Biology subjects

Sun, Y.-J.

Publications and source records attributed to Sun, Y.-J..

3 recordsLinked to original sources

bioRxiv2024

Cancer therapy via neoepitope-specific monoclonal antibody cocktails

BackgroundCellular heterogeneity presents a significant challenge to cancer treatment. Antibody therapies targeting individual tumor-associated antigens can be extremely effective but are not suited for all patients and often fail against tumors with heterogeneous expression as tumor cells with low or no antigen expression escape targeting and develop resistance. Simultaneously targeting multiple tumor-specific proteins with multiple antibodies has the potential to overcome this barrier and improve efficacy, but relatively few widely expressed cancer-specific antigens are known. In contrast, neoepitopes, which arise from mutations unique to tumor cells, are considerably more abundant. However, since neoepitopes are not commonly shared between individuals, a patient-customized approach is necessary and motivates efforts to develop an efficient means to identify suitable target mutations and isolate neoepitope-specific monoclonal antibodies. MethodsHere, focusing on the latter goal, we use directed evolution in yeast and phage display systems to engineer antibodies from non-immune, human antibody fragment libraries that are specific for neoepitopes previously reported in the B16F10 melanoma model. ResultsWe demonstrate proof-of-concept for a pipeline that supports rapid isolation and functional enhancement of multiple neoepitope peptide-targeted monoclonal antibodies and demonstrate their robust binding to B16F10 cells and potent effector functions in vitro. These antibodies were combined and evaluated in vivo for anti-cancer activity in tumor-bearing mice, where they suppressed B16F10 tumor growth and prolonged survival. ConclusionsThese findings emphasize the potential for clinical application of patient-customized antibody cocktails in the treatment of the many cancers poorly addressed by current therapies.

immunology↗

bioRxiv2022

Optical control of CRISPR-Cas editing with cyclically caged guide RNAs

The CRISPR/Cas system has been proved as one of the most powerful tools for precise gene editing. However, the approaches for precise control over the genome editing and regulatory events are still desirable. Here, we reported a spatiotemporal and efficient CRISPR/Cas9 and Cpf1-mediated editing with photo-sensitive circular gRNAs. This approach relies on only two or three pre-installed photolabile substituents followed by a simple covalent cyclization, which provides a robust synthesize approach in comparison to heavily modified gRNAs. In established cells stably expressing Cas9, the circular gRNA in coordination with light irradiation could direct a precise cleavage of GFP and VEGFA within a pre-defined cutting region. We have also achieved light-mediated MSTN gene editing in embryos, whereas a new bow-knot-type gRNA showed no background editing in the absence of light irradiation. Together, our work provides a significantly improved method to precisely manipulate where and when genes are edited.

biochemistry↗

bioRxiv2019

Integrative model to coordinate the oligomerization and aggregation mechanisms of CCL5

The CC-type chemokine ligand 5 (CCL5) is involved in the pathogenesis of many inflammatory conditions. The oligomerization and aggregation of CCL5 are considered to be responsible for its inflammatory properties. The CC-type dimer acts as the basic unit to constitute the oligomer. However, the structural basis of CCL5 oligomerization remains controversial. In this study, NMR and biophysical analyses proposed evidence that no single dimer-dimer interaction dominates in the oligomerization process of CCL5. CCL5 could oligomerize alternatively through two different interactions, E66-K25 and E66-R44/K45. In addition, a newly determined trimer structure reported an interfacial interaction through the N-terminal 12FAY14 sequence. The interaction contributes to aggregation and precipitation. In accordance with the observations, an integrative model explains the CCL5 oligomerization and aggregation process. CCL5 assembly consists of two types of dimer-dimer interactions and one aggregation mechanism. For full-length CCL5, the molecular accumulation triggers oligomerization through the E66-K25 interaction, and the 12FAY14 interaction acts as a secondary effect to derive aggregation. The E66-R44/K45 interaction dominates in CCL5 N-terminal truncations. The interaction would lead to filament-like formation in solution.

biochemistry↗