Increased Th2 Cytokine Research Articles

The Toxicology of Engineered Nanomaterials in Asthma.

The explosive growth of the nanotechnology industry has necessitated the examination of engineered nanomaterials (ENMs) for their toxicity. The unique properties that make ENMs useful also make them a health risk, and individuals with pre-existing diseases such as asthma are likely more susceptible. This review summarizes the current literature on the ability of ENMs to both exacerbate and directly cause asthma. Recent studies highlight the ability of metal nanoparticles (NPs) and carbon nanotubes (CNTs) to not only exacerbate pre-existing asthma in animal models but also initiate allergic airway disease directly. CNTs alone are shown to cause airway mucus production, elevated serum IgE levels, and increased TH2 cytokine levels, all key indicators of asthma. The ability of ENMs to modulate the immune response in asthma varies depending on their physicochemical properties and exposure timing. CNTs consistently exacerbate asthma, as do Ni and TiO2 NPs, whereas some NPs like Au attenuate asthma. Evidence is strong that ENMs can contribute to allergic airway disease; however, more work is required to determine their mechanisms, and more epidemiological studies are needed to validate results from animal models.

Vitamin D receptor restricts T helper 2-biased inflammation in the heart.

The aberrant immune responses play a critical role in the pathogenesis of myocarditis. Vitamin D receptor (VDR) has immune regulatory functions. This study aims to investigate the role of VDR in restricting the immune inflammation in the heart. The human heart samples were obtained from the heart transplantation. T helper (Th)2 and Th1 responses in the heart tissue were characterized by histology and immune assay. VDR-/- mice and recombination activating gene 2-/- mice were used in the experiments to test the role of VDR in maintaining the homeostasis in the heart. The results showed that, besides tissue damage, lower expression of VDR, high frequency of Th2 cells and increase in Th2 cytokines in the hearts of patients with myocarditis at the end stage of heart failure. The spontaneous Th2-biased inflammation was observed in the hearts of VDR-/- mice. CD4+ T cells from the VDR-/- mouse hearts were at highly activating status. The naïve VDR-/- CD4+ T cells and naïve CD4+ T cells from human hearts with myocarditis were prone to differentiate into Th2 cells. VDR formed complexes with GATA3, the interleukin (IL)-4 transcription factor, to prevent the Il4 gene transcription. Transplantation with VDR-/-CD4+ T cells induced the Th2-biased inflammation in the hearts of Rag2-/- mice. Reconstitution of VDR in CD4+ T cells inhibited the Th2-biased inflammation in the heart. VDR-deficiency contributes to the pathogenesis of myocarditis. To enhance the VDR expression in CD4+, T cells haves the therapeutic potential for the treatment of myocarditis.

Abstract B199: Targeting the tumor microenvironment with first-in-class Semaphorin4D MAb for combination immunotherapy

Abstract Purpose: Mechanistic findings in preclinical studies demonstrate that antibody blockade of Semaphorin 4D (SEMA4D, CD100) reduces expansion of MDSC and shifts the balance of immune cells within the TME to facilitate tumor rejection. Efficacy is further enhanced when combined with various immunotherapies. Design of phase 1/2 combination trials of VX15/2503, a humanized IgG4 antibody targeting SEMA4D, with immune checkpoint inhibition will be presented. Methods: Anti-SEMA4D antibodies were evaluated alone and in combination with other immunotherapies in various preclinical models. Antitumor activity and immune response was characterized by immunohistochemistry, flow cytometry, functional assays, and cytokine, chemokine, and gene expression analysis. A phase I trial for single agent VX15/2503 was completed. Results: SEMA4D restricts migration of monocytes and promotes expansion of suppressive myeloid cells in vitro. Strong expression of SEMA4D at the invasive margins of actively growing tumors in vivo restricts the infiltration and modulates polarization of leukocytes in the TME. Antibody blockade of SEMA4D facilitated recruitment of activated DCs and T lymphocytes in preclinical models. MDSCs were significantly reduced in tumor and blood following treatment, and new data characterizing MDSC function in preclinical models will be described. A significant shift towards increased Th1 cytokines (IFNg, TNFa) and CTL-recruiting chemokine CXCL9, with concurrent reduction in Treg-, MDSC- and M2-macrophage promoting chemokines (CCL2, CXCL1, CXCL5,) was also observed. Accordingly, Teff:Treg ratio (3x, p<0.005) and CTL activity (4x, p<0.0001) were increased. These changes in the tumor environment are associated with durable tumor rejection and immunologic memory in murine colon, breast, HNSCC, and melanoma models. Importantly, anti-SEMA4D treatment can further enhance activity of immunotherapies and chemotherapy. For example, combinations with immune checkpoint inhibitor anti-LAG3 or anti-CTLA-4 causes complete tumor regression in 90% or 100% of mice, as compared to ~20% with monotherapy (p<0.01). New data include synergistic activity of combinations of anti-SEMA4D with anti-LAG3 and additional studies combining with epigenetic modulators, including treatment of established tumors. SEMA4D blockade represents a novel mechanism to promote functional immune infiltration into the tumor and enhance immunotherapy. VX15/2503 treatment was well tolerated in a phase I multiple ascending dose trial in patients with advanced refractory solid tumors. Plans for several clinical trials will be presented, including a phase 1b/2 of combination therapy with avelumab in immunotherapy-naïve NSCLC, and combination with anti-PD-1 or Ipilimumab in various indications. A neoadjuvant trial of VX15 with anti-PD-1 in patients with metastatic colorectal and pancreatic cancers will be described, as well as a phase 1/2 trial of VX15 in pediatric and osteosarcoma patients. Citation Format: Elizabeth E. Evans, Holm Bussler, Crystal Mallow, Christine Reilly, Sebold Torno, Maria Scrivens, Cathie Foster, Alan Howell, Leslie Balch, John E. Leonard, Terrence L. Fisher, Clint Allen, Paul Clavijo, Siwen Hu-Lieskovan, Antoni Ribas, Ernest S. Smith, Maurice Zauderer. Targeting the tumor microenvironment with first-in-class Semaphorin4D MAb for combination immunotherapy [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B199.

Increased Th1 cytokine secretion by chiisanogenin and chiisanoside isolated from Acanthopanax chiisanensis

Acanthopanax species (Araliaceae) is used traditionally in Korea, Japan, and China, and is known for its ginsenglike activities and among them, Acanthopanax chiisanensis Nakai is one of the most abundant. In this study, we investigated the effects of chiisanoside and chiisanogenin isolated from A. chiisanensis on the secretion of interleukin (IL)-2, IL-12, tumor necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ) by human lymphocyte cell line U937. Our results show an increase in Th1 cytokine (IL-2, IL-12, TNF-α, and IFN-γ) secretion which suggests that chiisanogenin and chiisanoside from A. chiisanensis may influence the immune response towards a predominance of Th1 cytokines in the immune system. Further studies on Th2 cytokine secretion may be needed to confirm this conclusion.

Hepatitis B virus core particles containing multiple epitopes confer protection against enterovirus 71 and coxsackievirus A16 infection in mice.

Human enterovirus 71 (EV71) and coxsackievirus A16 (CA16) are the two major causative agents of hand-foot-and-mouth disease (HFMD). To investigate novel combined vaccines to prevent EV71 and CA16 infection, we constructed chimeric virus-like particles (tHBc/SPA or tHBc/SP VLPs) displaying conserved epitopes of EV71 (aa 208-222 of VP1 and aa 248-263 of VP2) and CA16 (aa271-285 of VP1) using a truncated hepatitis B virus core carrier (tHBc). Immunization with the chimeric VLPs induced epitope- or virus-specific IgG and neutralization antibodies against EV71 and CA16 in the mice. Compared with inactivated EV71, the chimeric VLPs induced significantly increased Th1 cytokine (IFN-γ, IL-2) production and decreased Th2 cytokine (IL-4, IL-10) responses. Neonatal mice born to dams immunized with the recombinant particles were completely protected from lethal EV71 and partially protected from CA16 infection. Co-expression of the conserved human MHC class I CD4+ T cell epitope (aa248-263 of VP2) did not improve the antiviral immunity of the chimeric VLP vaccine in mice. Our results demonstrate that experimental combination vaccines comprised of EV71 and CA16 epitopes induce both humoral and cellular immune responses and therefore support further preclinical and clinical development of a bivalent VLP vaccine targeting both CA16 and EV71.

Vitexin inhibits inflammation in murine ovalbumin-induced allergic asthma

Vitexin is an important component of various medicinal plants frequently used to treat asthma, such as Crataegus spp., Vitex spp., Passiflora spp., and Echinodorus spp. However, there is no information about the vitexin potential as anti-asthmatic. The aim of the present work was to evaluate the anti-hypersensitive activity of vitexin in a murine ovalbumin (OVA)-induced allergic asthma model. Mice were sensitized to OVA by i.p. injection on days 1st and 10th, followed by a daily challenge with OVA using a nebulizer, from days 19th to 24th. Vitexin or dexamethasone were orally administered 1h before each OVA challenge. Vitexin attenuates migration induced by OVA-hypersensitivity of eosinophil, neutrophil, and mononuclear cells in bronchoalveolar lavage fluid (BALF). Histological analysis of the lungs shows that vitexin suppressed leukocyte infiltration, mucus production and pulmonary edema. Increases in Th2 cytokines in BALF in OVA-induced asthma is also attenuated by vitexin, as well as plasma levels of IgE. Overall, these results suggest that vitexin can suppress OVA-induced allergic inflammation in mice and provide a strong rationale for further developing vitexin as a candidate treatment for allergic hypersensitivity. These data corroborate the popular use of vitexin-rich plants for asthma treatment.

A Novel Multi-Epitope Vaccine Based on Urate Transporter 1 Alleviates Streptozotocin-Induced Diabetes by Producing Anti-URAT1 Antibody and an Immunomodulatory Effect in C57BL/6J Mice.

Hyperuricemia (HUA) is related to diabetes. Uric acid-induced inflammation and oxidative stress are risk factors for diabetes and its complications. Human urate transporter 1 (URAT1) regulates the renal tubular reabsorption of uric acid. IA-2(5)-P2-1, a potent immunogenic carrier designed by our laboratory, can induce high-titer specific antibodies when it carries a B cell epitope, such as B cell epitopes of DPP4 (Dipeptidyl peptidase-4), xanthine oxidase. In this report, we describe a novel multi-epitope vaccine composing a peptide of URAT1, an anti-diabetic B epitope of insulinoma antigen-2(IA-2) and a Th2 epitope (P2:IPALDSLTPANED) of P277 peptide in human heat shock protein 60 (HSP60). Immunization with the multi-epitope vaccine in streptozotocin-induced diabetes C57BL/6J mice successfully induced specific anti-URAT1 antibody, which inhibited URAT1 action and uric acid reabsorption, and increased pancreatic insulin level with a lower insulitis incidence. Vaccination with U-IA-2(5)-P2-1 (UIP-1) significantly reduced blood glucose and uric acid level, increased Th2 cytokines interleukin (IL)-10 and IL-4, and regulated immune reactions through a balanced Th1/Th2 ratio. These results demonstrate that the URAT1-based multi-epitope peptide vaccine may be a suitable therapeutic approach for diabetes and its complications.

The leukotriene receptor antagonist pranlukast attenuates airway remodeling by suppressing TGF-β signaling

Background/ObjectiveAsthma is a chronic airway disease characterized by airway eosinophilic inflammation and remodeling, which are associated with a loss in lung function. Although both contribute significantly to asthma pathogenesis, mechanistic studies and drug discovery have focused on inflammatory targets. In this study, we investigated the effect of the leukotriene receptor antagonist pranlukast on allergic airway inflammation and remodeling in vivo and in vitro. MethodFour groups of female BALB/c mice (control; ovalbumin [OVA]-sensitized and -challenged; dimethyl sulfoxide [DMSO]-treated OVA; and pranlukast-treated OVA) were examined. Lung pathology, cytokine production, and airway hyperresponsiveness (AHR) measurements were compared among these groups. A human fetal lung fibroblast HFL-1 cell line was used in the peribranchial fibrosis analysis. ResultsOVA-sensitized and -challenged mice exhibited allergic airway inflammation and significant increases in Th2 cytokines. Pranlukast-treated mice showed significant attenuation of allergic airway inflammation. The pranlukast treatment decreased AHR and attenuated airway remodeling to goblet cell hyperplasia, collagen deposition, α-smooth muscle actin expression, and pro-fibrotic gene expression. We further demonstrated that pranlukast not only inhibited transforming growth factor-beta 1 (TGF-β1)-induced Smad signaling in human fetal lung fibroblast cells but also simultaneously reduced collagen synthesis and pro-fibrotic gene expression. ConclusionsThe leukotriene receptor antagonist pranlukast can reduce airway inflammation and remodeling by inhibiting TGF-β/Smad signaling in an OVA-sensitized and -challenged asthma mouse model, thus suppressing AHR.

Icaritin Improves Antibody-Induced Thrombocytopenia in a Mouse Model by Regulating T-cell Polarization.

Previous studies have shown that icaritin (ICT) has significant protective effects on immune thrombocytopenia (ITP), and the present study aimed to discuss the mechanism of this protective effect from the aspect of regulating T-cell polarization by an antibody-induced ITP mice model. Mice were given rat anti-mouse CD41 antibody (MWReg30) by intraperitoneal injection for 7 d to produce ITP model. At the same time, ICT was administrated at 10 mg/kg/d orally for 9 d. Peripheral blood platelets were counted by hematology analyzer. Spleen index was also tested. Spleen T-helper cell (Th), cytotoxic T-cell (CTL), Th1, Th2, Th17, regulatory T-cell (Treg), and follicular helper T-cell (Tfh) were quantified by flow cytometry. Serum Th1/Th2/Th17 cytokines were tested by mouse Th1/Th2/Th17 cytometric bead array (CBA) kit and transforming growth factor beta (TGF-β) were analyzed by enzyme-linked immunosorbent assay (ELISA) kit. The results indicated that ICT (10 mg/kg) protected against MWReg30-induced ITP, as evidenced by increased blood platelets and decreased spleen index. In addition, the imbalance of Th/CTL in ITP mice spleen was regulated by ICT. Meanwhile, ICT inhibited Th1, Th17, and Tfh and improved Th2 and Treg in ITP mice spleen. Furthermore, the results of CBA and ELISA suggested that ICT decreased serum Th1- and Th17-related cytokines and increased Th2 cytokines, as well as promoted the release of TGF-β. These results demonstrated that the protective effect of ICT on ITP was mediated by regulating T-cell polarization.

Reduced CD200 expression is associated with altered Th1/Th2 cytokine production in placental trophoblasts from preeclampsia.

To determine if altered trophoblast CD200 and CD200R expressions promote inflammatory cytokine production in preeclamptic placentas. Placental tissue CD200 and CD200R expressions were determined by immunostaining. Tissue sections from first-, second-, and third-trimester, normal term, and preeclamptic placentas were used. CD200 and CD200R expressions and cytokine production of TNFα, sTNFR1, INFγ, IL-4, IL-6, IL-8, and IL-10 were determined in trophoblasts from normal and preeclamptic placentas and in normal trophoblasts transfected with CD200 siRNA. CD200, but not CD200R, expression was significantly reduced in trophoblasts from preeclamptic compared to normal placentas. Trophoblast from preeclamptic placentas and trophoblast transfected with CD200 siRNA produced significantly more TNFα, sTNFR1, IL-6, and IL-8, but significantly less IL-10, than trophoblasts from normal control placentas. Downregulation of CD200 expression resulted in an imbalance of increased Th1 cytokine and decreased Th2 cytokine production in placental trophoblasts in preeclampsia.

Local IL-25 contributes to Th2-biased inflammatory profiles in nasal polyps.

IL-25 has been proposed to play a key role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to evaluate the association of IL-25 with the Th2-biased inflammatory profiles in CRSwNP. Nasal polyp (NP) tissues and control uncinate process tissues were collected from 92 patients with CRSwNP, 20 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 16 normal control subjects. IL-25 expression was examined using immunohistochemistry and immunofluorescence staining, flow cytometry, RT-qPCR, and ELISA. The inflammatory profiles and clinical characteristics of 2 NP subtypes (IL-25high and IL-25low ) were evaluated, and the effects of IL-25 on Th2 cytokine production in cultured dispersed polyp cells were examined invitro. The mRNA and protein levels of IL-25 were significantly increased in the polyp tissues compared with the control uncinate process tissues. The IL-25high subtype showed greater computed tomography scores, endoscopic scores, and Th2 response. Exposure to IL-25 activated type 2 innate lymphoid cells and Th2 cells in NP simultaneously which further increased Th2 cytokine production invitro. Local IL-25 plays a crucial role in promoting Th2-biased inflammatory profiles in NP and may serve as a promising therapeutic target in CRSwNP patients.

Endocrine Factors Determining Immune Polarization during Perinatal Transition.

In utero the skewness of the adaptive immune system towards Th2 ('antiinflammatory') direction and low of Th1/Th2 cell ratio defend the fetus against rejection by the maternal immune system. Th2 dominance at birth is also of importance as it prevents uncontrolled inflammatory processes during parturition. This condition should change rapidly after birth. In an extrauterine milieu that is inherent with exposure to microorganisms, Th1 ('proinflammatory') polarization (i. e. increased Th1 cytokine production along with high Th1/Th2 ratio) are required to maintain an efficient immune response. After birth, maternal hormone supplies including estrogen, progesterone, testosterone, and antiinflammatory prostaglandins cease abruptly. As these hormones have an immune modulatory action favoring Th2, and inhibiting Th1 polarization, their low level supports the strengthening of Th1-type immunity. During parturition a dramatic but transient increase of several hormones (oxytocin, thyorid hormones, and catecholamines) occurs. Again, the net effect of high hormone levels favors Th2 activation, followed by Th1 polarization when hormonal levels reach their postnatal levels. The perinatal change of these components results in the quick cessation of Th1 inhibition and supports the maturation of adaptive immunity to provide an effective response against extrauterine microorganisms.

Epithelial-derived IL-33 promotes intestinal tumorigenesis in ApcMin/+ mice

Increased expression of Interleukin (IL)-33 has been detected in intestinal samples of patients with ulcerative colitis, a condition associated with increased risk for colon cancer, but its role in the development of colorectal cancer has yet to be fully examined. Here, we investigated the role of epithelial expressed IL-33 during development of intestinal tumors. IL-33 expression was detected in epithelial cells in colorectal cancer specimens and in the ApcMin/+ mice. To better understand the role of epithelial-derived IL-33 in the intestinal tumorigenesis, we generated transgenic mice expressing IL-33 in intestinal epithelial cells (V33 mice). V33 ApcMin/+ mice, resulting from the cross of V33 with ApcMin/+ mice, had increased intestinal tumor burden compared with littermate ApcMin/+ mice. Consistently, ApcMin/+ mice deficient for IL-33 receptor (ST2), had reduced polyp burden. Mechanistically, overexpression of IL-33 promoted expansion of ST2+ regulatory T cells, increased Th2 cytokine milieu, and induced alternatively activated macrophages in the gut. IL-33 promoted marked changes in the expression of antimicrobial peptides, and antibiotic treatment of V33 ApcMin/+ mice abrogated the tumor promoting-effects of IL-33 in the colon. In conclusion, elevated IL-33 signaling increases tumor development in the ApcMin/+ mice.

Abstract 3661: Breaking down the barrier restricting infiltration and differentiation of APC in the tumor microenvironment with a first-in-class antibody targeting Semaphorin4D, and rational combination therapies

Abstract Purpose: We expand mechanistic findings in preclinical studies to demonstrate that antibody blockade of Semaphorin 4D (SEMA4D, CD100) reduces expansion of MDSC and shifts the balance of myeloid cells within the TME to facilitate tumor rejection. Efficacy is further enhanced when combined with various immunotherapies. Design of Phase 1b/2 combination trials of VX15/2503, a humanized IgG4 antibody targeting SEMA4D, with immune checkpoint inhibition will be presented. Methods: Anti-SEMA4D antibodies were evaluated alone and in combination with other immunotherapies in various preclinical models. Anti-tumor activity and immune response was characterized by immunohistochemistry, flow cytometry, functional assays, and cytokine, chemokine and gene expression analysis. A Phase I trial for single agent VX15/2503 was completed, and several 1b/2 combination immunotherapy trials are planned. Results: SEMA4D restricts migration of monocytes and promotes expansion of suppressive myeloid cells in vitro. Strong expression of SEMA4D at the invasive margins of actively growing tumors in vivo restricts the infiltration and modulates polarization of leukocytes in the TME. Antibody blockade of SEMA4D facilitated recruitment of activated DCs and T lymphocytes in preclinical models. M-MDSCs were significantly reduced in tumor and blood following treatment. A significant shift towards increased Th1 cytokines (IFNγ, TNFα) and CTL-recruiting chemokine CXCL9, with concurrent reduction in Treg-, MDSC- and M2-macrophage promoting chemokines (CCL2, CXCL1, CXCL5) was observed. Accordingly, Teff:Treg ratio (3x, p<0.005) and CTL activity (4x, p<0.0001) were increased. These coordinated changes in the tumoral immune context are associated with durable tumor rejection and immunologic memory in murine colon, breast, and melanoma models. Importantly, anti-SEMA4D treatment can further enhance activity of co-administered immunotherapies and chemotherapy. For example, the combination with immune checkpoint inhibitor anti-CTLA-4 causes complete tumor regression in 100% of mice, as compared to 22% with monotherapy (p<0.01). Additional studies of combinations with other immunomodulators, including treatment of established tumors with HDAC inhibitor Entinostat, will be presented. Conclusions: SEMA4D blockade represents a novel mechanism to promote functional immune infiltration into the tumor and enhance immunotherapy. VX15/2503 treatment was well tolerated in a Phase I multiple ascending dose trial in patients with advanced refractory solid tumors. Phase 1b/2 trials of combination therapy with avelumab in NSCLC patients who are immunotherapy naïve, and combinations with anti- anti-PD-1 and/or anti-CTLA-4 in melanoma and HNSCC patients who are refractory to PD1 inhibitors are planned in 2017. Citation Format: Elizabeth E. Evans, Holm Bussler, Crystal Mallow, Christine Reilly, Sebold Torno, Maria Scrivens, Cathie Foster, Alan Howell, Stephen R. Comeau, Leslie Balch, Alyssa Knapp, John E. Leonard, Terrence L. Fisher, Siwen Hu-Lieskovan, Antoni Ribas, Ernest S. Smith, Maurice Zauderer. Breaking down the barrier restricting infiltration and differentiation of APC in the tumor microenvironment with a first-in-class antibody targeting Semaphorin4D, and rational combination therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3661. doi:10.1158/1538-7445.AM2017-3661

Fungal immunomodulatory protein-fve could modulate airway remodel through by affect IL17 cytokine.

Asthma is one of the most common allergic diseases. Our previous studies have reported that FIP-fve in acute allergic mouse model can reduce inflammation, improve the balance of the Th1/Th2 system. However, the effects of reducing airway remodeling on FIP-fve is still unknown. We hypothesized that orally administrated FIP-fve should be able to reduce airway remodeling in chronic allergic models. The chronic asthma animal model was established with 6-8 weeks female Balb/c mice. After intranasal challenges with OVA, the airway inflammation and AHR were determined by a BUXCO system. BALF was analyzed with Liu's stain and ELISA assay. Lung histopathologic changes and Collagen deposition were assayed with H&E, Masson's trichrome and IHC stain. FIP-fve significantly decreased the number of infiltrating inflammatory cells and Th2 cytokines and increased Th1 cytokines in BALF and serum compared with the OVA sensitized mice. FIP-fve had a better effect than corticosteroid could reduce infiltrating cells in lung especially neutrophils and eosinophils. We also found that the oral FIP-fve group suppressed IL-17 and enhanced IL-22 in the serum and BALF. In addition, oral FIP-fve decreased MMP9 expression, collagen expression and airway remodeling in lung tissues. FIP-fve had anti-inflammatory effects on OVA-induced airway inflammation and an effect to inhibited Th17cells to reduced airway remodeling and collagen expression. Moreover, FIP-fve might be a potential alternative therapy for allergic airway diseases.

Biofilm-Induced Type 2 Innate Immunity in a Cystic Fibrosis Model of Pseudomonas aeruginosa.

Biofilm-producing strains of Pseudomonas aeruginosa are a major cause of morbidity and mortality in cystic fibrosis (CF) patients. In these patients, increased levels of IL-17 as well as of IL-5 and IL-13 along with arginase (Arg)-positive macrophages have been observed in bronchoalveolar lavage fluid. While IL-17 is a strong proinflammatory cytokine associated with host defense against bacterial and fungal infections and is also elevated in several autoimmune diseases, IL-5/IL-13 and Arg1-positive M2 macrophages are part of the anti-inflammatory type 2 (Th2) immunity. To study whether increased IL-5 and IL-13 levels are related to biofilm formation, which is frequently observed in CF patients colonized by P. aeruginosa, we utilized an agarose bead-embedded P. aeruginosa rat model commonly employed in in vivo biofilm studies. We showed that “sterile” agarose bead instillation in rat notably increased lung transcript levels of IL-5 and IL-13 at two post-instillation study-points, day 1 and day 3. Concurrently, increased infiltration of type 2 innate cells such as eosinophils and Arg1 positive M2 activated macrophages (Arg1+CD68+) was also observed both at day 1 and day 3 while the proportion of M1 activated macrophages (iNOS+CD68+) at these time-points decreased. In contrast, P. aeruginosa-loaded beads caused a drastic elevation of proinflammatory Th1 (IFNγ, TNFα, IL-12a) and antibacterial Th17 (IL-17a, IL-17f, IL-22, IL-23a) cytokines along with a high influx of neutrophils and M1 macrophages, while Th2 cytokines (IL-5 and IL-13) drastically declined at day 1 post-infection. Interestingly, at day 3 post-infection, both Th1 and Th17 cytokines sharply declined and corroborated with decreased M1 and increased M2 macrophages. These data suggest that while IL-17 is linked to episodes of acute exacerbations of infection in CF patients, the increased Th2 cytokines and M2 macrophages observed in these patients are largely due to the biofilm matrix. The data presented here has important implications for clinical management of CF patients.

Identification of differentially expressed genes associated with clinical response after treatment of breast cancer skin metastases with imiquimod.

e12541 Background: Imiquimod, a Toll-like receptor 7 agonist, activates innate immunity and has a response rate of 20% in breast cancer skin metastases. Tumor regression is associated with increased tumor infiltrating lymphocytes and increased Th1 cytokines in tumor supernatant, however gene expression changes are unknown. This is the first report of gene expression changes induced by imiquimod treatment in breast cancer skin metastases. Methods: FFPE-extracted mRNA from 8 patients pre and post 8 weeks of imiquimod treatment was analyzed using Nanostring PanCancer Immune Profiling Panel. Gene expression and pathway analysis was conducted with nSolver 3.0 with clinical response as outcome, controlling for HER2 ER/PR status, with 5% significance level used. Results: In all patients, imiquimod was associated with upregulation of genes in innate immunity such as TLR7, IL-1, T-cell, B-cell, and NK related genes. Three patients had a clinical response after imiquimod. Forty-two differentially expressed genes were identified in responders vs. non-responders after imiquimod. Reponders had up-regulation of T cell (CD2, SPN), NK cell (KLRC2), B cell (CD48), lymphocyte (LY96), and IL-2 (IL2RG) related genes. The top upregulated pathways were cytotoxicity, NK cell function, and antigen processing. Pre-treatment, the responders had upregulation of TNF and IL-17 related genes (TNFRSF10B, IL17RA) compared to non-responders. Comparing pre-treatment to post-treatment, Imiquimod was associated with mRNA expression changes in 72 genes in responders vs non responders. The top upregulated genes involved activation of lymphocytes (SH2D1A), NK cells (KLRC2), DCs (CLEC4C), several chemokines, IL7R and immune regulators PLD1 and IRF5. Conclusions: Clinical response to Imiquimod treatment of breast cancer skin metastases is associated with upregulation of genes in innate immunity suggestive of an anti-tumor immune response. Inhibition of negative feedback by addition of PLD1 inhibitors may enhance treatment response. Understanding the genetic signature of imiquimod can enhance prediction of response and inform possible combination therapies in the future.

Efficacy and safety of pegylated human IL-10 (AM0010) in combination with an anti-PD-1 in renal cell cancer.

4567 Background: IL-10 has anti-inflammatory activity and stimulates the cytotoxicity and proliferation of CD8+ T cells at higher concentrations. IL-10 receptors and PD1 are expressed on activated CD8 T cells, providing a rationale for combining AM0010 and an anti-PD1. The efficacy and safety profile for AM0010 alone was established in poor to intermediate risk RCC pts treated in 3rdLOT. Objective responses were observed in 4 of 15 pts with RCC. In the dose escalation of AM0010 plus pembrolizumab, 4 of 8 patients had an objective response. The mPFS was 16.7 months and the mOS has not been reached, median follow up (mFU) is 19.3 mo. Methods: In this Phase 1b, 29 pts. with metastatic RCC were enrolled until Nov. 18 2016 on AM0010 (10 ug/kg daily SC) and nivolumab (3mg/kg, q2wk IV). 2 had favorable, 20 had intermediate and 4 had poor IMDC risk (3 were not available). Pts. had a median of 1 prior therapy (range 1-3). All pts. had received a VEGFR-TKI. Tumor responses were assessed with irRC. Immune responses were evaluated by serum cytokines, activation of blood derived T cells and peripheral T cell clonality. Results: AMO010 plus nivolumab was well tolerated. TrAEs were reversible. There were no autoimmune colitis, pneumonitis, or endocrine disorders. 14 patients had at least 1 G3/4 TrAE, including anemia (9), thrombocytopenia (5), hypertriglyceridaemia (4). 2 pts had a reversible cytokine release syndrome with splenomegaly and increased immune mediated red blood cell phagocytosis most likely precipitated by T-cell activation, as both pts had tumor responses. As of Jan 31 2017, partial responses (PR) were observed in 8 of 26 evaluable pts (31%). An additional 13 of 26 pts had stable disease (41%), 7 pts had tumor reductions of more than 30%. The mPFS and mOS has not been reached with a mFU of 5.2 mo. (range 0.3-10.3). AM0010 + anti-PD1 increased Th1 cytokines in the serum while decreasing TGFb, an expansion of proliferating PD1+ Lag3+ activated CD8 T cells and de-novo oligoclonal expansion of T cell clones in the blood. Conclusions: AM0010 in combination with nivolumab is well-tolerated in RCC pts. The efficacy and the observed CD8 T cell activation is promising and encourages the continued study of AM0010 in combination with nivolumab. Clinical trial information: NCT02009449.

PEGylated human IL-10 (AM0010) in combination with pembrolizumab in anti-PD1 and CTLA-4 refractory melanoma.

3084 Background: Melanoma has a high response rate to anti-PD-1 alone. More than 50% of melanoma on anti-PD-1 progress within one year. IL-10 inhibits inflammation and stimulates the cytotoxicity and proliferation of tumor infiltrating CD8+ T cells at higher concentrations. IL-10 receptors and PD1 are induced on activated CD8 T cells, providing a mechanistic rationale for combining AM0010 and anti-PD1. AM0010 alone has established tolerability and anti-tumor activity in a phase 1 study. Objective responses were observed in 4 of 15 pts with RCC, one patient with uveal melanoma and cutaneous T cell lymphoma, each. Methods: 25 melanoma pts who had progressed on prior anti-CTLA4 and on prior anti-PD-1 containing regimen were treated with AM0010 (20mg/kg qd, SQ) and pembrolizumab (2mg/kg, q3wk IV). Patients had a median of 3.5 prior therapies (range 2-6) and a median of 2 prior immune therapies (range 1-6). Tumor responses were monitored following irRC. Immune responses were measured by analysis of serum cytokines, activation of blood derived T cells and peripheral T cell clonality. Results: AM0010 plus pembrolizumab was well tolerated. All treatment related adverse events (TrAE) were reversible. DLTs and SAEs leading to study discontinuation were not observed. G3/4 TrAEs were observed in 11 of 25 pts and included fatigue (8) thrombocytopenia (6), anemia (4), rash (1) and hypertriglyceridemia (1). There were no objective tumor responses. 9 of 20 evaluable pts had stable disease (DCR = 45%). As of Jan. 31 2017, the mPFS was 2.0 mo. and the mOS was not reached, with a mFU of 15.5 mos (range 10.0-18.4). AM0010 plus pembrolizumab increased Th1 cytokines as well as the number and proliferation of PD1+ Lag3+ activated CD8 T cells in the blood while reducing inflammatory cytokines and TGFb. A de-novo oligoclonal expansion of T cell clones in the blood and an increase of tumor infiltrating Granzyme+ PD1+ CD8+ T cells in tumor biopsies of treated patients was observed. Conclusions: AM0010 in combination with anti-PD1 is well-tolerated in refractory melanoma pts. The clinical activity and the observed CD8+ T cell activation may suggest to study AM0010 in combination with an anti-PD-1 in melanoma patients with less prior treatments. Clinical trial information: NCT02009449.

PEGylated human IL-10 (AM0010) monotherapy in refractory metastatic colorectal cancer.

3571 Background: Colorectal Cancer (CRC) has been refractory to immune therapies. The clinical benefit of immunotherapy is thought to depend on the expansion of activated, intratumoral, tumor specific cytotoxic CD8+ T cells which are low in most CRCs. AM0010 stimulates the survival, expansion and cytotoxicity of intratumoral CD8+ T cells. Patients with CRC who have progressed on SOC first and second line of therapy have a reported 7.1 months OS with TAS-102 (Meyer et al. NEJM372;20, 2015). In this Phase 1 study the efficacy of AM0010 was studied in refractory metastatic CRC patients. Methods: CRC pts progressing on a median of 4 prior therapies (range 2-7) were treated daily with AM0010 in doses of 1 ug/kg SQ daily to 40 ug/kg in a dose escalation design. Tumor responses were assessed using irRC. Serum cytokines, activation of blood derived T cells and peripheral T cell clonality were analyzed. Pretreatment archival tissue samples were evaluated by IHC for tumor infiltration by CD8+T cells. Results: AM0010 was tolerated with reversible TrAEs. 10 pts (of 27) had a G3/4 TrAE. There were no objective responses. 11 patients were treated in dose escalation cohorts (1-10 ug/kg) and 16 pts were treated at or above RP2D (20 ug/kg or 40 ug/kg). Seven of 25 pts with at least one radiographic response evaluation had stable disease at 8 weeks. One patient had SD for 19.4 months. The mPFS (ITT n = 27 pts) was 1.6 months, mOS was 11.7 (range 2.4 – 32+) months. The median follow-up is 25.2 months (range 13-35). AM0010 increased Th1 cytokines IL-18 and IFNg in the serum of patients, while decreasing mediators of chronic, tumor promoting inflammation (Th17 cytokines) and TGFb. Tumor infiltrating granzyme B+ CD8+ T cells increased during the treatment. AM0010 induced de-novo oligoclonal expansion of T cell clones in patients. Conclusions: AM0010 is well tolerated in patients with refractory CRC. Although objective tumor responses were not seen in this very advanced CRC population, the observed immune activation including clonal T cell expansion, prolonged stable disease, and the mOS of 11.7 months is encouraging in this advanced CRC population. Future study of AM0010 in combination with FOLFOX in a second – line of therapy colorectal cancer patients is being planned. Clinical trial information: NCT02009449.