The Likelihood of Confusion blog published an interesting article regarding some of the Andy Warhol’s works and in particular those which include trademarks, for example the case with the Campbell’s soup.
The article discusses the issue whether such use can infringe the trademark rights, though in the case of Campbell’s soup they probably were more satisfied their products and brands to be associated with one of the most famous US artist.
As a whole, the practice in US is that in such kind cases there is no infringement because the subject matter is art. In contrast, if there is a merchandising use such as using a brand on shirts and so on, trademark claims can be invoked.
More information here.