Figure 1.

Flavivirus genome and proteins. The flavivirus genome consists of a single positive-stranded RNA molecule with a 5′ methylguanosine cap followed by an untranslated region (UTR), open reading frame (ORF) and a 3′ UTR with multiple variable stem loop structures. The genome is translated from a single ORF into a polyprotein that is proteolytically cleaved by both viral and host proteases. The genome codes for three structural proteins (capsid, membrane, and envelope) and seven non-structural proteins (NS1, NS2a, NS2b, NS3, NS4a, NS4b, and NS5). Theoretically, peptides of any of these structural or non-structural proteins have the potential to be targets of the virus-specific T cell response. Multiple flavivirus cross-reactive T cell epitopes with murine MHC restriction have been demonstrated in various murine models, the breadth of which are indicated by the triangles below the polyprotein. For detailed information on these identified cross-reactive epitopes see Table 2.