gC1qR Antibody Can Modulate Endothelial Cell Permeability in Angioedema

Area of Science:

• Immunology
• Vascular Biology
• Complement System

Background:

• Angioedema involves swelling due to increased vascular permeability, often linked to bradykinin (BK) overproduction.
• BK formation involves high molecular weight kininogen (HK) binding to gC1qR on endothelial cells.
• Endothelial cells' gC1qR expression is modulated by shear stress.

Purpose of the Study:

• To investigate the effects of BK and hereditary angioedema (HAE) patient plasma on endothelial cell permeability and gC1qR expression under shear stress.
• To evaluate the inhibitory potential of monoclonal antibody (mAb) 74.5.2 on HK binding to gC1qR and subsequent endothelial cell permeability.

Main Methods:

• Human dermal microvascular endothelial cells (HDMECs) were exposed to shear stress with BK or HAE plasma.
• Endothelial cell permeability was assessed using FITC-conjugated bovine serum albumin.
• gC1qR expression, HK binding, and cell morphology were quantified via ELISA and immunofluorescence microscopy.

Main Results:

• BK significantly increased HDMEC permeability, whereas HAE plasma and shear stress alone did not.
• mAb 74.5.2 effectively inhibited HK binding to recombinant gC1qR.
• mAb 74.5.2 reduced HAE plasma-induced changes in HDMEC permeability.

Conclusions:

• Monoclonal antibody 74.5.2 shows potential as a therapeutic agent for preventing angioedema.
• Targeting the gC1qR receptor offers a promising strategy for managing angioedema.
• Further research into mAb 74.5.2 is warranted for clinical application in angioedema treatment.