Biology subjects

Janda, C. Y.

Publications and source records attributed to Janda, C. Y..

4 recordsLinked to original sources

bioRxiv2026

Domain-resolved epitope mapping of B7-H3-targeting VHH-Fcs defines isoform-selective binders for antibody-drug conjugate development

The immune checkpoint molecule B7-H3 has emerged as one of the most actively pursued therapeutic targets in solid tumors, and multiple B7-H3-targeting antibody-drug conjugates have entered clinical evaluation. B7-H3 occurs as a 2Ig isoform carrying a single IgV-IgC domain pair and a predominant 4Ig isoform carrying two tandem pairs of near-identical sequence in their extracellular domains. Resolving which pair an antibody engages, or how antibodies distinguish the two isoforms, requires epitope mapping at residue level. Here we generated a panel of six B7-H3-targeting VHH-Fcs and characterized them by surface plasmon resonance, epitope binning, domain-resolved deep mutational scanning and receptor internalization, benchmarked against the clinically advanced antibodies ifinatamab, mirzotamab and vobramitamab. Most VHH-Fcs bound the membrane-proximal pair more tightly than the distal pair, and 4Ig 10- to 100-fold more tightly than 2Ig, whereas the three clinical antibodies showed no such discrimination. Displaying each domain pair independently on yeast identified the residues that account for this selectivity. Internalization varied several-fold among binders, including between VHH-Fc 620 and 636, which have near-identical footprints and comparable affinities. VHH-Fc 620 internalized most efficiently, also compared to ifinatamab, and was conjugated to exatecan through a protease-cleavable linker. The conjugate showed B7-H3-dependent cytotoxicity that scaled with B7-H3 cell surface density, though it was less potent than ifinatamab-exatecan. Affinity, epitope and internalization therefore behaved as independent characteristics rather than integrating to predict antibody-drug conjugate potency. Together, these results define the molecular basis for isoform-selective recognition of B7-H3 and identify VHH-Fc 620 as a starting point for isoform-selective targeting.

cancer biology↗

bioRxiv2026

A Dual-Pathway Wnt-IL-13 Fusion Protein Enhances Human Intestinal Regeneration Through Tuft Cell Activation

Compromised intestinal regenerative responses drive severe inflammatory conditions, such as inflammatory bowel disease and graft-versus-host disease, affecting millions of people worldwide each year. Despite extensive research, effective therapies remain limited, and no curative treatments are currently available. We recently discovered that human intestinal tuft cells promote tissue repair following injury through Wnt and IL-4/IL-13 signaling pathways. Building on this discovery, here we report the engineering and functional validation of a synthetic Wnt-IL-13 fusion protein that simultaneously activates both the Wnt and IL-4/IL-13 signaling pathways to enhance human intestinal tuft cell activity. Employing human organoids technology, we demonstrate that this therapeutic approach promotes mucosal healing.

biochemistry↗

bioRxiv2025

Cell surface proteomics of patient-derived malignant rhabdoid tumor organoids identifies ROBO1 as potential CAR T cell target for pediatric solid tumors.

Malignant rhabdoid tumors are highly aggressive pediatric malignancies with limited treatment options and poor outcomes. To expand therapeutic options, we employed mass spectrometry-based cell surface proteomics on malignant rhabdoid tumor and patient-matched normal kidney organoids to identify potential CAR T cell targets. Integrating these findings with transcriptomics and protein expression data, we revealed ROBO1 as a promising target, showing strong and uniform expression across malignant rhabdoid and other pediatric tumors. ROBO1-targeted CAR T cells displayed potent anti-tumor activity in vitro, effectively eliminating tumor cells in co-cultures with organoids from malignant rhabdoid tumors, rhabdomyosarcoma, and neuroblastoma. In vivo, ROBO1 CAR T cells infiltrated tumors, induced potent tumor regression and significantly increased survival in malignant rhabdoid tumor-bearing mice. These findings establish ROBO1 as a compelling therapeutic target for CAR T cell therapy and offer a promising approach to address the critical need for effective treatments in high-risk pediatric solid tumors. Statement of significanceThis study identifies ROBO1 as a promising CAR T cell target for pediatric solid tumors. Using patient-derived tumor organoids and tissues, we demonstrate strong ROBO1 expression across several tumor entities and robust anti-tumor efficacy of ROBO1-targeted CAR T cells in vitro and in vivo, underscoring its potential for clinical translation.

cancer biology↗

bioRxiv2022

Structure of the Wnt-Frizzled-LRP6 initiation complex reveals the basis for co-receptor discrimination

Wnt morphogens are critical for embryonic development and tissue regeneration. Canonical Wnts form ternary receptor complexes composed of tissue-specific Frizzled receptors together with the shared LRP5/6 co-receptors to initiate {beta}-catenin signaling. The structure of a ternary complex of an affinity-matured XWnt8-Frizzled8-LRP6 complex elucidates the basis of co-receptor discrimination by canonical Wnts by means of their N-termini and linker domains that engage the LRP6 E1E2 domain funnels. Chimeric Wnts bearing modular linker grafts were able to transfer LRP6 domain specificity between different Wnts and enable non-canonical Wnt5a to signal through the canonical pathway. Synthetic peptides comprising the linker domain serve as Wnt-specific antagonists. The structure of the ternary complex provides a topological blueprint for the orientation and proximity of Frizzled and LRP6 within the Wnt cell surface signalosome.

biophysics↗