The present disclosure provides modified immune cells (e.g., modified T cells) comprising a chimeric antigen receptor (CAR) having affinity for a prostate-specific membrane antigen (PSMA) (e.g., human PSMA). The present disclosure provides modified immune cells (e.g., modified T cells) comprising a CAR having affinity for PSMA and a dominant negative receptor and/or a switch receptor. The present disclosure provides modified immune cells (e.g., modified T cells) comprising a CAR having affinity for PSMA and a dominant negative receptor and/or a switch receptor, wherein the modified cell is capable of expressing and secreting a bispecific antibody.