CLDN18.2 and 4-1BB bispecific antibody givastomig exerts antitumor activity through CLDN18.2-expressing tumor-directed T-cell activation.

Background: Claudin18.2 (CLDN18.2) is a tight junction protein that has been identified as a clinically proven target in gastric cancer.

Phosphorylation of FOXP3 controls regulatory T cell function and is inhibited by TNF-α in rheumatoid arthritis.

Regulatory T (Treg) cells suppress autoimmune disease, and impaired Treg cell function is associated with rheumatoid arthritis. Here we demonstrate that forkhead box P3 (FOXP3) transcriptional activity and, consequently, Treg cell suppressive function are regulated by phosphorylation at Ser418 in the C-terminal DNA-binding domain. In rheumatoid arthritis-derived Treg cells, the Ser418 site was specifically dephosphorylated by protein phosphatase 1 (PP1), whose expression and enzymatic activity were induced in the inflamed synovium by tumor necrosis factor α (TNF-α), leading to impaired Treg cell function.

TNF-α impairs differentiation and function of TGF-β-induced Treg cells in autoimmune diseases through Akt and Smad3 signaling pathway.

Deficiency in the TGF-β-induced regulatory T (iTreg) cell differentiation is associated with compromised immune homeostasis and plays a key role in many autoimmune diseases. Therapeutic intervention to enhance in situ iTreg differentiation has become a promising treatment modality for autoimmune diseases. Here we describe that the development of autoimmune inflammation in experimental autoimmune encephalomyelitis (EAE) is associated with selective impairment of iTreg differentiation largely due to the increased production of TNF-α.

Drug targets in the cytokine universe for autoimmune disease.

In autoimmune disease, a network of diverse cytokines is produced in association with disease susceptibility to constitute the 'cytokine milieu' that drives chronic inflammation. It remains elusive how cytokines interact in such a complex network to sustain inflammation in autoimmune disease. This has presented huge challenges for successful drug discovery because it has been difficult to predict how individual cytokine-targeted therapy would work.

Regulatory immune responses induced by IL-1 receptor antagonist in rheumatoid arthritis.

Anakinra, a human recombinant IL-1 receptor antagonist, is approved for the treatment of RA. In this study, 12 patients received the placebo plus MTX treatment, 38 patients received Anakinra combined with MTX treatment. Compared with the placebo plus MTX group, serum levels of IL-17, IFN-γ, IL-21 and IL-1β significantly decreased, the percentages of Th17 cells and Th1 cells were lower and the percentage of Treg cells was higher after receiving Anakinra combined with MTX treatment.

Leukemia inhibitory factor inhibits T helper 17 cell differentiation and confers treatment effects of neural progenitor cell therapy in autoimmune disease.

Neural progenitor cell (NPC) therapy is considered a promising treatment modality for multiple sclerosis (MS), potentially acting through neural repair. Here, we showed that intravenous administration of NPCs ameliorated experimental autoimmune encephalomyelitis (EAE) by selectively inhibiting pathogenic T helper 17 (Th17) cell differentiation. Leukemia inhibitory factor (LIF) produced by NPCs was responsible for the observed EAE suppression.

Liver X receptor (LXR) mediates negative regulation of mouse and human Th17 differentiation.

Th17 cells are a subset of CD4+ T cells with an important role in clearing certain bacterial and fungal pathogens. However, they have also been implicated in autoimmune diseases such as multiple sclerosis. Exposure of naive CD4+ T cells to IL-6 and TGF-β leads to Th17 cell differentiation through a process in which many proteins have been implicated.

Regulation of Th1 and Th17 cell differentiation and amelioration of experimental autoimmune encephalomyelitis by natural product compound berberine.

Berberine (BBR), an isoquinoline alkaloid derived from plants, is widely used as an anti-inflammatory remedy in traditional Chinese medicine. In this study, we showed that BBR was efficacious in the amelioration of experimental autoimmune encephalomyelitis (EAE) through novel regulatory mechanisms involving pathogenic Th1 and Th17 cells. BBR inhibited differentiation of Th17 cells and, to a lesser degree, Th1 cells through direct actions on the JAK/STAT pathway, whereas it had no effect on the relative number of CD4(+)Foxp3(+) regulatory T cells.

Role of osteopontin in synovial Th17 differentiation in rheumatoid arthritis.

Objective: Osteopontin (OPN) that is aberrantly produced in rheumatoid synovium is thought to play an important role in rheumatoid arthritis (RA). This study was undertaken to investigate the role of OPN in the differentiation and accumulation of Th17 cells in rheumatoid synovium.

Methods: Peripheral blood mononuclear cells and purified CD4+ T cells derived from patients with RA or healthy controls were used to test the effect of OPN in vitro.

High doses of alpha-galactosylceramide potentiate experimental autoimmune encephalomyelitis by directly enhancing Th17 response.

Alpha-galactosylceramide (alpha-GC) is widely known to activate invariant natural killer T (iNKT) cells to suppress myelin antigen-specific Th1 responses, protecting susceptible mice against experimental autoimmune encephalomyelitis (EAE). Here, we demonstrate an unexpected finding that high doses of alpha-GC exacerbated, rather than ameliorated, EAE. Similar results were observed when MOG(35-55)-specific T cells treated with high-dose alpha-GC were transferred into naïve syngeneic recipient mice.

IL-21 regulates Th17 cells in rheumatoid arthritis.

IL-21 is a type I cytokine that like IL-2, IL-4, IL-7, IL-9, and IL-15 uses the common gamma chain of cytokine receptor. IL-21 has been shown to regulate the function of T cells, B cells, natural killer cells, and dendritic cells in immune responses. Although activated CD4(+) T cells produce IL-21, recent data suggest that novel subsets of effector T cells are the major producers in immune responses.

Crucial role of interleukin-7 in T helper type 17 survival and expansion in autoimmune disease.

Interleukin-7 receptor (IL-7R) is genetically associated with susceptibility to multiple sclerosis. Here we describe that IL-7 is essential for survival and expansion of pathogenic T helper type 17 (T(H)17) cells in experimental autoimmune encephalomyelitis (EAE). IL-7 directly expanded effector T(H)17 cells in EAE and human T(H)17 cells from subjects with multiple sclerosis, whereas it was not required for T(H)17 differentiation.

Thymic regulation of autoimmune disease by accelerated differentiation of Foxp3+ regulatory T cells through IL-7 signaling pathway.

The exact role of adult thymus in autoimmune disease state is poorly understood. We show here that thymus regulated experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, as evidenced by loss of spontaneous recovery in thymectomized EAE mice. There was progressive enrichment for CD4 single-positive Foxp3(+) regulatory T cells in thymocytes during the course of EAE and they suppressed the disease when adoptively transferred.

Regulatory and pro-inflammatory phenotypes of myelin basic protein-autoreactive T cells in multiple sclerosis.

MBP-specific autoreactive T cells are considered pro-inflammatory T cells and thought to play an important role in the pathogenesis of multiple sclerosis (MS). Here, we report that MBP(83-99)-specific T cells generated from MS patients (n = 7) were comprised of pro-inflammatory and regulatory subsets of distinct phenotypes. The pro-inflammatory phenotype was characterized by high production of IFN-gamma, IL-6, IL-21 and IL-17 and low expression of FOXP3, whereas the regulatory subset expressed high levels of FOXP3 and exhibited potent regulatory functions.

Regulatory effects of IFN-beta on production of osteopontin and IL-17 by CD4+ T Cells in MS.

IFN-beta currently serves as one of the major treatments for MS. Its anti-inflammatory mechanism has been reported as involving a shift in cytokine balance from Th1 to Th2 in the T-cell response against elements of the myelin sheath. In addition to the Th1 and Th2 groups, two other important pro-inflammatory cytokines, IL-17 and osteopontin (OPN), are believed to play important roles in CNS inflammation in the pathogenesis of MS.

Role of osteopontin in induction of monocyte chemoattractant protein 1 and macrophage inflammatory protein 1beta through the NF-kappaB and MAPK pathways in rheumatoid arthritis.

Objective: Osteopontin (OPN) is a proinflammatory protein with a critical role in leukocyte migration. Although OPN has been implicated in rheumatoid arthritis (RA), its underlying mechanism remains unknown. In this study, we investigated the role and molecular mechanism of OPN in the induction of 2 key chemokines, monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein 1beta (MIP-1beta), in RA.

Regulatory properties of copolymer I in Th17 differentiation by altering STAT3 phosphorylation.

Th17 and Th1 play an important role in multiple sclerosis for which copolymer I (COP-I) is a treatment option. We described here that the treatment effect of COP-I correlated with its unique regulatory properties on differentiation and survival of Th17 in experimental autoimmune encephalomyelitis mice, which was mediated through down-regulation of STAT3 phosphorylation. The effect of COP-I on Th17 differentiation required CD14(+) monocytes through IL-6 signaling as a key mediator to regulate STAT3 phosphorylation and subsequent RORgammat expression in Th17 cells.

Induction of CD4+CD25+Foxp3+ regulatory T cell response by glatiramer acetate in type 1 diabetes.

Glatiramer acetate (GA) is an immunomodulatory peptide drug used to treat multiple sclerosis. Its treatment effect has been expanded to other autoimmune conditions such as uveoretinitis, inflammatory bowel disease, graft rejection and hepatic fibrosis. Here, we report that GA was effective in altering the clinical course of diabetes in cyclophosphamide (CY)-potentiated non-obese diabetic (CY-NOD) mice.

A new approach to the blocking of alloreactive T cell-mediated graft-versus-host disease by in vivo administration of anti-CXCR3 neutralizing antibody.

Chemokines and chemokine receptors play critical roles in directing the migration of alloreactive donor T cells into graft-vs-host disease (GVHD) target organs. However, blockade of GVHD by antagonist Ab against chemokine receptors remains an elusive goal. Using a mouse model of human GVHD, we demonstrate that in vivo administration of anti-CXCR3 Ab for 21 days (long-term), but not for 7 days (short-term), inhibits alloreactive CD8(+) T cell-mediated GVHD.

Novel immunomodulatory properties of berbamine through selective down-regulation of STAT4 and action of IFN-gamma in experimental autoimmune encephalomyelitis.

Berbamine (BM) is an herbal compound derived from Berberis vulgaris L commonly used in traditional Chinese medicine. In this study, we show that BM has potent anti-inflammatory properties through novel regulatory mechanisms, leading to reduced encephalitogenic T cell responses and amelioration of experimental autoimmune encephalomyelitis (EAE). The treatment effect of BM was attributable to its selective inhibitory effect on the production and action of IFN-gamma in CD4(+) T cells, which was mediated through altered STAT4 expression in T cells.

Role of GADD45 beta in the regulation of synovial fluid T cell apoptosis in rheumatoid arthritis.

Rheumatoid arthritis (RA) is characterized by persistent Th1 cell infiltration and production of inflammatory cytokines in the location of joint lesion. It is known that infiltrated Th1 cells in the synovial fluid (SF) of RA patients are resistant to apoptosis. Here we demonstrate that Th1 cells accumulated in patient SF expressed a high level of GADD45 beta (Growth Arrest and DNA Damage-inducible 45 beta) which further inhibited Th1 cell apoptosis.

Anti-inflammatory properties and regulatory mechanism of a novel derivative of artemisinin in experimental autoimmune encephalomyelitis.

Ethyl 2-[4-(12-beta-artemisininoxy)]phenoxylpropionate (SM933) is a novel derivative of artemisinin, an herbal compound approved for the treatment of malaria. In this study, we show that SM933 has unique anti-inflammatory properties through regulation of signaling pathways, leading to amelioration of experimental autoimmune encephalomyelitis. The anti-inflammatory properties of SM933 were characterized by inhibition of encephalitogenic T cell responses that were altered to exhibit a Th2 immune deviation and reduced activity and concentration of NO and inducible NO synthase.

Critical regulation of CD4+ T cell survival and autoimmunity by beta-arrestin 1.

CD4+ T cells are important in adaptive immunity, but their dysregulation can cause autoimmunity. Here we demonstrate that the multifunctional adaptor protein beta-arrestin 1 positively regulated naive and activated CD4+ T cell survival. We found enhanced expression of the proto-oncogene Bcl2 through beta-arrestin 1-dependent regulation of acetylation of histone H4 at the Bcl2 promoter.

Vaccination with selected synovial T cells in rheumatoid arthritis.

Objective: This pilot clinical study was undertaken to investigate the role of T cell vaccination in the induction of regulatory immune responses in patients with rheumatoid arthritis (RA).

Methods: Autologous synovial T cells were selected for pathologic relevance, rendered inactive by irradiation, and used for vaccination. Fifteen patients received T cell vaccination via 6 subcutaneous inoculations over a period of 12 months.

Association of CD4+CD25+Foxp3+ regulatory T cells with chronic activity and viral clearance in patients with hepatitis B.

Chronic activity of hepatitis B is thought to involve aberrant immune tolerance of unknown mechanism. In this study, we examined the role of CD4(+)CD25(+)Foxp3(+) regulatory T cells in disease activity and viral clearance in hepatitis B. Patients with chronic active hepatitis B (CAH) and asymptomatic HBV carriers (AsC) exhibited a significantly high frequency of CD4(+)CD25(+)Foxp3(+) T cells as opposed to that of controls and resolved HBV infection.