Engineered multi-component system for identification and characterisation of T-cell receptors and T-cell antigens

A method of selecting a component of or output from an analyte engineered antigen-presenting cell T-cell receptor (eAPC:T) system, wherein the eAPC-T system comprises an analyte engineered antigen-presenting cell (eAPC) and an analyte cell (analyte TC), wherein the eAPC is a cell that is engineered to lack endogenous expression of a target antigen-presenting complex and/or lacks endogenous expression of a target analyte antigenic molecule, wherein the eAPC comprises a genomic receiver site for integration of an open reading frame (ORF) encoding the target analyte antigen and wherein the analyte TC expresses on its surface a T cell receptor (analyte TCR), the method comprising:

• (a) detecting a reported signal response from the eAPC:
• T system, wherein the reported signal response is based on an interaction between the target analyte antigen and the analyte TCR;
• and
• (b) selecting a component of or a output from the eAPC:
• T system based on the presence or absence of the reported signal response, wherein the component is selected from the eAPC or the analyte TC, and wherein the output is selected from an affinity reagent or a non-cell based particle (NCBP).