Unravelling Protein Dynamics for Comprehensive Spatial Biology Insight using isPLA

Course overview

Detecting protein expression is an important, yet unidimensional approach to understanding tissue milieu, cell function and communication. The formation and dissociation of protein complexes, as well as post-translational modifications (PTMs) are essential to protein function. To this end, uncovering protein-protein interactions (PPIs) and PTMs in their native environment is critical for a more complete appreciation of spatial biology. In this workshop, we will discuss the latest advancements in in situ proximity ligation-based interactomics that allow for highly sensitive and specific visualization of free and interacting proteins and add another dimension to cell/tissue profiling. We will describe the general principles of the technology and how it achieves subcellular resolution, and will compare it to classical methods. Furthermore, we will touch upon upcoming innovations and discuss the possibilities for automation, multiplexing and the integration of the in situ proximity ligation assay (isPLA) into common spatial biology platforms. After the theoretical and technical introduction, we will report on use cases currently under investigation in drug development. We will demonstrate how isPLA can discriminate between cell surface and intracellular drug targets in histological tissue sections, which is particularly important for therapeutic modalities like chimeric antigen receptor T lymphocytes and T-cell engagers, as they only target proteins expressed on cell surfaces. In addition, the workshop will explore how this technology can shed light on the colocalization (or lack thereof) of antibody therapeutics and their cognate drug targets, as well as toxic histopathology lesions in tissues. Lastly, we will show how the assay can help researchers detect and quantify the formation of homo- and heterodimers that drive pharmacological responses. These selected examples highlight the potential value of isPLA for medical research and development.