Immunogenic properties of collagen and ovalbumin modified by chlorination

Hypochlorite (HOCl/OCl^–), a product of activated neutrophils, significantly contributes to protein oxidation which occurs at a site of inflammation. Proteins modified by chlorination changed their biological activity such as enzymatic activity, resistance to proteolytic cleavage and immunogenecity. We previously reported that ovalbumin (OVA) modified with HOCl was processed and presented more efficiently than native OVA. Recently we have shown that HOCl, at the same concentrations, diminished arthritogenic and immunogenic properties of collagen type II (CII). In this study we evaluate the capacity of CII and OVA modified with HOCl to stimulate antigen-specific immune response to epitopes present on native proteins. Chlorination of OVA with 1mM HOCl results in its enhanced immunogenic properties. Chlorinated OVA more effectively stimulated OVA-specific T cell hybridoma and IgG production than native OVA. In contrast to that 3 mM HOCl completely abolished the capacity of CII to stimulate B cell response specific to native form of collagen but retained its ability to stimulate antigen specific T cells. Thus, oxidative protein modification with HOCl will result in different biological effect depending on the presence of target molecules in functionally active center of chlorinated proteins.