Tumstatin attenuates the promotion effect of IL-17 secreted by Th17 cells on the stemness maintenance of glioma cells

The presence and clinical significance of IL-17 and IL-17-expressing cells have been studied for several cancers, although their correlation with tumor development remains controversial. Peripheral blood was collected from healthy donors and glioma patients to isolate peripheral blood mononuclear cells (PBMCs). The percentage of IL-17-expressing cells and the production of inflammatory cytokines in PBMCs and tissues were measured. Human IL‑17 cDNA was then inserted into the pEGFP‑N1 plasmid and transfected into the glioma U87MG cell line, and tumstatin was used to block the effect of the IL-17 overexpression. Stem cell transcription factors were evaluated in each group using qRT-PCR and western blotting, and proliferation and migration were detected using colony formation and wound-healing assays. The cells were then subcutaneously inoculated into nude mice to evaluate the growth of glioma. Compared with healthy donors, the PBMCs from glioma patients showed a significant accumulation of IL-17-expressing T cells. Th17 cell differentiation-related cytokines (IL-23, TGF-β and IL-6) were increased in the tumor microenvironment. IL‑17 transfection increased the mRNA and protein expression of stem cell transcription factors in U87MG cells in vitro. The proliferation and migration of U87MG cells were also increased. Moreover, the pEGFP‑N1‑IL‑17‑U87MG cells grew more rapidly than other cells. However, tumstatin-treated U87MG cells showed significantly inhibited the effects of IL-17 overexpression. Tumstatin effectively suppressed IL-17-derived U87MG cell growth by downregulating stem cell maintenance factors and inducing proliferation and migration. These findings indicated that IL-17 represents a potential prognostic marker for glioma, while tumstatin has potential in the treatment for glioma.

Vitamin D Supplementation Modulates ICOS+ and ICOS- Regulatory T Cell in Siblings of Children With Type 1 Diabetes

OBJECTIVES

Vitamin D plays an immunoregulatory activity. The aim of this study was to assess the correlation between blood serum 25(OH)D levels and Th17 and Treg circulating subsets, mainly Treg/inducible costimulatory-positive (ICOS+), which seems to have a protective role in autoimmunity, in children with type 1 diabetes mellitus (T1D) and their healthy siblings (S). The secondary aim was to evaluate the impact of vitamin D supplementation on these subsets.

PATIENTS AND METHODS

22 T1D and 33 S were enrolled. Glucose, hemoglobin A1c, 25 OH vitamin D (25[OH]D), T helper type 17 (Th17; CD4+CCR6+), regulatory T cells (Treg; CD4+CD25+Foxp3+), and Treg/ICOS+ cells were evaluated. According to human leukocyte antigen (HLA) haplotypes, subjects were classified as "at risk" (HLA+), "protective haplotypes" (HLA-; "nested controls"), and "undetermined" (HLAUND). T1D and S subjects were supplemented with cholecalciferol 1000 IU/die and evaluated after 6 months.

RESULTS

Vitamin D insufficiency (74.4%) and deficiency (43%) were frequent. S subjects with 25(OH)D levels <25 nmol/L had Th17, Treg (p < 0.01), and Treg/ICOS+ (P < 0.05) percentages higher than subjects with 25(OH)D >75 nmol/L. Treg/ICOS+ percentages (P < 0.05) were higher in HLA- S subjects compared to percentages observed in S with T1D. At baseline, in S subjects, a decreasing trend in Th17 and Treg/ICOS+ values (P < 0.05) from vitamin D deficiency to sufficiency was observed; 25(OH)D levels were negative predictors of Treg/ICOS+ (R2 = 0.301) and Th17 percentages (R2 = 0.138). After 6 months, supplemented S subjects showed higher 25(OH)D levels (P < 0.0001), and lower Th17 (P < 0.0001) and Treg/ICOS+ (P < 0.05) percentages than at baseline; supplemented T1D patients only had a decrease in Th17 levels (P < 0.05).

CONCLUSION

Serum 25(OH)D levels seem to affect Th17 and Treg cell subsets in S subjects, consistent with its immunomodulating role. HLA role should be investigated in a larger population.

The disease stage-associated imbalance of Th1/Th2 and Th17/Treg in uterine cervical cancer patients and their recovery with the reduction of tumor burden

Background

Nearly all uterine cervical cancer (UCC) cases result from human papillomavirus (HPV) infection. After high-risk HPV infection, most HPV infections are naturally cleared by humoral and cell-mediated immune responses. Thus, cervical lesions of only few patients progress into cervical cancer via cervical intraepithelial neoplasia (CIN) and lead to persistent oncogenic HPV infection. This suggests that immunoregulation plays an instrumental role in the carcinogenesis. However, there was a few studies on the relation between the immunologic dissonance and clinical characteristics of UCC patients.

Method

We examined the related immune cells (Th1, Th2, Th17, and Treg cells) by flow cytometric analysis and analyzed their relations with UCC stages, tumor size, differentiation, histology type, lymph node metastases, and vasoinvasion. Next, we quantified the Th1, Th2, Th17, and Treg cells before and after the operation both in UCC and CIN patients.

Results

When compared with stage I patients, decreased levels of circulating Th1 cells and elevated levels of Th2, Th17, and Treg cells were detected in stage II patients. In addition, the imbalance of Th1/Th2 and Th17/Treg cells was related to the tumor size, lymph node metastases, and vasoinvasion. We found that immunological cell levels normalized after the operations. In general, immunological cell levels in CIN patients normalized sooner than in UCC patients.

Conclusions

Our findings suggested that peripheral immunological cell levels reflect the patient’s condition.

PPARγ Deficiency in Carbon Nanotube-elicited Granulomatous Inflammation Promotes a Th17 Response to a Microbial Antigen

BACKGROUND

The pathological consequences of interaction between environmental carbon pollutants and microbial antigens have not been fully explored. We developed a murine model of multi-wall carbon nanotube (MWCNT)-elicited granulomatous disease which bears a striking resemblance to sarcoidosis, a human granulomatous disease. Because of reports describing lymphocyte reactivity to mycobacterial antigens in sarcoidosis patients, we hypothesized that addition of mycobacterial antigen (ESAT-6) to MWCNT might elicit activation in T cells.

METHODS

Macrophage-specific peroxisome-proliferator-activated receptor gamma (PPARγ) knock out (KO) mice were studied along with wild-type mice because our previous report indicated PPARγ deficiency in sarcoidosis alveolar macrophages. MWCNT+ESAT-6 were instilled into mice. Controls received vehicle (surfactant-PBS) or ESAT-6 and were evaluated 60 days post-instillation. As noted in our recent publication, lung tissues from PPARγ KO mice instilled with MWCNT+ESAT-6 yielded more intensive pathophysiology, with elevated fibrosis.

RESULTS

Inspection of mediastinal lymph nodes (MLN) revealed no granulomas but deposition of MWCNT. MLN cell counts were higher in PPARγ KO than in wild-type instilled with MWCNT+ESAT-6. Moreover, the CD4:CD8 T cell ratio, a major clinical metric for human disease, was increased in PPARγ KO mice. Bronchoalveolar lavage (BAL) cells from PPARγ KO mice instilled with MWCNT+ESAT-6 displayed increased Th17 cell markers (RORγt, IL-17A, CCR6) which associate with elevated fibrosis.

CONCLUSION

These findings suggest that PPARγ deficiency in macrophages may promote ESAT-6-associated T cell activation in the lung, and that the MWCNT+ESAT-6 model may offer new insights into pathways of lymphocyte-mediated sarcoidosis histopathology.

A directly GP130-targeting small molecule ameliorates collagen-induced arthritis (CIA) by inhibiting IL-6/GP130 signalling and Th17 differentiation

Rheumatoid arthritis is a chronic inflammatory disease associated with joint inflammation and destruction driven by T helper 17 (Th17) cells. Interleukin-6 (IL-6) is secreted by many cell types, including macrophages and synovial fibroblasts. It induces the differentiation and function of Th17 cells that can increase lymphocytic infiltration in the joint. LMT-28 can suppress IL-6 signalling through direct binding to glycoprotein-130 and alleviate inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease. The purpose of this study was to assess whether LMT-28 could potently inhibit Th17 differentiation and to determine the mechanism involved in the attenuating effect of LMT-28 on rheumatoid arthritis through the IL-6 signalling pathway. LMT-28 reduced the arthritis score and showed protective effects against bone and cartilage destruction in collagen-induced arthritis (CIA) mice. In mice with CIA, LMT-28 markedly decreased serum levels of IL-6, TNF and IL-1β compared to vehicle control. Moreover, LMT-28 attenuated Th17 cell activation in lymph nodes of CIA mice. We demonstrated that LMT-28 suppressed differentiation of Th17 in mouse splenocytes and human peripheral blood mononuclear cells (PBMCs). Additionally, LMT-28 inhibited phosphorylation of GP130, STAT3 and ERK induced by Hyper-IL-6 in human fibroblast-like synoviocytes (FLS). Collectively, these results suggest that LMT-28 can inhibit differentiated/activated-Th17 cells in rheumatoid arthritis by blocking activation of the STAT3 pathway. LMT-28 can attenuate rheumatoid arthritis by inhibiting differentiation/activation of Th17 cells and suppressing the proliferation and signalling activation of the IL-6/solubleIL-6 receptor complex stimulated FLS.

Ex Vivo Generated Human Cord Blood Myeloid-Derived Suppressor Cells Attenuate Murine Chronic Graft-versus-Host Diseases

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells with anti-inflammatory activity, and expanded murine MDSCs are capable of attenuating preclinical acute graft-versus-host disease (aGVHD) severity. Two murine cGVHD models were used to evaluate the effectiveness of ex vivo cultured human cord blood (hCB) MDSCs in chronic GVHD (cGVHD). First, GVHD recipients surviving in a classic C57BL/6 into MHC-mismatched BALB/c aGVHD model developed cGVHD. Second, donor pretreatment with granulocyte colony-stimulating factor (G-CSF) induced cGVHD. hCB-MDSCs (1 × 10⁶) were intravenously injected to determine their preventive effects (on days 5, 7, 10, and 21) or therapeutic effects (on days 21, 28, and 35). In the first model the onset of clinical cutaneous cGVHD was significantly delayed in preventive hCB-MDSCs-treated allogeneic recipients. Pathologic scoring of target organs confirmed these clinical results. Importantly, thymic tissues of GVHD mice treated with hCB-MDSCs were less severely damaged, showing higher numbers of double (CD4 and CD8) positive T cells with reduced expansion of donor-type CD4 and CD8 T cells. Moreover, late infusion of hCB-MDSCs controlled the severity of established cGVHD that had occurred in control recipients. In the second model, cGVHD induced by G-CSF-mobilized stem cell graft was associated with promotion of Th 17 and Th 2 differentiation. hCB-MDSCs attenuated clinical and pathologic cGVHD severity. Increased production of IL-17 and more infiltration of T cells and macrophages in cGVHD mice were markedly reduced after hCB-MDSCs treatment. Importantly, Foxp3⁺ regulatory T cells and IFN-γ-producing T cells were expanded, whereas IL-17- and IL-4-producing T cells were decreased in allogeneic recipients of hCB-MDSCs. Taken together, these results showed that hCB-MDSCs have preclinical capability of attenuating cGVHD by preserving thymus function and regulating Th 17 signaling, suggesting a possible therapeutic strategy for clinical application.

Emerging Concepts of Adaptive Immunity in Leprosy

Leprosy is a chronic intracellular infection caused by the acid-fast bacillus, Mycobacterium leprae. The disease chiefly affects the skin, peripheral nerves, mucosa of the upper respiratory tract, and the eyes. The damage to peripheral nerves results in sensory and motor impairment with characteristic deformities and disability. Presently, the disease remains concentrated in resource-poor countries in tropical and warm temperate regions with the largest number of cases reported from India. Even though innate immunity influences the clinical manifestation of the disease, it is the components of adaptive immune system which seem to tightly correlate with the characteristic spectrum of leprosy. M. leprae-specific T cell anergy with bacillary dissemination is the defining feature of lepromatous leprosy (LL) patients in contrast to tuberculoid leprosy (TT) patients, which is characterized by strong Th1-type cell response with localized lesions. Generation of Th1/Th2-like effector cells, however, cannot wholly explain the polarized state of immunity in leprosy. A comprehensive understanding of the role of various regulatory T cells, such as Treg and natural killer T cells, in deciding the polarized state of T cell immunity is crucial. Interaction of these T cell subsets with effector T cells like Th1 (IFN-γ dominant), Th2 (interluekin-4 dominant), and Th17 (IL-17+) cells through various regulatory cytokines and molecules (programmed death-1/programmed death ligand-1) may constitute key events in dictating the state of immune polarization, thus controlling the clinical manifestation. Studying these important components of the adaptive immune system in leprosy patients is essential for better understanding of immune function, correlate(s) the immunity and mechanism(s) of its containment.

Secukinumab (AIN-457) for the treatment of Psoriasis

Secukinumab (also known as AIN-457) is a human monoclonal antibody targeting IL-17A, which has been recently FDA-approved for the treatment of moderate to severe psoriasis and psoriatic arthritis with coexistent moderate to severe plaque psoriasis based on clinical trials demonstrating excellent efficacy. This review will address the rationale for targeting the IL-23/Th17/IL-17 axis, the role of IL-17 and Th17 cells in psoriasis and other chronic inflammatory diseases, and will examine pre-clinical studies, pharmacologic properties, clinical efficacy, and the safety profile of secukinumab.

Immune responses in neonates

Neonates have little immunological memory and a developing immune system, which increases their vulnerability to infectious agents. Recent advances in the understanding of neonatal immunity indicate that both innate and adaptive responses are dependent on precursor frequency of lymphocytes, antigenic dose and mode of exposure. Studies in neonatal mouse models and human umbilical cord blood cells demonstrate the capability of neonatal immune cells to produce immune responses similar to adults in some aspects but not others. This review focuses mainly on the developmental and functional mechanisms of the human neonatal immune system. In particular, the mechanism of innate and adaptive immunity and the role of neutrophils, antigen presenting cells, differences in subclasses of T lymphocytes (Th1, Th2, Tregs) and B cells are discussed. In addition, we have included the recent developments in the neonatal mouse immune system. Understanding neonatal immunity is essential to development of therapeutic vaccines to combat newly emerging infectious agents.

T helper 17 and Tregs: a novel proposed mechanism for NB-UVB in vitiligo

Narrowband ultraviolet (NB-UV)B is accepted as corner stone therapy for vitiligo. Its influence on the expression of IL-17, IL- 22 and FoxP3 as markers for the Th17 and Tregs lineages has not been studied before in the context of non-segmental vitiligo (NSV). The study included 20 active NSV patients who received 36 NB-UVB sessions and 20 controls. Clinical evaluation Vitiligo Area Scoring Index (VASI) and determination of tissue expression of IL-17, IL-22 and FoxP3 by qRT-PCR (lesional, perilesional) were carried out before and after therapy. Baseline levels of IL-17 and IL-22 were significantly higher in patients, whereas FoxP3 was significantly lower. After therapy, IL-17 and IL-22 significantly dropped, whereas FoxP3 significantly increased (lesional, perilesional). Baseline and post-treatment VASI showed significant positive correlations with IL-17 and IL-22 and significant negative correlation with FoxP3 expression. Restoration of the balance between Th17 and Tregs might represent a novel pathway for the improvement that NB-UVB exerts in vitiligo patients.