Cytokine pre-activation of cryopreserved xenogeneic-free human mesenchymal stromal cells enhances resolution and repair following ventilator-induced lung injury potentially via a KGF-dependent mechanism

Abstract

Background: Human mesenchymal stem/stromal cells (hMSCs) represent a promising therapeutic strategy for ventilator-induced lung injury (VILI) and acute respiratory distress syndrome. Translational challenges include restoring hMSC efficacy following cryopreservation, developing effective xenogeneic-free (XF) hMSCs and establishing true therapeutic potential at a clinically relevant time point of administration. We wished to determine whether cytokine pre-activation of cryopreserved, bone marrow-derived XF-hMSCs would enhance their capacity to facilitate injury resolution following VILI and elucidate mechanisms of action. Methods: Initially, in vitro studies examined the potential for the secretome from cytokine pre-activated XF-hMSCs to attenuate pulmonary epithelial injury induced by cyclic mechanical stretch. Later, anaesthetised rats underwent VILI and, 6 h following injury, were randomized to receive 1 × 10 7 XF-hMSC/kg that were (i) naive fresh, (ii) naive cryopreserved, (iii) cytokine pre-activated fresh or (iv) cytokine pre-activated cryopreserved, while control animals received (v) vehicle. The extent of injury resolution was measured at 24 h after injury. Finally, the role of keratinocyte growth factor (KGF) in mediating the effect of pre-activated XF-hMSCs was determined in a pulmonary epithelial wound repair model. Results: Pre-activation enhanced the capacity of the XF-hMSC secretome to decrease stretch-induced pulmonary epithelial inflammation and injury. Both preactivated fresh and cryopreserved XF-hMSCs enhanced resolution of injury following VILI, restoring oxygenation, improving lung compliance, reducing lung leak and improving resolution of lung structural injury. Finally, the secretome of pre-activated XF-hMSCs enhanced epithelial wound repair, in part via a KGF-dependent mechanism.

Mesenchymal Stem/Stromal Cells Therapy for Sepsis and Acute Respiratory Distress Syndrome

“…Recent studies demonstrating MSC efficacy include a report on the cytokine preactivation of MSCs which enhances their therapeutic efficacy in a VILI model. 39 In a LPSinduced ARDS model, naive and LPS preactivated adiposederived stem cells resulted in less inflammatory neutrophil infiltration, reduced lung injury scores, and reduced collagen deposition indicating an effect on the short-term inflammatory and long-term fibrotic effects of LPS injury. 64 Injection of induced pluripotent stem cells (iPS) iPS MSCs into ex vivo ECMO simulation circuits reduces inflammatory cytokine production.…”

“…38 A recent study has demonstrated the beneficial effects of pretreating MSCs with inflammatory "cytomix" to simulate the inflammatory microenvironment in VILI and showed that MSCs may confer their beneficial effects in this model in a KGF-mediated action. 39 This would suggest that consideration of the disease state is imperative in its treatment with MSCs. MSCs activated through toll-like receptor (TLR)-3 by poly I:C, whose role is to simulate double-stranded RNA similar to a viral signaling factor, enhanced MSCs' ability to induce an antiapoptotic phenotype in neutrophils.…”

Emerging pharmacological therapies for ARDS: COVID-19 and beyond

“…MSCs have immunomodulatory and pro-reparative effects and show efficacy in preclinical models of ARDS [ 10 , 11 ]. A single IV infusion of allogeneic, bone marrow-derived human MSCs was well tolerated in nine patients with moderate to severe ARDS in a 2015 phase 1 dose escalation trial [ 12 ].…”

“…REMAP-CAP—Randomized, Embedded, Multifactorial Adaptive Platform Trial for Community-Acquired Pneumonia. NCT02735707 4.MSCs Immunomodulatory and pro-resolution effects Promising in preclinical and phase 1/2 ARDS studies [ 10 , 11 , 15 ] ACE2-/- MSCs were well tolerated, improved pulmonary function and immune response in a case series of 7 COVID-19 patients [ 95 ] 1. REALIST—Study of MSC Repair in COVID-19-induced ARDS.…”

Mesenchymal stromal cells for acute respiratory distress syndrome (ARDS), sepsis, and COVID-19 infection: optimizing the therapeutic potential

“…In models of ARDS and sepsis preconditioning with various agents has been investigated but has yet to translate to clinical trials. Horie et al, 2020, demonstrated in a rodent VILI model, MSCs primed with a combination of cytokines (IL-1β, TNF-α, and IFN-γ) enhanced resolution of histological evidence of VILI, restored oxygenation, improved lung compliance, and reduced lung edema [145]. Baudry et al, 2019, demonstrated that IFN-γ preconditioned MSCs, in a murine sepsis model, had beneficial effects on the microcirculation by increasing the flow of leucocytes, decreasing leucocyte adhesion, and increasing red blood cell velocity [77].…”