Central to this innovation is DoriVac, a DNA origami-based vaccine platform uniquely designed to deliver antigens with precision to lymph nodes (LNs), the strategic hubs of immune activation. Following administration of two doses, DoriVac markedly increased the population of IFNγ-secreting cytotoxic CD8+ T cells as evidenced by detailed flow cytometry analysis. This elevation indicates a robust functional response, as IFNγ production is pivotal in orchestrating antiviral immunity through direct cytotoxic activity and by shaping the adaptive immune response.

Moreover, DoriVac treatment amplified the presence of CD107a+ CD8+ T cells, which are indicative of degranulating cytotoxic lymphocytes actively releasing cytotoxic molecules. This physiological marker confirms that the T cells are not merely present but are effectively engaging in immune cytolytic activity within the lymph nodes, a crucial mechanism for clearing infected cells. The upregulation of activation markers PD-1 and CD69 within the CD8+ T cell subset further signifies a heightened activation state, demonstrating that these immune cells are primed and ready for potent effector functions.

The comprehensive immunological characterization extends beyond the lymph nodes to systemic levels, with splenic analyses showing a significant expansion of antigen-specific CD8+ T cells. Utilizing IFNγ ELISpot assays on day 35 post-vaccination, researchers observed a dramatic increase in SARS-CoV-2 antigen-specific CD8+ splenocytes in mice treated with DoriVac when compared to those receiving traditional bolus vaccine formulations. This enhanced T cell frequency underscores the vaccine’s ability to elicit long-lasting and systemic cellular immunity, crucial for durable protection against viral pathogens.

What distinguishes DoriVac from prior vaccine constructs is its sophisticated mode of antigen and adjuvant co-delivery. Unlike the physical mixture of square DNA origami backbone (SQB), free HIV-HR2 peptides, and free CpG oligonucleotides—which failed to match the activation levels—DoriVac’s integrated nanoparticle configuration ensures spatially controlled presentation of both antigen and immune-stimulatory motifs. This spatial arrangement fosters synergistic activation of dendritic cells and subsequent priming of CD8+ T cells, resulting in superior immunogenicity.

These findings bear immense implications for the broader field of vaccinology, particularly for vaccines targeting infectious diseases demanding robust cellular immunity. Traditional vaccine platforms often skew heavily towards humoral, antibody-based responses, whereas viruses and certain intracellular pathogens necessitate the engagement of killer T cells for effective immunity. DoriVac’s capacity to robustly activate CD8+ cytotoxic T lymphocytes addresses this critical gap and may translate into improved protection against viruses such as SARS-CoV-2, HIV, and other emerging pathogens.

The molecular underpinnings harnessed by the DoriVac platform exploit principles of DNA nanotechnology—specifically DNA origami, which allows the folding of long single-stranded DNA into defined nanoscale shapes. This enables precision engineering of multivalent antigen arrays and co-delivery of potent Toll-like receptor ligands, such as CpG, within tailored nanostructures optimized for lymphatic trafficking and antigen presentation.

Comprehensive flow cytometric analysis revealed that following vaccination, the proportion of CD8+ IFNγ+ T cells within the lymph nodes significantly rose, accompanied by increased expression of degranulation marker CD107a. These markers correlate with enhanced effector functionality, suggesting that the DNA origami platform is capable of inducing not only proliferation but functional cytolytic competency of CD8+ T cells, a landmark achievement highlighting the translational potential of DNA nanostructure-based vaccines.

Importantly, the study demonstrates that the antigen-specific activation is not driven merely by the presence of vaccine components but is dependent on their precise nanoscale organization. Control experiments with dispersed antigens and adjuvants lacked the robust immune activation observed with DoriVac, underscoring the critical role of the DNA origami scaffold in potentiating immune cell engagement.

The heightened upregulation of PD-1 on CD8+ T cells post-DoriVac vaccination, while generally associated with T cell exhaustion in chronic infections, here reflects an activation phenotype in the acute vaccination context. Alongside CD69 upregulation, these markers collectively validate the presence of an early, active immune response, signaling that the T cells are not anergic but primed for antigen-specific responses.

Examining the systemic immune compartment, the spleen revealed a statistically significant elevation in IFNγ-secreting antigen-specific CD8+ T cells at day 35, indicating that the vaccine not only instigates local lymph node activation but drives sustained systemic immunity. These antigen-specific T cells are instrumental in mediating long-term immune surveillance and rapid responsiveness upon pathogen encounter.

The vaccine’s enhanced performance in T cell activation translates into tangible immunological advantages that could revolutionize vaccine responses. By prioritizing cellular immunity alongside humoral responses, DoriVac offers a comprehensive shield capable of stronger and more versatile protective mechanisms against infectious agents.

The findings hold translational promise, particularly in the face of global pandemics caused by viruses where effective CD8+ T cell immunity is crucial for viral clearance and long-term immune memory. Leveraging DNA nanotechnology’s precision and versatility, DoriVac fundamentally elevates vaccine design, moving beyond traditional paradigms towards nanoengineered immunotherapies.

This study’s methodological rigor, employing multiparametric flow cytometry, ELISpot assays, and rigorous statistical analyses, provides robust validation of the platform’s superiority. The conclusion is compelling: DNA origami nanoparticles offer a powerful, tunable approach toward enhanced vaccine efficacy, particularly by enhancing cytotoxic T cell responses often difficult to elicit with existing vaccines.

Future perspectives include the adaptation of this technology to other infectious diseases and potentially oncology vaccines, where cellular immune responses are pivotal. The modularity of the DNA origami platform permits incorporation of diverse antigenic epitopes and adjuvants, enabling rapid customization for emerging pathogens or tumor-specific targets.

In summary, the research spearheaded by Zeng et al. marks a pivotal milestone in vaccine innovation, harnessing the structural sophistication of DNA origami to dramatically boost antigen-specific CD8+ T cell immunity. This breakthrough is poised to accelerate the development of next-generation vaccines with potent, multifaceted protection, setting a new standard for immunological engineering in combating infectious diseases.

Subject of Research:
Vaccine development using DNA origami nanoparticles to improve cellular immune responses, specifically cytotoxic CD8+ T cell activation against infectious diseases such as SARS-CoV-2.

Article Title:
DNA origami vaccine nanoparticles improve humoral and cellular immune responses to infectious diseases.

Article References:
Zeng, Y.C., Young, O.J., Xiong, Q. et al. DNA origami vaccine nanoparticles improve humoral and cellular immune responses to infectious diseases. Nat. Biomed. Eng (2026). https://doi.org/10.1038/s41551-026-01614-w

Image Credits:
AI Generated

DOI:
https://doi.org/10.1038/s41551-026-01614-w

Messenger RNA (mRNA) vaccines have undoubtedly transformed public health, especially highlighted by their rapid deployment during the COVID-19 pandemic. However, their variable efficacy among individuals and the need for frequent updates to counter viral mutations have exposed critical vulnerabilities. Manufacturing complexities, stringent cold chain requirements, and unpredictable dosing within lipid nanoparticle delivery vehicles have also underscored the necessity for complementary strategies. The DNA origami-based DoriVac seeks to address these challenges by enabling unparalleled control over vaccine composition at the nanoscale, ensuring precise spatial arrangement of immune-stimulating elements and antigens.

At the heart of DoriVac’s technology lies DNA origami, a technique that engineers DNA to fold into highly defined three-dimensional nanostructures. These square block-shaped constructs serve a dual purpose: one face displays immune-activating adjuvant molecules, while the opposing side presents pathogen-specific antigens. This spatially controlled display is critical; by tuning the nanometer-scale distances between adjuvant molecules, researchers optimize the activation of dendritic cells, the immune system’s sentinel antigen-presenting cells. Enhanced dendritic cell activation cascades into a more vigorous and diverse mobilization of humoral and cellular immunity, including potent B cell antibody production and activation of CD4+ and CD8+ T cell subsets essential for viral clearance and long-term protection.

The Wyss Institute team deployed the DoriVac platform to develop vaccines that incorporate the HR2 peptide, a conserved region found in the spike proteins of diverse viruses such as SARS-CoV-2, HIV, and Ebola. These vaccines elicited compelling immune responses in murine models, significantly surpassing those generated by free antigens and adjuvants administered without the nanostructured framework. Notably, the SARS-CoV-2 HR2-targeting DoriVac induced a broad spectrum of immune cells, encompassing activated dendritic cells, memory T cells proficient in cytotoxic functions, and antibody-secreting plasma cells, all key players in sustained antiviral immunity.

Transitioning from animal studies to human systems, researchers employed an advanced human lymph node-on-a-chip platform to simulate and assess how DoriVac would perform in a human immune context. This microfluidic technology provides a dynamic and controllable environment that closely mimics the physiology of human lymphoid tissue, where initial immune activation occurs. Here, the SARS-CoV-2 HR2 DoriVac vaccine profoundly stimulated dendritic cells to secrete inflammatory cytokines and expanded populations of functional CD4+ and CD8+ T cells. Such results underscore the considerable translational potential of DoriVac vaccines and support their progression toward clinical evaluation.

Perhaps most strikingly, direct comparisons between DoriVac vaccines presenting the full SARS-CoV-2 spike protein and commercially available mRNA vaccines from Moderna and Pfizer/BioNTech revealed that DoriVac could elicit comparable levels of T cell and B cell responses. This parity was observed in preclinical mouse models receiving booster doses—a gold standard in assessing vaccine efficacy. The implications extend beyond immune activation; the structural stability of DoriVac vaccines circumvents the necessity for ultracold storage that hampers mRNA vaccine distribution, particularly in resource-constrained settings. Moreover, the relatively straightforward manufacturing process promises scalability and cost-effectiveness, factors critical for global vaccine accessibility.

The molecular precision of DoriVac offers significant advantages in safety and customization. By programming immune recognition mechanisms at the nanoscale, it minimizes off-target effects commonly associated with lipid nanoparticle-based delivery systems. Additionally, the self-adjuvanted nature of the DNA origami vaccine enhances immune stimulation without requiring separate adjuvant components. Early studies indicate a favorable safety profile, further substantiating the platform’s suitability for diverse clinical applications.

DoriVac’s creation is the culmination of interdisciplinary collaboration integrating expertise from structural DNA nanotechnology, immunology, microengineering, and virology. Led by Professor William Shih and Dr. Yang (Claire) Zeng, the initiative represents a fusion of fundamental science and translational vision. Zeng’s leadership in advancing DoriVac encompassed initial cancer immunotherapy applications, which serendipitously dovetailed with infectious disease needs amidst the ongoing pandemic. The coupling of DNA origami with organ-on-chip technologies, engineered by Dr. Donald Ingber’s team, exemplifies this synergy, producing predictive human immune models conducive to accelerating vaccine development cycles.

As the scientific community anticipates the next generation of vaccines with enhanced efficacy, durability, and accessibility, platforms like DoriVac may form the cornerstone of future pandemic preparedness. Their modularity permits rapid reprogramming to address emerging pathogens, while their robust immune activation profiles enhance both the magnitude and breadth of protective responses. This novel approach not only augments our arsenal against known viral threats but also charts a sophisticated path to anticipate and mitigate future infectious disease challenges.

With promising preclinical data validating the feasibility and superiority of DoriVac, the research consortium is poised to advance toward clinical trials. Commercialization efforts led by DoriNano, co-founded by Dr. Zeng, aim to translate this innovation from laboratory benches to global healthcare systems. Their success could redefine vaccine paradigms, merging the blueprint of life, DNA, with cutting-edge immunoengineering, to deliver vaccines that are smarter, safer, and more widely available.

In sum, DoriVac represents an exciting convergence of nanotechnology and immunotherapy, encapsulating the potential to revolutionize vaccine science. By delivering a potent cocktail of vaccine and adjuvant with nanometer precision, this platform amplifies immune responses beyond current capabilities. Its stability and manufacturability hold promise for equitable distribution worldwide, breaking down barriers imposed by cold chains and supply complexities. As infectious diseases continue to challenge humanity, such innovations may well be our most formidable defense.

Subject of Research: Animals

Article Title: DNA origami vaccine nanoparticles improve humoral and cellular immune responses to infectious diseases

Web References:

• Wyss Institute Technology: DoriVac Information
• Wyss Institute at Harvard University: https://wyss.harvard.edu

Image Credits: Wyss Institute at Harvard University

Keywords: DNA origami, vaccine development, infectious diseases, immunology, adjuvants, dendritic cells, antigen presentation, humoral immunity, cellular immunity, SARS-CoV-2, mRNA vaccines, nanotechnology