Dual inhibition of Angiopoietin-2 and VEGF-A with a monoclonal antibody improves pulmonary capillary leakage in murine experimental sepsis

Abstract

Aims and Objectives: We tested in murine sepsis the therapeutic potential of a novel heterodimeric bispecific monoclonal IgG1-Cross antibody (Ab) of Angpt-2 and VEGF - termed “A2V”. Methods: Cecal ligation and puncture (CLP) was used to induce polymicrobial sepsis. A2V or IgG control Ab was injected i.p. 1 hr before CLP. Histology, fluorescence immunohistochemistry (IF) and quantitative RT-PCR was performed 16hrs after CLP. In vitro human umbilical vein endothelial cells (ECs) were stimulated with plasma from septic shock patients +/- A2V followed by immunocytochemistry and real-time transendothelial electrical resistance measurements. Results: IF showed that septic mice treated with A2V have a reduced induction of the endothelial adhesion molecule ICAM-1, consecutively a trend towards reduced transmigration of inflammatory cells (A2V: 42.2 ± 1.0 vs IgG 48.5 ± 1.7 Gr-1+ cells/HPF, p=0.08) and reduced tissue levels of inflammatory cytokines (e.g. IL-6 mRNA: A2V 9.4 ± 3.2 vs. IgG 83.9 ± 36.7-fold over control, p=0.03) in the lung. Moreover, endothelial permeability was improved both in vivo and in an in vitro after A2V. All together these changes led to an improved survival by 38 % (p=0.02). Conclusion: Dual inhibition of Angpt-2 and VEGF-A improves survival in murine sepsis making it a potential therapeutic against pulmonary vascular barrier breakdown and tissue inflammation.