Murine class II (Ia) molecules associate with human invariant chain
Glimcher, L.H.; Polla, B.S.; Poljak, A.; Morton, C.C.; McKean, D.J.
Journal of Immunology 138(5): 1519-1523
1987
ISSN/ISBN: 0022-1767 PMID: 3468175 Document Number: 302844
Polymorphic class II (Ia) major histocompatibility complex (MHC) gene products associated intracytoplasmically with a third nonpolymorphic class II molecule, the invariant chain (Ii), which is encoded by gene(s) unlinked to the MHC. Although the role of the Ii chain in the expression of cell surface Ia molecules is unclear, it has been suggested that the Ii chain helps in the assembly and intracellular transport of class II antigens. In this study, we demonstrate that the murine polymorphic class II antigens of an interspecies mouse-human hybrid, which has segregated the murine invariant chain gene, associated with the human invariant chain gene intracytoplasmically. The murine Ia antigens are expressed on the cell surface and can function as restriction elements in antigen presentation to T cells. The biochemical analysis demonstrates that the regions of the Ii gene that are critical to its interaction with Ia molecules are conserved between species.