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Background: Interleukin17 (IL17) is an important cytokine in host defense at mucosal surfaces and also mediates many autoimmune diseases, including rheumatoid arthritis (RA). In recent years, many types of research relevant to the structure and function of IL17 have been identified. However, there is no bibliometric analysis in this research field. This study aims to explore the history, research hotspots, and emerging trends of IL17 from the perspective of the structure and function dynamics. Methods: Articles relevant to IL17 in the last two decades were retrieved through the Web of Science Core Collection (WoSCC) database. The bibliometric analysis was performed by VOSview. Results: A total of 882 papers in this research were analyzed from 65 countries, and the rate of published articles has increased from 2008 annually, with the USA, China, and Germany leading the research effort. Frontiers in Immunology has significantly impacted research in this field and the University of Pittsburgh was the leading institution. Gaffen, Sarah L. from the University of Pittsburgh was the most productive researcher in this field and Papp Ka from the Probity Medical Research Incorporate of Canada is the most co-cited author. The analysis of keywords showed that inflammation, expression, Th17 cells, and cytokines were the main hotspots and frontier directions of IL17. The trend of clinical application in the future is the development of new therapy drugs based on the structure of IL17 or IL17 signaling pathway molecular. Conclusions: Our research summarized the developments and research trends of IL17 and would help researchers understand the research status of IL17 and provide a reference for future researchers as soon as possible. [ABSTRACT FROM AUTHOR]

Lipoarabinomannans (LAMs) are major lipoglycans of the mycobacterial envelope and constitute immunodominant epitopes of mycobacteria. In this paper, we show that mannose-capped (ManLAM) and non-mannose- capped (PILAM) mycobacterial lipoglycans insert into T helper cell rafts without apparent binding to known receptors. T helper cells modified by the insertion of PILAM responded to CD3 cross-linking by decreasing type 1 (IL-2 and IFN-?) and increasing type 2 (IL-4 and IL-5) cytokine production. Modification by the mannose-capped ManLAMs had similar, but more limited effects on T helper cell cytokine production. When incorporated into isolated rafts, PILAMs modulated membrane-associated kinases in a dose-dependent manner, inducing increased phosphorylation of Src kinases and Cbp/PAG in Th1 rafts, while decreasing phosphorylation of the same proteins in Th2 rafts. Mycobacterial lipoglycans thus modify the signalling machineries of rafts/microdomains in T helper cells, a modification of the membrane organization that eventually leads to an overall enhancement of type 2 and inhibition of type 1 cytokine production. [ABSTRACT FROM AUTHOR]

Background: Chronic migraine places a disabling burden on patients, which is extensively modeled by the nitroglycerin (NTG)-treated animal model. Although the NF-κB pathway is involved in an increase in CGRP levels and activation of the trigeminal system in the NTG model, the relationship between NTG and neuroinflammation remains unclear. This study aimed to optimize a chronic NTG rat model with hyperalgesia and the ethological capacity for estimating migraine therapies and to further explore the underlying mechanism of NTG-induced migraine. Methods: Rats were administered different doses of NTG s.c. daily or every 2 d; 30 min and 2 h later, the mechanical threshold was tested. After 9 d, the rats were injected with EB or Cy5.5 for the permeability assay. The other animals were sacrificed, and then, brainstem and caudal trigeminal ganglion were removed to test CGRP, c-Fos and NOS activity; Cytokines levels in the tissue and serum were measured by ELISA; and NF-κB pathway and blood–brain barrier (BBB)-related indicators were analyzed using western blotting. Immunohistochemistry was performed to observe microglial polarization and IL-17A+ T cell migration in the medulla oblongata. Results: NTG (10 mg/kg, s.c., every 2 d for a total of 5 injections) was the optimal condition, resulting in progressive hyperalgesia and migraine behavior. TNC neuroinflammation with increases in cytokines, CGRP and c-Fos and activation of the NF-κB pathway was observed, and these changes were alleviated by ibuprofen. Furthermore, NTG administration increased BBB permeability by altering the levels functional proteins (RAGE, LRP1, AQP4 and MFSD2A) and structural proteins (ZO-1, Occludin and VE-cadherin-2) to increase peripheral IL-17A permeation into the medulla oblongata, activating microglia and neuroinflammation, and eventually causing hyperalgesia and migraine attack. Conclusions: This study confirmed that NTG (10 mg/kg, s.c., every 2 d for a total of 5 injections) was the optimal condition to provoke migraine, resulting in mechanical hyperalgesia and observable migraine-like behavior. Furthermore, IL-17A crossed the blood–brain barrier into the medulla oblongata, triggering TNC activation through microglia-mediated neuroinflammation. This process was a novel mechanism in NTG-induced chronic migraine, suggesting that IL-17A might be a novel target in the treatment of migraine. [ABSTRACT FROM AUTHOR]

The article reports on the new pathway that assists the immune system in regulating inflammatory response. Various studies have noted the efficacy of generating cytokine interleukin-27 (IL-27) and the promotion of IL-10- producing T cells in controlling inflammation. The authors highlight that studies also highlighted the capability of transforming growth factor-β (TGFβ) in increasing this response and in promoting the differentiation of non-pathogenic TH17 cells.

This review focuses on the structure and molecular action mechanisms of chimeric antigen receptors (CARs) and major aspects of the manufacturing and clinical application of products for the CAR-T (CAR-modified T lymphocyte) therapy of hematological and solid tumors with special emphasis on the strategies for combined use of CAR-T therapy with immuno-oncological monoclonal antibodies (checkpoint inhibitors) and cytokines to boost survival, persistence, and anti-tumor efficacy of CAR-T therapy. The review also summarizes preclinical and clinical data on the additive effects of the combined use of CAR-T therapy with interleukins and monoclonal antibodies targeting immune checkpoints. [ABSTRACT FROM AUTHOR]

Presents the findings of studies on the role of the cytokine interleukin-25 in regulating protective T helper 2-cell response. Therapeutic effect of interleukin-25 on mice with Trichuris muris infection; Correlation between delayed clearance of parasitic helminth Nippostrongylus brasiliensis and delayed induction of T helper 2-cell response; Cause of the increased number of non-B cells in the mesenteric lymph nodes.

Objective: To investigate whether Shen-Fu Injection (参附注射液, SFI) reduces post-resuscitation immune dysfunction in a porcine model of cardiac arrest by modulating apoptosis of regulatory T lymphocytes (Treg) in the spleen. Methods: After 8-min untreated ventricular fibrillation and 2-min basic life support, 24 pigs were divided into 3 groups with a random number table, i.e. SFI group, epinephrine (EP) group, and saline (SA) group (8 in each group), which received central venous injection of SFI (1.0 mL/kg), EP (0.02 mg/kg) and SA, respectively. The same procedure without CA initiation was achieved in the sham-operated (sham) group ( n=6). After successful return of spontaneous circulation (ROSC), apoptosis rate of splenic Treg was detected by flow cytometry; and the mRNA expression of forkhead/winged helix transcription factor (Foxp3) of splenic Treg was detected by real time-polymerase chain reaction; and the levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in porcine splenic Treg were detected by using enzyme-linked immunosorbent assay (ELISA). Results: Compared with the sham group, the apoptosis rate of Treg was significantly decreased, and the levels of Foxp3 mRNA expression, IFN-γ, IL-4 and IFN-γ/IL-4 were increased in the SA group ( P<0.05 or P<0.01). Compared with the EP and SA groups, SFI treatment increased the apoptosis rate of Treg and reduced the levels of Foxp3 mRNA expression, IFN-γ and IFN-γ/IL-4 ( P<0.05). Conclusions: SFI has signifificant effects in attenuating post-resuscitation immune dysfunction by modulating apoptosis of Treg in the spleen. [ABSTRACT FROM AUTHOR]

Interleukin 35 (IL-35) belongs to the IL-12 family of heterodimeric cytokines but has a distinct functional profile. IL-35 suppresses T cell proliferation and converts naive T cells into IL-35-producing induced regulatory T cells (iTr35 cells). Here we found that IL-35 signaled through a unique heterodimer of receptor chains IL-12R?2 and gp130 or homodimers of each chain. Conventional T cells were sensitive to IL-35-mediated suppression in the absence of one receptor chain but not both receptor chains, whereas signaling through both chains was required for IL-35 expression and conversion into iTr35 cells. Signaling through the IL-35 receptor required the transcription factors STAT1 and STAT4, which formed a unique heterodimer that bound to distinct sites in the promoters of the genes encoding the IL-12 subunits p35 and Ebi3. This unconventional mode of signaling, distinct from that of other members of the IL-12 family, may broaden the spectrum and specificity of IL-35-mediated suppression. [ABSTRACT FROM AUTHOR]

Interleukin 9 (IL-9) is a cytokine linked to lung inflammation, but its cellular origin and function remain unclear. Here we describe a reporter mouse strain designed to map the fate of cells that have activated IL-9. We found that during papain-induced lung inflammation, IL-9 production was largely restricted to innate lymphoid cells (ILCs). IL-9 production by ILCs depended on IL-2 from adaptive immune cells and was rapidly lost in favor of other cytokines, such as IL-13 and IL-5. Blockade of IL-9 production via neutralizing antibodies resulted in much lower expression of IL-13 and IL-5, which suggested that ILCs provide the missing link between the well-established functions of IL-9 in the regulation of type 2 helper T cell cytokines and responses. [ABSTRACT FROM AUTHOR]

Interleukin-32 (IL-32) is a pro-inflammatory cytokine conditionally produced by T cells, natural killer (NK) cells, monocytes, epithelial cells and keratinocytes, which has an important role in host resistance against infectious disease. Interestingly, elevated levels of IL-32 transcripts in fine needle aspirates of tumor tissue have also been correlated with objective clinical responses in cancer patients receiving immunotherapy. To evaluate the antitumor impact of IL-32 gene therapy, we treated BALB/c mice bearing established subcutaneous CMS4 sarcomas with intratumoral (i.t.) injections of syngenic dendritic cells (DCs) engineered to express human IL-32β complementary DNA (that is, DC.IL32). Although ectopic expression of IL-32β by DC resulted in only modest phenotypic changes in these antigen-presenting cells, DC.IL32 produced higher levels of IL-12p70 than control DC. DC.IL32 were more potent activators of type-1 T-cell responses in vitro and in vivo, with i.t. administration of DC.IL32 leading to the CD8+ T-cell-dependent (but CD4+ T-cell- and NK cell-independent) suppression of tumor growth. Effective DC.IL32-based therapy promoted infiltration of tumors by type-1 (that is, CXCR3+VLA-4+GrB+) CD8+ T cells and CD11b+CD11c+ host myeloid DC, but led to reductions in the prevalence of CD11b+Gr1+ myeloid-derived suppressor cells and CD31+ blood vessels. [ABSTRACT FROM AUTHOR]

Interleukin 17 (IL-17)-producing helper T cells (TH17 cells) require exposure to IL-23 to become encephalitogenic, but the mechanism by which IL-23 promotes their pathogenicity is not known. Here we found that IL-23 induced production of the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) in TH17 cells and that GM-CSF had an essential role in their encephalitogenicity. Our findings identify a chief mechanism that underlies the important role of IL-23 in autoimmune diseases. IL-23 induced a positive feedback loop whereby GM-CSF secreted by TH17 cells stimulated the production of IL-23 by antigen-presenting cells. Such cross-regulation of IL-23 and GM-CSF explains the similar pattern of resistance to autoimmunity when either of the two cytokines is absent and identifies TH17 cells as a crucial source of GM-CSF in autoimmune inflammation. [ABSTRACT FROM AUTHOR]

Interleukin (IL)-10 is an important regulatory cytokine that can modulate excessive immune mediated injury. Several distinct cell types have been demonstrated to produce IL-10, including most recently CD8+ cytotoxic T lymphocytes (CTLs) responding to respiratory virus infection. Here we report that CD4+ T cell help in the form of IL-2 is required for IL-10 production by CTLs, but not for the induction of CTL effector cytokines. We show that IL-2 derived from CD4+ helper T cells cooperates with innate immune cell-derived IL-27 to amplify IL-10 production by CTLs through a Blimp-1-dependent mechanism. These findings reveal a previously unrecognized pathway that coordinates signals derived from innate and helper T cells to control the production of a regulatory cytokine by CTLs during acute viral infection. [ABSTRACT FROM AUTHOR]

Interleukin 2 (IL-2), a cytokine linked to human autoimmune disease, limits IL-17 production. Here we found that deletion of the gene encoding the transcription factor STAT3 in T cells abrogated IL-17 production and attenuated autoimmunity associated with IL-2 deficiency. Whereas STAT3 induced IL-17 and the transcription factor RORγt and inhibited the transcription factor Foxp3, IL-2 inhibited IL-17 independently of Foxp3 and RORγt. STAT3 and STAT5 bound to multiple common sites across the locus encoding IL-17. The induction of STAT5 binding by IL-2 was associated with less binding of STAT3 at these sites and the inhibition of associated active epigenetic marks. 'Titration' of the relative activation of STAT3 and STAT5 modulated the specification of cells to the IL-17-producing helper T cell (TH17 cell) subset. Thus, the balance rather than the absolute magnitude of these signals determined the propensity of cells to make a key inflammatory cytokine. [ABSTRACT FROM AUTHOR]

Here we describe a reporter mouse strain designed to map the fate of cells that have activated interleukin 17A (IL-17A). We found that IL-17-producing helper T cells (TH17 cells) had distinct plasticity in different inflammatory settings. Chronic inflammatory conditions in experimental autoimmune encephalomyelitis (EAE) caused a switch to alternative cytokines in TH17 cells, whereas acute cutaneous infection with Candida albicans did not result in the deviation of TH17 cells to the production of alternative cytokines, although IL-17A production was shut off in the course of the infection. During the development of EAE, interferon-γ (IFN-γ) and other proinflammatory cytokines in the spinal cord were produced almost exclusively by cells that had produced IL-17 before their conversion by IL-23 ('ex-TH17 cells'). Thus, this model allows the actual functional fate of effector T cells to be related to TH17 developmental origin regardless of IL-17 expression. [ABSTRACT FROM AUTHOR]

T helper (Th) 17 cells have been classified as a new lineage, distinct from Th1, Th2 and Treg. Their development requires a unique combination of cytokines and depends on distinct intracellular events, resulting in the production of the signature cytokines interleukin (IL)-17A, IL-17F and IL-22. The differential cytokine expression patterns in Th cells suggest a division of labour in the response against a variety of pathogens. Th17 have an important function in the host-defense-response against extracellular pathogens, but they also have become notorious for their role in the pathogenesis of many autoimmune and allergic disorders. Animal models of autoimmune disorders have shown that Th17 effector molecules and transcription factors play a crucial role in both development and maintenance of the disease. The discovery of Th17 not only enhanced our insight into these disorders but also placed a Th subset at the interface between the innate and adoptive immune systems with the potential to regulate subsequent immunity against pathogens. [ABSTRACT FROM AUTHOR]

Immature CD4+CD8+ (double-positive (DP)) thymocytes are signaled via T cell antigen receptors (TCRs) to undergo positive selection and become responsive to intrathymic cytokines such as interleukin 7 (IL-7). We report here that cytokine signaling is required for positively selected thymocytes to express the transcription factor Runx3, specify CD8 lineage choice and differentiate into cytotoxic-lineage T cells. In DP thymocytes genetically engineered to be cytokine responsive, IL-7 signaling induced TCR-unsignaled DP thymocytes to express Runx3 and to differentiate into mature CD8+ T cells, completely circumventing positive selection. We conclude that TCR-mediated positive selection converts DP cells into cytokine-responsive thymocytes, but it is subsequent signaling by intrathymic cytokines that specifies CD8 lineage choice and promotes differentiation into cytotoxic-lineage T cells. [ABSTRACT FROM AUTHOR]

The physiological regulation of the expression of interleukin (IL)-9, a cytokine traditionally regarded as being TH2 associated, remains unclear. Here, we show that IL-9-expressing T cells generated in vitro in the presence of transforming growth factor-β and IL-4 express high levels of mRNA for IL-17 receptor B (IL-17RB), the receptor for IL-25. Treatment of these cells with IL-25 enhances IL-9 expression in vitro. Moreover, transgenic and retroviral overexpression of IL-17RB in T cells results in IL-25-induced IL-9 production that is IL-4 independent. In vivo, the IL-25–IL-17RB pathway regulates IL-9 expression in allergic airway inflammation. Thus, IL-25 is a newly identified regulator of IL-9 expression. [ABSTRACT FROM AUTHOR]

Interleukin 17 (IL-17)-producing helper T cells (TH-17 cells), together with their effector cytokines, including members of the IL-17 family, are emerging as key mediators of chronic inflammatory and autoimmune disorders. Here we present the crystal structure of a complex of IL-17 receptor A (IL-17RA) bound to IL-17F in a 1:2 stoichiometry. The mechanism of complex formation was unique for cytokines and involved the engagement of IL-17 by two fibronectin-type domains of IL-17RA in a groove between the IL-17 homodimer interface. Binding of the first receptor to the IL-17 cytokines modulated the affinity and specificity of the second receptor-binding event, thereby promoting heterodimeric versus homodimeric complex formation. IL-17RA used a common recognition strategy to bind to several members of the IL-17 family, which allows it to potentially act as a shared receptor in multiple different signaling complexes. [ABSTRACT FROM AUTHOR]

Interleukin 17 (IL-17)-producing CD4+ helper T cells (TH-17 cells) share a developmental relationship with Foxp3+ regulatory T cells (Treg cells). Here we show that a TH-17 population differentiates in the thymus in a manner influenced by recognition of self antigen and by the cytokines IL-6 and transforming growth factor-β (TGF-β). Like previously described TH-17 cells, the TH-17 cells that developed in the thymus expressed the transcription factor RORγt and the IL-23 receptor. These cells also expressed α4β1 integrins and the chemokine receptor CCR6 and were recruited to the lung, gut and liver. In the liver, these cells secreted IL-22 in response to self antigen and mediated host protection during inflammation. Thus, TH-17 cells, like Treg cells, can be selected by self antigens in the thymus. [ABSTRACT FROM AUTHOR]

The authors recount their discovery of how pathogen-induced interleukin 12 production leads to TH1 T cell polarization. Simultaneously they discovered the suppressive cytokine interleukin 10 inhibits antigen-presenting cells, thus regulating development of TH1 cells. [ABSTRACT FROM AUTHOR]

Interleukin 22 (IL-22) is a member of the IL-10 cytokine family that is involved in inflammatory and wound healing processes. Originally considered a T helper type 1 (TH1)-associated cytokine, IL-22 has since been shown to be produced mainly by IL-17-producing helper T cells (TH-17 cells). Here we describe a previously uncharacterized IL-22-producing human helper T cell population that coexpressed the chemokine receptor CCR6 and the skin-homing receptors CCR4 and CCR10. These cells were distinct from both TH-17 cells and TH1 cells. Downregulation of either the aryl hydrocarbon receptor (AHR) or the transcription factor RORC by RNA-mediated interference affected IL-22 production, whereas IL-17 production was affected only by downregulation of RORC by RNA-mediated interference. AHR agonists substantially altered the balance of IL-22- versus IL-17-producing cells. This subset of IL-22-producing cells may be important in skin homeostasis and pathology. [ABSTRACT FROM AUTHOR]

Alternative splicing results in multiple protein isoforms derived from a single gene. The magnitude of this process ranges from a complete loss of function to gain of new function. We examined, as a paradigm, alternative splicing of the non-redundant human cytokine, interleukin-7 (IL-7). We show that extensive IL-7 splicing in human tissues of different histology, including MTB+ granuloma lesions, transformed tissue and tumor cell lines. IL-7 splice variants were expressed as recombinant proteins. A differentially spliced IL-7 isoform, lacking exon 5, leads to STAT-5 phosphorylation in CD4+ and CD8+ T cells, promotes thymocyte maturation and T-cell survival. Human tumor lesions show aberrant IL-7 isoform expression, as compared with the autologous, non-transformed tissue. Alternatively spliced cytokines, such as IL-7, represent candidates for diagnostics and therapeutic interventions.Genes and Immunity (2009) 10, 132–140; doi:10.1038/gene.2008.90; published online 18 December 2008 [ABSTRACT FROM AUTHOR]

One of the characteristic features of anaplastic lymphoma kinase (ALK)(+), anaplastic large cell lymphoma (ALK(+)ALCL) is the constitutive activation of signal transducers and activators of transcription-3 (STAT3), a defect believed to be important for the pathogenesis of these tumors. In this report, we describe the existence of an autocrine stimulatory loop involving interleukin-22 (IL-22) that contributes to STAT3 activation and tumorigenicity of ALK(+)ALCL. The IL-22 receptor, a heterodimer composed of IL-22R1 and IL-10R2, was expressed in all ALK(+)ALCL cell lines and tumors examined. The expression of IL-22R1 in ALK(+)ALCL is aberrant, as this protein is absent in benign lymphocytes. Although ALK(+)ALCL cells produce endogenous IL-22, addition of recombinant IL-22 to ALK(+)ALCL cell lines significantly increased STAT3 activation, cell proliferation and colony formation in soft agar. Opposite biological effects were observed in cells treated with recombinant IL-22 binding protein (a naturally occurring IL-22 decoy) or IL-22-neutralizing antibody. Nucleophosmin (NPM)-ALK, the characteristic fusion gene oncoprotein expressed in ALK(+)ALCL, directly contributes to the aberrant expression of IL-22R1, as transfection of NPM-ALK in Jurkat cells-induced IL-22R1 expression and IL-22-mediated STAT3 activation. To conclude, for the first time, we demonstrate the importance of the IL-22 autocrine pathway in a lymphoid malignancy, and reveal yet another novel function of NPM-ALK. [ABSTRACT FROM AUTHOR]

Classically naïve CD4+ have been thought to differentiate into two possible lineages, T helper 1 (Th1) or T helper 2 (Th2) cells. Within this paradigm the pathogenesis of autoimmunity was suggested to predominantly relate to Th1 cells and the production of IFN-γ. However, there were many aspects of this model that did not seem to fit, not the least of which was that IFN-γ was protective in some models of autoimmunity. During the past 2 years, remarkable progress has been made to characterize a new lineage of helper T cells. Designated Th17 cells, this lineage selectively produces proinflammatory cytokines including IL-17, IL-21, and IL-22. In the mouse, the differentiation of this new lineage is initiated by TGFβ-1 and IL-6 and IL-21, which activate Stat3 and induce the expression of the transcription factor retinoic acid-related orphan receptor (RORγt). IL-23, which also activates Stat3, apparently serves to maintain Th17 cells in vivo. In human cells, IL-1, IL-6, and IL-23 promote human Th17 differentiation, but TGFβ-1 is reportedly not needed. Emerging data have suggested that Th17 plays an essential role in the host defense against extracellular bacteria and fungi and in pathogenesis of autoimmune diseases. Selectively targeting the Th17 lineage may be beneficial for the treatment of inflammatory and autoimmune diseases. [ABSTRACT FROM AUTHOR]

On activation, naive T cells differentiate into effector T-cell subsets with specific cytokine phenotypes and specialized effector functions. Recently a subset of T cells, distinct from T helper (TH)1 and TH2 cells, producing interleukin (IL)-17 (TH17) was defined and seems to have a crucial role in mediating autoimmunity and inducing tissue inflammation. We and others have shown that transforming growth factor (TGF)-β and IL-6 together induce the differentiation of TH17 cells, in which IL-6 has a pivotal function in dictating whether T cells differentiate into Foxp3+ regulatory T cells (Treg cells) or TH17 cells. Whereas TGF-β induces Foxp3 and generates Treg cells, IL-6 inhibits the generation of Treg cells and induces the production of IL-17, suggesting a reciprocal developmental pathway for TH17 and Treg cells. Here we show that IL-6-deficient (Il6-/-) mice do not develop a TH17 response and their peripheral repertoire is dominated by Foxp3+ Treg cells. However, deletion of Treg cells leads to the reappearance of TH17 cells in Il6-/- mice, suggesting an additional pathway by which TH17 cells might be generated in vivo. We show that an IL-2 cytokine family member, IL-21, cooperates with TGF-β to induce TH17 cells in naive Il6-/- T cells and that IL-21-receptor-deficient T cells are defective in generating a TH17 response. [ABSTRACT FROM AUTHOR]

Recent data from three laboratories have identified the TEC kinases, ITK and RLK, as crucial regulators of CD8+ T-cell development into the conventional lymphocyte lineage. In the absence of ITK and RLK, CD4+CD8+ thymocytes upregulate the T-box transcription factor eomesodermin, and develop into mature CD8+ T cells that resemble memory cells, exhibit immediate effector cytokine production and depend on IL-15. Furthermore, the selection of these non-conventional 'innate' T cells results from interactions with haematopoietic cells in the thymus. These findings lead to the hypothesis that altered TCR signalling, together with distinct co-stimulatory signals, is the basis for the development of non-conventional T-cell lineages. [ABSTRACT FROM AUTHOR]

For over 35 years, immunologists have divided T-helper (TH) cells into functional subsets. T-helper type 1 (TH1) cells—long thought to mediate tissue damage—might be involved in the initiation of damage, but they do not sustain or play a decisive role in many commonly studied models of autoimmunity, allergy and microbial immunity. A major role for the cytokine interleukin-17 (IL-17) has now been described in various models of immune-mediated tissue injury, including organ-specific autoimmunity in the brain, heart, synovium and intestines, allergic disorders of the lung and skin, and microbial infections of the intestines and the nervous system. A pathway named TH17 is now credited for causing and sustaining tissue damage in these diverse situations. The TH1 pathway antagonizes the TH17 pathway in an intricate fashion. The evolution of our understanding of the TH17 pathway illuminates a shift in immunologists' perspectives regarding the basis of tissue damage, where for over 20 years the role of TH1 cells was considered paramount. [ABSTRACT FROM AUTHOR]

Interleukin-2 and interleukin-15 have pivotal roles in the control of the life and death of lymphocytes. Although their heterotrimeric receptors have two receptor subunits in common, these two cytokines have contrasting roles in adaptive immune responses. The unique role of interleukin-2 is in the elimination of self-reactive T cells to prevent autoimmunity. By contrast, interleukin-15 is dedicated to the prolonged maintenance of memory T-cell responses to invading pathogens. As discussed in this Review, the biology of these cytokines will affect the development of novel therapies for malignancy and autoimmune diseases, as well as the design of vaccines against infectious diseases. [ABSTRACT FROM AUTHOR]

The activation-induced differentiation of naive CD4+ T cells generates functionally divergent type 1 helper T cells (Th1) or type 2 helper T cells (Th2) effector cell populations, characterized by secretion of Interferon (IFN)-?or Interleukin (IL)-4, respectively. Inappropriate generation of Th subsets may contribute to immune dysfunction. The decision to generate Th1/Th2 lineages is critically regulated by cytokines, such that IL-12 induces Th1 differentiation, while IL-4 induces Th2 differentiation. Genetic factors influence the pathway of Th differentiation, as displayed by the preferential generation of divergent Th populations by different inbred strains of mice. We employ two complementary genetic techniques to identify genes that regulate the default IL-4 secretion profiles of T cells from BALB/c and B6 mice. We performed a genome-wide linkage analysis of the progeny of a backcross between BALB/c and B6 mice to identify three loci, T-cell secretion of interleukin-4 (Tsi)1-3, on chromosomes 7, 19 and 15, respectively, which regulate in vitro T-cell IL-4 production. We have also employed mRNA representational difference analysis to isolate a gene, Flj20274, which is differentially expressed in T cells that secrete high levels of IL-4. Significantly, Flj20274 was mapped to the point of peak linkage within Tsi1 and is a strong candidate for Tsi1.Genes and Immunity (2005) 6, 290-297. doi:10.1038/sj.gene.6364192 Published online 7 April 2005 [ABSTRACT FROM AUTHOR]

The aim of this study was to profile the changes in intracellular and plasma cytokines during the neonatal period and evaluate the impact of breast feeding on these parameters. For this purpose, we measured the interleukin (IL)-2 and IL-4 producing CD3+/CD69+ T-cells using flow cytometry and plasma concentrations of interferon (IFN)-gamma and IL-4 using ELISA, in 122 healthy term neonates, aged 6–12 h, born to non-atopic parents, and 25 healthy children aged 1–12 years. A total of 42/122 neonates exclusively breast-fed (BF) and 39/122 formula fed (FF) were studied again on the 30th day of life for the above parameters. Finally, a clinical evaluation for the presence of atopic disease was conducted at 2 years of age. We found that at birth, the percentage of CD3+/CD69+/IL-4+ T-cells (median = 15.8%, range = 4.4%–49%) and plasma concentrations of IL-4 (median = 0.22 pg/ml, range = 0.18–0.25 pg/ml) were significantly higher (P<0.0001) compared to those of children (median = 1.6%, range = 0.16%–2.7% for CD3+/CD69+/IL-4+ and median = 0.17 pg/ml, range = 0.13–0.26 pg/ml for IL-4), whereas plasma concentrations of IFN-gamma were significantly lower in neonates (median = 0.42 pg/ml, range = 0.3–1.5 pg/ml) than in children (median = 1.2 pg/ml, range = 0.3–2.6 pg/ml, P<0.0001). During the neonatal period, only the CD3+/CD69+/IL-4+ T-cells increased significantly in both BF and FF groups. Comparison between BF and FF groups revealed no significant difference in any of the parameters measured. Moreover, no difference in the development of atopy during the first 2 years of life was found between BF and FF infants. Conclusion: our findings demonstrate that during the entire neonatal period type 2 immunity dominates, regardless of the mode of feeding, whereas type 1 immunity dominates during childhood. Moreover, in the absence of family history of atopy, the mode of feeding per se does not play a crucial role in the development of atopy within the first 2 years of life. [ABSTRACT FROM AUTHOR]

Summary:We report the effects exerted by cytokine combinations, including stem cell factor (SCF), interleukin-7, interleukin-4 and interleukin-2, on the amplification of T cells from cord blood (CB) mononuclear cells cultured for 10-11 days under serum-deprived conditions. Of all the combinations investigated, SCF+interleukin-7 sustained the best fold increase (FI) of total nucleated cells (FI=6.4±1.17), amplifying preferentially CD4+ over CD8+ T-cell subsets (FI=4.72±0.79 vs 2.73±1.2, respectively, P<0.05). The addition of interleukin-2 to this combination did not significantly increase the total number of cells generated (FI=7.4±2.27), but allowed preferential amplification of CD8+ over CD4+ T cells (FI=6.04±0.14 vs 1.67±0.6, respectively, P<0.05). Single-strand conformation polymorphism analysis of the T-cell receptor V?-chain rearrangements expressed by the expanded T cells indicated that the complexity of the T-cell repertoire had increased after 10 days of culture in the presence of SCF and IL-7. Interestingly, a modest expansion (FI=8.67±1.5) of myeloid progenitor cells was also observed in these cultures. These results indicate that it is possible to expand specific T-cell subsets for adoptive immunotherapy without losing myeloid progenitor cells necessary for neutrophil recovery after CB transplantation, by modulating the cytokines added to the cultures.Bone Marrow Transplantation (2003) 31, 713-723. doi:10.1038/sj.bmt.1703904 [ABSTRACT FROM AUTHOR]

Helicobacter pylori infection is associated with chronic infiltration by various cell types, including T cells, whose cytokine production may regulate the inflammatory reaction as well as local immune response to the bacterium. We prospectively analyzed the constituents of the cellular infiltrates and the cytokines produced by T cells in antral biopsies obtained from 73 subjects with and without H. pylori infection, before and after eradication therapy, and compared them with a histological grade of gastritis. We found that T cells predominated in cell number, followed by granulocytes/monocytes and plasma cells in both H. pylori-infected and H. pylori-uninfected subjects. Despite the absence of H. pylori infection, more than 70% of gastric CD4-positive T cells obtained from uninfected tissue produced interferon-gamma (IFN-gamma) in the cytosol. Upon receptor cross-linking of a CD3 and a CD28 molecule, T cells in both infected and uninfected tissue continuously secreted a far greater amount of IFN-gamma than those in peripheral blood mononuclear cell controls for a period of cell culture, whereas the increase in interleukin-4 (IL-4) was very small, and no increase in IL-2 secretion was seen. In H. pylori-infected patients, IFN-gamma secretion was correlated with the grade of mononuclear cell infiltration and decreased to an uninfected control level after eradication therapy. We did not see the effect of eradication on IL-4 secretion. Anti-H. pylori antibody of the IgG2 subclass was remarkably increased in H. pylori-infected subjects. These results together suggest that gastric T cells are already differentiated to produce a large amount of IFN-gamma by a mechanism unrelated to H. pylori infection. H. pylori infection appeared to activate T cells to secrete even more IFN-gamma, which may contribute to maintaining a perpetual inflammation in H. pylori-infected stomach. [ABSTRACT FROM AUTHOR]

The recent discovery of CD4+ T cells characterized by secretion of interleukin (IL)-17 (TH17 cells) and the naturally occurring regulatory FOXP3+ CD4 T cell (nTreg) has had a major impact on our understanding of immune processes not readily explained by the TH1/TH2 paradigm. TH17 and nTreg cells have been implicated in the pathogenesis of human autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease and psoriasis. Our recent data and the work of others demonstrated that transforming growth factor-β (TGF-β) and IL-6 are responsible for the differentiation of naive mouse T cells into TH17 cells, and it has been proposed that IL-23 may have a critical role in stabilization of the TH17 phenotype. A second pathway has been discovered in which a combination of TGF-β and IL-21 is capable of inducing differentiation of mouse TH17 cells in the absence of IL-6 (refs 6–8). However, TGF-β and IL-6 are not capable of differentiating human TH17 cells and it has been suggested that TGF-β may in fact suppress the generation of human TH17 cells. Instead, it has been recently shown that the cytokines IL-1β, IL-6 and IL-23 are capable of driving IL-17 secretion in short-term CD4+ T cell lines isolated from human peripheral blood, although the factors required for differentiation of naive human CD4 to TH17 cells are still unknown. Here we confirm that whereas IL-1β and IL-6 induce IL-17A secretion from human central memory CD4+ T cells, TGF-β and IL-21 uniquely promote the differentiation of human naive CD4+ T cells into TH17 cells accompanied by expression of the transcription factor RORC2. These data will allow the investigation of this new population of TH17 cells in human inflammatory disease. [ABSTRACT FROM AUTHOR]

The article reports on a study which suggests that CD8+ T cells need regular breaks from intermittent Interleukin-7 (IL-7) because prolonged exposure to this cytokine promotes their death. The researchers have used a transgenic mice to establish the importance of losing the IL-7 receptor expression. The study indicates that interruptions in IL-7 signalling are crucial for CD8+ T cell homeostasis.

The article presents a study on the flexibility of CD4+ T-cell subsets. It identifies the requirement of adding cytokines in the differentiation between TH17 and inducible TReg cells which are important for the generation of Interleukin-9(IL-9)-producing T cells. The results show that IL-9 is a distinct population, showing none of other T-cell subsets' characteristics.

The anti-inflammatory cytokine IL-35 is produced by regulatory T (Treg) cells to suppress autoimmune and inflammatory responses. The role of IL-35 in type 1 diabetes (T1D) remains to be answered. To elucidate this, we investigated the kinetics of Treg cell response in the multiple low dose streptozotocin induced (MLDSTZ) T1D model and measured the levels of IL-35 in human T1D patients. We found that Treg cells were increased in MLDSTZ mice. However, the Treg cells showed a decreased production of anti-inflammatory (IL-10, IL-35, TGF-β) and increased pro-inflammatory (IFN-γ, IL-2, IL-17) cytokines, indicating a phenotypic shift of Treg cells under T1D condition. IL-35 administration effectively both prevented development of, and counteracted established MLDSTZ T1D, seemingly by induction of Eos expression and IL-35 production in Treg cells, thus reversing the phenotypic shift of the Treg cells. IL-35 administration reversed established hyperglycemia in NOD mouse model of T1D. Moreover, circulating IL-35 levels were decreased in human T1D patients compared to healthy controls. These findings suggest that insufficient IL-35 levels play a pivotal role in the development of T1D and that treatment with IL-35 should be investigated in treatment of T1D and other autoimmune diseases. [ABSTRACT FROM AUTHOR]