The present disclosure provides T-cell modulatory multimeric polypeptides that comprise an immunomodulatory polypeptide that exhibits reduced binding affinity to a cognate co-immunomodulatory polypeptide. A T-cell modulatory multimeric polypeptide is useful for modulating the activity of a T cell, and for modulating an immune response in an individual.本發明提供T細胞調節多聚體多肽,其包含對同源共免疫調節多肽展現降低之結合親和力的免疫調節多肽。T細胞調節多聚體多肽適用於調節T細胞之活性及調節個體之免疫反應。