In vitro degradation of mouse, rabbit and dog antibodies to Vibrio cholerae by succus entericus.

Abstract

Purified antibodies to Vibrio cholerae from mouse, rabbit and dog were digested in vitro by homologous intestinal secretions. When assessed with regard to their complement-dependent vibriocidal activity, IgG antibodies were generally more susceptible to degradation than IgM antibodies, High levels of tryptic inhibitors were required to inhibit this digestion. Rabbit IgG was unusual in being quite resistant to digestion. Gel filtration studies demonstrated that secretory IgA, isolated from mouse intestinal secretions, was resistant to proteolysis. Similar studies on dog IgG and mouse IgM demonstrated production of F(ab') 2-like fragments. Digestss of these antibodies, while devoid of Fc-mediated vibriocidal activity, retained significant protective activity for baby mice.