Human Neutrophil Elastase Degrades The Therapeutic Monoclonal Antibodies Effective in IBD

CURCIARELLO R; KOK K.; GIUFFRIDA P; SOBANDE T; JHONES S; DI SABATINO A; DOCENA G; MACDONALD TT

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias, LXV Reunión Anual de la Sociedad Argentina de Inmunología; 2017

Therapeutic monoclonal antibodieswhich are effective in other inflammatory diseases such as rheumatoidarthritis are less effective inflammatory bowel disease (IBD). Human NeutrophilElastase (HNE) is highly expressed in IBD mucosa, especially in ulcerativecolitis (UC). The aim of this study was to determine if HNE degrades biologics,rendering them ineffective, and whether its action can be reversed by its naturalinhibitor, Elafin.  Biologics (Infliximab, Adalumimab,Etanercept, Vedolizumab) were digested using different concentrations ofrecombinant HNE, in the absence or presence of Elafin, overnight. Neutrophilswhere isolated from human blood (4 UC patients and 2 healthy donors) bygradient centrifugation with Na-Dextran solution. Neutrophils where lysed andelastase activity was quantified. Antibody integrityafter recombinant or natural HNE digestion was then analysed by western blot,and the functional capacity of the antibodies to neutralise TNF-alpha wastested using recombinant human TNF-alpha and a TNFR reporter cell line.Recombinant and HNE from blood cells fully degrades allanti-TNF-alpha agents and Vedolizumab (anti-α4β7 integrin specific mAb) in a dose-dependent manner (HNE 0.125µg/ml to 5µg/ml degrades biologics from 6% to 99.9%, respectively).  This activityis significantly inhibited by recombinant Elafin (p<0.001).  Treatmentwith HNE also partially prevented the ability of the biologicalsto inhibit TNF-alpha bioactivity (HNE at 10µg/ml causes 90% reduction of theanti-TNF´s neutralizing ability, while HNE at 5 µg/ml diminishes only 25% theirneutralizing activity). These results may explain some of thereasons for primary non-responsiveness to anti-TNF alpha therapy in IBDpatients.