Provided herein are engineered B cells, such as for adoptive cell therapy. In some aspects, also provided are methods and compositions for engineering and producing the cells, compositions containing the cells, and methods for their administration to subjects. In some embodiments, the cells are engineered to produce and/or secrete an exogenous protein, such as a therapeutic protein, including antibodies and antigen-binding fragments thereof. In some aspects, features of the cells and methods provide for increased or improved activity, efficacy and/or persistence of the cells.
