“Cell-free” MEsenchymal Regenerative therapy for aLpha-1-antitrypsIN deficiency-associated lung diseases (MERLIN)

Alpha-1-antitrypsin (AAT) is a serine-proteinase inhibitor crucial to maintain protease–anti-protease homeostasis in the lungs. When AAT is deficient, the protease–anti-protease imbalance and the pro-inflammatory environment lead to the degradation of elastin, other basal membrane and matrix components, with the development of chronic obstructive pulmonary disease (COPD) and emphysema (the prevalence of severe AATD in individuals with COPD is between 0% and 12%, with a mean value of 3.6% [1]). The current standard of care is replacement (augmentation) therapy, by weekly i.v. infusion of human plasma purified AAT. Nevertheless, augmentation therapy is not universally accepted for preventing emphysema and has some downsides: it is expensive and requires repeated, lifelong intravenous infusions, and the optimal dose has yet to be determined, as AAT loses immunomodulatory effects (probably during purification). In this project, a new AAT deficiency therapy is being developed meant to effectively regenerate lung parenchyma, modulate inflammation, prevent the onset of bacterial infections, and stimulate the progenitor elements to trigger the healing process. To this aim, MERLIN develops and tests in cellular and murine models the first cell-free regenerative therapy for treating AAT deficiency-associated lung diseases based on ready-to-use, off-the-shelf and easily storable secretome (Sec) from heterologous adipose MSC. The project thesis is that MSC-Sec maintains the safety and efficacy properties of MSC, including anti-inflammatory, immunomodulatory, regenerative, pro-angiogenic, anti-protease and anti-infective properties, but with minimized technological, regulatory and economic burdens compared to parent cells. Specific aims of the project include 1) Pharmaceutical development of MSC-Sec in compliance with regulations in force. The project will deal with an essential aspect regarding MSC-Sec clinical application: its pharmaceuticalization. MSC-Sec will be formulated into a standardized injectable dosage form (lyoS) easily adoptable by the clinical community. 2) Evaluation of the therapeutic efficacy (as dose-response activity) of lyoS in cell models; this will allow studying the effects of lyoS in the regenerative responses and barrier function. 3) In vivo evaluation of lyoS effects in an elastase-induced COPD mouse model to evaluate the toxicity and the therapeutic efficacy in emphysema. 4) Description of the pathological mechanisms. In vitro and in vivo models will be evaluated at the functional level by proteomic analysis to identify pathways, processes and functions modulated by pathology and lyoS treatment; also, the same network models will be processed at the topological level to identify proteins and define hubs and bottlenecks that play a key role in pathological and regenerative mechanisms. Finally, we will reconstruct the interactions between proteins present in lyoS and targets in both in vitro and in vivo models using bipartite graphs.