Abstract: The present disclosure is related to improved methods for use of a humanized binding polypeptide specific for the alpha beta T cell receptor (??-TCR). In particular, this disclosure relates to improved methods of use of a humanized anti-??-TCR antibody, which is derived from the murine monoclonal antibody BMA031, in immunosuppressive therapy. Novel methods using humanized monoclonal antibodies and/or humanized monoclonal antibody fragments (e.g., anti-??TCR antibodies and/or fragments thereof) are also provided. Novel methods using repetitive administration of humanized monoclonal antibodies and/or humanized monoclonal antibody fragments (e.g., anti-??TCR antibodies and/or fragments thereof) to reduce ?? T cells in the subject relative to ?? T cells in the subject are provided.