The E3/19K protein of adenovirus type 2 binds to the domains of histocompatibility antigens required for CTL recognition.

Abstract

The E3/19K protein of human adenovirus type 2 binds to HLA class I antigens and blocks their terminal glycosylation and cell surface expression. The nature of this interaction is non‐covalent and involves neither disulfide bridges between the two molecules nor their carbohydrates. The murine H‐2 Kd antigen associates with the E3/19K protein in a similar fashion to human HLA antigens whereas the allelic product H‐2 Kk does not. Hybrid genes between the Kd and Kk alleles were constructed and their products were expressed in embryonic kidney cells together with the E3/19K protein. This allowed us to identify the alpha 1 and alpha 2 domains as the essential structures of the histocompatibility antigens for binding the viral protein. Interestingly, these domains are also crucial for T cell recognition. The implications for the evolution of adenoviruses and their ability to cause persistent infections are discussed.