Quijada, HectorBermudez, TadeoKempf, Carrie L.Valera, Daniel G.Garcia, Alexander N.Camp, Sara M.Song, Jin H.Franco, EvelynBurt, Jessica K.Sun, BelindaMascarenhas, Joseph B.Burns, KimberlieGaber, AmirOita, Radu C.Reyes Hernon, VivianBarber, ChristyMoreno-Vinasco, LilianaSun, XiaoguangCress, Anne E.Martin, DiegoLiu, ZhonglinDesai, Ankit A.Natarajan, ViswanathanJacobson, Jeffrey R.Dudek, Steven M.Bime, ChristianSammani, SaadGarcia, Joe G.N.2024-03-262024-03-262021-05-06Quijada H, Bermudez T, Kempf CL, et al. Endothelial eNAMPT amplifies pre-clinical acute lung injury: efficacy of an eNAMPT-neutralising monoclonal antibody. Eur Respir J. 2021;57(5):2002536. Published 2021 May 6. doi:10.1183/13993003.02536-2020https://hdl.handle.net/1805/39540Rationale: The severe acute respiratory syndrome coronavirus 2/coronavirus disease 2019 pandemic has highlighted the serious unmet need for effective therapies that reduce acute respiratory distress syndrome (ARDS) mortality. We explored whether extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a ligand for Toll-like receptor (TLR)4 and a master regulator of innate immunity and inflammation, is a potential ARDS therapeutic target. Methods: Wild-type C57BL/6J or endothelial cell (EC)-cNAMPT -/- knockout mice (targeted EC NAMPT deletion) were exposed to either a lipopolysaccharide (LPS)-induced ("one-hit") or a combined LPS/ventilator ("two-hit")-induced acute inflammatory lung injury model. A NAMPT-specific monoclonal antibody (mAb) imaging probe (99mTc-ProNamptor) was used to detect NAMPT expression in lung tissues. Either an eNAMPT-neutralising goat polyclonal antibody (pAb) or a humanised monoclonal antibody (ALT-100 mAb) were used in vitro and in vivo. Results: Immunohistochemical, biochemical and imaging studies validated time-dependent increases in NAMPT lung tissue expression in both pre-clinical ARDS models. Intravenous delivery of either eNAMPT-neutralising pAb or mAb significantly attenuated inflammatory lung injury (haematoxylin and eosin staining, bronchoalveolar lavage (BAL) protein, BAL polymorphonuclear cells, plasma interleukin-6) in both pre-clinical models. In vitro human lung EC studies demonstrated eNAMPT-neutralising antibodies (pAb, mAb) to strongly abrogate eNAMPT-induced TLR4 pathway activation and EC barrier disruption. In vivo studies in wild-type and EC-cNAMPT -/- mice confirmed a highly significant contribution of EC-derived NAMPT to the severity of inflammatory lung injury in both pre-clinical ARDS models. Conclusions: These findings highlight both the role of EC-derived eNAMPT and the potential for biologic targeting of the eNAMPT/TLR4 inflammatory pathway. In combination with predictive eNAMPT biomarker and NAMPT genotyping assays, this offers the opportunity to identify high-risk ARDS subjects for delivery of personalised medicine.en-USAttribution-NonCommercial 4.0 InternationalAcute lung injuryMonoclonal antibodiesCOVID-19SARS-CoV-2Article