Cell Th1 Cytokine Production Research Articles

Plasmacytoid Dendritic Cells Facilitate Th Cell Cytokine Responses throughout Schistosoma mansoni Infection.

Plasmacytoid dendritic cells (pDCs) are potent producers of type I IFN (IFN-I) during viral infection and respond to IFN-I in a positive feedback loop that promotes their function. IFN-I shapes dendritic cell responses during helminth infection, impacting their ability to support Th2 responses. However, the role of pDCs in type 2 inflammation is unclear. Previous studies have shown that pDCs are dispensable for hepatic or splenic Th2 responses during the early stages of murine infection with the trematode Schistosoma mansoni at the onset of parasite egg laying. However, during S. mansoni infection, an ongoing Th2 response against mature parasite eggs is required to protect the liver and intestine from acute damage and how pDCs participate in immune responses to eggs and adult worms in various tissues beyond acute infection remains unclear. We now show that pDCs are required for optimal Th2 cytokine production in response to S. mansoni eggs in the intestinal-draining mesenteric lymph nodes throughout infection and for egg-specific IFN-γ at later time points of infection. Further, pDC depletion at chronic stages of infection led to increased hepatic and splenic pathology as well as abrogated Th2 cell cytokine production and activation in the liver. In vitro, mesenteric lymph node pDCs supported Th2 cell responses from infection-experienced CD4+ T cells, a process dependent on pDC IFN-I responsiveness, yet independent of Ag. Together, these data highlight a previously unappreciated role for pDCs and IFN-I in maintaining and reinforcing type 2 immunity in the lymph nodes and inflamed tissue during helminth infection.

Integrated analysis of the molecular mechanisms in idiopathic pulmonary fibrosis.

Rationale: Idiopathic pulmonary fibrosis (IPF) is one of the most aggressive forms of idiopathic interstitial pneumonia. Some miRNAs may be associated with IPF and may affect the occurrence and development of IPF in various pathways. Many miRNAs and genes that may be involved in the development of IPF have been discovered using chip and high throughput technologies.Methods: We analyzed one miRNA and four mRNA databases. We identified hub genes and pathways related to IPF using GO, KEGG enrichment analysis, gene set variation analysis (GSVA), PPI network construction, and hub gene analysis. A comprehensive analysis of differentially expressed miRNAs (DEMs), predicted miRNA target genes, and differentially expressed genes (DEGs) led to the creation of a miRNA-mRNA regulatory network in IPF.Results: We found 203 DEGs and 165 DEMs that were associated with IPF. The findings of enrichment analyses showed that these DEGs were mainly involved in antimicrobial humoral response, antimicrobial humoral immune response mediated by antimicrobial peptide, extracellular matrix organization, cell killing, and organ or tissue specific immune response. The VEGFA, CDH5, and WNT3A genes overlapped between hub genes and the miRNA-mRNA regulatory network. The miRNAs including miR-199b-5p, miR-140-5p, miR-199a-5p, miR-125A-5p, and miR-107 that we predicted would regulate the VEGFA, CDH5, and WNT3A genes, which were also associated with IPF or other fibrosis-related diseases. GSVA indicated that metabolic processes of UTP and IMP, immune response, regulation of Th2 cell cytokine production, and positive regulation of NK cell-mediated immunity are associated with the pathogenesis and treatment of IPF. These pathways also interact with VEGFA, CDH5, and WNT3A.Conclusion: These findings provide a new research direction for the diagnosis and treatment of IPF.

Effector/memory CD4 T cells making either Th1 or Th2 cytokines commonly co-express T-bet and GATA-3.

Naïve CD4 T (NCD4T) cells post-activation undergo programming for inducible production of cytokines leading to generation of memory cells with various functions. Based on cytokine based polarization of NCD4T cells in vitro, programming for either ‘Th1’ (interferon-gamma [IFNg]) or ‘Th2’ (interleukin [IL]-4/5/13) cytokines is thought to occur via mutually exclusive expression and functioning of T-bet or GATA-3 transcription factors (TFs). However, we show that a high proportion of mouse and human memory-phenotype CD4 T (MCD4T) cells generated in vivo which expressed either Th1 or Th2 cytokines commonly co-expressed T-bet and GATA-3. While T-bet levels did not differ between IFNg-expressing and IL-4/5/13-expressing MCD4T cells, GATA-3 levels were higher in the latter. These observations were also confirmed in MCD4T cells from FVB/NJ or aged C57BL/6 or IFNg-deficient mice. While MCD4T cells from these strains showed greater Th2 commitment than those from young C57BL/6 mice, pattern of co-expression of TF was similar. Effector T cells generated in vivo following immunization also showed TF co-expression in Th1 or Th2 cytokine producing cells. We speculated that the difference in TF expression pattern of MCD4T cells generated in vivo and those generated in cytokine polarized cultures in vitro could be due to relative absence of polarizing conditions during activation in vivo. We tested this by NCD4T cell activation in non-polarizing conditions in vitro. Anti-CD3 and anti-CD28-mediated priming of polyclonal NCD4T cells in vitro without polarizing milieu generated cells that expressed either IFNg or IL-4/5/13 but not both, yet both IFNg- and IL-4/5/13-expressing cells showed upregulation of both TFs. We also tested monoclonal T cell populations activated in non-polarizing conditions. TCR-transgenic NCD4T cells primed in vitro by cognate peptide in non-polarizing conditions which expressed either IFNg or IL-4/5/13 also showed a high proportion of cells co-expressing TFs, and their cytokine commitment varied depending on genetic background or priming conditions, without altering pattern of TF co-expression. Thus, the model of mutually antagonistic differentiation programs driven by mutually exclusively expressed T-bet or GATA-3 does not completely explain natural CD4 T cell priming outcomes.

Cyclosporin A indirectly attenuates activation of group 2 innate lymphoid cells in papain-induced lung inflammation

Cyclosporin A (CsA) is a well-known immunosuppressant that is used against steroid-resistant asthma. Group 2 innate lymphoid cells (ILC2s) and type 2 helper T (Th2) cells produce Th2 cytokines including IL-5 and play important roles in asthma pathogenesis. Here, we studied the effects of CsA in allergen-induced lung inflammation in mice and found that CsA decreased the number of lung ILC2s and attenuated papain-induced activation of ILC2s accompanied with IL-5 expression. The ILC2 suppression mediated by CsA was not observed in culture or in lymphocyte-deficient Rag2−/− mice. Thus, we propose a new suppressive effect of CsA, i.e., administration of CsA indirectly suppresses maintenance and activation of lung ILC2s in addition to direct suppression of T-cell activation and cytokine production.

Sublingual immunotherapy for allergic rhinitis: subjective versus objective tools to evaluate its success

Biomarkers that enable objective evaluation of the clinical effects of immunotherapy for allergic rhinitis have yet to be identified. This study included 40 patients who were enrolled in a large randomized, double-blind, placebo-controlled, multicenter study examining the efficacy of sublingual immunotherapy (SLIT) using Japanese cedar (JC) pollen extract during two consecutive pollen seasons from 2010 to 2012. Based on changes in total nasal symptom medication score, patients in the SLIT and placebo groups were subdivided into two subgroups: good responders and poor responders. The levels of JC pollen-specific IL-10+Foxp3+ cells and specific Th2 cytokine-producing cells were measured and the association with the efficacy of SLIT was analysed. The total nasal symptom medication score was significantly lower in the SLIT group compared with the placebo group. The number of JC pollen-specific Th2 cytokine-producing cells increased during the pollen season in the placebo group and in poor responders in the SLIT group; however, the increases were inhibited in the good responders in the SLIT group. The number of JC pollen-specific IL-10+Foxp3+ cells increased only in these good responders. Changes in levels of allergen-specific Th2 cytokine-producing cells and IL-10+Foxp3+ cells could be objective biomarkers for SLIT.

Treatment of Hypereosinophilic Syndrome with Cutaneous Involvement with the JAK Inhibitors Tofacitinib and Ruxolitinib

Hypereosinophilic syndrome (HES) is a heterogeneous group of disorders characterized by persistent peripheral blood eosinophilia, eosinophil-mediated end-organ damage, and absence of other infectious or allergic causes of eosinophilia.(Gotlib, 2014, Valent et al., 2012) Treatment of HES is challenging and usually relies on corticosteroids, which have significant adverse effects.(Klion, 2015, Klion et al., 2006) There are 3 categories of HES: primary, secondary, and idiopathic. Primary HES is a myeloproliferative disease with clonal eosinophils. In secondary HES and idiopathic HES, other cells produce Th2 cytokines that promote polyclonal expansion and activation of eosinophils.(Roufosse, Cogan and Goldman, 2007) Lymphocytic variant HES (L-HES) is a subtype of secondary HES wherein the source of Th2 cytokines is a phenotypically abnormal CD4+ T cell (typically CD3-CD4+).(Simon, Plotz, Dummer and Blaser, 1999, Walker et al., 2015) We recently demonstrated the importance of Janus kinase-Signal transducer and activation of transcription (JAK-STAT) signaling in L-HES.(Walker, et al., 2015) Specifically, we showed a gain-of-function mutation in STAT3 and overexpression of STAT3 gene targets that were necessary and sufficient for the production of eosinophil-promoting Th2 cytokines. Based on these data, we hypothesized that inhibitors of this pathway, namely the JAK inhibitors tofacitinib (JAK1/3 inhibitor) and ruxolitinib (JAK1/2 inhibitor), would be effective treatment of secondary HES.

Sublingual immunotherapy for allergic rhinitis: subjective versus objective tools to evaluate its success.

Biomarkers that enable objective evaluation of the clinical effects of immunotherapy for allergic rhinitis have yet to be identified. This study included 40 patients who were enrolled in a large randomized, double-blind, placebo-controlled, multicenter study examining the efficacy of sublingual immunotherapy (SLIT) using Japanese cedar (JC) pollen extract during two consecutive pollen seasons from 2010 to 2012. Based on changes in total nasal symptom medication score, patients in the SLIT and placebo groups were subdivided into two subgroups: good responders and poor responders. The levels of JC pollen-specific IL-10+Foxp3+ cells and specific Th2 cytokine-producing cells were measured and the association with the efficacy of SLIT was analysed. The total nasal symptom medication score was significantly lower in the SLIT group compared with the placebo group. The number of JC pollen-specific Th2 cytokine-producing cells increased during the pollen season in the placebo group and in poor responders in the SLIT group; however, the increases were inhibited in the good responders in the SLIT group. The number of JC pollen-specific IL-10+Foxp3+ cells increased only in these good responders. Changes in levels of allergen-specific Th2 cytokine-producing cells and IL-10+Foxp3+ cells could be objective biomarkers for SLIT.

Long lasting SGK1 modulation in response to early life stress: Focus on epigenetic mechanisms

Exposure to a plethora of environmental challenges commonly triggers pathological type 2 cell-mediated inflammation. Here we report the pathological role of the Wnt antagonist Dickkopf-1 (Dkk-1) upon allergen challenge or non-healing parasitic infection. The increased circulating amounts of Dkk-1 polarized T cells to T helper 2 (Th2) cells, stimulating a marked simultaneous induction of the transcription factors c-Maf and Gata-3, mediated by the kinases p38 MAPK and SGK-1, resulting in Th2 cell cytokine production. Circulating Dkk-1 was primarily from platelets, and the increase of Dkk-1 resulted in formation of leukocyte-platelet aggregates (LPA) that facilitated leukocyte infiltration to the affected tissue. Functional inhibition of Dkk-1 impaired Th2 cell cytokine production and leukocyte infiltration, protecting mice from house dust mite (HDM)-induced asthma or Leishmania major infection. These results highlight that Dkk-1 from thrombocytes is an important regulator of leukocyte infiltration and polarization of immune responses in pathological type 2 cell-mediated inflammation.

First in-depth investigation of multiple inhibitory molecule expression by bona fide tumor-reactive T cells in ovarian cancer.

Abstract Ovarian cancer causes more deaths than any other cancer of the female reproductive system. However, novel therapies, including immunotherapy are now being utilized to treat this disease. In addition, efforts have been made to identify and evaluate the subsets of cells within the tumor environment that correspond with patient overall survival. The presence of intraepithelial CD3+ T cells and CD8+ T cells have been correlated with ovarian cancer patient survival and our lab has recently identified CD137 as a biomarker for naturally-occurring tumor-reactive T cells in melanoma and ovarian cancers. However, a thorough elucidation of the immune landscape of endogenous bulk and tumor-reactive T-cell has not been conducted. In our study, we used an in-depth multi-parameter flow cytometry panel to determine the expression of multiple inhibitory molecules, Th1 cytokines, and the effector phenotype in the bulk and tumor-reactive subsets in human ovarian cancer. We observed that the CD4+ and CD8+ T cells found within the tumor environment express inhibitory receptors, very limited Th1 cytokine producing cells and a decreased expression of Granzyme B within the CD8+ subset. The tumor-reactive subset expressed inhibitory molecules, but was still able to elicit an effector phenotype and comprise Th1 cytokine producing cells. In conclusion, using multi-parameter flow cytometry enabled us to investigate the expression of inhibitory molecules and determine the effector phenotype in the bulk TIL and tumor-reactive CD137+ subsets.

Akt1-mediated Gata3 phosphorylation controls the repression of IFNγ in memory-type Th2 cells.

Th2 cells produce Th2 cytokines such as IL-4, IL-5 and IL-13, but repress Th1 cytokine IFNγ. Recent studies have revealed various distinct memory-type Th2 cell subsets, one of which produces a substantial amount of IFNγ in addition to Th2 cytokines, however it remains unclear precisely how these Th2 cells produce IFNγ. We herein show that phosphorylation of Gata3 at Ser308, Thr315 and Ser316 induces dissociation of a histone deacetylase Hdac2 from the Gata3/Chd4 repressive complex in Th2 cells. We also identify Akt1 as a Gata3-phosphorylating kinase, and the activation of Akt1 induces derepression of Tbx21 and Ifng expression in Th2 cells. Moreover, T-bet-dependent IFNγ expression in IFNγ-producing memory Th2 cells appears to be controlled by the phosphorylation status of Gata3 in human and murine systems. Thus, this study highlights the molecular basis for posttranslational modifications of Gata3 that control the regulation of IFNγ expression in memory Th2 cells.

The Wnt Antagonist Dickkopf-1 Promotes Pathological Type 2 Cell-Mediated Inflammation

Exposure to a plethora of environmental challenges commonly triggers pathological type 2 cell-mediated inflammation. Here we report the pathological role of the Wnt antagonist Dickkopf-1 (Dkk-1) upon allergen challenge or non-healing parasitic infection. The increased circulating amounts of Dkk-1 polarized Tcells to T helper 2 (Th2) cells, stimulating a marked simultaneous induction of the transcription factors c-Maf and Gata-3, mediated by the kinases p38 MAPK and SGK-1, resulting in Th2 cell cytokine production. Circulating Dkk-1 was primarily from platelets, and the increase of Dkk-1 resulted in formation of leukocyte-platelet aggregates (LPA) that facilitated leukocyte infiltration to the affected tissue. Functional inhibition of Dkk-1 impaired Th2 cell cytokine production and leukocyte infiltration, protecting mice from house dust mite (HDM)-induced asthma or Leishmania major infection. These results highlight that Dkk-1 from thrombocytes is an important regulator of leukocyte infiltration and polarization of immune responses in pathological type 2 cell-mediated inflammation.

Abstract A49: Investigating the expression of inhibitory surface molecules in ovarian cancer tumor-infiltrating lymphocytes.

Abstract Ovarian cancer causes more deaths than any other cancer of the female reproductive system. However, novel therapies, including immunotherapy are now being utilized to treat this cancer. In addition, efforts have been made to identify and evaluate the subsets of cells within the tumor environment that correspond with patient overall survival. Although the presence of intraepithelial CD3+ T cells and CD8+ T cells have been correlated with patient survival and CD137, a co-stimulatory molecule, has been identified as a biomarker for tumor-reactive cells, studies have not thoroughly investigated the phenotype of the T cells, specifically the CD4+, CD8+, and CD137+ subsets. In our study, we used a multi-parameter flow cytometry to measure inhibitory molecules, Th1 cytokines, and the effector phenotype in the T-cell subsets. We observed that the CD4+ and CD8+ T cells found within the tumor environment express inhibitory receptors, very limited Th1 cytokine producing cells and a decreased expression of Granzyme B within the CD8+ subset. The CD137+ population also expressed inhibitory molecules, but was still able to exhibit an effector phenotype and comprise Th1 cytokine producing cells. In conclusion, using multi-parameter flow cytometry enabled us to investigate the expression of inhibitory molecules on the CD4+, CD8+, and CD137+ subsets and measure their effector phenotype. We found that the T cells express many inhibitory receptors and this may hinder their ability to become optimal effector cells that maintain tumor control. However, future studies utilizing antibodies that block these inhibitory receptors may increase the T cells' ability to exhibit an increased effector phenotype and contain more Th1 cytokine producing cells. Citation Format: Jessica Chacon, Tori Yamamoto, Thomas Garrabrant, Gabor Kari, Andrew Best, Qunrui Ye, Daniel Powell, Jr. Investigating the expression of inhibitory surface molecules in ovarian cancer tumor-infiltrating lymphocytes. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A49.

IL-18 is highly expressed in inflammatory infiltrates of submandibular glands in patients with immunoglobulin G4–related disease

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a new disease entity characterized by high serum IgG4 concentrations, infiltration of IgG4-positive plasmacytes, and fibrosis of various organs. Several groups have reported that IgG4-RD is a unique inflammatory disorder characterized by an immune reaction predominantly mediated by T helper (Th) 2 and regulatory T cells. Meanwhile, recent studies have demonstrated that interleukin (IL) 18 has a potential to trigger the production of Th2 cytokines by Th1 cells. We analyzed IL-18 expression in submandibular glands of patients with IgG4-RD (20 cases) and controls (19 cases) by immunohistochemical analysis and quantitative real-time reverse-transcription polymerase chain reaction. We found that IL-18 was highly expressed in submandibular glands of patients with IgG4-RD than in controls with both protein (P < .05, χ(2) test) and messenger RNA levels (P < .05, Mann-Whitney U test). In addition, the expression of IL-18 and IL-13 was correlated in submandibular glands of patients with IgG4-RD. Moreover, by analyzing dual immunofluorescence staining, a few numbers of cells were double positive for IL-13 and interferon γ at the inflammatory infiltrates of submandibular glands of patients with IgG4-RD. These data suggest a possibility that IL-13 is produced by Th1 cells. We speculated that IL-18 stimulates Th1 cells producing Th2 cytokines and enhances the immune reaction of Th2 cytokines in pathogenesis of IgG4-RD.

Identification of pertussis-specific effector memory T cells in preschool children.

Whooping cough remains a problem despite vaccination, and worldwide resurgence of pertussis is evident. Since cellular immunity plays a role in long-term protection against pertussis, we studied pertussis-specific T-cell responses. Around the time of the preschool acellular pertussis (aP) booster dose at 4 years of age, T-cell memory responses were compared in children who were primed during infancy with either a whole-cell pertussis (wP) or an aP vaccine. Peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with pertussis vaccine antigens for 5 days. T cells were characterized by flow-based analysis of carboxyfluorescein succinimidyl ester (CFSE) dilution and CD4, CD3, CD45RA, CCR7, gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) expression. Before the aP preschool booster vaccination, both the proliferated pertussis toxin (PT)-specific CD4(+) and CD8(+) T-cell fractions (CFSE(dim)) were higher in aP- than in wP-primed children. Post-booster vaccination, more pertussis-specific CD4(+) effector memory cells (CD45RA(-) CCR7(-)) were induced in aP-primed children than in those primed with wP. The booster vaccination did not appear to significantly affect the T-cell memory subsets and functionality in aP-primed or wP-primed children. Although the percentages of Th1 cytokine-producing cells were alike in aP- and wP-primed children pre-booster vaccination, aP-primed children produced more Th1 cytokines due to higher numbers of proliferated pertussis-specific effector memory cells. At present, infant vaccinations with four aP vaccines in the first year of life result in pertussis-specific CD4(+) and CD8(+) effector memory T-cell responses that persist in children until 4 years of age and are higher than those in wP-primed children. The booster at 4 years of age is therefore questionable; this may be postponed to 6 years of age.

Intestinal Helminth Colonization Regulates Lethal Graft Versus Host Disease and Preserves Graft Versus Tumor in Bone Marrow Transplanted Mice

Introduction.Graft versus host disease (GVHD) is a frequent and severe complication of allogeneic bone marrow transplantation (BMT). Novel and less toxic treatment regimens are needed to suppress GVHD and preserve graft versus tumor (GVT). Self-limited intestinal helminth colonization stimulates host regulatory T cell (Treg) subsets. The intestine is a prime organ in GVHD generation, with Tregs playing a pivotal role in controlling GVHD. Treg-mediated suppression of GVHD preserves GVT. We hypothesized that self-limited intestinal colonization with helminths protects BMT mice from lethal acute GVHD and preserves the GVT.Methods. Three weeks after administering 3rd stage adult Heligmosomoides polygyrus larvae into 5-6 week old male WT Balb/C recipient mice (H2d), we initiated H2b→H2d MHC I/II mismatch model of acute GVHD by total body irradiation (TBI; 850 cGy) and administration of total splenic T cells and T cell depleted (TCD) bone marrow (BM) cells from male C57BL/6 WT (MHC: H2b) donors into uninfected control and helminth-infected male wild-type (WT) Balb/C (MHC: H2d) bone marrow recipients. In certain experiments, we used donor T cells from TGFβ RII dominant negative (DN) (TGFβ RII DN) mice (MHC: H2b) whose T cells are unresponsive to TGFβ-mediated immune regulation due to over-expression of a truncated TGFβ receptor II. Th1 (IFNγ, TNFα) cytokine generation was analyzed by ELISA. Splenic and mesenteric lymph node (MLN) cells were stained for H2b, H2d, T cell surface markers and FoxP3. Tissues were analyzed for GVHD-related inflammation. GVT was assessed in uninfected and helminth-infected BMT recipients by administration of luciferase expressing A20 leukemia/lymphoma cells (A20-luc; H2d) and IVIS imaging. Statistical and survival difference between groups was determined by Student’s t-test and Kaplan Meier curves, respectively.Results. Helminths increased ~3-fold CD4 T cell and FoxP3+ Treg TGFβ generation (p<0.01 btw uninfected and helminth-infected). Helminths suppressed donor T cell Th1 cytokine production (p<0.05 btw control and helminth-infected mice (N=3)) and regulated clinical as well as histopathological (colon and lung) GVHD score (p<0.05 between control and helminth-infected, for each parameter from multiple experiments). Helminths promoted the survival of recipient T cells after TBI (Spleen control: 1.4±0.9 x 104 vs. helminth-infected: 11.0±6.9 x 104 CD3+ T cells (N=8; p<0.05); MLN control: 0.09±0.09 x 104 vs. helminth-infected: 6.0±5.2 x 104 (N=8; p<0.001)). Surviving T cells in H. polygyrus-colonized mice were enriched for FoxP3+ Tregs (spleen: 1.16±0.6 x 104 and MLN: 0.65 ±0.56 x 104 FoxP3+ Tregs). Recipient T cells enriched for Tregs survived during GVHD, as analyzed 6 days after BMT (3.3±1.1% of splenic and 15.9±3.5% of MLN host T cells being FoxP3+ Tregs). The number of recipient T cells in uninfected BMT mice was low for further Treg analysis. Helminths increased the number of GVHD-regulating donor-derived H2b+ FoxP3+ Tregs (Spleen: 66±32 x 103 (control) vs. 206±73 x 103 (helminth-infected) Tregs per mouse (p<0.05; N=6); MLN: 1.6 ±1.1 x 103 (control) vs. 4.9±2.0 x 103(helminth-infected) Tregs per mouse (p<0.05; N=4). Helminth infection was associated with >15 weeks survival of 40% of recipients, while all uninfected BMT recipient mice died of GVHD (p<0.01 between uninfected (N=10) and helminth-infected (N=10) WT recipients). Helminths did not promote the survival of recipients, when T cells unresponsive to TGFβ were used as donor lymphocytes. Helminths preserved the GVT in BMT mice transferred A20-luc. All uninfected and helminth-infected TCD BM transferred recipients died within few weeks displaying significant luciferase activity, while no luciferase signal was evident at day 70 in surviving (5/9) helminth-infected mice administered TCD BM and splenic T cells along with A20-luc. Uninfected mice (9/9) transferred splenic T cells, TCD BM and A20-luc died of GVHD without showing luciferase activity.Conclusions. Our results show that (1) helminths stimulate TGFβ producing host T cells and FoxP3+ Tregs that survive BMT conditioning with TBI; (2) helminths regulate GVHD by inducing donor Tregs and in a TGFβ dependent manner; (3) helminths preserve GVT. With a safe side-effect profile, helminths or helminth products have the potential to be investigated as an alternative strategy to prevent or treat GVHD. DisclosuresNo relevant conflicts of interest to declare.

Alcohol consumption and antitumor immunity: dynamic changes from activation to accelerated deterioration of the immune system.

The molecular mechanisms of how alcohol and its metabolites induce cancer have been studied extensively. However, the mechanisms whereby chronic alcohol consumption affects antitumor immunity and host survival have largely been unexplored. We studied the effects of chronic alcohol consumption on the immune system and antitumor immunity in mice inoculated with B16BL6 melanoma and found that alcohol consumption activates the immune system leading to an increase in the proportion of IFN-γ-producing NK, NKT, and T cells in mice not injected with tumors. One outcome associated with enhanced IFN-γ activation is inhibition of melanoma lung metastasis. However, the anti-metastatic effects do not translate into increased survival of mice bearing subcutaneous tumors. Continued growth of the subcutaneous tumors and alcohol consumption accelerates the deterioration of the immune system, which is reflected in the following: (1) inhibition in the expansion of memory CD8+ T cells, (2) accelerated decay of Th1 cytokine-producing cells, (3) increased myeloid-derived suppressor cells, (4) compromised circulation of B cells and T cells, and (5) increased NKT cells that exhibit an IL-4 dominant cytokine profile, which is inhibitory to antitumor immunity. Taken together, the dynamic effects of alcohol consumption on antitumor immunity are in two opposing phases: the first phase associated with immune stimulation is tumor inhibitory and the second phase resulting from the interaction between the effects of alcohol and the tumor leads to immune inhibition and resultant tumor progression.

IL-21 receptor signalling partially mediates Th2-mediated allergic airway responses.

Interleukin-21 (IL-21) has been implicated in the development of Th2-mediated immune responses; however, the exact role it plays in allergic diseases is not well understood. To elucidate the contribution of IL-21 receptor signalling to Th2-dependent immune responses in the lung. We compared allergic airway responses in wild-type BALB/c and Il21r-deficient mice exposed to local airway challenge with house dust mite (HDM). We demonstrate that IL-21R-deficiency reduces HDM-driven airway hyperresponsiveness (AHR) with only partial effects on airway inflammation. Concomitant with the reduction in AHR in Il21r-deficient mice, significant suppression was observed in protein levels of the Th2 cytokines IL-4, and IL-13. In contrast, IL-21R-deficiency was associated with an increase in PBS- and allergen-driven IgE levels, while IgG1 and IgG2a levels were decreased. Moreover, our results suggest that IL-21 may contribute to AHR through its ability to both directly induce Th2 cell survival and to impair regulatory T-cell suppression of Th2 cytokine production. Importantly, we show that IL-21-positive cells are increased in the bronchial mucosa of asthmatics compared with non-asthmatics. These results suggest that IL-21 plays an important role in the allergic diathesis by enhancing Th2 cytokine production through multiple mechanisms including the suppression of Treg inhibitory effects on Th2 cell cytokine production.

Interleukin-1 superfamily member, interleukin-33, in periodontal diseases

Interleukin (IL) -33 is a nuclear protein that is released from damaged cells and acts as an alarmin. We investigated the expression of IL-33 in human gingival fibroblasts after stimulation by tumor necrosis factor alpha (TNF-α). Human periodontal tissue samples were collected and fixed in phosphate-buffered 4% formalin in saline and processed to paraffin blocks. TNF-α was immunostained in samples of ten periodontitis patients and ten controls. Human gingival fibroblasts were isolated using an explant culture technique. The influence of TNF-α on IL-33 in gingival fibroblasts was analyzed using enzyme-linked immunosorbent assay (ELISA). The number of TNF-α positive cells was significantly greater in periodontitis samples than in controls. TNF-α was located mainly in macrophage- and fibroblast-like cells, vascular endothelial cells and epithelial cells. Analysis of IL-33 expression in cell culture lysates showed that TNF-α induced IL-33 in cultured gingival fibroblasts. Periodontitis samples are characterized by Th2 cell dominance, which has been linked to anti-inflammatory responses and periodontal repair. TNF-α-induced IL-33 may link inflammation directly to the IL-33-dependent stimulation of Th2 cytokine producing cells and participate in the induction of lymphocytes, which results in protective, anti-inflammatory and reparative responses.

Natural Helper Cells and TH2-Type Innate Immunity

Natural helper (NH) cells are a newly identified innate lymphocyte population, which respond to a combination of interleukin (IL)-2 and IL-25 or IL-33 to produce large amounts of TH2 cytokines, most notably, IL-5 and IL-13. We identified NH cells in lymphoid clusters in adipose tissues, which we termed fat-associated lymphoid clusters. IL-5 and IL-13 produced by activated NH cells induce eosinophilia and goblet cell hyperplasia, respectively, and play an important role in anti-helminth immunity and allergic diseases, such as asthma. In addition, NH cells produce TH2 cytokines constitutively in the absence of stimulation and support the self-renewal of B1 cells and IgA production by B cells. After our identification of NH cells, other groups have also reported novel TH2 cytokine-producing cells, such as nuocytes, and innate helper type 2 cells. There are similarities and differences between these newly identified cell populations and NH cells. Multipotent progenitor cell type 2 (MPP) cells can differentiate to other myeloid cells, making this a distinct cell type from the others. MPP cells, nuocytes, and innate helper type 2 cells respond to IL-25 alone in vivo, whereas NH cells do not respond to IL-25 without IL-2, although they respond strongly to IL-33. Localization of NH cells in fat-associated lymphoid clusters is an intriguing difference compared with the other cell types, which are found in the lymph node and/or spleen. This article summarizes current information regarding the emerging field of TH2-type innate lymphocytes.

OX40/OX40 Ligand Interactions in T-Cell Regulation and Asthma

The OX40 receptor is preferentially expressed by T cells, and its cognate ligand OX40L is primarily expressed by antigen-presenting cells such as dendritic cells following activation by thymic stromal lymphopoietin (TSLP). TSLP is released by the bronchial epithelium, airway smooth muscle, and some inflammatory cells in response to numerous insults such as allergens, viruses, and physical damage. OX40L is a costimulatory molecule that plays a sentinel role in the adaptive immune response by promoting T helper (Th) 2 polarization of naive T cells within the lymph node. These polarized T cells produce Th2 cytokines such as IL-4, IL-5, and IL-13, which have been implicated particularly in allergic eosinophilic asthma. Animal models have positioned both TSLP and OX40/OX40L as critical in the development of airway inflammation and hyperreactivity. In human disease, there is good evidence that TSLP is upregulated in asthma, but there are limited data to demonstrate overexpression of OX40 or OX40L in disease. Targeting the OX40/OX40L axis or TSLP presents a novel therapeutic strategy that has the potential of modifying the disease process and, therefore, impacting on its natural history. Whether this approach can demonstrate efficacy in established disease rather than at disease onset is unknown. Biologic therapies directed toward OX40/OX40L are in early phases of development, and results from these studies are eagerly awaited.