Lege Artis Medicinae

[Autoimmunity and the network of the antibody-forming cells: the "immunological homunculus"]

UHER Ferenc1

DECEMBER 25, 1991

Lege Artis Medicinae - 1991;1(18)

[Frank M. Burnet's clonal selection theory declares the deletion and/or anergy of self-reactive clones to be the fundamental mechanism responsible for self tolerance. There is ample evidence, however, that all healthy individuals have lymphocytes and , natural” antibodies that recognize self structures. In the 1970s, Niels K. Jerne postulated the network theory. It is based on the idea that the idiotype, the region of an immunoglobulin that is unique because it comprises the antigen-binding portion of the molecule, can act as both antigen and antibody within the same individual. Network theory views the immune system as a single, highly interconnected system, through idiotypes, a web of V domains. Antonio Coutinho adressed this problem and divided the repertoire of the B lymphocytes into two parts. He suggested that a set of naturally activated cells and the immunoglobulins they secrete, is reflected in the autonomous immune activities of the self-related network as the central immune system. In contrast, immune responses to external antigens are essentially allonomous clonal activities of another set of resting, rapidly turning over lymphocytes that follow the predictions of the clonal selection theory, making up the peripheral part of the system. Finally, Irun R. Cohen suggested that some, perhaps all, major autoantigens are indeed dominant because each one of them is encoded in the organizational structure of the immune system. This picture was termed the immunological homunculus by its analogy to the picture of the body encoded in the central nervous system. ]

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