Koch N, Lipp J, Pessara U, Schenck K, Wraight C, Dobberstein B
Trends Biochem Sci. 1989 Sep;14(9):383-6. doi: 10.1016/0968-0004(89)90013-3.
Most protein antigens cannot elicit a T-cell response unless they are processed to peptides, which are then presented to T lymphocytes by surface MHC class II molecules. Recent evidence supports an essential role of the invariant chain associated with class II MHC polypeptides in antigen processing.