Ingrid Teige

Neuron-mediated generation of regulatory T cells from encephalitogenic T cells suppresses EAE.

Neurons have been neglected as cells with a major immune-regulatory function because they do not express major histocompatibility complex class II. Our data show that neurons are highly immune regulatory, having a crucial role in governing T-cell response and central nervous system (CNS) inflammation. Neurons induce the proliferation of activated CD4+ T cells through B7-CD28 and transforming growth factor (TGF)-β1–TGF-β receptor signaling pathways, resulting in amplification of T-cell receptor signaling through phosphorylated ZAP-70, interleukin (IL)-2 and IL-9. The interaction between neurons and T cells results in the conversion of encephalitogenic T cells to CD25+TGF-β1+CTLA-4+FoxP3+ T regulatory (Treg) cells that suppress encephalitogenic T cells and inhibit experimental autoimmune encephalomyelitis. Suppression is dependent on cytotoxic T lymphocyte antigen (CTLA)-4 but not TGF-β1. Autocrine action of TGF-β1, however, is important for the proliferative arrest of Treg cells. Blocking the B7 and TGF-β pathways prevents the CNS-specific generation of Treg cells. These findings show that generation of neuron-dependent Treg cells in the CNS is instrumental in regulating CNS inflammation.

IFN-beta Gene Deletion Leads to Augmented and Chronic Demyelinating Experimental Autoimmune Encephalomyelitis.

Since the basic mechanisms behind the beneficial effects of IFN-β in multiple sclerosis (MS) patients are still obscure, here we have investigated the effects of IFN-β gene disruption on the commonly used animal model for MS, experimental autoimmune encephalomyelitis (EAE). We show that IFN-β knockout (KO) mice are more susceptible to EAE than their wild-type (wt) littermates; they develop more severe and chronic neurological symptoms with more extensive CNS inflammation and demyelination. However, there was no discrepancy observed between wt and KO mice regarding the capacity of T cells to proliferate or produce IFN-γ in response to recall Ag. Consequently, we addressed the effect of IFN-β on encephalitogenic T cell development and the disease initiation phase by passive transfer of autoreactive T cells from KO or wt littermates to both groups of mice. Interestingly, IFN-β KO mice acquired a higher incidence and augmented EAE regardless of the source of T cells. This shows that the anti-inflammatory effect of endogenous IFN-β is predominantly exerted on the effector phase of the disease. Histopathological investigations of CNS in the effector phase revealed an extensive microglia activation and TNF-α production in IFN-β KO mice; this was virtually absent in wt littermates. This coincided with an increase in effector functions of T cells in IFN-β KO mice, as measured by IFN-γ and IL-4 production. We suggest that lack of endogenous IFN-β in CNS leads to augmented microglia activation, resulting in a sustained inflammation, cytokine production, and tissue damage with consequent chronic neurological deficits.

CD1-Dependent Regulation of Chronic Central Nervous System Inflammation in Experimental Autoimmune Encephalomyelitis

The existence of T cells restricted for the MHC I-like molecule CD1 is well established, but the function of these cells is still obscure; one implication is that CD1-dependent T cells regulate autoimmunity. In this study, we investigate their role in experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, using CD1-deficient mice on a C57BL/6 background. We show that CD1−/− mice develop a clinically more severe and chronic EAE compared with CD1+/+ C57BL/6 mice, which was histopathologically confirmed with increased demyelination and CNS infiltration in CD1−/− mice. Autoantigen rechallenge in vitro revealed similar T cell proliferation in CD1+/+ and CD1−/− mice but an amplified cytokine response in CD1−/− mice as measured by both the Th1 cytokine IFN-γ and the Th2 cytokine IL-4. Investigation of cytokine production at the site of inflammation showed a CNS influx of TGF-β1-producing cells early in the disease in CD1+/+ mice, which was absent in the CD1−/− mice. Passive transfer of EAE using an autoreactive T cell line induced equivalent disease in both groups, which suggested additional requirements for activation of the CD1-dependent regulatory pathway(s). When immunized with CFA before T cell transfer, the CD1−/− mice again developed an augmented EAE compared with CD1+/+ mice. We suggest that CD1 exerts its function during CFA-mediated activation, regulating development of EAE both through enhancing TGF-β1 production and through limiting autoreactive T cell activation, but not necessarily via effects on the Th1/Th2 balance.

IFN-β Inhibits T Cell Activation Capacity of Central Nervous System APCs

We have previously investigated the physiological effects of IFN-β on chronic CNS inflammation and shown that IFN-β−/− mice develop a more severe experimental autoimmune encephalomyelitis than their IFN-β+/− littermates. This result was shown to be associated with a higher activation state of the glial cells and a higher T cell cytokine production in the CNS. Because this state suggested a down-regulatory effect of IFN-β on CNS-specific APCs, these results were investigated further. We report that IFN-β pretreatment of astrocytes and microglia (glial cells) indeed down-modulate their capacity to activate autoreactive Th1 cells. First, we investigated the intrinsic ability of glial cells as APCs and report that glial cells prevent autoreactive Th1 cells expansion while maintaining Ag-specific T cell effector functions. However, when the glial cells are treated with IFN-β before coculture with T cells, the effector functions of T cells are impaired as IFN-γ, TNF-α, and NO productions are decreased. Induction of the T cell activation marker, CD25 is also reduced. This suppression of T cell response is cell-cell dependent, but it is not dependent on a decrease in glial expression of MHC class II or costimulatory molecules. We propose that IFN-β might exert its beneficial effects mainly by reducing the Ag-presenting capacity of CNS-specific APCs, which in turn inhibits the effector functions of encephalitogenic T cells. This affect is of importance because activation of encephalitogenic T cells within the CNS is a prerequisite for the development of a chronic progressive CNS inflammation.

A phase 1 dose-escalation study of antibody BI-505 in relapsed/refractory multiple myeloma

Purpose: This multicenter, first-in-human study evaluated safety, tolerability, pharmacokinetics, and pharmacodynamics of BI-505, a human anti-ICAM-1 monoclonal antibody, in advanced relapsed/refractory multiple myeloma patients. Experimental Design: BI-505 was given intravenously, every 2 weeks, at escalating doses from 0.0004 to 20 mg/kg, with extension of therapy until disease progression for responding or stable patients receiving 0.09 mg/kg or higher doses. Results: A total of 35 patients were enrolled. The most common adverse events were fatigue, pyrexia, headache, and nausea. Adverse events were generally mild to moderate, and those attributed to study medication were mostly limited to the first dose and manageable with premedication and slower infusion. No maximum tolerated dose was identified. BI-505′s half-life increased with dose while clearance decreased, suggesting target-mediated clearance. The ICAM-1 epitopes on patient bone marrow myeloma were completely saturated at 10 mg/kg doses. Using the International Myeloma Working Group criteria, 7 patients on extended therapy had stable disease for more than 2 months. Conclusions: BI-505 can be safely administered at doses that saturate myeloma cell ICAM-1 receptors in patients. This study was registered at www.clinicaltrials.gov (NCT01025206). Clin Cancer Res; 21(12); 2730–6. ©2015 AACR.

Development and Characterization of Monoclonal Antibodies Specific for Mouse and Human Fcγ Receptors

FcγRs are key regulators of the immune response, capable of binding to the Fc portion of IgG Abs and manipulating the behavior of numerous cell types. Through a variety of receptors, isoforms, and cellular expression patterns, they are able to fine-tune and direct appropriate responses. Furthermore, they are key determinants of mAb immunotherapy, with mAb isotype and FcγR interaction governing therapeutic efficacy. Critical to understanding the biology of this complex family of receptors are reagents that are robust and highly specific for each receptor. In this study, we describe the development and characterization of mAb panels specific for both mouse and human FcγR for use in flow cytometry, immunofluorescence, and immunocytochemistry. We highlight key differences in expression between the two species and also patterns of expression that will likely impact on immunotherapeutic efficacy and translation of therapeutic agents from mouse to clinic.

Local therapy with CpG motifs in a murine model of allergic airway inflammation in IFN-β knock-out mice

BackgroundCpG oligodeoxynucleotides (CpG-ODN) are capable of inducing high amounts of type I IFNs with many immunomodulatory properties. Furthermore, type-I IFNs have been proposed to play a key role in mediating effects of CpG-ODN. The precise role of IFN-β in the immunomodulatory effects of CpG-ODN is not known.ObjectiveHere, we aimed to elucidate the role of IFN-β in the anti-allergic effect of CpG motifs.MethodsWe assessed the immune response in OVA-primed/OVA-challenged IFN-β knockout (-/-) mice compared to wild type (WT) control, after intranasal and systemic treatment with synthetic CpG motifs.ResultsVaccination with CpG-ODN reduced the number of cells in airways of OVA-sensitized WT but not IFN-β-/- mice. Although airway eosinophilia was reduced in both treated groups, they were significantly higher in IFN-β-/- mice. Other inflammatory cells, such as lymphocytes and macrophages were enhanced in airways by CpG treatment in IFN-β-/- mice. The ratio of IFN-γ/IL-4 cytokines in airways was significantly skewed to a Th1 response in WT compared to IFN-β-/- group. In contrast, IL-4 and IgE were reduced with no differences between groups. Ag-specific T-cell proliferation, Th1-cytokines such as IFN-γ, IL-2 and also IL-12 were significantly lower in IFN-β-/- mice. Surprisingly, we discovered that intranasal treatment of mice with CpG-ODN results in mild synovitis particularly in IFN-β-/- mice.ConclusionOur results indicate that induction of Th1 response by therapy with CpG-ODN is only slightly and partially dependent on IFN-β, while IFN-β is not an absolute requirement for suppression of airway eosinophilia and IgE. Furthermore, our finding of mild synovitis is a warning for possible negative effects of CpG-ODN vaccination.

Suppression of EAE by oral tolerance is independent of endogenous IFN-beta whereas treatment with recombinant IFN-beta ameliorates EAE.

IFN‐β is anticipated to have an important function in mucosal tolerance, as it is one of the major cytokines produced by plasmacytoid dendritic cells, and has recently been suggested as central to the maintenance of mucosal homeostasis. Here, we have investigated whether oral tolerance is dependent on endogenous IFN‐β by feeding low‐dose self‐antigen myelin basic protein to IFN‐β−/− mice with subsequent induction of experimental autoimmune encephalomyelitis (EAE). Our study shows that oral tolerance was readily induced in IFN‐β−/− mice compared with their wild‐type littermates (IFN‐β+/+). The non‐self‐antigen ovalbumin induced oral tolerance in both groups. These data indicate that endogenous IFN‐β is not required for induction of oral tolerance, whereas delivery of recombinant IFN‐β results in significant reduction in clinical score of EAE. Oral tolerance induction was associated with lower production of antigen‐specific IFN‐γ, no shift toward antigen‐specific Th2, Th17 or TGF‐β response was observed. Oral tolerance in IFN‐β−/− mice was also associated with the induction of regulatory and memory T cells in the mucosal‐associated immune organs, however this was not a prerequisite for establishment of oral tolerance.

A single-arm, open-label, phase 2 clinical trial evaluating disease response following treatment with BI-505, a human anti-intercellular adhesion molecule-1 monoclonal antibody, in patients with smoldering multiple myeloma

Background Smoldering multiple myeloma (SMM) is an indolent disease stage, considered to represent the transition phase from the premalignant MGUS (Monoclonal Gammopathy of Undetermined Significance) state towards symptomatic multiple myeloma (MM). Even though this diagnosis provides an opportunity for early intervention, few treatment studies have been done and the current standard of care is observation until progression. BI-505, a monoclonal antibody directed against intercellular adhesion molecule 1 (ICAM-1) with promising anti-myeloma activity in preclinical trials, is a possible treatment approach for this patient category with potential to eliminate tumor cells with minimal long-term side effects. BI-505 was well tolerated in an earlier phase 1 trial. Methods and findings In this phase 2 trial the effects of BI-505 in patients with SMM were studied. Four patients were enrolled and three of them completed the first cycle of treatment defined as 5 doses of BI-505, a total of 43 mg/kg BW, over a 7-week period. In the three evaluable patients, BI-505 showed a benign safety profile. None of the patients achieved a response as defined per protocol. EudraCT number: 2012-004884-29. Conclusions The study was conducted to assess the efficacy, safety and pharmacodynamics of BI-505 in patients with SMM. BI-505 showed no clinically relevant efficacy on disease activity in these patients with SMM, even if well tolerated. Trial registration ClinicalTrials.gov Identifier: NCT01838369.

A platform for phenotypic discovery of therapeutic antibodies and targets applied on Chronic Lymphocytic Leukemia

Development of antibody drugs against novel targets and pathways offers great opportunities to improve current cancer treatment. We here describe a phenotypic discovery platform enabling efficient identification of therapeutic antibody-target combinations. The platform utilizes primary patient cells throughout the discovery process and includes methods for differential phage display cell panning, high-throughput cell-based specificity screening, phenotypic in vitro screening, target deconvolution, and confirmatory in vivo screening. In this study the platform was applied on cancer cells from patients with Chronic Lymphocytic Leukemia resulting in discovery of antibodies with improved cytotoxicity in vitro compared to the standard of care, the CD20-specific monoclonal antibody rituximab. Isolated antibodies were found to target six different receptors on Chronic Lymphocytic Leukemia cells; CD21, CD23, CD32, CD72, CD200, and HLA-DR of which CD32, CD200, and HLA-DR appeared as the most potent targets for antibody-based cytotoxicity treatment. Enhanced antibody efficacy was confirmed in vivo using a patient-derived xenograft model.