CD4 and type 1 diabetes mellitus: In previous studies, we have applied our TCRL Ab approach to generate and characterize TCRL Abs against autoreactive T-cell epitopes associated with type 1 diabetes (T1D) and demonstrated that such TCRL Abs are able to block in vivo restimulation of CD4 T cells recognizing T1D-associated autoantigen GAD in the context of class II HLA-DR4 molecules (10, 15).