Recombinant Humanized Anti-CD28 Single Domain Antibody (re-CD28 clone 1)

Provided is a reshaped VH domain against human CD28 molecules. While the original mouse antibody CDRs were inserted into the human acceptor FRs, some residues in human acceptor FRs, which were different from those of the original mouse FRs in corresponding positions, were then determined or, alternatively, mutagenized to their conservative properties in kappa classification.