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Major histocompatibility complex class II invariant chain expression in non‐antigen‐presenting cells
Author(s) -
Veenstra Hanne,
Ferris William F.,
Bouic Patrick J. D.
Publication year - 2001
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1046/j.1365-2567.2001.01230.x
Subject(s) - epitope , major histocompatibility complex , antigen , monoclonal antibody , antigen presentation , antigen presenting cell , mhc class ii , biology , cd1 , microbiology and biotechnology , natural killer t cell , antigen processing , immunology , antibody , chemistry , t cell , mhc class i , immune system , cd8
Summary In contrast to the generally accepted belief, the major histocompatibility complex (MHC) class II invariant chain (Ii) is commonly expressed intracellularly in cells that do not present exogenous antigens. Such cells include resting peripheral blood T cells and natural killer (NK) cells. In T cells, the Ii is associated with a 77 000 molecular‐weight molecule (p77) that has yet to be identified. This molecule is co‐precipitated with the anti‐Ii monoclonal antibody (mAb) VCD‐1, but not with mAb BU‐45. This suggests that in the p77–Ii complex, the extracellular epitope of Ii recognized by BU‐45 is hidden, whereas the Ii epitope for VCD‐1 remains exposed. In antigen‐presenting cells (APCs), p77 association with the Ii was minimal, if detectable. The p77–Ii association in non‐professional APCs suggests that the Ii may have another, more general, function other than the one accepted in antigen presentation.