Luciferase immunoprecipitation systems for measuring antibodies in autoimmune and infectious diseases

Abstract

Antibody profiles have the potential to revolutionize personalized medicine by providing important information related to autoimmunity against self-proteins and exposure to infectious agents. One immunoassay technology, luciferase immunoprecipitation systems (LIPS), harnesses light-emitting recombinant proteins to generate robust, high-quality antibody data often spanning a large dynamic range of detection. Here, we describe the general format of LIPS and discuss studies using the technology to measure autoantibodies in several human autoimmune diseases including type 1 diabetes, Sjögren's syndrome, systemic lupus erythematosus, and immunodeficiencies secondary to anticytokine autoantibodies. We also describe the usefulness of evaluating antibodies against single or multiple antigens from infectious agents for diagnosis, pathogen discovery, and for obtaining individual exposure profiles. These diverse findings support the notion that the LIPS is a useful technology for generating antibody profiles for personalized diagnosis and monitoring of human health.

Fig 1

Schematic of the general steps involved in luciferase immunoprecipitation systems. (A) The DNA sequence of the antigen of interest is genetically fused to the C-terminus of Renilla luciferase (Ruc). These recombinant plasmids are then used to transfect Cos1 cells and cell lysate is harvested 48 hours later without purification. (B) Aliquots of a single extract for a Ruc-antigen or a mixture of multiple extracts for different Ruc-antigens are then incubated with serum samples. The antibody complexes are then captured by protein A/G beads and the unbound luciferase-tagged antigen is washed away. The amount of specific antibodies present is then determined by the amount of bound antigen present by adding luciferase substrate.