More stories on Th17 cells

Isthmin: A multifunctional secretion protein

Isthmin is a polypeptide secreted by adipocytes that was first detected in Xenopus gastrula embryos. Recent studies have focused on the biological functions of isthmin in growth and development, angiogenesis, and metabolism. Distinct spatiotemporal expression of isthmin-1 (ISM-1) was observed during growth and development. ISM-1 plays an important role in the occurrence and development of cancer by regulating cell proliferation, migration, angiogenesis, and immune microenvironments. Moreover, ISM-1, as a newly identified insulin-like adipokine, increases adipocyte glucose uptake and inhibits hepatic lipid synthesis. However, the biological function of ISM-1 remains largely unknown. In this review, we highlight the structure and physiological functions of isthmin and explore its application potential, contributing to a better understanding of its function and providing prevention and treatment strategies for various diseases.

Recent Progress in Multiple Sclerosis Treatment Using Immune Cells as Targets

Multiple sclerosis (MS) is an autoimmune-mediated demyelinating disease of the central nervous system. The main pathological features are inflammatory reaction, demyelination, axonal disintegration, reactive gliosis, etc. The etiology and pathogenesis of the disease have not been clarified. The initial studies believed that T cell-mediated cellular immunity is the key to the pathogenesis of MS. In recent years, more and more evidence has shown that B cells and their mediated humoral immune and innate immune cells (such as microglia, dendritic cells, macrophages, etc.) also play an important role in the pathogenesis of MS. This article mainly reviews the research progress of MS by targeting different immune cells and analyzes the action pathways of drugs. The types and mechanisms of immune cells related to the pathogenesis are introduced in detail, and the mechanisms of drugs targeting different immune cells are discussed in depth. This article aims to clarify the pathogenesis and immunotherapy pathway of MS, hoping to find new targets and strategies for the development of therapeutic drugs for MS.

IL-6 enhances CD4 cell motility by sustaining mitochondrial Ca2+ through the noncanonical STAT3 pathway

Interleukin 6 (IL-6) is known to regulate the CD4 T cell function by inducing gene expression of a number of cytokines through activation of Stat3 transcription factor. Here, we reveal that IL-6 strengthens the mechanics of CD4 T cells. The presence of IL-6 during activation of mouse and human CD4 T cells enhances their motility (random walk and exploratory spread), resulting in an increase in travel distance and higher velocity. This is an intrinsic effect of IL-6 on CD4 T-cell fitness that involves an increase in mitochondrial Ca²⁺ Although Stat3 transcriptional activity is dispensable for this process, IL-6 uses mitochondrial Stat3 to enhance mitochondrial Ca²⁺-mediated motility of CD4 T cells. Thus, through a noncanonical pathway, IL-6 can improve competitive fitness of CD4 T cells by facilitating cell motility. These results could lead to alternative therapeutic strategies for inflammatory diseases in which IL-6 plays a pathogenic role.

Mutual interaction of microbiota and host immunity during health and diseases

Microbiota-host interaction has attracted more and more attentions in recent years. The association between microbiota and host health is largely attributed to its influence on host immune system. Microbial-derived antigens and metabolites play a critical role in shaping the host immune system, including regulating its development, activation, and function. However, during various diseases the microbiota-host communication is frequently found to be disordered. In particular, gut microbiota dysbiosis associated with or led to the occurrence and progression of infectious diseases, autoimmune diseases, metabolic diseases, and neurological diseases. Pathogenic microbes and their metabolites disturb the protective function of immune system, and lead to disordered immune responses that usually correlate with disease exacerbation. In the other hand, the immune system also regulates microbiota composition to keep host homeostasis. Here, we will discuss the current advances of our knowledge about the interactions between microbiota and host immune system during health and diseases.

Soufeng sanjie formula alleviates collagen-induced arthritis in mice by inhibiting Th17 cell differentiation

Background

Rheumatoid arthritis (RA) is a chronic autoimmune disease. Soufeng sanjie formula (SF), which is composed of scolopendra (dried body of Scolopendra subspinipes mutilans L. Koch), scorpion (dried body of Buthus martensii Karsch), astragali radix (dried root of Astragalus membranaceus (Fisch.) Bge), and black soybean seed coats (seed coats of Glycine max (L.) Merr), is a traditional Chinese prescription for treating RA. However, the mechanism of SF in treating RA remains unclear. This study was aim to investigate the anti-arthritic effects of SF in a collagen-induced arthritis (CIA) mouse model and explore the mechanism by which SF alleviates arthritis in CIA mice.

Methods

For in vivo studies, female DBA/1J mice were used to establish the CIA model, and either SF (183 or 550 mg/kg/day) or methotrexate (MTX, 920 mg/kg, twice/week) was orally administered to the mice from the day of arthritis onset. After administration for 30 days, degree of ankle joint destruction and serum levels of IgG and inflammatory cytokines were determined. The balance of Th17/Treg cells in the spleen and lymph nodes was analyzed using flow cytometry. Moreover, the expression levels of retinoic acid receptor-related orphan nuclear receptor (ROR) γt and phosphorylated STAT3 (pSTAT3, Tyr705) in the spleen were detected by immunohistochemistry. Furthermore, the effect of SF on Th17 cells differentiation in vitro was investigated in CD4⁺ T cells under Th17 polarization conditions.

Results

SF decreased the arthritis score, ameliorated paw swelling, and reduced cartilage loss in the joint of CIA mice. In addition, SF decreased the levels of bovine collagen-specific IgG in sera of CIA mice. SF decreased the levels of inflammatory cytokines (TNF-α, IL-6, and IL-17A) and increased the level of IL-10 both in the sera and the joint of CIA mice. Moreover, SF treatment rebalanced the Th17/Treg ratio in the spleen and lymph nodes of CIA mice. SF also reduced the expression levels of ROR γt and pSTAT3 (Tyr705) in the spleen of CIA mice. In vitro, SF treatment reduced Th17 cell generation and IL-17A production and inhibited the expression of RORγt, IRF4, IL-17A, and pSTAT3 (Tyr705) under Th17 polarization conditions.

Conclusions

Our results suggest that SF exhibits anti-arthritic effects and restores Th17/Treg homeostasis in CIA mice by inhibiting Th17 cell differentiation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00448-9.

Systemic inflammation is negatively associated with early post discharge growth following acute illness among severely malnourished children - a pilot study

Background: Rapid growth should occur among children with severe malnutrition (SM) with medical and nutritional management. Systemic inflammation (SI) is associated with death among children with SM and is negatively associated with linear growth. However, the relationship between SI and weight gain during therapeutic feeding following acute illness is unknown. We hypothesised that growth post-hospital discharge is associated with SI among children with SM. Methods: We conducted secondary analysis of data from HIV-uninfected children with SM (n=98) who survived and were not readmitted to hospital during one year of follow-up. We examined the relationship between changes in absolute deficits in weight and mid-upper-arm circumference (MUAC) from enrolment at stabilisation to 60 days and one year later, and untargeted plasma proteome, targeted cytokines/chemokines, leptin, and soluble CD14 using multivariate regularized linear regression. Results: The mean change in absolute deficit in weight and MUAC was -0.50kg (standard deviation; SD±0.69) and -1.20cm (SD±0.89), respectively, from enrolment to 60 days later. During the same period, mean weight and MUAC gain was 3.3g/kg/day (SD±2.4) and 0.22mm/day (SD±0.2), respectively. Enrolment interleukins; IL17-alpha and IL-2, and serum amyloid P were negatively associated with weight and MUAC gain during 60 days. Lipopolysaccharide binding protein and complement component 2 were negatively associated with weight gain only. Leptin was positively associated with weight gain. Soluble CD14, beta-2 microglobulin, and macrophage inflammatory protein 1 beta were negatively associated with MUAC gain only. Glutathione peroxidase 3 was positively associated with weight and MUAC gain during one year. Conclusions: Early post-hospital discharge weight and MUAC gain were rapid and comparable to children with uncomplicated SM treated in the community. Higher concentrations of SI markers were associated with less weight and MUAC gain, suggesting inflammation negatively impacts recovery from wasting. This finding warrants further research on reducing inflammation on growth among children with SM.

Systemic inflammation is negatively associated with early post discharge growth following acute illness among severely malnourished children - a pilot study

Background: Rapid growth should occur among children with severe malnutrition (SM) when medically and nutritionally treated. Systemic inflammation (SI) is associated with death among children with SM and is negatively associated with linear growth. However, the relationship between SI and weight gain during therapeutic feeding following acute illness is unknown. We hypothesised that growth in the first 60 days post-hospital discharge is associated with SI among children with SM. Methods: We conducted secondary analysis of data from HIV-uninfected children with SM (n=98) who survived and were not readmitted to hospital during one year of follow up. We examined the relationship between changes in absolute deficits in weight and mid-upper-arm circumference (MUAC) from enrolment at stabilisation to 60 days later and untargeted plasma proteome, targeted cytokines/chemokines, leptin, and soluble CD14 (sCD14) using multivariate regularized linear regression. Results: The mean change in absolute deficit in weight and MUAC was -0.50kg (standard deviation; SD±0.69) and -1.20cm (SD±0.89), respectively, from enrolment to 60 days later. During the same period, mean weight and MUAC gain was 3.3g/kg/day (SD±2.4) and 0.22mm/day (SD±0.2), respectively. Enrolment inflammatory cytokines interleukin 17 alpha (IL17α), interleukin 2 (IL2), and serum amyloid P (SAP) were negatively associated with weight and MUAC gain. Lipopolysaccharide binding protein (LBP) and complement component 2 were negatively associated with weight gain only. Leptin was positively associated with weight gain. sCD14, beta-2 microglobulin (β2M), and macrophage inflammatory protein 1 beta (MIP1β) were negatively associated with MUAC gain only. Conclusions: Early post-hospital discharge weight and MUAC gain were rapid and comparable to children with uncomplicated SM treated with similar diet in the community. Higher concentrations of SI markers were associated with less weight and MUAC gain, suggesting inflammation negatively impacts recovery from wasting. This finding warrants further research on the role of inflammation on growth among children with SM.

Protective Immunity against Canine Distemper Virus in Dogs Induced by Intranasal Immunization with a Recombinant Probiotic Expressing the Viral H Protein

Canine distemper virus (CDV) elicits a severe contagious disease in a broad range of hosts. CDV mortality rates are 50% in domestic dogs and 100% in ferrets. Its primary infection sites are respiratory and intestinal mucosa. This study aimed to develop an effective mucosal CDV vaccine using a non-antibiotic marked probiotic pPG^ΔCm-T7g10-EGFP-H/L. casei 393 strain expressing the CDV H protein. Its immunogenicity in BALB/c mice was evaluated using intranasal and oral vaccinations, whereas in dogs the intranasal route was used for vaccination. Our results indicate that this probiotic vaccine can stimulate a high level of secretory immunoglobulin A (sIgA)-based mucosal and IgG-based humoral immune responses in mice. SIgA levels in the nasal lavage and lungs were significantly higher in intranasally vaccinated mice than those in orally vaccinated mice. Both antigen-specific IgG and sIgA antibodies were effectively elicited in dogs through the intranasal route and demonstrated superior immunogenicity. The immune protection efficacy of the probiotic vaccine was evaluated by challenging the immunized dogs with virulent CDV 42 days after primary immunization. Dogs of the pPG^ΔCm-T7g10-EGFP-H/L. casei 393 group were completely protected against CDV. The proposed probiotic vaccine could be promising for protection against CDV infection in dogs.

Cytokine production and signalling in human THP-1 macrophages is dependent on Toxocara canis glycans

The effect of Toxocara canis antigens on cytokine production by human THP-1 macrophages was studied in vitro. Toxocara Excretory–Secretory products (TES) and recombinant mucins (Tc-MUC-2, Tc-MUC-3, Tc-MUC-4, and Tc-MUC-5) as well as deglycosylated forms of these antigens were used in the study. TES products stimulated macrophages to produce the innate proinflammatory IL-1β, IL-6, and TNF-α cytokines regardless of the presence of glycans. Recombinant mucins induced glycan-dependent cytokine production. Sugar moieties led to at least 3-fold higher production of regulatory IL-10 as well as proinflammatory cytokines. The presence of glycans on mucins also affected the downstream signalling pathways in stimulated cells. The most prominent difference was noted in AKT and AMPK kinase activation. AKT phosphorylation was observed in cells stimulated with glycosylated mucins, whereas treatment with deglycosylated antigens led to AMPK phosphorylation. MAP kinase family members such as JNK and p38 and c-Jun transcription factor were phosphorylated in both cases what suggests that toll-like receptor signalling may be involved in mucin-treated macrophages. This pathway is however modified by other signalling molecules as only mucins containing intact sugars significantly induced the production of cytokines.

Single-cell Analysis of Immunophenotype and Cytokine Production in Peripheral Whole Blood via Mass Cytometry

Cytokines play a pivotal role in the pathogenesis of autoimmune diseases. Hence, the measurement of cytokine levels has been the focus of multiple studies in an attempt to understand the precise mechanisms that lead to the breakdown of self-tolerance and subsequent autoimmunity. Approaches thus far have been based on the study of one specific aspect of the immune system (a single or few cell types or cytokines), and do not offer a global assessment of complex autoimmune disease. While patient sera-based studies have afforded important insights into autoimmunity, they do not provide the specific cellular source of the dysregulated cytokines detected. A comprehensive single-cell approach to evaluate cytokine production in multiple immune cell subsets, within the context of "intrinsic" patient-specific plasma circulating factors, is described here. This approach enables monitoring of the patient-specific immune phenotype (surface markers) and function (cytokines), either in its native "intrinsic pathogenic" disease state, or in the presence of therapeutic agents (in vivo or ex vivo).

A New Perspective: Mitochondrial Stat3 as a Regulator for Lymphocyte Function

Stat3 as a transcription factor regulating gene expression in lymphocytes during the immune response is well known. However, since the pioneering studies discovering the presence of Stat3 in mitochondria and its role in regulating mitochondrial metabolism, only a few studies have investigated this non-conventional function of Stat3 in lymphocytes. From this perspective, we review what is known about Stat3 as a transcription factor and what is known and unknown about mitochondrial Stat3 (mitoStat3) in lymphocytes. We also provide a framework to consider how some of the functions previously assigned to Stat3 as regulator of gene transcription could be mediated by mitoStat3 in lymphocytes. The goal of this review is to stimulate interest for future studies investigating mitoStat3 in the immune response that could lead to the generation of alternative pharmacological inhibitors of mitoStat3 for the treatment of chronic inflammatory diseases.

The Th17 Lineage: From Barrier Surfaces Homeostasis to Autoimmunity, Cancer, and HIV-1 Pathogenesis

The T helper 17 (Th17) cells represent a subset of CD4+ T-cells with unique effector functions, developmental plasticity, and stem-cell features. Th17 cells bridge innate and adaptive immunity against fungal and bacterial infections at skin and mucosal barrier surfaces. Although Th17 cells have been extensively studied in the context of autoimmunity, their role in various other pathologies is underexplored and remains an area of open investigation. This review summarizes the history of Th17 cell discovery and the current knowledge relative to the beneficial role of Th17 cells in maintaining mucosal immunity homeostasis. We further discuss the concept of Th17 pathogenicity in the context of autoimmunity, cancer, and HIV infection, and we review the most recent discoveries on molecular mechanisms regulating HIV replication/persistence in pathogenic Th17 cells. Finally, we stress the need for novel fundamental research discovery-based Th17-specific therapeutic interventions to treat pathogenic conditions associated with Th17 abnormalities, including HIV infection.

Melatonin suppresses eosinophils and Th17 cells in hamsters treated with a combination of human liver fluke infection and a chemical carcinogen

BACKGROUND

The combination of Opisthorchis viverrini (OV) infection and chemical carcinogen induces cholangiocarcinoma (CCA) in hamsters via inflammation-mediated mechanisms. Thus, suppression of inflammatory cells at the initial stages of CCA development would be of benefit. We aimed to investigate whether IL-17-producing CD4+ T cells (Th17) and CD4+ Foxp3+ T cells (Treg) are involved in the early stages of CCA genesis and can be targeted for suppression by melatonin.

METHODS

Inflammation, an initial stage of CCA development, was induced in hamsters by a combination of O. viverrini infection and N-nitrosodimethylamine (NDMA) administration. Melatonin (50mg/kg) was additionally administered to one group for the 30days of the experiment. Liver tissue-resident T cells were investigated using immunostaining, western blotting, and real-time PCR.

RESULTS

OV+NDMA-induced CCA tissues showed significantly higher numbers of inflammatory cells, especially eosinophils, bile duct proliferation and IL-17+ cell infiltration compared to normal livers. Expression of Foxp3 was localized in the bile duct epithelial cells, and especially in the bile duct hyperplasia. Accumulation of CD4+ and IL-17+ cells and intense staining of the Foxp3+ marker were consistent with their protein levels. Infiltration of IL-17+ inflammatory cells and Foxp3+ cells, as well as increases in their transcription expression levels, were significantly lower in the melatonin-treated group. In contrast, increased CD4+ cell infiltration and TNF-α expression were also observed through melatonin treatment.

CONCLUSION

Melatonin exerts an immunomodulatory effect, suppressing eosinophils and Th17 cells and expression of Foxp3, but enhancing CD4+ cells and TNF-α. This suggests that melatonin may be used for CCA chemoprevention.

Effects of 1,25-dihydroxyvitamin D3 on IL-17/IL-23 axis, IFN-γ and IL-4 expression in systemic lupus erythematosus induced mice model

OBJECTIVES

Systemic lupus erythematosus (SLE) is a multi-factorial autoimmune disease which may be characterized by T lymphocytes dysfunctions. Th17 cells have been identified as new effector cells, which play an important role in the pathogenesis. In recent years, immunomodulatory effect of vitamin D3 has been noticed. In the present experiment, the effect of vitamin D3 on the expression of IL-17, IL-23, IL-4 and IFN-γ were assessed in activated chromatin-induced mouse model for SLE.

MATERIALS AND METHODS

Five groups of mice were included in this study; Group one received active chromatin +CFA + PBS; Group 2 received vitamin D3 starting 2 weeks before disease induction; Group 3 received vitamin D3 (50 ng/day) starting with the disease establishment; Group 4 received non active chromatin +CFA + PBS; Group 5 received CFA + PBS. On day 56 splenocytes were isolated and gene expression of interleukin IL-17, IL-23, IL-4 and IFN-γ were analyzed by Real-Time PCR method. Proteinuria and serum anti-dsDNA and Th17 levels were measured using commercial kits.

RESULTS

The results showed that IL-17, IL-23, and IFN-γ mRNA expression, and IL-17 titers were decreased remarkably and that of IL-4 increased in mice which received vitamin D3 before SLE induction. Administration of vitamin D3 after the establishment of SLE failed to affect the IL-17 or IL-23 mRNA levels. Lastly, pre-treatment of mice with vitamin D3 decreased the anti-ds DNA antibody titer.

CONCLUSION

Our findings showed that vitamin D3 supplementation in lupus induced mice through modulating the expression rate of some inflammatory cytokines diminished the inflammatory conditions in SLE.

What role does tobacco smoking play in multiple sclerosis disability and mortality? A review of the evidence

There is increasing evidence of tobacco smoking as an associative factor in multiple sclerosis (MS). Numerous studies have been conducted investigating the effects of smoking before the onset of MS as well as its impact on disease course. This special report reviews the available evidence and summarizes the contribution of smoking to increased mortality in patients with MS. It also explores some putative mechanisms for the involvement of tobacco constituents in the pathology of MS and the effects of smoking on disease-modifying treatments.

The IL17F and IL17RA Genetic Variants Increase Risk of Cerebral Malaria in Two African Populations

Cerebral malaria (CM) is a neurological complication of infection with Plasmodium falciparum that is partly caused by cytokine-mediated inflammation. It is not known whether interleukin-17 (IL-17) cytokines, which regulate inflammation, control the development of CM. To evaluate the involvement of IL-17 cytokines in CM, we analyzed 46 common polymorphisms in IL17A, IL17F, and IL17RA (which encodes the common receptor chain of the members of the IL-17 family) in two independent African populations. A case-control study involving 115 Nigerian children with CM and 160 controls from the community (CC) showed that IL17F reference single nucleotide polymorphism (SNP) 6913472 (rs6913472) (P = 0.004; odds ratio [OR] = 3.12), IL17F rs4715291 (P = 0.004; OR = 2.82), IL17RA rs12159217 (P = 0.01; OR = 2.27), and IL17RA rs41396547 (P = 0.026; OR = 3.15) were independently associated with CM. A replication study was performed in 240 nuclear Malian family trios (two parents with one CM child). We replicated the association for 3 SNPs, IL17F rs6913472 (P = 0.03; OR = 1.39), IL17RA rs12159217 (P = 0.01; OR = 1.52), and IL17RA rs41396547 (P = 0.04; OR = 3.50). We also found that one additional SNP, IL17RA rs41433045, in linkage disequilibrium (LD) with rs41396547, was associated with CM in both Nigeria and Mali (P = 0.002; OR = 4.12 in the combined sample). We excluded the possibility that SNPs outside IL17F and IL17RA, in strong LD with the associated SNPs, could account for the observed associations. Furthermore, the results of a functional study indicated that the aggravating GA genotype of IL17F rs6913472 was associated with lower IL-17F concentrations. Our findings show for the first time that IL17F and IL17RA polymorphisms modulate susceptibility to CM and provide evidence that IL-17F protects against CM.

American tegumentary leishmaniasis: mRNA expression for Th1 and Treg mediators are predominant in patients with recent active disease

Besides the Th1×Th2 paradigm, Treg and Th17 cytokines may play a role in the response to American tegumentary leishmaniasis. Considering the sensitivity and accuracy of qPCR and the lack of studies using this approach, we evaluated mRNA expression for IFN-γ, TNF-α, IL-4, IL-10, IL-6, IL-17A, IL-22, TGF-β, Foxp3 and RORC in peripheral blood mononuclear cells (PBMC) from patients with active disease, after stimulation with L. (V.) braziliensis soluble or insoluble fractions. Our results show that the antigens promoted specific mRNA expression related to the immune response in patients with ATL, and the insoluble fraction seems to stimulate the immune response in a higher intensity. The pro-inflammatory response was also fueled by IFN-γ and TNF-α, probably due to the active disease. IL-4, in certain way, seems to regulate this response along with IL-10 that may be produced by Treg cells, which are supposedly present in the patients' samples due the evidenced expression of Foxp3, in the presence of AgIns. In contrast, down-regulated RORC suggests that the significant levels of IL-6 expressed in response to AgSol were not able to induce an expressive Th17 profile along with TGF-β, which might have predominantly contributed to the development of a regulatory profile in the active disease.

Toxocara canis mucins among other excretory-secretory antigens induce in vitro secretion of cytokines by mouse splenocytes

The effect of Toxocara larval antigens on cytokine secretion by mouse splenocytes was studied in vitro. Recombinant mucins were produced in Pichia pastoris yeast, and Toxocara excretory-secretory (TES) antigens were collected from in vitro culture of L2 larvae. Tc-MUC-2, Tc-MUC-3, Tc-MUC-4, and Tc-MUC-5 were expressed as glycoproteins and were specifically recognized by Toxocara canis-infected dog serum antibodies. Mouse splenocytes stimulated with recombinant mucins produced IL-5, IL-6, and TGF-β. Cell stimulation with whole TES products was more effective and resulted in secretion of IL-4, IL-5, IL-6, IL-10, and TGF-β and downregulation of TNF-α production. IFN-γ and IL-17 secretion was noted only after ConA treatment. Cells originating from infected animals produced significantly smaller amounts of these two cytokines compared to control cells, which suggests that Th1 and Th17 response in infected mice is strongly inhibited. However, splenocyte stimulation with both TES and ConA upregulated the production of IFN-γ and IL-17. This shows that TES antigens have strong immunomodulatory properties and are able to induce a broad range of effects on murine immune cells.

Construction of the recombinant vaccine based on T-cell epitope encoding Der p1 and evaluation on its specific immunotherapy efficacy

Specific immunotherapy (SIT) is currently recognized as the only etiological therapy to ameliorate asthmatic symptom. The current study was aimed at evaluating the immune effect of vaccine MAT3T designed on MHCII pathway, which includes T cell fusion peptide encoding Dermatophagoides pteronyssinus class 1 allergen (Der p1). We initially cloned the nucleotide sequences of TAT, IhC and 3 segments of T cell epitope coding for Der p1, and reassembled these sequences in linear manner to form fusion gene named MAT3T, which was applied to immunize the asthmatic models of mice induced by Der p1 allergen for tentative SIT. ELISA results showed that MAT3T was able to increase the level of IFN-γ in BALF and allergen specific antibody IgG2a in serum, while decrease the level of IL-13 in BALF and allergen specific antibody IgE and IgG1. Pathological confirmation further revealed that the inflammatory reactions and inflammatory cell infiltration were totally reduced in lung tissue of mice after MAT3T treatment. Our results show that the recombinant allergen MAT3T can effectively correct the imbalance of Th1/Th2, and MAT3T may be used as candidate vaccine against asthma on SIT basis.

TNFα promotes Th17 cell differentiation through IL-6 and IL-1β produced by monocytes in rheumatoid arthritis

TNFα plays an important role in autoimmune pathogenesis and is the main therapeutic target of rheumatoid arthritis. However, its underlying mechanism is not completely understood. In this study, we described that Th17 cells were accumulated in synovial fluid, which was attributable to TNFα aberrantly produced in rheumatoid synovium. Interestingly, TNFα cannot induce IL-17 production of CD4⁺ T cells directly, but through the monocytes high levels of IL-1β and IL-6 in a TNFRI and TNFRII dependent manner from the active RA patients are produced. TNFα was shown to enhance the phosphorylation level of STAT3 and the expression level of transcription factor RORC of CD4⁺ T cells when cultured with CD14⁺ monocytes. Treatment with an approved TNFα blocking antibody showed marked reduction in the levels of IL-6, IL-1β, and IL-17 and the expression level of STAT3 phosphorylation in relation to Th17 cell differentiation in patients with rheumatoid arthritis. The study provides new evidence supporting the critical role of TNFα in the pathogenic Th17 cell differentiation in rheumatoid arthritis.

Effect of the blockade of the IL-23-Th17-IL-17A pathway on streptozotocin-induced diabetic retinopathy in rats

PURPOSE

T helper 17 (Th17) cells are believed to play a critical role in the chronic inflammatory and immune response in streptozotocin (STZ)-induced retinopathy. The purpose of our study was to investigate the effect of the IL-23-Th17-IL-17A pathway via the blood-retinal barrier on STZ-induced diabetic retinopathy in rats.

METHODS

The ratio of IL-17A(+)CD4(+) T cells in peripheral blood mononuclear cells of STZ-treated and wild-type rats was determined using flow cytometry. The IL-17A mRNA levels in the retinas were measured using real-time PCR. The protein expression of IL-17A in the peripheral blood and retinas was measured using an ELISA kit. The retinal structure in the wild-type and STZ-treated rats was examined using hematoxylin and eosin (H&E) staining. Additionally, the permeability of the blood-retinal barrier was quantified using the Evans blue technique.

RESULTS

The ratio of IL-17A(+)CD4(+) T cells in peripheral blood mononuclear cells was markedly increased in rats treated with STZ compared to the wild-type group. IL-17A protein levels in the peripheral blood and retinas were also significantly elevated in STZ-treated rats. However, when the anti-IL 23Rp19 antibody was injected into the vitreous cavity in the eyes of STZ-treated rats for a period of one week, retinal pigment epithelium cells became markedly tighter, and micrangium and endothelial cells were significantly reduced. The expression of IL-17A mRNA and protein in the retina also decreased significantly compared with the placebo-treated group.

CONCLUSIONS

This study provided further insight into the function of the IL-23-Th17-IL-17A pathway in STZ-induced diabetic retinopathy in rats. Local injection of the anti-IL-23Rp19 antibody may improve the structure of the blood-retinal barrier, thus offering the potential for treatment using intravitreal anti-IL-23Rp19 antibodies.

The Differentiation of CD4(+) T-Helper Cell Subsets in the Context of Helminth Parasite Infection

Helminths are credited with being the major selective force driving the evolution of the so-called “type 2” immune responses in vertebrate animals, with their size and infection strategies presenting unique challenges to the immune system. Originally, type 2 immune responses were defined by the presence and activities of the CD4⁺ T-helper 2 subset producing the canonical cytokines IL-4, IL-5, and IL-13. This picture is now being challenged by the discovery of a more complex pattern of CD4⁺ T-helper cell subsets that appear during infection, including Tregs, Th17, Tfh, and more recently, Th22, Th9, and ThGM. In addition, a clearer view of the mechanisms by which helminths and their products selectively prime the CD4⁺ T-cell subsets is emerging. In this review, we have focused on recent data concerning the selective priming, differentiation, and functional role of CD4⁺ T-helper cell subsets in the context of helminth infection. We argue for a re-evaluation of the original Th2 paradigm and discuss how the observed plasticity of the T-helper subsets may enable the parasitized host to achieve an appropriate compromise between elimination, tissue repair, containment, and pathology.

Imbalances of CD4(+) T-cell subgroups in Crohn's disease and their relationship with disease activity and prognosis

BACKGROUND AND AIM

The CD4(+) T-cell subgroups play central pathophysiological roles in Crohn's disease (CD); however, their clinical relevance requires additional clarification and remains controversial. We investigated their balance in Chinese CD patients and explored their clinical significance.

METHODS

Peripheral blood mononuclear cells and serum were collected from 46 Chinese CD patients and 23 healthy donors. Circulating Treg, Th1, Th2, and Th17 cells were flow cytometrically analyzed. Subgroup-restricted transcription factor expression was determined by real-time polymerase chain reaction. Serum concentrations of the main cytokines produced by each subgroup were measured by cytometric bead arrays or enzyme-linked immunosorbent assay.

RESULTS

Lower Treg proportion (6.0 ± 1.2% vs 7.8 ± 1.5%, P = 0.030), FOXP3 mRNA expression (0.58-fold, P = 0.030), and circulating soluble TGFβ-1 (19.1 ± 9.9 vs 32.7 ± 16.8 ng/mL, P = 0.038) were observed in CD patients versus controls. The Th1 and Th17 proportions were higher in CD patients (17.8 ± 6.6% vs 7.8 ± 1.5%, P < 0.001; and 3.7 ± 1.8% vs 1.8 ± 0.7%, P = 0.022, respectively), as were transcription factors T-bet (4.6-fold, P = 0.043) and RORγt (14-fold, P < 0.001) and related cytokines (P < 0.05). Th2 proportion, GATA3 mRNA expression, and serum interleukin-4 concentration in CD patients were similar to controls (P > 0.05). Treg/Th1 and Treg/Th17 ratios were higher in inactive versus active CD patients (0.6 ± 0.4 vs 0.3 ± 0.1, P = 0.022; and 3.7 ± 2.0 vs 1.7 ± 1.4, P = 0.013, respectively). During follow-up, patients with lower Treg/Th1 and Treg/Th17 ratios were at higher recurrence risk.

CONCLUSIONS

Imbalances among Treg, Th1, and Th17 subgroups were found in Chinese CD patients. Treg/Th1 and Treg/Th17 ratios are associated with disease activity and are potential prognostic indicators for predicting CD recurrence.

In situ immune response in human chromoblastomycosis--a possible role for regulatory and Th17 T cells

BACKGROUND

Chromoblastomycosis is a chronic fungal infection that affects skin and subcutaneous tissue. Lesions can be classified in tumorous, verrucous, cicatricial and plaque type. The cellular immune response in the severe form of the disease seems to correlate with a Th2 pattern of cytokines. The humoral immune response also seems to play a role. We intended to explore the populations of regulatory T cells and the Th17 pattern.

METHODOLOGY

Twenty-three biopsies of verrucous form were obtained from patients with clinical, culture and histopathological diagnostic of chromoblastomycosis, without treatment. It was performed an immunohistochemistry method to detect Foxp3, CD25, TGF-β, IL-6, IL-17 and IL-23.

PRINCIPAL FINDINGS

IL-17 was the only cytokine with high expression in CBM when compared to normal skin. The expression of Treg cells, TGF- β, IL-6 and IL-23 were similar to normal skin.

CONCLUSIONS/SIGNIFICANCE

The constitution of a local immune response with high expression of IL-17 and low expression of other cytokines could be at least in part, an attempt to help the immune system against fungal infection. On the other hand, high levels of local immune response mediated by Th17 profile could overcome the role of Treg cells. The inefficient immunomodulation as a consequence of the unbalance by Treg/Th17 cells seems to corroborate with the less effective immune response against fungi.

The immune system in children with malnutrition--a systematic review

BACKGROUND

Malnourished children have increased risk of dying, with most deaths caused by infectious diseases. One mechanism behind this may be impaired immune function. However, this immune deficiency of malnutrition has not previously been systematically reviewed.

OBJECTIVES

To review the scientific literature about immune function in children with malnutrition.

METHODS

A systematic literature search was done in PubMed, and additional articles identified in reference lists and by correspondence with experts in the field. The inclusion criteria were studies investigating immune parameters in children aged 1-60 months, in relation to malnutrition, defined as wasting, underweight, stunting, or oedematous malnutrition.

RESULTS

The literature search yielded 3402 articles, of which 245 met the inclusion criteria. Most were published between 1970 and 1990, and only 33 after 2003. Malnutrition is associated with impaired gut-barrier function, reduced exocrine secretion of protective substances, and low levels of plasma complement. Lymphatic tissue, particularly the thymus, undergoes atrophy, and delayed-type hypersensitivity responses are reduced. Levels of antibodies produced after vaccination are reduced in severely malnourished children, but intact in moderate malnutrition. Cytokine patterns are skewed towards a Th2-response. Other immune parameters seem intact or elevated: leukocyte and lymphocyte counts are unaffected, and levels of immunoglobulins, particularly immunoglobulin A, are high. The acute phase response appears intact, and sometimes present in the absence of clinical infection. Limitations to the studies include their observational and often cross-sectional design and frequent confounding by infections in the children studied.

CONCLUSION

The immunological alterations associated with malnutrition in children may contribute to increased mortality. However, the underlying mechanisms are still inadequately understood, as well as why different types of malnutrition are associated with different immunological alterations. Better designed prospective studies are needed, based on current understanding of immunology and with state-of-the-art methods.

Isthmin 1 is a secreted protein expressed in skin, mucosal tissues, and NK, NKT, and th17 cells

Using a comprehensive microarray database of human gene expression, we identified that in mammals, a secreted protein known as isthmin 1 (ISM1) is expressed in skin, mucosal tissues, and selected lymphocyte populations. ISM1 was originally identified in Xenopus brain during development, and it encodes a predicted ∼50-kDa protein containing a signal peptide, a thrombospondin domain, and an adhesion-associated domain. We confirmed the pattern of expression of ISM1 in both human and mouse tissues. ISM1 is expressed by DX5(+) lung lymphocytes that include NK and NKT-like cells, and is also expressed by some CD4(+) T cells upon activation but its expression increases significantly when CD4(+) T cells were polarized to the Th17 lineage in vitro. The presence of IFN-γ during CD4(+) T cell polarization inhibits ISM1 expression. Given that ISM1 has been reported to have anti-angiogenic properties, these observations suggest that ISM1 is a mediator of lymphocyte effector functions and may participate in both innate and acquired immune responses.

A mouse air pouch model for evaluating the immune response to Taenia crassiceps infection

The experimental system of Taenia crassiceps cysticerci infection in BALB/c mice is considered to be the most representative model of cysticercosis. In our work, mice were sacrificed 7 and 30days after infection, and pouch fluid was collected to determine the number of accumulated cells and the concentrations of IFNγ, IL-2, IL-4, IL-6, IL-10 and nitric oxide. The injection of 50 nonbudding cysticerci into normal mouse dorsal air pouches induced a high level of IFNγ and nitric oxide production relative to the parasite load. The air pouch provides a convenient cavity that allows studying the cellular immunological aspects of the T. crassiceps parasite. The nonbudding cysticerci recovered from the air pouches contained cells that can reconstitute complete cysts in the peritoneal cavity of mice. In conclusion, these results demonstrate that the air pouch model is an alternative tool for the evaluation of the immune characteristics of T. crassiceps infection.

Expression of T-helper-associated cytokines in the serum of pituitary adenoma patients preoperatively and postperatively

Pituitary adenomas are benign tumors, However, 30% of them may develop into invasive tumors by invading the surrounding tissues. The studies have shown that several cytokines were expressed in human anterior pituitary adenomas, therefore, we speculate that the cytokines are important in human anterior pituitary tumorigenesis. The current study is designed to investigate expression profiles of cytokines in the serum of patients with pituitary adenomas. This was done by selecting 75 cases with pituitary adenoma, including invasive and non-invasive pituitary adenomas and collected blood samples of preoperative, 1 month, 3 months, and 6 months after surgery, respectively. We used the cell flow instrument to detect the level of Lymphocytes and subsets and immunoglobulin and complement in the peripheral blood, and by ELISA detecting the content of cytokines (IL-17, IL-4, IL-5, TNF-α, INF-γ) in the serum of pituitary adenoma patients. The results show that the level of IL-4, IL-5 and IL-17 was increased substantially before surgery but they decreased substantially after surgery, IFN-γ, TNF-a was increased after surgery, the ratio of Th1/Th2 (IFN-γ/IL-4) was significantly lower before surgery and increased distinctly post-operation. These data indicated that there is some cross-regulation among Th1, Th2 and Th17 subsets and that cytokines are important in tissue inflammatory lesions of pituitary adenomas and promoting invasive development.

Emerging targets in lipid-based therapy

The use of prostaglandins and NSAIDS in the clinic has proven that lipid mediators and their associated pathways make attractive therapeutic targets. When contemplating therapies involving lipid pathways, several basic agents come to mind. There are the enzymes and accessory proteins that lead to the metabolism of lipid substrates, provided through diet or through actions of lipases, the subsequent lipid products, and finally the lipid sensors or receptors. There is abundant evidence that molecules along this lipid continuum can serve as prognostic and diagnostic indicators and are in fact viable therapeutic targets. Furthermore, lipids themselves can be used as therapeutics. Despite this, the vernacular dialog pertaining to "biomarkers" does not routinely include mention of lipids, though this is rapidly changing. Collectively these agents are becoming more appreciated for their respective roles in diverse disease processes from cancer to preterm labor and are receiving their due appreciation after decades of ground work in the lipid field. By relating examples of disease processes that result from dysfunction along the lipid continuum, as well as examples of lipid therapies and emerging technologies, this review is meant to inspire further reading and discovery.

Hsp65-producing Lactococcus lactis prevents experimental autoimmune encephalomyelitis in mice by inducing CD4+LAP+ regulatory T cells

Heat shock proteins (Hsps) participate in the cellular response to stress and they are hiperexpressed in inflammatory conditions. They are also known to play a major role in immune modulation, controlling, for instance, autoimmune responses. In this study, we showed that oral administration of a recombinant Lactococcus lactis strain that produces and releases LPS-free Hsp65 prevented the development of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. This was confirmed by the reduced inflammatory cell infiltrate and absence of injury signs in the spinal cord. The effect was associated with reduced IL-17 and increased IL-10 production in mesenteric lymph node and spleen cell cultures. Hsp65-producing-L. lactis-fed mice had a remarkable increase in the number of natural and inducible CD4+Foxp3+ regulatory T (Treg) cells and CD4+LAP+ (Latency-associated peptide) Tregs - which express the membrane-bound TGF-β - in spleen, inguinal and mesenteric lymph nodes as well as in spinal cord. Moreover, many Tregs co-expressed Foxp3 and LAP. In vivo depletion of LAP+ cells abrogated the effect of Hsp65-producing L. lactis in EAE prevention and worsened disease in medium-fed mice. Thus, Hsp65-L.lactis seems to boost this critical regulatory circuit involved in controlling EAE development in mice.

Expression of IL-17, IL-23 and their receptors in minor salivary glands of patients with primary Sjögren's syndrome

The main purpose of this study was to determine the expression of interleukins-17/-23 (ILs-17/-23) and receptors of interleukins-17/-23 (IL-17R, IL-23R) in minor salivary glands (MSGs) of patients with primary Sjögren's syndrome (pSS). Expression of IL-17, IL-23 and receptors of IL-17/-23 was analyzed in MSGs from 25 patients with pSS, 25 patients with probable preclinical pSS, and 25 patients with nonautoimmune sicca syndrome by immunohistochemistry. Comparison of the expression of IL-17, IL-23 and receptors of IL-17, IL-23 in MSG of patients with pSS with probable preclinical pSS, and with nonautoimmune sicca syndrome showed significant differences between three groups. However, the expression of IL-17, IL-23 and receptors of IL-17/-23 in MSG was comparable in pSS and probable preclinical pSS patients. We did not find correlation between the expression of IL-17 and IL-23 and of IL-17R and IL-23R in patients with pSS. These results demonstrate an involvement of IL-17/-23 system in the early pSS pathogenesis.

WITHDRAWN: MyD88 is required for the recruitment of eosinophils and neutrophils but dispensable for host protective immune responses during Fasciola hepatica infection

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Cytokines in autoimmunity: role in induction, regulation, and treatment

Cytokines play a pivotal role in the pathogenesis of autoimmune diseases. The precise triggers for the breakdown of self-tolerance and the subsequent events leading to the induction of pathogenic autoimmune responses remain to be defined for most of the naturally occurring autoimmune diseases. Studies conducted in experimental models of human autoimmune diseases and observations in patients have revealed a general scheme in which proinflammatory cytokines contribute to the initiation and propagation of autoimmune inflammation, whereas anti-inflammatory cytokines facilitate the regression of inflammation and recovery from acute phase of the disease. This idea is embodied in the T helper (Th) 1/Th2 paradigm, which over the past two decades has had a major influence on our thinking about the role of cytokines in autoimmunity. Interestingly, over the past decade, the interleukin (IL)-17/IL-23 axis has rapidly emerged as the new paradigm that has compelled us to critically re-examine the cytokine-driven immune events in the pathogenesis and treatment of autoimmunity. In this 2-volume special issue of the journal, leading experts have presented their research findings and viewpoints on the role of cytokines in the context of specific autoimmune diseases.

Lymphocyte calcium influx kinetics in multiple sclerosis treated without or with interferon β

Kv1.3 and IKCa1 potassium channels play an important role in the maintenance of calcium-influx during lymphocyte activation and present a possible target for selective immunomodulation. We investigated the calcium-influx characteristics of Th1, Th2, CD4, CD8 T-lymphocytes isolated from multiple sclerosis patients without or with interferon-beta therapy, and its modulation by Kv1.3 and IKCa1 channel inhibitors using flow cytometry. Specific immunomodulation of the CD8 subset can be reached through inhibition of Kv1.3 channels in multiple sclerosis patients without interferon-beta. However, this effect is not specific enough concerning all lymphocyte subsets influencing the autoimmune response, since it also affects anti-inflammatory Th2 cells.

Regulatory T-Cell (Treg) hybridoma as a novel tool to study Foxp3 regulation and Treg fate

The CD25(+)Foxp3(+) regulatory T-cells (Treg) that had lost CD25 and Foxp3 in vivo (ex-Treg) exist but are difficult to study. We generated antigen (Ag)-specific Treg hybridomas from iTreg clones (iTreg-hyb) using iTreg of DO11.10.Foxp3-GFP mice and presented evidence that they behave like ex-Treg. The iTreg-hyb displayed little CD25 and Foxp3-GFP but strong expression could be induced with OVA(323-339) in the presence of Ag-presenting cells, rIL-2 and rTGF-β1. They displayed all of the iTreg-associated markers examined except CTLA-4, the latter was also absent in the ex-Treg. They lacked the Helios transcription factor, suggesting they were derived from iTreg. Similar to ex-Treg, the iTreg-hyb produced high level of IL-2 and Foxp3 under specific activation conditions. Two unusual properties were observed. First, the ability to induce Foxp3-GFP upon activation is progressively lost in culture over a period of 2-4 weeks. Second, Rag2(-/-) spleen cells alone selectively induced Foxp3-GFP expression albeit 30 times less efficient than Ag-specific activation. We identified cell-free supernatant, IL-6, IL-9, and IL-27 as Foxp3-inducing factors. Our study has significant implications to the stability, plasticity and fate of Treg. The usefulness and limitation of iTreg-hyb as a novel tool to study Foxp3 regulation and the fate of specific Treg subsets are discussed.

Gut, bugs, and brain: role of commensal bacteria in the control of central nervous system disease

The mammalian gastrointestinal track harbors a highly heterogeneous population of microbial organisms that are essential for the complete development of the immune system. The gut microbes or "microbiota," coupled with host genetics, determine the development of both local microbial populations and the immune system to create a complex balance recently termed the "microbiome." Alterations of the gut microbiome may lead to dysregulation of immune responses both in the gut and in distal effector immune sites such as the central nervous system (CNS). Recent findings in experimental autoimmune encephalomyelitis, an animal model of human multiple sclerosis, suggest that altering certain bacterial populations present in the gut can lead to a proinflammatory condition that may result in the development of autoimmune diseases, in particular human multiple sclerosis. In contrast, other commensal bacteria and their antigenic products, when presented in the correct context, can protect against inflammation within the CNS.

Burn induces a Th-17 inflammatory response at the injury site

INTRODUCTION

The high incidence of morbidity and mortality following major burn can be in part attributed to immune dysfunction and wound healing complications. Inflammation plays a major role in the complex process of wound repair. Recently, a novel class of T-helper cells, termed Th-17 cells, has been found to secrete the pro-inflammatory cytokines IL-17 and IL-22. The Th-17 response also involves other cytokines, such as IL-6 and TGF-β, which have been shown to be associated with burn-induced inflammation. Nonetheless, the relationships between the Th-17 response and post-burn inflammation are unknown.

METHODS

C57BL/6 male mice (n = 5-6/group) were subjected to a major burn (25% TBSA) or sham procedure. Three hours thereafter, skin samples were collected (uninjured skin and burn skin) and processed for the determination of Th-17 cytokine (IL-6, IL-17, IL-22, IL-23, IL-27, and TGF-β) levels by ELISA.

RESULTS

At 3h after burn a significant (~3-fold) increase in tissue levels of IL-17 and IL-22 was observed at the burn site as compared to sham skin. The burn-induced Th-17 response was independent of statistically significant changes in other Th-17 cytokines (i.e., IL-6, IL-23, IL-27 and TGF-β).

CONCLUSIONS

These findings indicate the development of a robust Th-17 response at the burn site that may play an important role in subsequent immune and wound healing derangements.

Increased prevalence of IL-17-producing peripheral blood lymphocytes in pre-eclampsia

PROBLEM

Systemic inflammation is a dominant component in the pathogenesis of pre-eclampsia. Besides the imbalance of Th1 and Th2 cells, alterations of the prevalence of Th17 and regulatory T cells have also been suggested to contribute to inflammation. We aimed to describe the prevalence of these four CD4 lymphocyte subtypes in pre-eclampsia and normal pregnancy, along with that of IL-17-producing CD8 and NK cells.

METHOD OF STUDY

Twenty pre-eclamptic and 22 normal pregnant women were enrolled in this study. Using flow cytometry, we determined the prevalence of IL-17-producing cells among the CD4, CD8 and NK cell subsets. Furthermore, we measured the prevalence of CD4+ Tregs, and Th1/Th2 cells were characterized using cell surface chemokine receptor markers.

RESULTS

We demonstrated that there is a shift not only in the Th1/Th2 but also in the Th17/Treg balance favouring skewness towards a pro-inflammatory status in pre-eclampsia. The proportion of CD8 and NK cells that express IL-17 was also higher in pre-eclampsia.

CONCLUSION

The prevalence of IL-17-producing CD4, CD8 and NK cells is elevated in pre-eclampsia, indicating that both the innate and adaptive arms of the immune system are involved in the development of the exaggerated maternal systemic inflammation observed in this pregnancy-specific disorder.