Browsing by Author "Wu, Kuan-Lin"

Now showing 1 - 6 of 6
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    Bone-Specific Enhancement of Antibody Therapy for Breast Cancer Metastasis to Bone
    (American Chemical Society, 2022) Tian, Zeru; Yu, Chenfei; Zhang, Weijie; Wu, Kuan-Lin; Wang, Chenhang; Gupta, Ruchi; Xu, Zhan; Wu, Ling; Chen, Yuda; Zhang, Xiang H.-F.; Xiao, Han; Bioengineering; Biosciences; Chemistry
    Despite the rapid evolution of therapeutic antibodies, their clinical efficacy in the treatment of bone tumors is hampered due to the inadequate pharmacokinetics and poor bone tissue accessibility of these large macromolecules. Here, we show that engineering therapeutic antibodies with bone-homing peptide sequences dramatically enhances their concentrations in the bone metastatic niche, resulting in significantly reduced survival and progression of breast cancer bone metastases. To enhance the bone tumor-targeting ability of engineered antibodies, we introduced varying numbers of bone-homing peptides into permissive sites of the anti-HER2 antibody, trastuzumab. Compared to the unmodified antibody, the engineered antibodies have similar pharmacokinetics and in vitro cytotoxic activity, but exhibit improved bone tumor distribution in vivo. Accordingly, in xenograft models of breast cancer metastasis to bone sites, engineered antibodies with enhanced bone specificity exhibit increased inhibition of both initial bone metastases and secondary multiorgan metastases. Furthermore, this engineering strategy is also applied to prepare bone-targeting antibody–drug conjugates with enhanced therapeutic efficacy. These results demonstrate that adding bone-specific targeting to antibody therapy results in robust bone tumor delivery efficacy. This provides a powerful strategy to overcome the poor accessibility of antibodies to the bone tumors and the consequential resistance to the therapy.
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    Breaking Through the Current Obstacles of Non-Canonical Amino Acid Technology
    (2022-08-26) Wu, Kuan-Lin; Xiao, Han
    Genetic code expansion (GCE) technology has enabled more than 200 chemically and structurally diverse non-canonical amino acids (ncAAs) to be site-specifically introduced to proteins with high specificity and fidelity. This technology has allowed us to study biological processes including structure, catalysis, transport, and defense at a new level of molecular precision. Despite the massive success of GCE technology, there are still deficiencies that restrict its utility. First, high level of ncAA supplement is required for stop codon suppression, which is ineffective and eco-unfriendly. Second, there are only limited chemical functionalities that could be incorporated into proteins by GCE. Third, lots of reported ncAA only showed the genetic incorporation without demonstrating applications in solving actual biological questions. In this dissertation, we describe the above limitations of GCE technology and provide new insights and progressions. First, multiple “completely autonomous” species that possess the biosynthetic and translational machinery for making proteins that contain the 21st amino acid: O-methyltyrosine have been generated. We demonstrated that the endogenous biosynthesis of ncAA reaches higher intracellular ncAA concentration than attained through exogenous feeding, leading to greater genetic incorporation efficiency. Importantly, we showed that the limited bioavailability of exogenously fed ncAAs in multicellular systems can also be overcome by endogenous biosynthesis. The advantages of the autonomous system not only allow for enhanced efficiency of ncAA incorporation but also open new opportunities in multicellular systems for encoding ncAAs with poor bioavailability. Second, to expand the chemical toolbox of GCE technology, we designed and synthesized an isocyanide-containing ncAA: ε-N-2-isocyanoisobutyryl-lysine (NCibK). A mutant pyrrolysine tRNA synthetase HibK-1RS/tRNAPyl CUA pair that specifically recognize NCibK was identified. Several bioconjugation reactions at both small molecule and protein level have been demonstrated, showing the robustness of the methodology. The ease of synthesis, versatility of reactivity, and good compatibility of isocyanides make NCibK an attractive ncAA for future biological applications. Third, we demonstrate new applications for the reported ncAA 4-fluorophenyl lysine (FPheK) to resolve current limitations in cancer therapeutics and its production. A methodology to synthesize a bispecific small molecule - antibody conjugate from a commercially available antibody without protein engineering was developed. This methodology provides a powerful platform to generate bispecific agents by conjugating small-molecule-like ligands targeting different membrane markers to human antibodies, or to generate various kinds of antibody drug conjugates (ADC). In summary, the work in this dissertation has shown advances in every aspect of current obstacles in non-canonical amino acid technology.
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    Harnessing the power of antibodies to fight bone metastasis
    (AAAS, 2021) Tian, Zeru; Wu, Ling; Yu, Chenfei; Chen, Yuda; Xu, Zhan; Bado, Igor; Loredo, Axel; Wang, Lushun; Wang, Hai; Wu, Kuan-Lin; Zhang, Weijie; Zhang, Xiang H.-F.; Xiao, Han; Bioengineering; Biosciences; Chemistry
    Antibody-based therapies have proved to be of great value in cancer treatment. Despite the clinical success of these biopharmaceuticals, reaching targets in the bone microenvironment has proved to be difficult due to the relatively low vascularization of bone tissue and the presence of physical barriers. Here, we have used an innovative bone-targeting (BonTarg) technology to generate a first-in-class bone-targeting antibody. Our strategy involves the use of pClick antibody conjugation technology to chemically couple the bone-targeting moiety bisphosphonate to therapeutic antibodies. Bisphosphonate modification of these antibodies results in the delivery of higher conjugate concentrations to the bone metastatic niche, relative to other tissues. In xenograft mice models, this strategy provides enhanced inhibition of bone metastases and multiorgan secondary metastases that arise from bone lesions. Specific delivery of therapeutic antibodies to the bone, therefore, represents a promising strategy for the treatment of bone metastatic cancers and other bone diseases. Precision modification of antibodies with bone-targeting moieties unleashes their potential for the treatment of bone metastases. Precision modification of antibodies with bone-targeting moieties unleashes their potential for the treatment of bone metastases.
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    Protein target highlights in CASP15: Analysis of models by structure providers
    (Wiley, 2023) Alexander, Leila T.; Durairaj, Janani; Kryshtafovych, Andriy; Abriata, Luciano A.; Bayo, Yusupha; Bhabha, Gira; Breyton, Cécile; Caulton, Simon G.; Chen, James; Degroux, Séraphine; Ekiert, Damian C.; Erlandsen, Benedikte S.; Freddolino, Peter L.; Gilzer, Dominic; Greening, Chris; Grimes, Jonathan M.; Grinter, Rhys; Gurusaran, Manickam; Hartmann, Marcus D.; Hitchman, Charlie J.; Keown, Jeremy R.; Kropp, Ashleigh; Kursula, Petri; Lovering, Andrew L.; Lemaitre, Bruno; Lia, Andrea; Liu, Shiheng; Logotheti, Maria; Lu, Shuze; Markússon, Sigurbjörn; Miller, Mitchell D.; Minasov, George; Niemann, Hartmut H.; Opazo, Felipe; Phillips Jr, George N.; Davies, Owen R.; Rommelaere, Samuel; Rosas-Lemus, Monica; Roversi, Pietro; Satchell, Karla; Smith, Nathan; Wilson, Mark A.; Wu, Kuan-Lin; Xia, Xian; Xiao, Han; Zhang, Wenhua; Zhou, Z. Hong; Fidelis, Krzysztof; Topf, Maya; Moult, John; Schwede, Torsten; Bioengineering; Biosciences; Chemistry
    We present an in-depth analysis of selected CASP15 targets, focusing on their biological and functional significance. The authors of the structures identify and discuss key protein features and evaluate how effectively these aspects were captured in the submitted predictions. While the overall ability to predict three-dimensional protein structures continues to impress, reproducing uncommon features not previously observed in experimental structures is still a challenge. Furthermore, instances with conformational flexibility and large multimeric complexes highlight the need for novel scoring strategies to better emphasize biologically relevant structural regions. Looking ahead, closer integration of computational and experimental techniques will play a key role in determining the next challenges to be unraveled in the field of structural molecular biology.
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    Synthesis of precision antibody conjugates using proximity-induced chemistry
    (Ivyspring, 2021) Cao, Yu J.; Yu, Chenfei; Wu, Kuan-Lin; Wang, Xuechun; Liu, Dong; Tian, Zeru; Zhao, Lijun; Qi, Xuexiu; Loredo, Axel; Chung, Anna; Xiao, Han; Bioengineering; Biosciences; Chemistry
    Rationale: Therapeutic antibody conjugates allow for the specific delivery of cytotoxic agents or immune cells to tumors, thus enhancing the antitumor activity of these agents and minimizing adverse systemic effects. Most current antibody conjugates are prepared by nonspecific modification of antibody cysteine or lysine residues, inevitably resulting in the generation of heterogeneous conjugates with limited therapeutic efficacies. Traditional strategies to prepare homogeneous antibody conjugates require antibody engineering or chemical/enzymatic treatments, processes that often affect antibody folding and stability, as well as yield and cost. Developing a simple and cost-effective way to precisely couple functional payloads to native antibodies is of great importance. Methods: We describe a simple proximity-induced antibody conjugation method (pClick) that enables the synthesis of homogeneous antibody conjugates from native antibodies without requiring additional antibody engineering or post-synthesis treatments. A proximity-activated crosslinker is introduced into a chemically synthesized affinity peptide modified with a bioorthogonal handle. Upon binding to a specific antibody site, the affinity peptide covalently attaches to the antibody via spontaneous crosslinking, yielding an antibody molecule ready for bioorthogonal conjugation with payloads. Results: We have prepared well-defined antibody-drug conjugates and bispecific small molecule-antibody conjugates using pClick technology. The resulting conjugates exhibit excellent in vitro cytotoxic activity against cancer cells and, in the case of bispecific conjugates, superb antitumor activity in mouse xenograft models. Conclusions: Our pClick technology enables efficient, simple, and site-specific conjugation of various moieties to the existing native antibodies. This technology does not require antibody engineering or additional UV/chemical/enzymatic treatments, therefore providing a general, convenient strategy for developing novel antibody conjugates.
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    Unleashing the potential of noncanonical amino acid biosynthesis to create cells with precision tyrosine sulfation
    (Springer Nature, 2022) Chen, Yuda; Jin, Shikai; Zhang, Mengxi; Hu, Yu; Wu, Kuan-Lin; Chung, Anna; Wang, Shichao; Tian, Zeru; Wang, Yixian; Wolynes, Peter G.; Xiao, Han; Bioengineering; Biosciences; Chemistry; Physics and Astronomy; Center for Theoretical Biological Physics
    Despite the great promise of genetic code expansion technology to modulate structures and functions of proteins, external addition of ncAAs is required in most cases and it often limits the utility of genetic code expansion technology, especially to noncanonical amino acids (ncAAs) with poor membrane internalization. Here, we report the creation of autonomous cells, both prokaryotic and eukaryotic, with the ability to biosynthesize and genetically encode sulfotyrosine (sTyr), an important protein post-translational modification with low membrane permeability. These engineered cells can produce site-specifically sulfated proteins at a higher yield than cells fed exogenously with the highest level of sTyr reported in the literature. We use these autonomous cells to prepare highly potent thrombin inhibitors with site-specific sulfation. By enhancing ncAA incorporation efficiency, this added ability of cells to biosynthesize ncAAs and genetically incorporate them into proteins greatly extends the utility of genetic code expansion methods.