Expression data from CD4+ and CD11c+ cells from DO11.10 RAG2-/- mice. Mus musculus

Abatacept is a recombinant CTLA-4 moleculed fused to a mutated human IgG molecule, which is clinically used in rheumatoid arthritis by inhibiting CD28-costimulation. This study aimed to inverstigate the ability of abatacept -mediated costimulation blockade to induce antigen-specific tolerance during primary immune responses. This is important as some studies have suggested that costimulation blockade can lead to CD4+ T cell anergy which could be beneficial for early therapy of autoimmune diseases such as rheumatoid arthritis. In addition we also investigated the effect that abatacept has on CD11c+ antigen presenting cells. This is important as costimulation blocakde can affect the biderectional interaction between CD4+ T cells and CD11c+ cells influencing the immunological outcome. We used microarrays to identify if abatacept treatment leads to antigen specific anergy using transgenic animals and models of priming and oral tolerance that established a synchronised monoclonal response. In addition this magnified the effect on the CD11c+ antigen presenting cells. Overall design: This study included 5 experimental groups. DO11.10 RAG2-/- mice have CD4+ T cells specific for the ovalbumin (OVA) peptide OVA323-339. These mice were immunised with CFA/OVA s.c. (primed group) or tolerised by feeding with OVA (50mg/kg) in the drinking water. CD4+ cells were isolated 10 days post immunisation from draining lymph nodes (LNs) of unimmunised (pooled LNs and Spleen), orally tolerised (mesenteric LNs), primed (axillary LNs), primed treated with control IgG (axillary LNs) and primed treated with abatacept (axillary LNs). For CD11c+ cells cells were isolated by pooled secondary lymphoid organs (LNs and spleen).