Contemporary models for peripheral tolerance and the classical 'historical postulate'.
The formulators of Clonal Selection Theory proposed that what distinguishes self from foreign antigens is their early appearance in development, and their continuous presence thereafter. This early presence of a self antigen in an animals life history was envisaged to ensure that lymphocytes specific for the self antigen were silenced rather than activated. I call this idea 'the historical postulate'. Contemporary models for the activation/inactivation of helper T cells implicitly violate this postulate. I argue against such a violation and for a model of T helper cell activation/inactivation that reconciles contemporary observations with the postulate.
Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E5, Canada.
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Bretscher
D000938:Antigen-Presenting Cells / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D049673:History, 20th Century; D006801:Humans; D008213:Lymphocyte Activation; D018448:Models, Immunological; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D017634:Self Tolerance / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000949:Histocompatibility Antigens Class II; D011948:Receptors, Antigen, T-Cell