title: Molecular recognition of antigen involves lattice formation between CD4, MHC class II and TCR molecules.
abstract: Recent evidence indicates that CD4 stably binds to major histocompatibility complex (MHC) class II only after assuming an oligomeric state: the membrane-distal CD4 D1-D2 module interacts directly with MHC class II, whereas the membrane-proximal CD4 D3-D4 module mediates oligomerization. This results in the formation of aggregates critical for T-cell activation. The T-cell receptor (TCR) regulates specific crosslinking and is itself dependent on lattice formation to trigger physiological T-cell responses. Here, Toshiko Sakihama, Alex Smolyar and Ellis Reinherz discuss the molecular nature of CD4-MHC class II clustering and how, despite each of the component interactions being of low affinity, the molecular matrix renders T-cell recognition extremely specific and sensitive.
authors.affiliation: Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: T
authors.initials: T
authors.lastname: Sakihama
authors.forename: A
authors.initials: A
authors.lastname: Smolyar
authors.forename: E L
authors.initials: EL
authors.lastname: Reinherz
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D015704:CD4 Antigens / Q000737:chemistry / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry / Q000378:metabolism
chemical_list: D015704:CD4 Antigens; D000949:Histocompatibility Antigens Class II; D011948:Receptors, Antigen, T-Cell