Matching Items (6)
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- All Subjects: Immunology
- Creators: Yan, Hao
Description
DNA nanotechnology has been a rapidly growing research field in the recent decades, and there have been extensive efforts to construct various types of highly programmable and robust DNA nanostructures. Due to the advantage that DNA nanostructure can be used to organize biochemical molecules with precisely controlled spatial resolution, herein we used DNA nanostructure as a scaffold for biological applications. Targeted cell-cell interaction was reconstituted through a DNA scaffolded multivalent bispecific aptamer, which may lead to promising potentials in tumor therapeutics. In addition a synthetic vaccine was constructed using DNA nanostructure as a platform to assemble both model antigen and immunoadjuvant together, and strong antibody response was demonstrated in vivo, highlighting the potential of DNA nanostructures to serve as a new platform for vaccine construction, and therefore a DNA scaffolded hapten vaccine is further constructed and tested for its antibody response. Taken together, my research demonstrated the potential of DNA nanostructure to serve as a general platform for immunological applications.
ContributorsLiu, Xiaowei (Author) / Liu, Yan (Thesis advisor) / Chang, Yung (Thesis advisor) / Yan, Hao (Committee member) / Allen, James (Committee member) / Zhang, Peiming (Committee member) / Arizona State University (Publisher)
Created2012
Description
Efforts to quantify the diversity of the T cell repertoire have generally been unsuccessful because not all factors accounting for diversity have been considered. In order to get an accurate representation of the T cell repertoire, one must incorporate analysis of germline gene diversity, diversity from somatic recombination, joining diversity from N- and P- nucleotides, and TCR chain pairing diversity. Because of advances in high-throughput sequencing techniques, estimates have been able to account for diversity from TCR genes. However the ability to account for chain pairing diversity has been more difficult. In order to do so, single cell sorting techniques must be employed. These techniques, though effective, are time consuming and expensive. For this reason, no large-scale analyses have been done on the immune repertoires using these techniques. In this study, we propose a novel method for linking the two TCR chain sequences from an individual cell. DNA origami nanostructure technology is employed to capture and bind the TCRγ and TCRδ chain mRNA inside individual cells using probe strands complementary to the C-region of those sequences. We then use a dual-primer RT and ligation molecular strategy to link the two sequences together. The result is a single amplicon containing the CDR3 region of the TCRγ and TCRδ. This amplicon can then be easily PCR amplified using sequence specific primers, and sequenced. DNA origami nanostructures offer a rapid, cost-effective method alternative to conventional single cell sorting techniques, as both TCR mRNA can be captured on one origami molecule inside a single cell. At present, this study outlines a proof-of-principle analysis of the method to determine its functionality. Using known TCRγ and TCRδ sequences, the DNA origami and RT/PCR method was tested and resulting sequence data proved the effectiveness of the method. The original TCRγ and TCRδ sequences were linked together as a single amplicon containing both CDR3 regions of the genes. Thus, this method can be employed in further research to elucidate the γδ T cell repertoire. This technology is also easily adapted to any gene target or cell type and therefore presents a large opportunity to be used in other immune repertoire analysis and other immunological studies (such as the rapid identification and subsequent production of antibodies).
ContributorsPoindexter, Morgan Elizabeth (Author) / Blattman, Joseph (Thesis director) / Yan, Hao (Committee member) / Schoettle, Louis (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Originally conceived as a way to scaffold molecules of interest into three-dimensional (3D) crystalline lattices for X ray crystallography, the field of deoxyribonucleic acid (DNA) nanotechnology has dramatically evolved since its inception. The unique properties of DNA nanostructures have promoted their use not only for X ray crystallography, but for a suite of biomedical applications as well. The work presented in this dissertation focuses on both of these exciting applications in the field: 1) Nucleic acid nanostructures as multifunctional drug and vaccine delivery platforms, and 2) 3D DNA crystals for structure elucidation of scaffolded guest molecules.Chapter 1 illustrates how a wide variety of DNA nanostructures have been developed for the delivery of drugs and vaccine components. However, their applications are limited under physiological conditions due to their lack of stability in low salt environments, susceptibility to enzymatic degradation, and tendency for endosomal entrapment. To address these issues, Chapter 2 describes a PEGylated peptide coating molecule was designed to electrostatically adhere to and protect DNA origami nanostructures and to facilitate their cytosolic delivery by peptide-mediated endosomal escape. The development of this molecule will aid in the use of nucleic acid nanostructures for biomedical purposes, such as the delivery of messenger ribonucleic acid (mRNA) vaccine constructs. To this end, Chapter 3 discusses the fabrication of a structured mRNA nanoparticle for more cost-efficient mRNA vaccine manufacture and proposes a multi-epitope mRNA nanostructure vaccine design for targeting human papillomavirus (HPV) type 16-induced head and neck cancers.
DNA nanotechnology was originally envisioned to serve as three-dimensional scaffolds capable of positioning proteins in a rigid array for their structure elucidation by X ray crystallography. Accordingly, Chapter 4 explores design parameters, such as sequence and Holliday junction isomeric forms, for efficient crystallization of 3D DNA lattices. Furthermore, previously published DNA crystal motifs are used to site-specifically position and structurally evaluate minor groove binding molecules with defined occupancies. The results of this study provide significant advancement towards the ultimate goal of the field.
ContributorsHenry, Skylar J.W. (Author) / Stephanopoulos, Nicholas (Thesis advisor) / Anderson, Karen (Thesis advisor) / Blattman, Joseph (Committee member) / Yan, Hao (Committee member) / Arizona State University (Publisher)
Created2023
Description
Cell immunotherapies have revolutionized clinical oncology. While CAR T cell therapy has been very effective in clinical studies, off-target immune toxicity limits eligible patients. Thus, NK cells have been approached with the same therapy design since NK cells have a more favorable safety profile. Therefore, the purpose of this research project is to explore DNA nanotech-based NK cell engagers (NKCEs) that force an immunological synapse between the NK cell and the cancer cell, leading to cancer death. DNA tetrabody (TB) and DNA tetrahedron (TDN) are fabricated and armed with HER2 affibody for tight adhesion to HER2+ cancer cell lines like SKBR3. Overall, relationship between TB-NK treatment and cancer cell apoptosis is still unclear. TB-NK treatment induces an apoptotic profile similar to PMA/IO stimulation. Pilot cell assay needs to be replicated with additional controls and a shortened treatment window. For DNA TDN fabrication, HER2 affibody polishing with Ni-NTA affinity chromatography achieves high purity with 20% to 100% high-imidazole elution gradient. ssDNA-HER2 affibody conjugation is optimal when ssDNA is treated with 40-fold excess sulfo-SMCC for 4 hours. In conclusion, the manufacturing of DNA-based NKCEs is rapid and streamlined, which gives these NKCEs the potential to become a ready to use immunotherapy.
ContributorsLuca, Michael (Author) / Yan, Hao (Thesis director) / Stephanopoulos, Nicholas (Committee member) / Blattman, Joseph (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of International Letters and Cultures (Contributor) / School of Molecular Sciences (Contributor)
Created2024-05
Description
Peptide-based vaccines represent a promising strategy to develop personalized treatments for cancer immunotherapy. Despite their specificity and low cost of production, these vaccines have had minimal success in clinical studies due to their lack of immunogenicity, creating a need for more effective vaccine designs. Adjuvants can be incorporated to enhance their immunogenicity by promoting dendritic cell activation and antigen cross-presentation. Due to their favorable size and ability to incorporate peptides and adjuvants, nanoparticles represent an advantageous platform for designing peptide vaccines. One prime example is RNA origami (RNA-OG) nanostructures, which are nucleic acid nanostructures programmed to assemble into uniform shapes and sizes. These stable nanostructures can rationally incorporate small molecules giving them a wide array of functions. Furthermore, RNA-OG itself can function as an adjuvant to stimulate innate immune cells. In the following study, self-adjuvanted RNA-OG was employed as a vaccine assembly platform, incorporating tumor peptides onto the nanostructure to design RNA-OG-peptide nanovaccines for cancer immunotherapy. RNA-OG-peptide was found to induce dendritic cell activation and antigen cross-presentation, which mobilized tumor-specific cytotoxic T cells to elicit protective anti-tumor immunity in tumor-bearing mice. These findings demonstrate the therapeutic potential of RNA-OG as a stable, carrier-free nanovaccine platform. In an attempt to further enhance the efficacy by optimizing the amount of peptides assembled, RNA-OG was complexed with polylysine-linked peptides, a simple strategy that allowed peptide amounts to be varied. Interestingly, increasing the peptide load led to decreased vaccine efficacy, which was correlated with an ineffective CD8+ T cell response. On the other hand, the vaccine efficacy was improved by decreasing the amount of peptide loaded onto RNA-OG, which may have attributed to greater complex stability compared to the high peptide load. These results highlight a simple strategy that can be used to optimize vaccine efficacy by altering the load of assembled peptides. These studies advance our understanding of RNA-OG as a peptide vaccine platform and provide various strategies to improve the design of peptide vaccines for translation into cancer immunotherapy.
ContributorsYip, Theresa (Author) / Chang, Yung (Thesis advisor) / Borges Florsheim, Esther (Committee member) / Lake, Douglas (Committee member) / Yan, Hao (Committee member) / Arizona State University (Publisher)
Created2024
Description
There are many biological questions that require single-cell analysis of gene sequences, including analysis of clonally distributed dimeric immunoreceptors on lymphocytes (T cells and B cells) and/or the accumulation of driver/accessory mutations in polyclonal tumors. Lysis of bulk cell populations results in mixing of gene sequences, making it impossible to know which pairs of gene sequences originated from any particular cell and obfuscating analysis of rare sequences within large populations. Although current single-cell sorting technologies can be used to address some of these questions, such approaches are expensive, require specialized equipment, and lack the necessary high-throughput capacity for comprehensive analysis. Water-in-oil emulsion approaches for single cell sorting have been developed but droplet-based single-cell lysis and analysis have proven inefficient and yield high rates of false pairings. Ideally, molecular approaches for linking gene sequences from individual cells could be coupled with next-generation high-throughput sequencing to overcome these obstacles, but conventional approaches for linking gene sequences, such as by transfection with bridging oligonucleotides, result in activation of cellular nucleases that destroy the template, precluding this strategy. Recent advances in the synthesis and fabrication of modular deoxyribonucleic acid (DNA) origami nanostructures have resulted in new possibilities for addressing many current and long-standing scientific and technical challenges in biology and medicine. One exciting application of DNA nanotechnology is the intracellular capture, barcode linkage, and subsequent sequence analysis of multiple messenger RNA (mRNA) targets from individual cells within heterogeneous cell populations. DNA nanostructures can be transfected into individual cells to capture and protect mRNA for specific expressed genes, and incorporation of origami-specific bowtie-barcodes into the origami nanostructure facilitates pairing and analysis of mRNA from individual cells by high-throughput next-generation sequencing. This approach is highly modular and can be adapted to virtually any two (and possibly more) gene target sequences, and therefore has a wide range of potential applications for analysis of diverse cell populations such as understanding the relationship between different immune cell populations, development of novel immunotherapeutic antibodies, or improving the diagnosis or treatment for a wide variety of cancers.
ContributorsSchoettle, Louis (Author) / Blattman, Joseph N (Thesis advisor) / Yan, Hao (Committee member) / Chang, Yung (Committee member) / Lindsay, Stuart (Committee member) / Arizona State University (Publisher)
Created2017