Activation of autoreactive CD4+ T cells is synchronous to islet autoantibody seroconversion and shows an IFNγ signature

Islet autoantibody seroconversion is the first detectable evidence of autoimmunity preceding type 1 diabetes. Autoantibodies are markers of pre-diabetes, but T cells mediate beta cell destruction. Little is known about the timing of autoreactive T cell activation against beta cell antigens in the prediabetic period. The BABYDIET study followed children with a strong genetic predisposition for type 1 diabetes with frequent samples during infancy and offered the possibility to search for T cell activation against islet antigens. Samples from children that progressed to seroconversion and from HLA-matched autoantib…