Long-Lasting Immune Responses 4 Years after GAD-Alum Treatment in Children with Type 1 Diabetes
2011 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 6, no 12Article in journal (Refereed) Published
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 GAD(65). Frequencies of naive, central and effector memory CD4+ and CD8+ T cells were measured, together with cytokine secretion, proliferation, gene expression and serum GAD(65) 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 GAD(65), but not with control antigens, compared with placebo subjects. GAD(65)-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 GAD(65) enzymatic activity. In conclusion, memory T- and B-cell responses persist 4 years after GAD-alum-treatment. In parallel to a GAD(65)-induced T-cell activation, our results show induction of T-cell inhibitory pathways important for regulating the GAD(65) immunity.
National CategoryMedical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-74156DOI: 10.1371/journal.pone.0029008ISI: 000298366600057OAI: oai:DiVA.org:liu-74156DiVA: diva2:480861
Funding Agencies|Swedish Research Council|K2008-55x-20652-01-3|Swedish Child Diabetes Foundation (Barndiabetesfonden)||Medical Research Council of Southeast Sweden||Juvenile Diabetes Research Foundation (JDRF)|1-2008-106|Ile-de-France CODDIM||Inserm Avenir Program||2012-01-202012-01-202012-10-24