FC BINDING REGIONS IN PROTEIN-A ARE NOT RESPONSIBLE FOR THE POLYCLONAL-B CELL ACTIVATING PROPERTY OF PROTEIN-A

To test whether the polyclonal B cell activating property of protein A is due to its ability to bind to the Fc part of immunoglobulins, experiments were carried out with purified monomeric or dimeric Fc‐binding fragments of protein A. Neither monomeric nor dimeric fragments induced polyclonal antibody synthesis in vitro, whereas intact protein A was a strong activator. It is concluded that the Fc binding part of protein A is not responsible for activation of polyclonal antibody synthesis. Copyright © 1979, Wiley Blackwell. All rights reserved