Profiling Norovirus Antibody Specificity and Function Using Luciferase Immunoprecipitation System (LIPS) Assays

The luciferase immunoprecipitation system (LIPS) assay is a liquid-phase immunoassay that quantitates antigen-specific serum antibodies by measuring luminescence emitted by reporter enzyme Renilla luciferase (Ruc) fused to an antigen of interest. The LIPS assay can be utilized as a high-throughput and sensitive serological method for profiling serum antibodies recognizing diverse antigens. Initially adapted to assess the presence of antibodies to noroviruses, it was later modified to measure the ability of antibodies to block norovirus carbohydrate binding, a well-established correlate with neutralizing antibody levels. Thus, LIPS and the subsequent LIPS-Blockade assays offer alternatives to standard immunosorbent assays for detecting antibodies and measuring functionality. This chapter provides a detailed protocol for detecting human norovirus-specific serum antibodies with the LIPS assay and for measuring carbohydrate-blockade antibodies with the LIPS-Blockade assay.