A Unique in vivo Approach to Producing Epitope-specific MHCII TCR-like Antibodies 9257

Abstract Description The ability to observe, detect, and track the presentation of specific epitopes via major histocompatibility complex II (MHCII) can be a valuable tool in the context of many immunological questions. The current available methods most often used, such as, mass spectrometry, T-cell recognition and ELISPOT assays are limited in their utility and functionality, while soluble T cell receptors (TCR) have proven to be difficult to engineer and often have low affinity for their target. TCR-like antibodies capable of recognizing epitope-specific MHCII with high affinity and specificity are a preferable tool in many cases. However, current methods of TCR-like antibody production are time intensive and often require the building of comprehensive antibody libraries with multiple rounds of selection to determine antibodies of high affinity for their target. Therefore, we sought to develop a reliable and efficient pipeline capable of producing epitope-specific TCR-like antibodies of high affinity without the need for in vitro affinity optimization. Here we utilize lipid nanoparticle delivery of single-chain peptide-MHCII mRNA constructs to mice and rely on the in vivo antibody maturation process and rigorous selection of high affinity clones to develop monoclonal TCR-like antibodies. Through our pipeline we can successfully produce TCR-like antibodies of high affinity and specificity, and we continue to optimize it to do so consistently and reliably. Funding Sources Supported by NIAID 1R01AI180250-01A1 Topic Categories Antigen and Dendritic Cell Processing, Presentation, and Biology (AGDC)