Abstract
Rationale The SARS-CoV-2/COVID-19 pandemic has highlighted the serious unmet need for effective therapies that reduce ARDS mortality. We explored whether extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a ligand for Toll-like receptor 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 mAb imaging probe (99mTc-ProNamptorTM) 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 utilised in vitro and in vivo.
Results Immunohistochemical, biochemical, and imaging studies validated time-dependent increases in NAMPT lung tissue expression in both preclinical ARDS models. Intravenous delivery of either eNAMPT-neutralising pAb/mAb significantly attenuated inflammatory lung injury (H & E staining, BAL protein, BAL PMNs, plasma IL-6) in both preclinical 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 preclinical 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.
Abstract
Underscoring the therapeutic potential for targeting the eNAMPT/TLR4 pathway in ARDS/VILI, a humanised eNAMPT-neutralising monoclonal antibody (mAb) was highly effective in reducing the severity of ARDS in these dual complementary preclinical ARDS models.
Footnotes
Author Contributions: JGNG, SS – conception and design of the work, the analysis and interpretation of data for the work, the drafting and revision of the manuscript, approval of final version to be published; CB, AEC, ZL, DM – conception and design of the work, the analysis and interpretation of data for the work, critical revision of key intellectual content and approval of final version to be published. TB, SMC, ANG, CLK, HQ, DGV, JS – collection and analysis of data, revision of the manuscript, and approval of the final version to be published; CB, KB, JKB, AAD, SMD, EF, AG, JRJ, JM, LMV, VN, RCO, VRH, BS, XS – collected data and assisted with processing and manuscript revision
Support statement: This work was supported by the NIH/NHLBI grants P01HL126609, R01HL094394, and P01HL134610. National Heart, Lung, and Blood Institute; DOI: http://dx.doi.org/10.13039/100000050; Grant: P01HL126609, P01HL134610, R01HL094394.
Descriptor Number: 4.1 ALI/ARDS: Biological Mechanisms
Conflict of interest: Dr. Quijada has nothing to disclose.
Conflict of interest: Dr. Bermudez has nothing to disclose.
Conflict of interest: Dr. Kempf has nothing to disclose.
Conflict of interest: Mr. Valera has nothing to disclose.
Conflict of interest: Dr. Garcia has nothing to disclose.
Conflict of interest: Dr. Camp has nothing to disclose.
Conflict of interest: Dr. Song has nothing to disclose.
Conflict of interest: Dr. Franco has nothing to disclose.
Conflict of interest: Dr. Burt has nothing to disclose.
Conflict of interest: Dr. Sun has nothing to disclose.
Conflict of interest: Dr. Mascarenhas has nothing to disclose.
Conflict of interest: Dr. Burns has nothing to disclose.
Conflict of interest: Mr. Gaber has nothing to disclose.
Conflict of interest: Dr. OITA has nothing to disclose.
Conflict of interest: Reyes Hernon has nothing to disclose.
Conflict of interest: Dr. Barber has nothing to disclose.
Conflict of interest: Dr. Moreno-Vinasco has nothing to disclose.
Conflict of interest: Dr. SUN has nothing to disclose.
Conflict of interest: Dr. Cress has nothing to disclose.
Conflict of interest: Dr. Martin reports other from Aqualung, outside the submitted work;.
Conflict of interest: Dr. Liu has nothing to disclose.
Conflict of interest: NIH R01 (HL136603)- Ankit Desai
Conflict of interest: Dr. Natarajan has nothing to disclose.
Conflict of interest: Dr. Jacobson has nothing to disclose.
Conflict of interest: Dr. Dudek has nothing to disclose.
Conflict of interest: Dr. Bime has nothing to disclose.
Conflict of interest: Dr. Sammani has nothing to disclose.
Conflict of interest: Dr. Garcia reports grants and non-financial support from Aqualung Therapeutics, Corp, during the conduct of the study; grants and personal fees from Aqualung Therapeutics, Corp, outside the submitted work; In addition, Dr. Garcia has a patent US Patent No. 9,409,983 issued.
- Received June 27, 2020.
- Accepted November 5, 2020.
- Copyright ©ERS 2020
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