Intracellular Cytokine Analysis Research Articles

JAK/STAT signaling in rheumatoid arthritis leukocytes is uncoupled from serum cytokines in a subset of patients

ObjectiveRheumatoid Arthritis (RA) is a systemic autoimmune disease involving pro-inflammatory cytokines that can be therapeutically targeted by antibodies or kinase inhibitors. Nevertheless, these drugs fail in a subset of patients independent of the abundance of the targeted cytokines. We aim to explore the cellular basis of this phenomenon by analyzing the relation of cytokine abundance and activation of downstream signaling pathways in RA. MethodsThe study included 62 RA patients and 9 healthy controls (HC). Phosphorylation of STAT 1–6 in various immune cell subsets was determined ex vivo using a novel robust flow cytometry-based protocol. Serum concentrations of IL-6, IL-10, IL-12p70, IL-17 A, interferon gamma, and TNFα in the same samples were measured using highly sensitive single molecule array (SIMOA). ResultsWe found an increase in circulating cytokines in RA patients, while STAT activity was lower in RA patients compared to HC. Based on STAT activity we determined three endotypes in active RA patients (cDAI>10, n = 28): 1) those with active STAT5a/b signaling in T cells (n = 7/28), 2) those with a low STAT activity in all assessed cell types (n = 14/28), and 3) those with active STAT1 and STAT3 signaling mainly in myeloid cells (n = 7/28). Integrating intracellular STAT activation and cytokine analysis revealed diminished JAK/STAT signaling in a subset of patients (n = 8/20) despite elevated serum cytokine concentrations. ConclusionDiminished JAK/STAT signaling in active RA may partly explain unresponsiveness to therapy targeting cytokine signaling. Analysis of JAK/STAT phosphorylation may identify patients at risk for non-response to these therapies.

IFNγ-Producing B Cells Play a Regulating Role in Infection-Mediated Inhibition of Allergy.

The hygiene hypothesis suggests that some infections may inhibit the development of allergic diseases, but the mechanism remains unclear. Our previous study has shown that Chlamydia muridarum (Cm) lung infection can inhibit local eosinophilic inflammation induced by ovalbumin (OVA) through the modulation of dendritic cell (DC) and T cell responses in mice. In this study, we explored the role of B cells in the chlamydial-infection-mediated modulation of allergic responses. The results showed that adoptive transfer of B cells isolated from Cm-infected mice (Cm-B cells), unlike those from naïve mice (naïve B cells), could effectively inhibit allergic airway eosinophilia and mucus overproduction, as well as Th2 cytokine responses. In addition, total IgE/IgG1 and OVA-specific IgE/IgG1 antibodies in the serum were also decreased by the adoptive transfer of Cm-B cells. Intracellular cytokine analysis showed that B cells from Cm-infected mice produced higher levels of IFNγ than those from naïve mice. More interestingly, the inhibiting effect of adoptively transferred Cm-B cells on allergic reactions was virtually abolished by the simultaneous blockade of IFNγ using a monoclonal antibody. The results suggest that B cells modulated by chlamydial lung infection could play a regulatory role in OVA-induced acute allergic responses in the lung via the production of IFNγ. The results provide new insights into the targets related to the prevention and treatment of allergic diseases.

A semi high-throughput whole blood-based flow cytometry assay to detect and monitor Bordetella pertussis-specific Th1, Th2 and Th17 responses.

The characterization of B. pertussis (Bp) antigen-specific CD4+ T cell cytokine responses should be included in the evaluation of immunogenicity of pertussis vaccines but is often hindered by the lack of standardized robust assays. To overcome this limitation, we developed a two-step assay comprising a short-term stimulation of fresh whole blood with Bp antigens and cryopreservation of the stimulated cells, followed later on by batch-wise intracellular cytokine analysis by flow cytometry. Blood samples collected from recently acellular (aP) vaccine boosted subjects with a whole-cell- or aP-primed background was incubated for 24 hrs with Pertussis toxin, Filamentous hemagglutinin or a Bp lysate (400µl per stimulation). Antigen-specific IFN-γ-, IL-4/IL-5/IL-13-, IL-17A/IL-17F- and/or IL-22-producing CD4+ T cells were quantified by flow cytometry to reveal Th1, Th2, and Th17-type responses, respectively. The frequencies of IFN-γ-producing CD8+ T cells were also analyzed. We demonstrate high reproducibility of the Bp-specific whole blood intracellular staining assay. The results obtained after cryopreservation of the stimulated and fixed cells were very well correlated to those obtained without cryopreservation, an approach used in our previously published assay. Optimization resulted in high sensitivity thanks to very low non-specific backgrounds, with reliable detection of Bp antigen-specific Th1, Th2 and Th17-type CD4+ T cells, in the lowest range frequency of 0.01-0.03%. Bp antigen-specific IFN-γ+ CD8+ T lymphocytes were also detected. This test is easy to perform, analyse and interpret with the establishment of strict criteria defining Bp antigen responses. Thus, this assay appears as a promising test for evaluation of Bp antigen-specific CD4+ T cells induced by current and next generation pertussis vaccines.

Immune-modulation by 7, 8-diacetoxy-4-methylthiocoumarin in total body-irradiated mice: Implications for the mitigation of radiation-induced hematopoietic injury

AimsDevelopment of novel medical countermeasures (MCMs) against acute radiation syndrome (ARS) and the associated lethality involves protection from and/or mitigation of radiation-induced hematopoietic injury, a critical clinical component of ARS. We earlier identified the molecule 7,8-diacetoxy-4-methylthiocoumarin (DAMTC) as a potent mitigator of hematopoietic injury and mortality in C57BL/6 mice when administered 24 h following total body irradiation (TBI). In the present study, we investigated mechanisms and functional relevance of immune modulation by DAMTC during the mitigation of hematopoietic injury. Main methodsC57BL/6 mice were subjected to TBI doses of 3 and 7.6Gy; administered DAMTC intra-peritoneally 24 h post TBI. Isolation, characterization, intra-cellular cytokine analysis of myeloid cells from bone marrow and spleen accompanied by flow cytometric determination and characterization of B-lymphocytes, serum isolation from peripheral blood and cytokine analysis. Key findingsResults showed that DAMTC induced stimulation of pro-inflammatory myeloid subsets in the bone marrow and spleen of TBI mice. Further, it promoted a favorable transition from Th2 to Th1 immunity, triggered humoral immunity, and activated an intricately balanced inflammatory response that appear to contribute to immune-modulation. SignificanceThus, the present study shows that immune-modulation maybe one of the contributing factors for the mitigation of hematopoietic injury by DAMTC and underscores its efficacy as a potent mitigator of hematopoietic injury that merits to be developed further as a novel MCM to combat H-ARS.

Effect of physical training on cytokine expression in CD4+ T lymphocytes in subjects with stable COPD.

Introduction:Although evidence suggests that physical exercise reduces systemic inflammation, at the plasma level, there are still contradictions in chronic obstructive pulmonary disease (COPD). In this sense, analysis of intracellular cytokines could clear off the effect of physical exercise on the inflammatory profile of these subjects.Aim:The aim was to evaluate the effect of physical training on cytokine expression in CD4+ T lymphocytes from subjects with COPD.Methods:This is a randomized controlled trial. Subjects with stable COPD were grouped into two groups, exercise and control. In total, 23 subjects with stable COPD were evaluated, of which 15 underwent aerobic strength training [physical exercise group (PEG)] and 8 underwent breathing exercises [respiratory physiotherapy group (RPG)]. Intracellular cytokines [interleukin (IL)-8, IL-13, IL-17, IL-6, IL-2, IL-10, and tumor necrosis factor alpha (TNF-α)] from CD4+ T lymphocytes were analyzed from peripheral blood through flow cytometry, before and after 8 weeks of intervention.Results:The PEG and RPG groups had a mean age of 68 ± 5.96 and 72.25 ± 6.86 years and predicted forced expiratory volume in the first second (FEV1) of 58.6 ± 15.99% and 39.75 ± 10.39%, respectively. It was possible to detect a significant reduction in IL-8 (p = 0.0125) and an increase in IL-13 (p = 0.0014) and an increase in TNF-α (p < 0.001) in both groups.Conclusion:Eight weeks of physical training, both peripheral and respiratory, were able to reduce concentrations of IL-8 and to increase IL-13, and TNF-α in CD4+ T lymphocytes in subjects with stable COPD. The findings reinforce the benefits of interventions in subjects with COPD, revealing data not previously investigated.

Immune Responses in 101HEMB01, a Phase 1/2 Open-Label, Single Ascending Dose-Finding Trial of DTX101 (AAVrh10FIX) in Patients with Severe Hemophilia B

▪Background: Humoral and cellular immune responses to adeno-associated virus (AAV) serotype rh10 (AAVrh10 vector) and to the human FIX transgene were analyzed in blood and serum samples from hemophilia B subjects enrolled in a phase 1/2 open-label, single-arm, multicenter, dose-finding study (101HEMB01; See also ASH 2017 Abstract: Pipe et al., 101HEMB01 is a phase 1/2 open-label, single ascending dose finding trial of DTX101 (AAVrh10FIX) in patients with moderate/severe hemophilia B that demonstrated meaningful but transient expression of human factor IX (hFIX)).Methods: T cell responses in blood PBMCs were analyzed by IFNγ ELISPOT and polychromatic flow cytometry. In addition, a multi-analyte profiling of secreted cytokines, chemokines, and growth factors in serum was performed. Furthermore, we performed a computational HLA class I affinity prediction analysis for each subject's FIX mutations. Humoral immune response in serum to AAVrh10 capsid was analyzed by IgG ELISA and by an in vitro neutralizing antibody (NAb) assay.Results: A total of 6 subjects were dosed. Subjects in Cohort 1 (n=3) and Cohort 2 (n=3) received a dose of DTX101 of 1.6x1012 GC/kg and 5.0x1012 GC/kg, respectively. Five out of six subjects had asymptomatic elevations in ALT of 40 U/L or higher. Subject 6 had a peak ALT of 914 U/L. IFNγ ELISPOT analysis showed a limited response to the AAVrh10 capsid 6-8 weeks after vector administration in subjects 3, 4, 5, and 6. The magnitude of the response was low and did not persist in subjects 3, 5, and 6. Intracellular cytokine analysis also showed low magnitude T cell responses to both the AAVrh10 capsid and FIX transgene. Subject 6 was the only subject with a strong CD4+ T cell IL-2+ IFNγ+ response to FIX that did not persist. HLA class I affinity prediction analysis revealed that subject 6 had high binding affinity for a single 9-mer peptide spanning the FIX mutation. Multi-analyte analysis in serum showed an increase in TGFa, IL-10, IL-7, and PDGF-AB/BB only observed in subject 6. IgG ELISA and NAb assay analyses showed strong antibody responses to AAVrh10 after vector administration in all six subjects. The antibody response remained stable for at least 52 weeks.Conclusion: Low magnitude and non-persisting T cell responses to AAVrh10 and FIX were detected in the peripheral blood of many patients, although there is no clear etiology for the higher elevation of transaminases observed in subject 6. Several aspects of his immune response do suggest that it differed qualitatively from that of the others, such as an exaggerated humoral response to the AAV capsid, a CD4 IL2 response against FIX, increases in serum growth factors associated with cell proliferation, differentiation and angiogenesis, and an increase of the anti-inflammatory cytokine IL10. Studies in nonhuman primates indicate that the T cell compartment in peripheral blood does not reflect that of the target of AAV, or in this case the liver, which could complicate the analysis of host immune responses to gene therapy in humans. DisclosuresWilson:REGENXBIO: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; University of Pennsylvania: Patents & Royalties; Dimension Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Solid Gene Therapy: Membership on an entity's Board of Directors or advisory committees.

Immunosuppressive regulatory T cells are unable to suppress T helper 17 cells in post-traumatic osteoarthritis

Immunosuppressive regulatory T cells are unable to suppress T helper 17 cells in post-traumatic osteoarthritis

Probiotic bacteria Escherichia coli Nissle decrease the severity of intraocular inflammation in experimental autoimmune uveitis

AbstractPurposeThe purpose of the project was to test the influence of probiotic bacteria Escherichia coli Nissle (EcN) on severity of intraocular inflammation in experimental autoimmune uveitis (EAU).MethodsEAU was induced in C57BL/6J mice by interphotoreceptor retinoid binding protein in complete Freund´s adjuvant and pertussis toxin. The grade of uveitis (0–4) was assessed clinically (21st and 27th day) by using otoscope connected to camera and histologically (28th day) on hematoxylin and eosin stained tissues. Probiotic bacteria EcN were administered orally three times a week and saline solution was administered to control group. Different regimens of administration were tested as follows: administration throughout the experiment (47 eyes), prophylactically (26 eyes) and therapeutically (24 eyes). Mesenteric and cervical lymph nodes were collected at the end of experiment for flow cytometry analysis of lymphocyte populations (Treg, Th17, ILC3) and intracellular cytokines (IFNγ, TNFα, IL‐17).ResultsProbiotics significantly reduced the severity of uveitis compared to the control group in all three regimens by clinical evaluation i.e. throughout the experiment (p = 0.0003), prophylactically (p = 0.0015) and therapeutically (p = 0.02) and by histological evaluation throughout the experiment (p = 0.0002) and prophylactically (p = 0.0017). There was no significant difference in the lymphocyte population counts and cytokines production between groups.ConclusionsOrally administered probiotic bacteria EcN successfully prevented or reduced the severity of EAU in mice. This may have valuable implications for the control of sight‐threatening uveitis in patients.Supported by Ministry of Health of the Czech Republic (grant 17‐31248A) and Charles University Institutional Program SVV 260367.

Abstract 1423: AIM ACT, a novel nanoparticle-based technology that generates therapeutic numbers of functional tumor-specific CD8+ T cells with T stem cell, central and effector memory phenotype in 14 days

Abstract Background: Efficient ex-vivo generation of functional tumor-specific T cells with an optimal memory phenotype remains a significant hurdle to the broad application of adoptive cell transfer (ACT) protocols for the treatment of cancer. Genetically engineered T cells represent a currently available option, but the genetic manipulation of T cells presents significant challenges in terms of manufacturing, cost and addressing tumor escape mechanisms. Here, we describe a novel nanoparticle-based approach for generating tumor-specific T cells at clinical grade and scale from the endogenous T cell repertoire using artificial antigen presenting cells (aAPC). Methods: aAPC consist of a paramagnetic nanoparticle to which humanized HLA-A2-Ig dimer-molecules and anti-CD28 antibodies are covalently linked. aAPC are loaded with multiple HLA-A2 restricted peptides and used to magnetically enrich and expand tumor-specific CD8+ T cells. Using peptide loaded aAPC, a fully enclosed and automated GMP T cell expansion platform has been developed that consistently generates clinically relevant numbers of tumor-specific, T stem cell, central and effector memory CD8+ T cells in 14 days, providing an alternative to genetically manipulated T cells. Results: Starting from a healthy donor leukopak, tumor-specific CD8+ T cells were generated using an aAPC cocktail loaded with 5 HLA-A2 epitopes from AML tumor antigens WT1, PRAME and Cyclin A1. On average, 1-2 x109 T cells were generated that were &amp;gt;90% of the memory phenotype that averaged 18% T stem cells, 40% central memory and 35% effector memory CD8+ T cells. AML-specific T cells were expanded 500 to &amp;gt;5000-fold from low frequency precursor populations. The system has also been used to generate MM specific T cells of the same quality from both from fresh leukopacks and cryopreserved PBL. All generated T cells were fully functional, as demonstrated by intra-cellular cytokine analysis and tumor cell killing. Conclusion: AIM ACT is a novel nanoparticle-based T cell platform developed for the rapid, streamlined generation of clinically-relevant numbers of tumor-specific, T stem cell, central and effector memory CD8+ T cells from donor PBMC in 14 days. The platform described here will be used to generate multi-antigen specific CD8+ T cell products that will be evaluated in multi-center P1/2 clinical trials. These trials will enroll r/r MM patients and r/r AML patients pre- and post-allogeneic hematopoietic stem cell transplant. The flexibility of the AIM ACT system, as shown has potential for clinical evaluation in other hematological tumors and can be used for targeting neo-epitopes. Citation Format: Sojung Kim, Lauren Suarez, Emily Lu, Celine Walmacq, Daniel Dembrow, Juan Varela, Dan Bednárik, Kenneth Carter, Naimish Pandya, Kristi Jones, Mathias Oelke. AIM ACT, a novel nanoparticle-based technology that generates therapeutic numbers of functional tumor-specific CD8+ T cells with T stem cell, central and effector memory phenotype in 14 days [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1423.

The DosR antigen Rv1737c from Mycobacterium tuberculosis confers inflammation regulation in tuberculosis infection.

There is an urgent need to identify the potential risk factors for activating latent Mycobacterium tuberculosis infection. In this study, we evaluated the immune function of Rv1737c, which is a latency-associated antigen of dormancy survival regulator (DosR) of M.tuberculosis in a mouse model. Our data showed that mice pretreated with recombinant Rv1737c (rRv1737c) exhibited higher levels of antigen-specific antibodies (IgG, IgM and IgA) than sham-treated mice. Following Bacilli Calmette-Guerin (BCG) challenge, rRv1737c adjuvanted with cholera toxin subunit B (CTB) induced diffuse lung inflammation and fibrosis compared to the control mice. The inflammatory pathogenesis due to rRv1737c pre-exposure was associated with a switch in the macrophage phenotype from M1 to activated M2 and was characterized by IL-10 production. Intracellular cytokine analysis further showed that the rRv1737c-pretreated mice exhibited an increased frequency of Th2 cells in the lungs, lymph nodes and spleen after BCG challenge. Furthermore, IFN-γ expression increased in the lungs after rRv1737c pretreatment compared to that in the sham mice. Accordingly, lung cells from rRv1737c-immunized mice stimulated with killed BCG produced higher levels of multiple cytokines, such as IFN-γ, IL-10 and IL-6. The results confirmed that the pathological features of rRv1737c promoted inflammation. Overall, our findings provide direct evidence of the pro-inflammatory function of rRv1737c in a murine model of BCG infection, indicating that Rv1737c is a pathogenic antigen of M.tuberculosis and may be key to the recurrence of latent infection.

Ascending aortic blood flow velocity is increased in children with primary snoring/mild sleep-disordered breathing and associated with an increase in CD8 + T cells expressing TNFα and IFNγ.

Sleep-disordered breathing (SDB) is associated with cardiovascular disease and systemic inflammation in adults but this remains to be explored in children, especially in children with the most common form of SDB, i.e. primary snoring/mild SDB. This pilot study investigated the relationship between the cardiovascular function and inflammation in children with mild SDB. Nineteen participants aged 5-14years underwent overnight polysomnography, cardiac magnetic resonance imaging (aortic blood flow velocity and left and right ventricular systolic function) and assessment for inflammatory markers (intracellular cytokine analysis of T cells by flow cytometry). Parents also completed the Sleep Disturbances Scale for Children (SDSC). Children with mild SDB exhibited increased ascending aortic peak systolic velocity compared to controls (SDB 119.95m/s vs. control 101.49m/s, p<0.05). No significant group differences were observed for left and right ventricular ejection fraction or mean aortic blood flow velocity from either the ascending aorta or pulmonary artery. Children with mild SDB had increased inflammatory markers as demonstrated by elevated T cell interferon gamma (IFNγ) (SDB 52±4% vs. control 25±3% positive cells, p<0.005) and tumour necrosis factor alpha (TNFα) (SDB 39±4% vs. control 20±2% positive cells, p<0.005) expression from CD8+ cells. A strong positive correlation was observed between ascending aorta peak blood flow velocity and both TNFα and IFNγ (TNFα, r=0.54, p<0.03; IFNγ, r=0.63, p<0.005, respectively). Polysomnography revealed that oxygen saturation (SaO2) nadir was significantly lower in children with mild SDB compared to controls (SDB 92.3±2.7% vs. control 94.4±1.6%, p<0.05). A lower SaO2 nadir was associated with an increased ascending aorta peak systolic velocity (r=-0.48, p<0.05). As well, both a lower SaO2 nadir and an increased ascending aorta peak systolic velocity were associated with higher SDSC Sleep-Disordered Breathing and Disorder of Initiating and Maintaining Sleep subscale scores but not the polysomnographic-derived Obstructive Apnea-Hypopnea Index. The finding of elevated ascending aortic peak systolic blood flow velocity and its association with increased inflammatory markers suggests that the profile of cardiovascular changes noted in adult SDB may also occur in children with mild SDB.

Early pregnancy immune biomarkers in peripheral blood may predict preeclampsia

We performed a prospective cohort study in 197 pregnant women. Peripheral blood was collected between 5 and 16 weeks of gestation. Intracellular cytokine analysis and immunophenotype were performed by flow-cytometry. Serum levels of cytokines and chemokines were analyzed by multiplex assay. 86 patients were eligible for the analysis and 10.5% (n=9) developed preeclampsia. Patients with preeclampsia had significantly higher percentage of CD3+CD4+TNFα+ T helper (Th) 1 cells (45.4±10.3 vs 37.1±8.5, P=0.032) and CD3+CD4+IL17+ Th 17 cells (2.4±1.3 vs 1.6±1.1, P=0.029) when compared to those of patients without preeclampsia. CD3+CD4+CD25+CD127dim/− T regulatory cells (Treg) cells (5.7±1.2% vs 7.0±1.6%, P=0.015) were significantly lower in patients with preeclampsia when compared to those without preeclampsia. Patients with preeclampsia had significantly higher TNFα/IL-10 cell ratio (43.8±10.3 vs 34.3±7.9, P=0.005) and Th17/Treg cell ratio (0.5±0.3 vs 0.2±0.2, P=0.011) when compared to those of patients without preeclampsia. IL-8 and Macrophage inflammatory protein (MIP)-1α serum levels were significantly higher in patients with preeclampsia when compared with patients without preeclampsia (Median=341.0 vs 87.6, U=152, P=0.020 and Median=35.7 vs 17.7, U=120, P=0.029 respectively). Serum MCP-1 levels were significantly lower in patients with preeclampsia when compared with patients without preeclampsia (Median=233.8 vs 390.9, U=183, P=0.021). The logistic regression predictive model combining TNFα/IL-10 ratios, IL-8 and MCP-1 serum levels had the best performance (AUC=0.886, 95%CI 0.8–0.9). We concluded that elevated Th1 and Th17 cell percentages, elevated TNFα/IL-10 and Th17/Treg cell ratios and decreased Treg cell percentages in early pregnancy are associated with preeclampsia.

Conjugated nanoliposome with the HER2/neu-derived peptide GP2 as an effective vaccine against breast cancer in mice xenograft model.

One of the challenging issues in vaccine development is peptide and adjuvant delivery into target cells. In this study, we developed a vaccine and therapeutic delivery system to increase cytotoxic T lymphocyte (CTL) response against a breast cancer model overexpressing HER2/neu.Gp2, a HER2/neu-derived peptide, was conjugated to Maleimide-mPEG2000-DSPE micelles and post inserted into liposomes composed of DMPC, DMPG phospholipids, and fusogenic lipid dioleoylphosphatidylethanolamine (DOPE) containing monophosphoryl lipid A (MPL) adjuvant (DMPC-DMPG-DOPE-MPL-Gp2). BALB/c mice were immunized with different formulations and the immune response was evaluated in vitro and in vivo. ELISpot and intracellular cytokine analysis by flow cytometry showed that the mice vaccinated with Lip-DOPE-MPL-GP2 incited the highest number of IFN-γ+ in CD8+ cells and CTL response. The immunization led to lower tumor sizes and longer survival time compared to the other groups of mice immunized and treated with the Lip-DOPE-MPL-GP2 formulation in both prophylactic and therapeutic experiments. These results showed that co-formulation of DOPE and MPL conjugated with GP2 peptide not only induces high antitumor immunity but also enhances therapeutic efficacy in TUBO mice model. Lip-DOPE-MPL-GP2 formulation could be a promising vaccine and a therapeutic delivery system against HER2 positive cancers and merits further investigation.

The Immunopathologic Effects of Mycoplasma pneumoniae and Community-acquired Respiratory Distress Syndrome Toxin. A Primate Model.

Mycoplasma pneumoniae infection has been linked to poor asthma outcomes. M. pneumoniae produces an ADP-ribosylating and vacuolating toxin called community-acquired respiratory distress syndrome (CARDS) toxin that has a major role in inflammation and airway dysfunction. The objective was to evaluate the immunopathological effects in primates exposed to M. pneumoniae or CARDS toxin. A total of 13 baboons were exposed to M. pneumoniae or CARDS toxin. At Days 7 and 14, BAL fluid was collected and analyzed for cell count, percent of each type of cell, CARDS toxin by PCR, CARDS toxin by antigen capture, eosinophilic cationic protein, and cytokine profiles. Serum IgM, IgG, and IgE responses to CARDS toxin were measured. All animals had a necropsy for analysis of the histopathological changes on lungs. No animal developed signs of infection. The serological responses to CARDS toxin were variable. At Day 14, four of seven animals exposed to M. pneumoniae and all four animals exposed to CARDS toxin developed histological "asthma-like" changes. T cell intracellular cytokine analysis revealed an increasing ratio of IL-4/IFN-γ over time. Both M. pneumoniae and CARDS toxin exposure resulted in similar histopathological pulmonary changes, suggesting that CARDS toxin plays a major role in the inflammatory response.

MicroRNA-142 regulates inflammation and T cell differentiation in an animal model of multiple sclerosis

BackgroundMicroRNAs have emerged as an important class of modulators of gene expression. These molecules influence protein synthesis through translational repression or degradation of mRNA transcripts. Herein, we investigated the potential role of miR-142a isoforms, miR-142a-3p and miR-142a-5p, in the context of autoimmune neuroinflammation.MethodsThe expression levels of two mature isoforms of miR-142 were measured in the brains of patients with multiple sclerosis (MS) and the CNS tissues from mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Expression analyses were also performed in mitogen and antigen-stimulated splenocytes, as well as macrophages and astrocytes using real-time RT-PCR. The role of the mature miRNAs was then investigated in T cell differentiation by transfection of CD4+ T cells, followed by flow cytometric analysis of intracellular cytokines. Luciferase assays using vectors containing the 3′UTR of predicted targets were performed to confirm the interaction of miRNA sequences with transcripts. Expression of targets were then analyzed in activated splenocytes and MS/EAE tissues.ResultsExpression of miR-142-5p was significantly increased in the frontal white matter from MS patients compared with white matter from non-MS controls. Likewise, expression levels of miR-142a-5p and miR-142a-3p showed significant upregulation in the spinal cords of EAE mice at days 15 and 25 post disease induction. Splenocytes stimulated with myelin oligodendrocyte glycoprotein (MOG) peptide or anti-CD3/anti-CD28 antibodies showed upregulation of miR-142a-5p and miR-142a-3p isoforms, whereas stimulated bone marrow-derived macrophages and primary astrocytes did not show any significant changes in miRNA expression levels. miR-142a-5p overexpression in activated lymphocytes shifted the pattern of T cell differentiation towards Th1 cells. Luciferase assays revealed SOCS1 and TGFBR1 as direct targets of miR-142a-5p and miR-142a-3p, respectively, and overexpression of miRNA mimic sequences suppressed the expression of these target transcripts in lymphocytes. SOCS1 levels were also diminished in MS white matter and EAE spinal cords.ConclusionsOur findings suggest that increased expression of miR-142 isoforms might be involved in the pathogenesis of autoimmune neuroinflammation by influencing T cell differentiation, and this effect could be mediated by interaction of miR-142 isoforms with SOCS1 and TGFBR-1 transcripts.

Immunological Prediction of Cytomegalovirus (CMV) Replication Risk in Solid Organ Transplantation Recipients: Approaches for Regulating the Targeted Anti-CMV Prevention Strategies.

The current cytomegalovirus (CMV) prevention strategies in solid organ transplantation (SOT) recipients have contributed towards overcoming the detrimental effects caused by CMV lytic infection, and improving the long-term success rate of graft survival. Although the quantification of CMV in peripheral blood is the standard method, and an excellent end-point for diagnosing CMV replication and modulating the anti-CMV prevention strategies in SOT recipients, a novel biomarker mimicking the CMV control mechanism is required. CMV-specific immune monitoring can be employed as a basic tool predicting CMV infection or disease after SOT, since uncontrolled CMV replication mostly originates from the impairment of immune responses against CMV under immunosuppressive conditions in SOT recipients. Several studies conducted during the past few decades have indicated the possibility of measuring the CMV-specific cell-mediated immune response in clinical situations. Among several analytical assays, the most advancing standardized tool is the QuantiFERON®-CMV assay. The T-Track® CMV kit that uses the standardized enzyme-linked immunospot assay is also widely employed. In addition to these assays, immunophenotyping and intracellular cytokine analysis using flow cytometry (with fluorescence-labeled monoclonal antibodies or peptide-major histocompatibility complex multimers) needs to be adequately standardized and validated for potential clinical applications.

Presence of Vasoactive Intestinal Polypeptide Signaling in Plasmacytoid Dendritic Cells Improves Survival in a Murine Allo-BMT Model

Introduction:Pre-clinical murine experiments and clinical data from allogeneic bone marrow transplantation (allo-BMT) have shown that increased numbers of plasmacytoid dendritic cells (pDC) in the bone marrow graft results in better clinical outcomes with less severe graft-versus-host disease (GvHD) and improved survival. The mechanism by which donor pDC modulate GvHD is unknown. Knowing that vasoactive intestinal polypeptide (VIP) is an immunosuppressive peptide , we reasoned that VIP signaling might play a role in regulating T-cell activation and expansion, and the VIP pathway may be a potential therapeutic target for regulating GvHD in allo-BMT. We have tested the hypothesis that VIP synthesis by donor pDCs can modulate T cell alloreactivity.Methods:To explore the mechanisms by which pDC and VIP signaling regulate T cell activation in murine allo-BMT, we prepared B6-background donor cell grafts and transplanted them into lethally irradiated B10.BR recipients. In experiment 1, recipients were transplanted with grafts containing the combination of 5 x 103 VIP-GFP hematopoietic stem cells (HSC) and 3 x 106 VIP-wild type (VIP-WT) or VIP-knock out (VIP-KO) splenocytes. At day 7, splenocytes were isolated for flow cytometric analysis looking for GFP signal, which represents VIP-promotor activity. Experiment 2 used combinations of 5 x 103 VIP-WT HSC, 1 x 106 luciferase+ T cells, and 50 x 103 VIP-WT or VIP-KO pDC from B6 as donor grafts. Recipients were monitored for survival and GvHD based on fur texture, posture, activity, skin integrity and weight loss. T cell expansion was measured by bioluminescent imaging (BLI). Serum cytokines from bleeds at day 3 and day 8 post-transplant were analyzed using a Luminex 38 plex panel. Some recipients were euthanized on day 3 for intracellular cytokine analysis of splenic T cells.Results:In experiment 1, 7 days post-transplant, analysis of splenocytes from all mice showed increased activity of the VIP gene promoter in donor pDC that were derived from HSC, compared to other cell types. The VIP promoter signal was also stronger in donor HSC-derived pDCs, if originally transplanted with VIP-KO splenocytes. In experiment 2 over 70% of mice receiving HSC+T+VIP-WT pDC in the BM graft survived to day 100 post-transplant, while those getting VIP-KO pDC instead only had 30% survival (Fig 1A). All surviving recipients were fully engrafted by day 30. BLI revealed greater total T-cell proliferation (measured as radiance) in recipients of VIP-KO pDC (Fig 1B). Furthermore, recipients of VIP-KO pDC had more severe acute GvHD, with increased weight loss and GvHD clinical scores (Fig 1C, 1D). Some recipients were euthanized and their serum were collected for cytokine analysis on day 8 post-transplant, which showed up-regulation of pro-inflammatory or chemotactic cytokines MCP1, IL-1, IL-12, IL-17 in T cells co-transplanted with VIP-KO pDC compared to WT pDC.Conclusion:The present findings show that: 1) VIP is produced by donor pDC early after allo-BMT; 2) absence of VIP production by donor pDC leads to increased T-cell expansion in a murine allo-BMT model. Thus the pDC-T cell VIP signaling pathway is a critical element in controlling donor T cell alloreactivity after allo-BMT. Future studies will include VIP qPCR to confirm VIP production in donor pDC post-transplant, and determine the mechanism by which VIP production by pDC regulates T cell activity and modulates GvHD. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Cholinergic Stimulation Prevents the Development of Autoimmune Diabetes: Evidence for the Modulation of Th17 Effector Cells via an IFNγ-Dependent Mechanism.

Type I diabetes (T1D) results from T cell-mediated damage of pancreatic β-cells and loss of insulin production. The cholinergic anti-inflammatory pathway represents a physiological link connecting the central nervous and immune systems via vagus nerve, and functions to control the release of proinflammatory cytokines. Using the multiple low-dose streptozotocin (MLD-STZ) model to induce experimental autoimmune diabetes, we investigated the potential of regulating the development of hyperglycemia through administration of paraoxon, a highly specific acetylcholinesterase inhibitor (AChEI). We demonstrate that pretreatment with paraoxon prevented hyperglycemia in STZ-treated C57BL/6 mice. This correlated with a reduction in T cell infiltration into pancreatic islets and preservation of the structure and functionality of β-cells. Gene expression analysis of pancreatic tissue revealed that increased peripheral cholinergic activity prevented STZ-mediated loss of insulin production, this being associated with a reduction in IL-1β, IL-6, and IL-17 proinflammatory cytokines. Intracellular cytokine analysis in splenic T cells demonstrated that inhibition of AChE led to a shift in STZ-induced immune response from a predominantly disease-causing IL-17-expressing Th17 cells to IFNγ-positive Th1 cells. Consistent with this conclusion, inhibition of AChE failed to prevent STZ-induced hyperglycemia in IFNγ-deficient mice. Our results provide mechanistic evidence for the prevention of murine T1D by inhibition of AChE and suggest a promising strategy for modulating disease severity.

Helper and cytotoxic T-cell subsets (Th1, Th2, Tc1, and Tc2) in benign and malignant salivary gland tumors.

The objective of this study was to explore the prevalence of T helper type 1 (Th1; CD4(+) IFN-γ (+) ) and Th2 (CD4(+) IL-4(+) ) cells, as well as cytotoxic T cell type 1 (Tc1; CD8(+) IFN-γ(+) ) and Tc2 cells (CD8(+) IL-4(+) ) in peripheral blood of the patients with salivary gland tumors (SGTs). Thirty new patients with SGTs and 15 healthy controls were recruited. After intracellular cytokine staining, data acquisition and analysis were performed by flow cytometry. The mean percentages of Th1 and Tc1 cells, as well as the ratios of Th1/Th2 and Tc1/Tc2, were observed to be significantly lower in patients with malignant SGTs in comparison with controls. Furthermore, the geometric mean fluorescent intensity (geometric MFI, representing the cytokine expression intensity) for IL-4 production by Th2 and Tc2 lymphocytes was significantly higher in patients with malignant tumors than controls. Positive correlations were observed between the mean percentage of Tc2 cells with Th2 cells, and with the tumor size in patients with benign and malignant tumors, respectively. The findings suggest that the imbalance of Th1/Th2 and Tc1/Tc2 ratios, as well as the increase in the expression of IL-4 by Th2 and Tc2 lymphocytes, may contribute to the pathogenesis of SGTs, especially in malignant cases.

Peripheral Blood Immunological Features Associated with Aortic Valve Disease and Ascending Throcic Aorta Aneurysm and Dilation

INTRODUCTION: Ascending thoracic aortic aneurysm (TAA) is a multi-factorial process in which histological modifications and immune-mediated inflammation are closely associated. The predominant role of a Th1-mediated response in influencing aortic wall remodeling, dilation, and aneurysm formation has been suggested by previous studies. Recently, the importance of chemokine receptors for Th1 cells recruitment into vascular inflammatory sites, as well as of the balance between pro- and anti-inflammatory T-cell subsets in influencing the severity of coronary artery disease, have been described.MATERIAL AND METHODS: We evaluated activation markers and chemokine receptors expression on peripheral T-cell and NK cell subsets of subject with aortic valve disease associated with ascending TAA (ascending aortic diameter &gt; 4 cm) and undergoing elective surgery for TAA (Group A), in comparison with patients with aortic valve disease without TAA (ascending aortic diameter &lt; 4 cm) (Group B). Peripheral blood samples from the two groups were also compared for intracellular T-lymphocyte cytokine production, frequency of regulatory T cells (Treg) and soluble levels of cytokine and chemokines. The aortic size index (ASI) was considered a parameter able to reflect aortic pathophysiological modifications leading to aortic dilation.RESULTS: The results demonstrated correlations between ASI values and CCR5 expression on CD3+, CD3+/CD8+, CD4+ and CD4+/CD28- T-cell subsets. In Group A the expression of CCR5 was higher on CD3+/CD8+, CD4+ and CD4+/CD28- T-cell subsets, when compared with Group B. CD4+ and CD4+/CD28- T-cells in Group A showed also a higher expression for the co-stimulatory molecule CD28 and the activation marker CD25, respectively. An increased expression of CXCR3 was found on CD4+, CD3+/CD8+ and CD3+/TCR+ T-cell subsets in Group A. A higher circulating fraction of NK cells, together with a higher NK cell positivity for CX3CR1, were observed in aneurysmatic patients. Intracellular cytokine analysis demonstrated a higher fraction of CD3+/CD4+ T-cells producing IL-17A and IL-10 in Group A, together with a higher intracellular content for IL-21. Finally, a higher soluble level of fractalkine (CX3CL1) has been detected in aneurysm group.CONCLUSION: Results indicate a higher activation state, migratory capacity and cytotoxic potential of peripheral blood NK and T-cell subsets in patients with aortic valve disease associated with ascending TAA, when compared with patients affected by aortic valve disease alone. These findings, together with the observed higher polarization towards a Th17 in patients with aortic aneurysm could suggest the involvement of autoimmune mechanisms leading to cellular loss, inflammation and fibrosis during ascending aortic wall dilation and aneurysmatic progression.Journal of Universal College of Medical Sciences Vol. 3, No. 1, 2015: 11-20