The disclosure provides synthetic immune receptors (SIRs), nucleic acids encoding the SIRs, methods of making and using the SIRs, in, for example, adoptive cell therapy.

An immunoresponsive cell, such as a T-cell expressing a second generation chimeric antigen receptor comprising: (a) a signalling region; (b) a co-stimulatory signalling region; (c) a transmembrane domain; and (d) a binding element that specifically interacts with a first epitope on a target antigen; and a chimeric costimulatory receptor comprising (e) a co-stimulatory signalling region which is different to that of (b); (f) a transmembrane domain; and g) a binding element that specifically interacts with a second epitope on a target antigen. This arrangement is referred to as parallel chimeric activating receptors (pCAR). Cells of this type are useful in therapy, and kits and methods for using them as well as methods for preparing them are described and claimed.