RESUMEN
The use of recombinant adeno-associated virus (AAV) vectors is a popular choice for in vivo gene therapy, with hundreds of ongoing clinical trials targeting various genetic diseases. However, due to limited material availability and the complexity of AAV structure, there is a critical lack of comprehensive studies on AAV degradation pathways. In this study, we intended to elucidate the degradation pathways for a model AAV9 with GFP as the transgene under relevant stressed conditions. We assessed a diverse set of critical quality attributes and examined the overall impact of various stresses on transgene expression. This assessment revealed various degradation mechanisms of AAV9 and demonstrated the potential risk of a base formulation in causing AAV9 instability and potency loss under thermal stress at 25 and 40 °C while maintaining stability under freeze-thaw stress, interfacial stress due to membrane filtration, and short-term storage of up to 4 weeks at 5 °C.
RESUMEN
Fibrotic diseases, such as idiopathic pulmonary fibrosis (IPF) and systemic scleroderma (SSc), are commonly associated with high morbidity and mortality, thereby representing a significant unmet medical need. Interleukin 11 (IL11)-mediated cell activation has been identified as a central mechanism for promoting fibrosis downstream of TGFß. IL11 signaling has recently been reported to promote fibroblast-to-myofibroblast transition, thus leading to various pro-fibrotic phenotypic changes. We confirmed increased mRNA expression of IL11 and IL11Rα in fibrotic diseases by OMICs approaches and in situ hybridization. However, the vital role of IL11 as a driver for fibrosis was not recapitulated. While induction of IL11 secretion was observed downstream of TGFß signaling in human lung fibroblasts and epithelial cells, the cellular responses induced by IL11 was quantitatively and qualitatively inferior to that of TGFß at the transcriptional and translational levels. IL11 blocking antibodies inhibited IL11Rα-proximal STAT3 activation but failed to block TGFß-induced profibrotic signals. In summary, our results challenge the concept of IL11 blockade as a strategy for providing transformative treatment for fibrosis.