Nuclear localization of dengue 2 virus core protein detected with monoclonal antibodies

Anti-dengue 2 virus core protein monoclonal antibodies (MAbs) reacted with antigens in the cytoplasm and in, or on, the nucleus of dengue 2 and dengue 4, but not dengue 1, dengue 3, Kunjin or Murray Valley encephalitis virus-infected cells. These MAbs also reacted with the core protein from dengue 1, 2 and 4 virions in Western blots. The antigens detected by these MAbs could not be detected in uninfected or heat-shocked cells, but were first detected in infected cells approximately 32 h post-infection. PEPSCAN epitope mapping suggested that all the MAbs react with a region of the dengue 2 virus core protein (9RNTPFNMLKRE19) which is adjacent to a putative nuclear localization sequence (6KKAR9) and spans a possible second site for the initiation of synthesis of core protein (12PFN decreases MLKR18).