In the relentless global battle against influenza A virus (IAV), scientists have long grappled with the virus’s notorious ability to mutate, evade immune responses, and resist antiviral therapies. Responsible for multiple devastating pandemics throughout history, IAV continues to pose significant public health threats, causing thousands of hospitalizations and fatalities annually despite the availability of seasonal vaccines. The key challenge lies in the virus’s genetic flexibility, which enables it to shuffle, mutate, and recombine its genome, thereby outpacing conventional therapeutic and vaccination endeavors. Overcoming this formidable obstacle demands groundbreaking innovations capable of targeting conserved viral genomic elements while ensuring safety and efficacy within human lung tissues.
Conventional preclinical models have fallen short in accurately replicating the human lung environment and immune responses to IAV infection. Animal models frequently fail to emulate the intricate host-pathogen interactions and drug delivery dynamics characteristic of human lungs, limiting their translational relevance. Moreover, rapidly advancing gene editing technologies such as CRISPR offer promising antiviral avenues; yet, their human sequence specificity complicates meaningful testing in non-human systems. This gap underscores the urgency for sophisticated experimental platforms that recapitulate the human respiratory microenvironment for rigorous evaluation of antiviral modalities.
Addressing these limitations, researchers at Harvard University’s Wyss Institute for Biologically Inspired Engineering have pioneered a microfluidic “breathing” human lung alveolus chip (Lung Chip) designed to simulate its physiological counterpart with unprecedented fidelity. Leveraging advanced organ-on-chip technology, this Lung Chip encompasses living human lung epithelial and vascular endothelial cells cultured along microfluidic channels under dynamic mechanical stretch mirroring breathing motions. This biomimetic environment fosters authentic airway barrier functions, cellular responses to infection, and inflammatory signaling, providing a versatile testbed for studying respiratory virus pathogenesis and treatment responses.
Harnessing this innovative platform, the Wyss team developed a pan-influenza CRISPR RNA-based therapeutic targeting a highly conserved sequence within the IAV genome. This approach circumvents the virus’s mutational plasticity by focusing on viral genomic regions resistant to genetic variation across diverse IAV strains, thereby offering broad-spectrum antiviral potential. The CRISPR machinery was encapsulated within engineered nanoparticles designed for efficient pulmonary delivery and selective affinity to lung epithelial cells lining the microfluidic channels of the Lung Chip. This nanoformulation ensures targeted intracellular delivery of the CRISPR RNA complexes while minimizing systemic exposure.
Upon administering a single dose of these CRISPR-loaded nanoparticles to the infected Lung Chip model, researchers observed a substantial reduction in viral load—exceeding 50%—demonstrating potent suppression of IAV replication. Beyond viral clearance, this treatment significantly attenuated the host’s inflammatory response, a major driver of disease pathology, as evidenced by dampened pro-inflammatory cytokine expression profiles. These findings attest to both the antiviral efficacy and therapeutic safety of the CRISPR RNA intervention within a human-relevant respiratory framework.
Comprehensive transcriptomic analyses further illuminated the specificity of the CRISPR RNA therapy, revealing only minimal off-target gene editing effects in the Lung Chip system. This highlights the precision of the designed CRISPR components and underscores the capability of the Lung Chip model to detect subtle transcriptomic perturbations, an essential aspect of preclinical safety assessment rarely achievable in animal models. Such high-content molecular profiling adds a critical dimension to antiviral drug development, facilitating early identification of potential adverse effects.
The convergence of microfluidic organ-on-chip technology with cutting-edge CRISPR therapeutics exemplifies a transformative paradigm for respiratory infectious disease research. By faithfully emulating human lung microenvironment dynamics and facilitating precise antiviral delivery, this platform surmounts longstanding barriers posed by species-specific differences and physiological complexity observed in traditional models. This advancement not only expedites preclinical evaluation but also strengthens translational prospects for novel interventions targeting genetically diverse and rapidly evolving pathogens like IAV.
Donald E. Ingber, M.D., Ph.D., Founding Director of the Wyss Institute, emphasizes the strategic value of the Lung Chip system in pandemic preparedness efforts. He notes that the ability to test pan-influenza CRISPR therapies for broad strain coverage and low off-target risks within human-derived tissue improves confidence in clinical applicability. Given the continual emergence of new IAV variants and the persistent threat of global outbreaks, such innovative antiviral strategies are poised to shift the trajectory in influenza management and patient outcomes dramatically.
Further supporting this work are the collaborative contributions from research groups specializing in drug delivery and molecular engineering, including Associate Director Natalie Artzi, Ph.D., whose expertise in nanoparticle science enabled efficient CRISPR RNA encapsulation and targeted pulmonary administration. Together, these interdisciplinary efforts underpin a comprehensive approach to confronting viral diseases at the intersection of bioengineering, molecular genetics, and translational medicine.
This pioneering study appears in the latest edition of the journal Lab on a Chip and represents a landmark achievement in the application of human organ-on-chip technology for infectious disease therapeutics. The integration of sophisticated microfluidics with precision gene editing lays a foundation for future explorations into other respiratory pathogens and potential combinatorial treatments, heralding a new era of personalized and adaptable antiviral medicine.
Funding support from the Defense Advanced Research Projects Agency (DARPA) and the Wyss Institute further illustrates the high priority placed on innovative preclinical models and gene editing solutions to counteract viral pandemics. The goal remains to bridge the gap between bench-side discoveries and bedside implementation, enabling rapid responses to emerging infectious threats while ensuring safety and efficacy through human-centric platforms.
In sum, the Wyss Institute’s Lung Chip serves as a cutting-edge testing ground where the next generation of CRISPR RNA therapeutics can be refined, improving our arsenal against influenza A virus and potentially other respiratory viral diseases. By faithfully recapitulating human respiratory physiology and immune responses, this system promises to accelerate antiviral development, offering hope for robust pandemic preparedness and improved global health outcomes.
Subject of Research: Cells
Article Title: Preclinical assessment of pan-influenza A virus CRISPR RNA therapeutics in a human lung alveolus chip
Web References: http://dx.doi.org/10.1039/D5LC00156K
Image Credits: Wyss Institute at Harvard University
Keywords: Influenza, Infectious diseases, In vitro assays, Disease prevention, Antivirals, Human genetics, Gene expression, Inflammatory response, Inflammation, Drug delivery, Nanoparticles, Side effects, Epidemiology, Health care, Disease outbreaks
