Activation and deactivation of immune receptor tyrosine-based motifs are key mechanisms regulating T cell responses, transducing signals from antigen receptors, integrins, cytokine receptors, checkpoint receptors, and more. However, genetically encoded methods to specifically report and manipulate immune tyrosine motif activities are lacking. Using a novel protein binder design combined with yeast display technology, we present an approach to map and rewire immune signaling activities in living cells and tissues.

Small molecules have many features that are difficult to access within antibodies, including both covalent functionalities and pharmacophores that modulate target activity. We have established a chemically expanded antibody engineering platform that enables access to small molecule features during antibody discovery and engineering. This talk will describe examples of 1) semi-rational "covalentizing" of existing antibodies; and 2) high-throughput discovery of pharmacophore-modified, enzyme-inhibiting antibodies.

Soluble T cell receptor (TCR)-based bispecific therapeutics can co-opt T cells to eradicate infected and cancerous cells via peptide-HLA (pHLA) and CD3 recognition. However, native TCRs require extensive affinity maturation for efficacy in clinically validated bispecific formats, posing a significant barrier to their development. Here, we describe the development and application of a high-throughput yeast-based platform to rapidly generate and characterize TCR variants with substantially improved affinities and functional potencies, while retaining target specificity, enabling the development of potent and specific soluble TCR-based therapeutics.

Mammalian display libraries can be interrogated consecutively for manufacturability and specificity. Similarly, libraries secreting antibodies are a perfect match for microfluidics-assisted high throughput function first screens. The versatility and fruitful options arising from combining these emerging technologies will be discussed.

Cystine-knot peptides (CKPs) are naturally occurring peptides that exhibit exceptional chemical and proteolytic stability. We leveraged CKPs as scaffolds to construct phage-displayed libraries and yield highly selective and potent picomolar inhibitors of HTRA1. Our findings reveal an intriguing mechanism for modulating the activity of HTRA1, and highlight the utility of CKP-based phage display platforms in uncovering potent and selective inhibitors against challenging therapeutic targets.

We have developed a modular approach for cytosolic penetration of tumor cells based on bispecific antibodies containing a masked cytosol-penetrating Fab on one arm and a tumor-targeting scFv linked via an endosomal cleavable linker on the other arm. Such TME-dependent as well as TAA-specific cytosol-penetrating antibodies have the potential to serve as a platform to deliver macromolecular cargoes for addressing intracellular targets in tumor cells.

Warburg metabolism has been known for almost a century. Using proton transistor nanoprobes, we recently discovered a severely polarized extracellular acidic region (SPEAR) both at single cancer cell and tumor tissue level. The severe tumor acidity is well tolerated by cancer cells but is highly toxic to T cells, suggesting an immune evasive mechanism by tumor glycolytic metabolism.

To understand antibody sequence diversity before and after phage panning selections, we performed four parallel pannings against HPV18 VLP with HuCAL Platinum library, and used PacBio NGS platform in analyzing antibody sequences. We confirmed unselected library has well distributed germline usage. Panning more than 3 rounds is unnecessary. For large diversity libraries, different panning campaigns targeting same antigen can give us very different sets of antibody candidates with unique sequences.

Miniproteins combine the benefits of (1) complex three-dimensional surfaces capable of supporting high-affinity, specific binding to tumor-associated antigens and (2) small size that ensures fast clearance by kidney filtration. The Aktis discovery engine includes yeast surface display and medicinal chemistry by solid-phase peptide synthesis. Our most advanced asset, AKY-1189, has demonstrated efficacy against Nectin-4-expressing xenografts in mice and favorable biodistribution in human patients.

DARPins (Designed Ankyrin Repeat Proteins) are small, naturally-derived binding proteins of 15 kDa that can be generated against a broad range of tumor targets. We developed MP0712, a half-life-extended DLL3 Radio DARPin Therapeutic (RDT), utilizing Lead-212 (Pb-212), an alpha particle-emitting isotope with a 10.6-hour half-life, which is well-suited for targeted alpha therapy (TAT) due to its unique physical properties. Preclinical studies demonstrate a favorable tumor-to-kidney ratio, strong tumor efficacy, and minimal toxicity, positioning MP0712 as potential future treatment option for SCLC patients. 

Tumor-targeting therapies have begun to transform the oncology treatment landscape, but current agents are only suitable for a limited patient population. TwoStep Therapeutics leverages an engineered tumor-targeting peptide (PIP) that can selectively bind several tumor-associated integrins, offering broad applicability across solid tumors. This talk will focus on the development of PIP-drug conjugates, their efficacy and safety, and how this general approach can expand the utility of precision medicine beyond conventional single-antigen targeting approaches.

Peripherally administered enzyme replacement therapies (ERTs) to address lysosomal storage disorders are limited in their ability to target the CNS. Such ERTs are also limited by their instability in serum. To generate enzymes with sustained activity in serum we developed a novel enzyme engineering strategy utilizing both yeast surface display and secretion. We show durable activity with a POC enzyme in serum for many days. By fusing engineered enzymes to a TfR transport vehicle for delivery across the BBB we show improved substrate reduction in brains of a relevant mouse disease model.