Modernization’s Doppelgänger

This is the author accepted manuscript. The final version is available from Cambridge University Press via http://dx.doi.org/10.1017/S147924431500041

Long-Lasting Immune Responses 4 Years after GAD-Alum Treatment in Children with Type 1 Diabetes

A phase II clinical trial with glutamic acid decarboxylase (GAD) 65 formulated with aluminium hydroxide (GAD-alum) has shown efficacy in preserving residual insulin secretion in children and adolescents with recent-onset type 1 diabetes (T1D). We have performed a 4-year follow-up study of 59 of the original 70 patients to investigate long-term cellular and humoral immune responses after GAD-alum-treatment. Peripheral blood mononuclear cells (PBMC) were stimulated in vitro with GAD65. Frequencies of naïve, central and effector memory CD4+ and CD8+ T cells were measured, together with cytokine secretion, proliferation, gene expression and serum GAD65 autoantibody (GADA) levels. We here show that GAD-alum-treated patients display increased memory T-cell frequencies and prompt T-cell activation upon in vitro stimulation with GAD65, but not with control antigens, compared with placebo subjects. GAD65-induced T-cell activation was accompanied by secretion of T helper (Th) 1, Th2 and T regulatory cytokines and by induction of T-cell inhibitory pathways. Moreover, post-treatment serum GADA titres remained persistently increased in the GAD-alum arm, but did not inhibit GAD65 enzymatic activity. In conclusion, memory T- and B-cell responses persist 4 years after GAD-alum-treatment. In parallel to a GAD65-induced T-cell activation, our results show induction of T-cell inhibitory pathways important for regulating the GAD65 immunity

Characteristics of GADA in Type 1 Diabetes following Immunomodulation with GAD65

Type 1 diabetes (T1D) is a serious autoimmune disease which increases worldwide and affects children at a young age, but there still is no cure available. Clinical intervention trials in recent onset T1D patients are therefore very important, since even a modest preservation of β-cell function has proven to reduce end-organ complications. Glutamic acid decarboxylase 65 (GAD65) is one of the major antigens in T1D, to which autoantibodies (GADA) are formed. Immunomodulation with aluminum-formulated GAD65 (GAD-alum) has been considered both in the prevention and intervention of T1D. In a phase II trial using GADalum we showed clinical benefits in C-peptide preservation, but unfortunately a following larger European phase III trial failed to reach primary end-point. The general aim of this thesis was to study the characteristics and phenotypes of GADA following immunomodulation with GAD-alum in T1D patients during a phase II and III trial. In the phase II trial, a transient increase of the GADA IgG3 and IgG4 subclasses, and a decrease in IgG1 was detected as part of the treatment-induced GADA levels after 2 GADalum doses, a result interpreted to be T helper (Th) 2-associated. This Th2-associated immune response was also observed, in parallel to increased GADA levels, during the following phase III trial including a larger group of patients. However, enhanced Th2-like IgG subclass distribution, reflected as increased IgG4 frequency, was in contrast only observed in the group treated with 4 doses of GAD-alum. In addition, the GADA fold-change was associated with in vitro GAD65-stimulated cytokine secretion, but only in patients receiving 2 GAD-alum doses. Furthermore, a 4-year follow-up of the phase II trial showed that the effect of GAD-alum treatment was long-lasting as GADA titers remained elevated. Even though the phase III trial did not reach primary end-point, and was closed after 15 months, preservation of β-cell function was observed in the small sub-group of Swedish patients receiving 2 GAD-alum doses that completed the 30 months trial-period. During the trials, concerns were raised whether the elevated GADA titers might induce Stiff person syndrome (SPS), a disease affecting the nervous system, but in vitro analysis of GADA phenotypes showed that the GAD65-enzyme activity and GADA epitope distribution differed from that detected in SPS patients. Continued research to clarify how immunomodulation with autoantigens affects immune responses and also to identify which patients are suitable for treatment, is crucial for optimizing future T1D intervention- and prevention trials

Increased expression of regulatory T cell-associated markers in recent-onset diabetic children

CD4+CD25hi T cells are thought to be crucial for the maintenance of immunological tolerance to self antigens. In this study, we investigated the frequencies of these cells in the early stage of type 1 diabetes, as well as in a setting of possible pre-diabetic autoimmunity. Hence, the expression of FOXP3, CTLA-4, and CD27 in CD4+ CD25hi T cells was analyzed using flow cytometry in 14 patients with recent onset type 1 diabetes, in 9 at-risk individuals, and 9 healthy individuals with no known risk for type 1 diabetes. Our results show there were no differences in the frequency of CD4+CD25hi cells between groups. However, compared to controls, recent-onset type 1 diabetic patients had higher expression of FOXP3, CTLA-4, and CD27 in CD4+ CD25hi cells from peripheral blood. The median fluorescence intensity of FOXP3 was significantly higher in CD4+CD25hi cells from patients with type 1 diabetes than from controls. Furthermore, a positive correlation between the frequency of FOXP3+ cells and the median fluorescence intensity of FOXP3 was observed among patients with type 1 diabetes. These data suggest that the frequency of CD4+CD25hi FOXP3+ T cells in the periphery is not decreased but rather increased at onset of type 1 diabetes. Thus, functional deficiencies rather than reduced numbers of CD4+CD25hi cells could contribute to the development of type 1 diabetes.

N.B.: When citing this work, cite the original article. Original Publication:

GAD-alum treatment in patients with type 1 diabetes and the subsequent effect on GADA IgG subclass distribution, GAD(65) enzyme activity and humoral respons

Effect of simultaneous vaccination with H1N1 and GAD-alum on GAD(65)-induced immune response

Aims/hypothesis A European Phase III trial of GAD formulated with aluminiumhydroxide (GAD-alum) failed to reach its primary endpoint (preservation of stimulated C-peptide secretion from baseline to 15 months in type 1 diabetes patients), but subgroup analysis showed a clinical effect when participants from Nordic countries were excluded, raising concern as to whether the mass vaccination of the Swedish and Finnish populations with the Pandemrix influenza vaccine could have influenced the study outcomes. In the current study, we aimed to assess whether Pandemrix vaccination affects the specific immune responses induced by GAD-alum and the C-peptide response. Methods In this secondary analysis, we analysed data acquired from the Swedish participants in the Phase III GAD-alum trial who received subcutaneous GAD-alum vaccination (two doses, n = 43; four doses, n = 46) or placebo (n = 48). GAD autoantibodies (GADA) and H1N1 autoantibodies, GAD(65)-induced cytokine secretion and change in fasting and stimulated C-peptide levels from baseline to 15 months were analysed with respect to the relative time between H1N1 vaccination and the first injection of GAD-alum. Results GADA levels at 15 months were associated with the relative time between GAD-alum and Pandemrix administration in participants who received two doses of the GAD-alum vaccine (p = 0.015, r = 0.4). Both in participants treated with two doses and four doses of GAD-alum, GADA levels were higher when the relative time between vaccines was amp;gt;= 210 days (p amp;lt; 0.05). In the group that received two doses of GAD-alum, levels of several GAD(65)-induced cytokines were higher in participants who received the H1N1 vaccination and the first GADalum injection at least 150 days apart, and the change in fasting and stimulated C-peptide at 15 months was associated with the relative time between vaccines. Neither of these effects were observed in individuals who received four doses of GAD-alum. Conclusions/interpretation In individuals who received two doses of GAD-alum, receiving the Pandemrix vaccine closer to the first GAD-alum injection, i.e. amp;lt; 150 days, seemed to affect both GAD(65)-induced immune response and C-peptide preservation.Funding Agencies|JDRF [17-2011-249]; Swedish Research Council [K2008-55x-20,652-01-3]; Swedish Child Diabetes Foundation (Barndiabetesfonden); Medical Research Council of Southeast Sweden; Diamyd Medical</p

Open Journal of Immunology

Increased expression of regulatory T cell-associated markers in recent-onset diabetic childre

Treatment in Children with Type

A phase II clinical trial with glutamic acid decarboxylase (GAD) 65 formulated with aluminium hydroxide (GAD-alum) has shown efficacy in preserving residual insulin secretion in children and adolescents with recent-onset type 1 diabetes (T1D). We have performed a 4-year follow-up study of 59 of the original 70 patients to investigate long-term cellular and humoral immune responses after GAD-alum-treatment. Peripheral blood mononuclear cells (PBMC) were stimulated in vitro with GAD65. Frequencies of naïve, central and effector memory CD4+ and CD8+ T cells were measured, together with cytokine secretion, proliferation, gene expression and serum GAD65 autoantibody (GADA) levels. We here show that GAD-alumtreated patients display increased memory T-cell frequencies and prompt T-cell activation upon in vitro stimulation wit