Inhaled CRISPR-Cas9 Nanoparticles Target STING1 in Alveolar Macrophages to Reverse Pulmonary Fibrosis in Mice
核心洞察
Researchers developed phosphatidylserine-modified lipid nanoparticles (DOPS LNPs (搜索)) loaded with Cas9 mRNA (搜索) and Sting1 (搜索)-targeting sgRNA for inhaled delivery to alveolar macrophages.
In a bleomycin-induced mouse model of pulmonary fibrosis, three inhalations achieved a 59.73% Sting1 (搜索) indel frequency and reduced collagen build-up with improved lung function.
The DOPS LNP formulation outperformed commercial LNPs by more than sevenfold in macrophage expression efficiency, with no meaningful off-target editing or anti-SpCas9 antibody response detected.
A research team has demonstrated that inhaled CRISPR-Cas9 nanoparticles can selectively disrupt the Sting1 (搜索) gene in alveolar macrophages, achieving significant reductions in fibrosis and improvements in lung function in a mouse model of idiopathic pulmonary fibrosis (搜索) (IPF). The findings, which address a long-standing challenge of delivering gene-editing therapeutics to the distal lung, position macrophage-targeted CRISPR inhalation as a potential disease-modifying strategy for a condition with a median survival of just 3–5 years post-diagnosis.
The STING signalling pathway in alveolar macrophages has been identified as a key driver of chronic inflammation and fibrotic remodelling in IPF. Current antifibrotic drugs can slow disease progression but do not reverse it, underscoring the urgent need for therapies that target the underlying cellular mechanisms.
Engineering macrophage-tropic lipid nanoparticles
To overcome the delivery barrier, the team developed phosphatidylserine-modified lipid nanoparticles (DOPS LNPs (搜索)) through a systematic orthogonal screening strategy. The phosphatidylserine surface modification was designed to promote selective uptake by macrophages, capitalizing on the natural propensity of these cells to recognize phosphatidylserine as an "eat-me" signal.
Loaded with Cas9 mRNA (搜索) and a Sting1 (搜索)-targeting sgRNA, the DOPS LNP formulation outperformed commercial LNPs by more than sevenfold in macrophage expression efficiency. This dramatic improvement in delivery specificity represents a critical advance, as achieving sufficient editing in the target cell population has been a persistent obstacle for pulmonary gene therapies.
In vivo efficacy in a fibrosis model
Following inhalation in mice with bleomycin-induced fibrosis, the nanoparticles accumulated preferentially in alveolar macrophages. After three inhalations, the treatment achieved a Sting1 (搜索) indel frequency of 59.73%, indicating robust on-target gene disruption.
The therapeutic impact was measured across multiple endpoints. The treatment reduced collagen build-up in the lungs and lowered fibrosis scores, reflecting less severe tissue damage. Lung function improved across several measures after treatment, suggesting that Sting1 (搜索) disruption in alveolar macrophages can attenuate the fibrotic process and partially restore respiratory capacity.
Safety profile supports repeated dosing
On the safety side, deep sequencing found no meaningful editing at any of the five predicted off-target loci, demonstrating high specificity of the CRISPR-Cas9 system when delivered via the DOPS LNP platform. Furthermore, repeated dosing did not produce a detectable anti-SpCas9 antibody response, a finding that supports a safety and tolerability profile compatible with chronic, repeat-administration regimens—an important consideration for a progressive disease like IPF.
Together, these findings establish that inhaled, macrophage-targeted CRISPR-Cas9 nanoparticles can disrupt a validated fibrotic driver in the lung with high efficiency, specificity, and a favorable early safety profile. While the work remains preclinical, it opens a new therapeutic avenue for IPF and potentially other fibrotic lung diseases where the STING pathway contributes to pathogenesis.