T cells recognize antigen alone and not MHC molecules

Abstract

It is a central dogma of contemporary immunology that T cells engaged in immune responses to foreign antigens or cells recognize determinants on major histocompatibility complex (MHC) molecules. Here Ole Werdelin argues that this dogma is false. Taking the case of T-cell responses which are controlled by MHC class II molecules, he suggests that la molecules serve to bind antigen fragments and stabilize them in the membrane of presenting cells, shielding them from proteolytic degradation and permitting T cells to bind the epitopes so displayed.