Project Summary: Protein Expression and Automated Assays Core Biochemical, structural, and immunization experiments to evaluate new prime/boost regimens designed and selected to induce broadly neutralizing antibodies (bNAbs) will require expression and purification of large numbers of proteins, including HIV-1 envelope proteins and Abs. The Protein Expression and Automated Assays Core of this HIVRAD will (i) express and purify mg quantities of recombinant proteins and (ii) conduct assays to evaluate their activities and the properties of serum and monoclonal antibodies (mAbs) elicited by vaccinations. In Projects 1-3, Drs. Bjorkman, Hahn, Shaw, and Nussenzweig will make regular use of Core A-produced recombinant proteins and automated assays carried out on two Tecan Freedom Evo automated liquid handling stations for the characterization of Env immunogens and Abs from immunized mice, rabbits, and rhesus macaques (RMs). In addition, the availability of a Berkeley Lights Beacon Instrument at Caltech to Core A will allow Caltech, UPenn, and Rockefeller labs to rapidly conduct single B cell assays to assess degrees of Ab cross-reactivity across heterologous Envs and clone sequences of cross-reactive Abs. The specific aims of Core A are to use high- throughput methods for: (Aim 1) Expression and purification of mAbs, Env immunogens, and protein nanoparticles; (Aim 2) Evaluating binding and affinities of Env immunogens for Abs; (Aim 3) Evaluating the potency and breadth of Abs derived from vaccination studies to neutralize primary strains of HIV-1; and (Aim 4) Conducting B cell characterization and Ab discovery using a Berkeley Lights Beacon instrument. The Protein Expression and Automated Assays Core will be directed by Dr. Jost Vielmetter, an expert in protein expression, automated assay development, and data management. Dr. Kate Malecek, the director of Caltech’s Beacon facility, will supervise Beacon-related projects. Core A will maintain two custom-equipped Evo Freedom Liquid handling stations, a surface plasmon resonance instrument with high-throughput capabilities, and the Berkeley Lights Beacon instrument. Core A personnel will validate, refine, and trouble-shoot protocols for automated protein expression, binding, in vitro neutralization assays, Beacon isolation of single B cells from immunized animals, and perform assays for evaluating Abs and Env proteins for Projects 1-3. The core will also train and assist students, postdoctoral fellows, research assistants, and investigators in the analysis and interpretation of data from automated assays, keeping track of projects using a cloud-based Notebook application (Evernote), allowing all researchers to access data and experimental details in real time.