To brush up his public image before the polls, Congress scion Rahul Gandhi has roped in public relations agency Genesis Burson-Marsteller and Japanese advertising firm Dentsu which are expected to create a campaign that will consist of short films and print ads. br br The PR firm is learnt to have been tapped to handle his Twitter and Facebook accounts. Nearly Rs 500 crore will be spent on this marketing blitzkrieg, according to brand experts and advertising professionals.