Cell Cytokine Patterns Research Articles

Intracytoplasmic Expression of IL-6 and IL-17A in Circulating CD4+ T Cells Are Strongly Associated with and Predict Disease Activity in Rheumatoid Arthritis: A Case-Control Study in Ghana

Background T cell cytokines play important roles in the development and progression of rheumatoid arthritis (RA). Loss of Th1/Th2 and Th17/Treg balance has been reported in several inflammatory autoimmune diseases. However, their role in RA within hitherto rare Ghanaian context has not been explored. Here, we evaluated the intracytoplasmic CD4+ T cell cytokine patterns in rheumatoid arthritis patients in Ghana and determined their relationship with disease activity. Methods This case-control study included 48 newly diagnosed RA patients and 30 apparent healthy controls from two major hospitals in Ghana. Validated structured questionnaires were administered to obtain demographic data; blood samples were collected and processed for flow cytometric analysis. Results IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17A, IL-6/IL-4, and IL-17/IL-10 expressions were significantly higher in RA cases compared to the healthy controls. The expression of IL-6 (0.00 (0.00-0.98) vs. 0.82 (0.34-1.10) vs. 1.56 (1.39-1.68), p < 0.0001), IL-17A (0.00 (0.00-0.02) vs. 0.19 (0.09-0.30) vs. 0.99 (0.64-1.25), p < 0.0001), and IL-17A/IL-10 (0.00 (0.00-0.39) vs. 0.15 (0.09-0.26) vs. 0.88 (0.41-1.47), p < 0.0001) increased significantly from the healthy controls through RA patients with low DAS scores to RA patients with moderate DAS scores. IL-6 (β = 0.681, r2 = 0.527, p < 0.0001), IL-17A (β = 0.770, r2 = 0.593, p < 0.0001), and IL-17A/IL-10 (β = 0.677, r2 = 0.452, p < 0.0001) expressions were significantly directly associated with DAS28 scores. IL-6 (cutoff = 1.32, sensitivity = 100.0%, specificity = 100.0%, accuracy = 100.0%, and AUC = 1.000) and IL-17A (cutoff = 0.58, sensitivity = 100.0%, specificity = 100.0%, accuracy = 100.0%, and AUC = 1.000) presented with the best discriminatory power in predicting moderate DAS scores from low DAS scores. Conclusion Th1- and Th17-related cytokines predominate in the pathophysiology of RA, with IL-6 and IL-17 being principally and differentially expressed based on the severity of the disease. IL-6 and IL-17A could serve as useful prognostic and disease-monitoring markers in RA in the African context.

IL-21+ CD4+ T helper cells co-expressing IFN-γ and TNF-α accumulate in the joints of antinuclear antibody positive patients with juvenile idiopathic arthritis

Juvenile Idiopathic Arthritis (JIA) is currently classified into seven subgroups. Recently, antinuclear antibody (ANA) positive JIA patients were suggested to encompass a clinically homogenous new subgroup. CD4+ T helper (Th) cells play an essential role in JIA pathogenesis. Herein, we analyzed cytokine expression in synovial fluid (SF) CD4+ Th cells of JIA patients by using flow cytometry and compared cytokine patterns between JIA subgroups. We could show increased frequencies of IL-21 expressing CD4+ Th cells in the joints of ANA+ Oligo-/Poly-JIA patients, which co-expressed the Th-1 cytokines IFN-γ/TNF-α. In contrast, frequencies of IL-17 expressing cells were lowest in the joints of ANA+ Oligo-/Poly-JIA but enriched in that of ERA-JIA patients. This is the first description of a diverse SF Th cell cytokine pattern in different JIA subgroups. Additionally, we could define IL-21 as an effector cytokine expressed in SF Th cell in a significant proportion of ANA+ JIA patients.

Cross Interaction Between OGT and mTOR in T Cells and its Consequences in Autoimmunity

BackgroundSystemic Lupus Erythematosus (SLE) is a chronic autoimmune disease that has been studied extensively, yet an understanding of the mechanisms of this disease remains unclear. It is known that epigenetic mechanisms are involved in the disease. We found O‐GlcNAc Transferase (OGT), an X‐linked gene, overexpressed due to hypomethylation in T cells from lupus patients (J. Autoimmunity, 2013). Furthermore, it was reported that the mechanistic target of rapamycin (mTOR) modifies T cell cytokine patterns and contributes to the TReg defect in patients with lupus. (J. Immunology, 2014).PurposeTo investigate the role OGT has in T cell signaling in order to understand the contribution of its overexpression to lupus. In particular, we investigated the relationship between OGT and the mTOR pathway in T cells to understand their participation in the disease.MethodsHealthy female donors were recruited by advertising. The research was reviewed and approved by the University of South Alabama Review Board for Human Subject Research. Peripheral blood mononuclear cells (PBMC) were purified by density gradient centrifugation, then T cells were isolated by magnetic beads. One fraction was transiently transfected for 48 h with 2μg of OGT siRNA using a nucleofector device (Amaxa). Other fractions were subjected to different treatments. Cells were stimulated after treatments with PMA/Ionomycin for 4h and the whole cell extracts were separated by SDS‐PAGE electrophoresis. Protein expression was analyzed by immunoblotting using specific antibodies. ß actin was used as loading control.ResultsIncreasing the levels of glycosylated proteins with 100 mM Pugnac, a competitive inhibitor of O‐GlcNAc‐β‐N‐acetylglucosaminidase (OGA), or with 5mM Glucosamine, increased the phosphorylation of p70S6K, substrate of mTORC1, which indicates an increase in mTOR activity. On the other side, when OGT is knocked down by siRNA, as expected, the protein expression of OGT levels as well as glycosylated protein levels decreased. Interestingly, the activity of mTOR also decreased. Similar results were observed with 10 nM MHY1485, potent activator of mTOR, or with 50 nM rapamycin and 10 nM Torin‐1, both inhibitors of mTOR, which increased or decreased the phosphorylation of its substrate respectively. However, they were unable to modify the levels of glycosylation.ConclusionsThese results strongly suggest that mTOR activation is OGT‐dependent and is located downstream of OGT in T cells. Overexpression of OGT could be responsible for the increase in mTOR activity in T cells from lupus patients.Support or Funding InformationNIH 5R03 AR067518‐02Summer undergraduate research fellowship (SURF) University of South AlabamaDepartment of Biomedical Science, College of Allied Health, University of South Alabama

Autologous hematopoietic stem cell transplantation in systemic sclerosis induces long-lasting changes in B cell homeostasis toward an anti-inflammatory B cell cytokine pattern

BackgroundAutologous hematopoietic stem cell transplantation (aHSCT) is performed in patients with aggressive forms of systemic sclerosis (SSc). The profile of B cell reconstitution after aHSCT is not fully understood. The aim of this study was to investigate changes of B cell subsets and cytokine production of B cells in patients with SSc after aHSCT.MethodsPeripheral blood of six patients with SSc was collected at defined intervals up to 16 months after aHSCT. Immunophenotyping was performed, and B cell function was determined by measuring cytokine secretion in supernatants of stimulated B cell cultures.ResultsWithin 1 month after aHSCT, a peak in the percentage of CD38++/CD10+/IgD+ transitional B cells and CD38++/CD27++/IgD− plasmablasts was detected. Long-term changes persisted up to 14 months after aHSCT and showed an increased percentage of total B cells; the absolute B cell number did not change significantly. Within the B cell compartment, an increased CD27/IgD+ naïve B cell percentage was found whereas decreased percentages of CD27+/IgD+ pre-switched memory, CD27+/IgD− post-switched memory, and CD27−/IgD− double-negative B cells were seen after aHSCT. Cytokine secretion in B cell cultures showed significantly increased IL-10 concentrations 13 to 16 months after aHSCT.ConclusionA changed composition of the B cell compartment is present for up to 14 months after aHSCT indicating positive persisting effects of aHSCT on B cell homeostasis. The cytokine secretion profile of B cells changes in the long term and shows an increased production of the immune regulatory cytokine IL-10 after aHSCT. These findings might promote the clinical improvements after aHSCT in SSc patients.

Role of soluble inflammatory mediators and different immune cell populations in early control of symptomatic acute hepatitis C virus infection.

The natural course of acute Hepatitis C Virus (aHCV) infection is highly heterogeneous, and only few biomarkers have been identified to reliably predict the outcome of infection. We analysed a large panel of soluble inflammatory mediators, immune cell frequencies and phenotypes using peripheral blood samples from 26 patients with symptomatic aHCV infection from a controlled randomized clinical trial (ISRCTN88729946, www.isrctn.com). We found that patients with a spontaneous early HCV control demonstrated a distinct expression pattern of various soluble immune mediators including IFNα and IL-16. Immune cell phenotype and frequency differed between patients who cleared the viral infection early (n=13) and those who remained HCV RNA positive after 12 weeks of observation (n=13) with a reduced ratio of CD4+ T cells to NK cells in the non-early clearer. Further, correlation analyses of 50 cytokines and chemokines revealed more positive correlations in between the distinct cytokines, especially for IFNα and IL-16, and between the cytokines and HCV RNA levels in spontaneous early clearer patients. Beyond that, in vitro stimulation of CD4+ T cells with IL-16 reduced the susceptibility of these cells to killing by IFNα-activated NK cells. These data indicate that the immune cell composition and cytokine pattern varies considerably in patients with symptomatic aHCV infection. NK cell-mediated killing of CD4+ T cells might affect early control of HCV infection.

P075 Inflammation-induced cancer vs. cancer-induced inflammation is dependent on S1P lyase

The dichotomy of inflammation-induced cancer vs. cancer-induced inflammation is still enigmatic. Since sphingolipids are involved in both tumour cell survival and immune cell differentiation, migration and cytokine pattern we hypothesised their essential role in both mechanism of cancer development. We employed inducible S1P lyase (SGPL1) knockdown bone marrow-chimeric mice in a colitis associated colon cancer model leading to compartment-specific accumulation of sphingolipid levels. We found that, independent of the compartment of SGPL1 deficiency, haematopoietic or extra-haematopoietic, DSS/AOM-treated mice demonstrated tumours with s1pr1, stat3, and IL-6 elevation. However, compartment-specific actions of the SGPL1-S1P axis contributed both morphologically and genetically to a very distinct development of inflammation and carcinogenesis. Haematopoietic SGPL1 knockdown forced severe inflammatory colitis with delayed carcinogenesis characterised by pdcd4-down-regulation. In contrast, extra-haematopoietic SGPL1 knockdown triggered a much more rapid occurrence of epithelial-driven sphingosine kinase 1-positive tumours, exhibiting kras, egfr and IL23-p19 signatures and a weak but distinct Th2 driven immune microenvironment. Moreover, we found that SGPL1 derived from haematopoietic cells is sufficient for S1P-driven lymphocyte sequestration. In this study we demonstrate that compartment-specific sphingolipid modulation clarifies the dichotomy of inflammation-induced cancer vs. cancer-induced inflammation.

Diversity of TH cytokine profiles in patients with chronic rhinosinusitis: A multicenter study in Europe, Asia, and Oceania

To date, no study has evaluated the diversity of TH cell cytokine patterns of patients with chronic rhinosinusitis (CRS) among centers in different continents using identical methods. We sought to assess TH cytokine profiles in patients with CRS from Europe, Asia, and Australia. Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP; n=435) and control subjects (n=138) were recruited from centers in Adelaide, Benelux, Berlin, Beijing, Chengdu, and Tochigi. Nasal mucosal concentrations of TH2, TH17, and TH1 cytokines; eosinophilic cationic protein (ECP); myeloperoxidase (MPO); IL-8; and tissue total and Staphylococcus aureus enterotoxin (SE)-specific IgE were measured by using identical tools. Combinations of TH1/TH2/TH17 cytokine profiles in patients with CRSwNP varied considerably between regions. CRSwNP tissues from patients from Benelux, Berlin, Adelaide, and Tochigi were TH2 biased, whereas those from Beijing mainly demonstrated TH2/TH1/TH17 mixed patterns, and patients from Chengdu showed an even lower TH2 expression. Concentrations of IL-8 and tissue total IgE in patients with CRSwNP were significantly higher than those in control subjects in all regions. More than 50% of patients with CRSwNP in Benelux, Berlin, Adelaide, and Tochigi showed a predominantly eosinophilic endotype compared with less than 30% of patients in Beijing and Chengdu. SE-specific IgE was found in significantly greater numbers in patients with CRSwNP from Benelux, Adelaide, and Tochigi and significantly lower numbers in patients from Beijing and Chengdu. Moreover, the TH1/TH2/TH17 cytokine profiles in patients with CRSsNP showed diversity among the 6 regions. TH cytokine levels, eosinophilic/neutrophilic patterns, and SE-specific IgE expressions show extreme diversity among patients with CRS from Europe, Asia, and Oceania.

Mixed T helper cell signatures in chronic rhinosinusitis with and without polyps.

In chronic rhinosinusitis (CRS) different phenotypes have been reported based on cytokine profile and inflammatory cell patterns. The aim of this study was to characterize the intracytoplasmatic cytokines ofTcells infiltrating theinflamed sinonasal mucosa.MethodsInfiltrated T cells and tissue homogenates from sinonasal mucosal samples of 7 healthy subjects, 9 patients with CRS without nasal polyp (CRSsNP), 15 with CRS with nasal polyps (CRSwNP) and 5cystic fibrosis patients (CF-NP) were analyzed for cytokine expression using flow cytometry and multiplex analysis respectively. Intracytoplasmic cytokinesin T cells were analyzed after stimulation of nasal polyps with Staphylococcus aureus enterotoxin B for 24 hours.ResultsThe number of T cellsper total living cells was significantly higher in patients with CRSwNP vs. CRSsNP and controls. 85% of the CD4+ Tcells showed to be memory T cells. The effector T cells present in all tissues have apredominantTh1 phenotype. Only in CRSwNP, a significantfraction of T cellsproduced the Th2 cytokinesIL-4 and IL-5, while nasal polyps from CF patients were characterized by a higher CD4/CD8 T cell ratio and an increased number of Th17 cells. 24 h stimulation with SEB resulted in a significant induction of CD4+ T cells producing IL-10 (Tr1 cells).ConclusionT cell cytokine patternsin healthy and inflamed sinonasal mucosa revealed that Th2 cells (IL-4 and IL-5 producing cells) are significantly increased in CRSwNP mucosal inflammation. Exposure to SEB stimulates Tr1 cellsthat may contribute to the Th2 bias in CRSwNP.

Islet infiltration, cytokine expression and beta cell death in the NOD mouse, BB rat, Komeda rat, LEW.1AR1-iddm rat and humans with type 1 diabetes

Research on the pathogenesis of type 1 diabetes relies heavily on good animal models. The aim of this work was to study the translational value of animal models of type 1 diabetes to the human situation. We compared the four major animal models of spontaneous type 1 diabetes, namely the NOD mouse, BioBreeding (BB) rat, Komeda rat and LEW.1AR1-iddm rat, by examining the immunohistochemistry and in situ RT-PCR of immune cell infiltrate and cytokine pattern in pancreatic islets, and by comparing findings with human data. After type 1 diabetes manifestation CD8(+) T cells, CD68(+) macrophages and CD4(+) T cells were observed as the main immune cell types with declining frequency, in infiltrated islets of all diabetic pancreases. IL-1β and TNF-α were the main proinflammatory cytokines in the immune cell infiltrate in NOD mice, BB rats and LEW.1AR1-iddm rats, as well as in humans. The Komeda rat was the exception, with IFN-γ and TNF-α being the main cytokines. In addition, IL-17 and IL-6 and the anti-inflammatory cytokines IL-4, IL-10 and IL-13 were found in some infiltrating immune cells. Apoptotic as well as proliferating beta cells were observed in infiltrated islets. In healthy pancreases no proinflammatory cytokine expression was observed. With the exception of the Komeda rat, the animal models mirror very well the situation in humans with type 1 diabetes. Thus animal models of type 1 diabetes can provide meaningful information on the disease processes in the pancreas of patients with type 1 diabetes.

Follicular helper T cells in immune homeostasis

Follicular helper T cells in immune homeostasis

Plasma Melatonin and Urinary 6-Hydroxymelatonin Levels in Patients with Pulmonary Tuberculosis

Tuberculosis (TB) is the second most frequent cause of death in the world, after AIDS. Delay in diagnosing TB is an important worldwide problem. It seriously threatens public health. Cell-mediated immune responses play an important role in the pathogenesis of TB infection. The course of Mycobacterium tuberculosis (MTb) infection is regulated by two distinct T cell cytokine patterns. Melatonin is a biomolecule (mainly secreted by the pineal gland) with free radical scavenging, antioxidant and immunoregulatory properties. Melatonin has both its direct and indirect immunomodulatory effects on the immune system. In this study, we measured plasma melatonin and urine 6-hydroxy melatonin sulphate (6-HMS) concentrations in patients with newly diagnosed TB for the purpose of investigating whether there was a relationship between their levels and MTb infection. Thirty-one newly diagnosed patients presenting with active TB and 31 healthy subjects as the control group were included in this study. Blood and 24-h urine samples were collected from all individuals. Plasma melatonin levels and urine 6-HMS were measured. Our results show that in patients with TB, mean melatonin and 6-HMS concentrations were significantly lower than in the control subjects (p = 0.037, p < 0.001, respectively). We believe that the treatment of TB patients with melatonin might result in a wide range of health benefits including improved quality of life and reduced severity of infection in these patients. Supplementation with melatonin may be considered as an adjunctive therapy to classic treatment of pulmonary TB, especially during the acute phase of infection.

Relation of HLA-B27, Tumor Necrosis Factor-α Promoter Gene Polymorphisms, and T Cell Cytokine Production in Ankylosing Spondylitis — A Comprehensive Genotype-Phenotype Analysis from an Observational Cohort

In a pilot study, a distinct T cell cytokine pattern associated with HLA-B27 status and a tumor necrosis factor-α (TNF-α) promoter gene polymorphism was found at -308 (TNF-308). The objective of our study was to assess these associations in a different cohort of patients with ankylosing spondylitis (AS) and to evaluate any effect on clinical measurements. Peripheral T cell cytokine production of patients with AS (n = 121) from the German Spondyloarthritis Inception Cohort was assessed by flow cytometry and correlated with HLA-B27, TNF-238, and TNF-308, and with clinical measurements. In HLA-B27-positive, anti-TNF-naive patients with AS, the percentages of TNF-α-producing (5.02%) and interleukin 10-producing (0.31%) CD8+ cells were significantly lower in comparison to HLA-B27-negative patients (9.52%, p = 0.048, and 0.46%, p = 0.037, respectively). A nonsignificant trend was found for a lower production of TNF-α by CD4+ and interferon-γ by both CD4+ and CD8+ T cells, as compared to HLA-B27-negative patients with AS (p > 0.05 for all comparisons). The A allele at TNF-308 was associated with a lower percentage of TNF-α-producing CD4+ T cells. No significant correlations were found between clinical or radiological measurements and cytokine production or with TNF-α promoter gene polymorphisms. Modulation of T cell cytokines by HLA-B27 might play a role in AS pathogenesis in B27-positive individuals. No conclusive data were obtained for the TNF-308 polymorphism on cytokine production, and no effect of cytokines or genetic polymorphisms on clinical manifestations was observed.

Tamoxifen counteracts the allergic immune response and improves allergen‐induced dermatitis in mice

Tamoxifen (TX) represents the prototype selective oestrogen receptor modulator. In addition to its use in breast cancer, TX possesses immunomodulatory functions and displays beneficial effects in models of systemic lupus erythematosus. We hypothesized that TX might inhibit type I allergic reactions, which are also characterized by deviations in humoral immunity. To evaluate the effects of TX on the allergic immune response in appropriate mouse models. Balb/c mice were sensitized with ovalbumin (OVA)-alum by the intraperitoneal route, and humoral parameters, T cell cytokine patterns and OVA-induced ear swelling responses were determined in a preventive (start of TX treatment before sensitization) and a therapeutic setting (start after sensitization), respectively. In addition, the impact of TX on clinical signs, epidermal thickness and leucocyte infiltration of the skin was investigated in a model of allergen-induced dermatitis. Preventive TX treatment interfered with all aspects of the allergic immune response, leading to a reduction of allergen-specific Ig levels (IgE, IgG1 and IgG2a), a skewing effect in the T cell compartment with the inhibition of IL-4 and an abrogation of ear swelling responses. Interestingly, a therapeutic TX administration was also effective in reducing Ig levels and ear swelling responses. The vigorous systemic effects were additionally mirrored by local changes in allergen-dependent dermatitis with reduced clinical symptoms, diminished epidermal thickness and decreased CD4+ and CD8+ cell infiltrates. TX inhibits allergic responses when given preventively and also therapeutically, and improves allergen-induced dermatitis. Because of its effectiveness, TX could bear significant therapeutic potential for the treatment of allergies.

Dendritic cells lentivirally engineered to overexpress interleukin‐10 inhibit contact hypersensitivity responses, despite their partial activation induced by transduction‐associated physical stress

Dendritic cells (DCs) constitute an attractive target for immunotherapeutic approaches. Because DCs are largely refractory to transfection with plasmid DNA, several viral transduction protocols were established. The potential side-effects of lentiviral transduction on the phenotype and activation state of DCs left unstimulated after transduction have not been assessed. There is a need to analyse these parameters as a result of the requirement of using DCs with a low activation state for therapeutic strategies intended to induce tolerance. Lentivirally-transduced bone marrow (BM)-derived DCs (LV-DCs) in comparison with mock-transduced (Mock-DCs) and untreated DCs were analysed with regard to the induction of maturation processes on the RNA, protein and functional level. BM-DCs engineered to overexpress interleukin (IL)-10 were analysed for therapeutic potential in a mouse model of allergic contact dermatitis. Compared with untreated DCs, Mock-DCs and LV-DCs displayed an altered gene expression signature. Mock-DCs induced a stronger T cell proliferative response than untreated DCs. LV-DCs did not further augment the T cell proliferative response, but induced a slightly different T cell cytokine pattern compared to Mock-DCs. Accordingly, the gene promoter of the DC maturation marker fascin mediated efficient expression of the model transgene IL-10 in unstimulated-transduced BM-DCs. Nevertheless, IL-10 overexpressing BM-DCs exerted tolerogenic activity and efficiently inhibited the contact hypersensitivity response in previously hapten-sensitized mice. Lentiviral transduction of BM-DCs results in their partial activation. Nevertheless, the transduction of these DCs with a vector encoding the immunomodulatory cytokine IL-10 rendered them tolerogenic. Thus, lentivirally-transduced DCs expressing immunomodulatory molecules represent a promising tool for induction of tolerance.

Autologous bone marrow-derived rat mesenchymal stem cells promote PDX-1 and insulin expression in the islets, alter T cell cytokine pattern and preserve regulatory T cells in the periphery and induce sustained normoglycemia

Cell-based therapies offer considerable promise for prevention or cure of diabetes. We explored the potential of autologous, self-renewing, mesenchymal stem cells (MSC) as a clinically-applicable approach to promote glucose homeostasis. In vitro-expanded syngeneic bone marrow-derived MSC were administered following or prior to diabetes induction into a rat model of streptozotocin-induced beta cell injury. MSC were CD45 −/CD44 +/CD54 +/CD90 +/CD106 +. MSC spontaneously secreted IL-6, HGF, TGF-β1 and expressed high levels of SDF-1 and low levels of VEGF, IL-1β and PGE 2, but no EGF, insulin or glucagon. MSC homed to the pancreas and this therapy allowed for enhanced insulin secretion and sustained normoglycemia. Interestingly, immunohistochemistry demonstrated that, the islets from MSC-treated rats expressed high levels of PDX-1 and that these cells were also positive for insulin staining. In addition, peripheral T cells from MSC-treated rats exhibited a shift toward IL-10/IL-13 production and higher frequencies of CD4 +/CD8 + Foxp3 + T cells compared to the PBS-treated rats. These data suggest that the bioactive factors secreted by MSC establish a tissue microenvironment that supports beta cell activation/survival in the pancreas. In addition, because of anti-inflammatory and immunoregulatory effects of MSC on T cells, this work can lead to clinical trial of autologous MSC to prevent/cure type-1 diabetes.

Mycobacterium tuberculosis-specific CD4+, IFNγ+, and TNFα+ multifunctional memory T cells coexpress GM-CSF

Multifunctional T cells expressing several cytokines in parallel are thought to play a crucial role in protection against different infections. To characterize T cell cytokine patterns associated with disease and protection in Mycobacterium tuberculosis infection we determined the expression of IFNγ, IL-2, TNFα, and GM-CSF in T cell subpopulations from children with tuberculosis (TB) and healthy latently M. tuberculosis-infected children (LTBI) after short-term in vitro restimulation. We identified CD4+ effector memory T cells (TEM) as the major source of all measured cytokines after antigen-specific restimulation. TEM from children with TB expressed higher proportions of IFNγ, TNFα, and IL-2 after Mtb restimulation while no differences were detected for GM-CSF between both study groups. GM-CSF secretion strongly depended on antigen-specific stimulation. Analyses of multiple cytokine patterns revealed that the majority of GM-CSF-positive M. tuberculosis-specific memory T cells coexpressed IFNγ and TNFα therefore showing a characteristic feature of multifunctional T cells. We conclude that children with active TB possess higher proportions of IFNγ-, TNFα-, and/or IL-2-positive TEM than children with LTBI while GM-CSF coexpression reveals a novel subpopulation within CD4+ memory T cells not increased in children with active TB.

Differentiation and functions of T cell subsets.

The Tc1 and Tc2 subsets of CD8+ T effector cells secrete different patterns of cytokines, but have similar functions, including perforin- and Fas-dependent cytotoxicity, and induction of delayed type hypersensitivity (DTH) reactions involving oedema and granulocytic infiltration. The characteristic cytokines of Tc1 (gamma-interferon) and Tc2 (interleukins 4 and 5) are expressed in vivo during the DTH reaction. Tc1 cells that are deficient in cytokine synthesis also induce similar levels of DTH, supporting the lack of correlation between CD8+ T cell cytokine patterns and DTH. CD8+ T cells often produce lower cytokine levels than CD4 cells because the CD8 cells kill their antigen-presenting cells before full stimulation can occur. This effect can be counteracted by increasing the frequency of stimulation, or using perforin-deficient T cells. A multiparameter analysis of cytokine effects on CD8+ T cell differentiation has been initiated, on the basis of the principle that normal immune responses involve complex cytokine mixtures. All combinations of seven cytokines were tested. In some combinations, the combined effect could not have been predicted from individual cytokine functions. Conditions were identified in which each of interleukins 4, 10 and 12 could have opposite effects on CD8+ T cell differentiation.

The vitamin D receptor and its role in inflammation and host defence: interview with Dr Robert Modlin

Dr Robert Modlin was interviewed by Emma Quigley (Senior Editor, Expert Opinion) on 5th February 2007.Robert L Modlin, MD, is Professor in the Division of Dermatology and in the Department of Microbiology, Immunology and Molecular Genetics at the University of California, Los Angeles. He is also the Chief of the Division of Dermatology. He completed his undergraduate studies at Johns Hopkins University and received his medical degree at the New York University School of Medicine. Dr Modlin’s interest in leprosy began during his dermatology residency at the Los Angeles County/University of Southern California Medical Center. He has studied leprosy as a model to learn about mechanisms of host defence in humans. As such, Dr Modlin’s laboratory has made fundamental insights into T cell subsets, cytokine patterns, antigen presentation, innate immunity and antimicrobial mechanisms in the human immune response to infection. He has been awarded three patents for this research. Dr Modlin has published > 150 articles, including 12 papers in Science and Nature, 4 in Nature Medicine, received the Montagna Award for outstanding young investigator from the Society for Investigative Dermatology, a merit award from the National Institutes of Health and the Sulzberger lectureship of the American Academy of Dermatology. Dr Modlin is a member of the American Society of Clinical Investigation and the American Association of Physicians. He is the Deputy Editor for the Journal of Immunology, having served on the editorial board of the Journal of Clinical Investigation, Infection and Immunity and Immunology. Dr Modlin has served on the Society for Investigative Dermatology Board of Directors.

Blockade of Interleukin-12 Function by Protein Vaccination Attenuates Atherosclerosis

Interleukin-12 (IL-12) has been identified as a key inducer of a type 1 T-helper cell cytokine pattern, which is thought to contribute to the development of atherosclerosis. We sought to study the role of IL-12 in atherosclerosis by inhibition of IL-12 using a newly developed vaccination technique that fully blocks the action of IL-12. LDL receptor-deficient (LDLr(-/-)) mice were vaccinated against IL-12 by 5 intramuscular injections of IL-12-PADRE complex in combination with adjuvant oil-in-water emulsion (low dose)/MPL/QS21 every 2 weeks. Two weeks thereafter, atherogenesis was initiated in the carotid artery by perivascular placement of silicone elastomer collars. IL-12 vaccination resulted in the induction of anti-IL-12 antibodies that functionally blocked the action of IL-12 as determined in an IL-12 bioassay. Blockade of IL-12 by vaccination of LDLr(-/-) mice resulted in significantly reduced (68.5%; P<0.01) atherogenesis compared with control mice without a change in serum cholesterol levels. IL-12 vaccination also resulted in a significant decrease in intima/media ratios (66.7%; P<0.01) and in the degree of stenosis (57.8%; P<0.01). On IL-12 vaccination, smooth muscle cell and collagen content in the neointima increased 2.8-fold (P<0.01) and 4.2-fold (P<0.01), respectively. Functional blockade of endogenous IL-12 by vaccination resulted in a significant 68.5% reduction in atherogenesis in LDLr(-/-) mice. Vaccination against IL-12 also improved plaque stability, from which we conclude that the blockade of IL-12 by vaccination may be considered a promising new strategy in the treatment of atherosclerosis.

Blood Cell Types and Cytokine Patterns in Solid Tumour Patients

Blood Cell Types and Cytokine Patterns in Solid Tumour Patients