Cleavage of Human Immunoglobulins by Proteinase from Staphylococcus Aureus

Abstract

Many pathogenic bacteria release proteinases that cleave Ig.¹ The proteolytic damage of antibodies by bacterial exoproducts is usually taken to be a factor of virulence which compromises the immunological protection of the host against infection. Most existing studies of bacterial proteinases have concentrated on the cleavage of human IgA because of its important role in defense on mucosal surfaces that are the entrance point for most infections. Bacterial proteinases usually cleave IgAl selectively in the hinge region. A more extensive cleavage or the cleavage of both IgA subclasses occurs only rarely.^1,2 The cleavage of more immunoglobulin classes has so far been described only in Pseudomonas aeruginosa ³, Serratia marcescens ⁴, and Proteus mirabilis.⁵