Development of a Surface Programmable Activation Receptor system (SPAR): A living cell biosensor for rapid pathogen detection

Abstract

Efficient pathogen detection is essential for the successful treatment and prevention of infectious disease; however, current methods are often too time intensive to be clinically relevant in cases requiring immediate intervention. We have developed a Surface Programmable Activation Receptor (SPAR) diagnostic platform comprised of universal biosensor cells engineered for use in combination with custom or commercial antibodies to achieve rapid and sensitive pathogen detection. SPAR cells are stably transfected Jurkat T cells designed to constitutively express a modified T cell mouse Fc{gamma}RI receptor on the cell surface and a high level of the luminescent reporter protein aequorin in the cytoplasm. The modified mFc{gamma}RI-CD3{zeta} receptor protein binds with high affinity to the Fc region of any full-length mouse IgG2a and some IgG2 antibodies: this allows customized target detection via the selection of specific antibodies. T-cell receptor aggregation in response to target antigen binding results in signal transduction which, when amplified via the endogenous T cell signal cascade, triggers the rapid intracellular release of calcium. Increased Ca2+ concentrations activate the expressed reporter protein aequorin resulting in the immediate emission of detectable light. Testing demonstrates the accurate and specific detection of numerous targets including P. aeruginosa, E. coli O111, and E. coli O157. We report that the SPAR biosensor cell platform is a reliable pathogen detection method that enables the rapid identification of bacterial causative agents using standard laboratory instrumentation. The technology lends itself to the development of efficient point-of-care testing and may aid in the implementation of effective and pathogen-specific clinical therapies.