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Use of Single Chain MHC Technology to Investigate Co-agonism in Human CD8+ T Cell Activation
Published on: February 28, 2019
Expression, purification and assembly of soluble multimeric MHC class II-invariant chain complexes
Dušana Majera1, Katarina Črnigoj Kristan, Jacques Neefjes
1Department of Biochemistry, Molecular and Structural Biology and Centre for Protein and Structure Production, Jozef Stefan Institute, Ljubljana, Slovenia.
Major histocompatibility class (MHC) II molecules are essential for running adaptive immune response. They are produced in the ER and targeted to late endosomes with the help of invariant chain (Ii) trimers. Ii trimerization may be induced by the Ii TM domain. To enable mechanistic and structural studies of MHC class II-Ii assembly, soluble forms of the complexes were expressed. We show that Ii trimerizes in the absence of the transmembrane part, prior to binding of α/β chains. The biochemical analysis supports the suggestion that the MHC class II-Ii complexes are not necessarily trimers of trimers, but that the Ii trimer can also be occupied by one or two MHC class II complexes.
Major histocompatibility class (MHC) II molecules are essential for running adaptive immune response. They are produced in the ER and targeted to late endosomes with the help of invariant chain (Ii) trimers. Ii trimerization may be induced by the Ii TM domain. To enable mechanistic and structural studies of MHC class II-Ii assembly, soluble forms of the complexes were expressed. We show that Ii trimerizes in the absence of the transmembrane part, prior to binding of α/β chains. The biochemical analysis supports the suggestion that the MHC class II-Ii complexes are not necessarily trimers of trimers, but that the Ii trimer can also be occupied by one or two MHC class II complexes.
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