-15R and CXCL10 expression. Monocytes released chemokines, CXCL10, MIP-1α and MIP-1β into cell culture supernatants after incubation with CPMV. DC subsets (pDC and mDC) and monocyte-derivedmacrophages also demonstrated evidence of activation after incubation with CPMV. Inhibitors of spleen tyrosine kinase (SYK), endocytosis or endocytic acidification impaired the capacity of CPMV to activate monocytes. Furthermore, CPMV activation of monocytes was partially blocked by a TLR7/8 antagonist. These data demonstrate that CPMV activates human monocytes in a manner dependent on SYK signalling, endosomal acidification and with an important contribution from TLR7/8 recognition.

Therapeutic potential of peptides from Ole e 1 in olive-pollen allergy

Olive-pollen allergy is one of the leading causes of respiratory allergy in Mediterranean countries and some areas of North America. Currently, allergen-specific immunotherapy is the only etiophatogenic treatment. However, this approach is not fully optimal, safe, or effective. Thus, efforts continue in the search for novel immunotherapy strategies, being one of the most promising the use of peptides derived from major allergens. This work tries to determine the therapeutic potential and safety of 5 dodecapeptides derived from the main allergen of olive-pollen allergy, Ole e 1. The immunomodulatory capacity of these peptides was studied using peripheral blood mononuclear cells (PBMCs) obtained from 19 olive-pollen-allergic patients and 10 healthy controls. We determined the capacity of these peptides to inhibit the proliferative response toward olive-pollen allergenic extract and to induce the regulatory cytokines, IL-10 and IL-35. To test the safety and absence of allergenicity of the peptides, the basophil activation was analyzed by flow-cytometry, using peripheral blood. The results showed that two of five peptides inhibited near to 30% the proliferative response against the total olive-pollen allergenic extract in olive-pollen-allergic patients. Inhibition increased to nearly 35% when the 5 peptides were used in combination. In both cases, a statistically significant induction of IL-10 and IL-35 secretion was observed in the supernatants of allergic patients PBMCs cultures. None of the 5 peptides induced basophil activation and cross-link inflammatory cell-bound IgE. In conclusion, these results open up new possibilities in the treatment of olive-pollen allergy, which could solve some of the problems facing current therapy approaches.

Monoclonal anti-dsDNA antibody 2C10 escorts DNA to intracellular DNA sensors in normal mononuclear cells and stimulates secretion of multiple cytokines implicated in lupus pathogenesis.

SummaryThere have been many studies on the mechanisms of internalization of DNA–anti‐DNA immune complexes by cells, including the one used for rheumatoid factor‐expressing mouse B cells. In parallel, studies on the role of intracellular DNA sensors in the pathogenesis of systemic lupus erythematosus (SLE) have been conducted, including the one using a mouse model lacking one of the sensors. These and other data have established a framework for understanding the pathogenic role of anti‐DNA antibodies, but studies on normal cells are limited. Here, we used the monoclonal anti‐dsDNA antibody 2C10, 2‐kbp dsDNA and healthy human peripheral blood mononuclear cells (PBMCs) to test whether and how 2C10 and/or DNA cause pathology in normal cells. We found that on culture with PBMCs, 2C10 preferentially entered monocytes and that DNA enhanced this internalization. In contrast, DNA alone was not significantly internalized by monocytes, but 2C10 facilitated its internalization. This was suppressed by cytochalasin D, but not by methyl‐β‐cyclodextrin, chloroquine or an Fc blocker, suggesting the involvement of macropinocytosis in this process. Internalization of 2C10 and DNA together resulted in production of interferon (IFN)‐α, IFN‐γ, tumor necrosis factor (TNF)‐α, monocyte chemoattractant protein‐1 (MCP‐1), interleukin (IL)‐1β, IL‐6, IL‐10 and IL‐33 by PBMCs. Cytokine production was suppressed by chloroquine and shikonin, but not by RU.521, suggesting dependence on activation of the Toll‐like receptor (TLR)‐9 and absent in melanoma 2 (AIM‐2) pathways. These results established a simple model to demonstrate that anti‐DNA antibodies can cause dysregulation of cytokine network mimicking systemic lupus erythematosus in culture of normal PBMCs, and emphasize again the importance of maintaining anti‐DNA antibodies at low levels by treatment.

Effects exerted by mesenchymal stem cells on monocytes obtained from patients with rheumatoid arthritis and progressive systemic sclerosis

In the context of autoimmune inflammatory diseases, the therapeutic benefits of mesenchymal stem cells (MSCs) could be found in their potential to exert immunosuppressive effects and to regulate the immune response. In pursuit of having a more complete look a the regulatory mechanisms performed by AT-MSC, we examined the influence of adipose stem cells (AT-MSC) on blood monocytes from patients with rheumatoid arthritis (RA). Comparison of the effect exerted by the soluble factors produced by AT-MSC vs. cell culture control media, on peripheral blood mononuclear cells (PBMC), showed a significant decrease in the percentage of HLA-DR expressing monocytes, 55.3% (IQR 30-65%) vs. 72% (IQR 62-81%), p = 0.001, as well as a significant decrease in mean fluorescence intensity MFI of HLA-DR was observed, 265 MFI (IQR 102-896 MFI) vs. 473 MFI IQR 160-2201 MFI), p = 0.001. The percentage of CD14 expressing monocytes and CD14 MFI, was increased in PBMC cultured with AT-MSC conditioned media as opposed to control media: 11.7% (IQR 7.6-16.5%) vs. 6.6% (IQR 4.6-11.8%), p = 0.013 and the surface expression density of CD14, 2702 (IQR 1548-3418) vs. 1540 (IQR 1146-2140), p = 0.05. sVEGF-A levels in PBMC cultures from PA patients cultured with conditioned media from AT-MSC were significantly higher than PBMC cultured with control media suppressing secretion of sVEGF-A, 5012 (IQR 2516-5054 pg/ml) vs. 561 pg/ml (IQR 288-699 pg/ml), p = 0.001.

P38 mitogen-activated protein kinase impairment of innate immune cells is a characteristic feature of HBeAg-negative chronic hepatitis B.

The mitogen-activated protein kinase p38 (MAPK) is implicated in the induction of immune responses by regulating the differentiation of T lymphocytes and production of cytokines. Our aim was to investigate p38MAPK phosphorylation in different stages of the natural history of hepatitis B virus (HBV) infection. Peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll-Hypaque density-based centrifugation from 10 patients with HBeAg-negative chronic hepatitis B [HBeAg(-) CHB;HBV-DNA>2000IU/mL], eight patients with HBeAg-negative chronic HBV infection [HBeAg(-) CI;undetectable HBV-DNA] and 8 healthy controls (HCs). p38MAPK phosphorylation was assessed by phospho-specific flow cytometry in PBMCs and cell subsets (CD3+,CD3-,CD56+,CD56-) after stimulation with cytokines (IL-12+IL-2 and IL-12+IL-18) or nonspecific stimuli [arsenite, phorbol 12-myristate 13-acetate (PMA) and ionomycin] at 0,30,60,120 and 240minutes using p38 phospho-specific conjugated antibodies. ΙFN-γ was determined by ELISA in PBMCs culture supernatants after stimulation with rhIL-2, rhIL-12 and rhIL-18, with and without pre-treatment with the p38 MAPK inhibitor, SB203580. HBeAg(-) CI patients showed the highest expression of phosphor-p38 MAPK in total PBMCs and subpopulations compared to HBeAg(-) CHB and HCs. A striking impairment in p38 phosphorylation was noted in CD56+ cells and in especially in NK cells (CD3-CD56+). SB203580-induced inhibition of p38MAPK phosphorylation was associated with suppression of IFN-γ production in all groups. The universal lack of p38 MAPK activation in CD56+ and in particular in NK cells from HBeAg(-) CHB patients during viremia suggests a potential cell-dependent implication of this pathway in the natural history of HBV infection.