HUMAN NEUTROPHIL ELASTASE DEGRADES THE THERAPEUTIC MONOCLONAL ANTIBODIES EFFECTIVE IN IBD

MACDONALD T; JONES S; KOK K; DOCENA G; SOBANDE T; CURCIARELLO R; DI SABATINO A,; GIUFFRIDA PAOLO

CABA

Congreso; Reunión Conjunta de Sociedades de Biociencia, LXV Reunión Annual de la Sociedad Argentina de Inmunología; 2017

Therapeutic monoclonal antibodies which are effective in other inflammatory diseases such as rheumatoid arthritis are less effective inflammatory bowel disease (IBD). Human Neutrophil Elastase (HNE) is highly expressed in IBD mucosa, especially in ulcerative colitis (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 natural inhibitor, Elafin. Biologics (Infliximab, Adalumimab, Etanercept, Vedolizumab) were digested using different concentrations of recombinant HNE, in the absence or presence of Elafin, overnight. Neutrophils where isolated from human blood (4 UC patients and 2 healthy donors) by gradient centrifugation with Na-Dextran solution. Neutrophils where lysed and elastase activity was quantified. Antibody integrity after recombinant or natural HNE digestion was then analysed by western blot, and the functional capacity of the antibodies to neutralise TNF-alpha was tested using recombinant human TNF-alpha and a TNFR reporter cell line. Recombinant and HNE from blood cells fully degrades all anti-TNF-alpha agents and Vedolizumab (anti-α4β7 integrin specific mAb) in a dose-dependent manner (HNE 0.125µg/ml to 5 µg/ml degrades biologics from 6% to 99.9%, respectively). This activity is significantly inhibited by recombinant Elafin (p