From interception to incorporation: degeneracy and promiscuous recognition as precursors of a paradigm shift in immunology.

The paper evaluates the role of the concept of degeneracy in current immunology. The historical background of the notion is considered, as well as that of related concepts like 'cross-reactivity' and 'promiscuity'. A distinction is made between degeneracy, as a property of a system and promiscuity, as a property of antibodies and lymphocytes, followed by a discussion of the relation of degeneracy to the clonal selection theory (CST). Attempts to accommodate the notion of degeneracy with the CST theory are critically reviewed. The notion of specific agency is identified as central for this debate, and an alternative conception of the immune response, focused on incorporation rather than interception, is discussed.