Examines the intracellular replication of Legionella pneumophilia with mammalian cells. Attachment and entry of L. pneumophilia to mammalian cells; Trafficking process of L. pneumophilia phagosome and loci required for intracellular replication; Role of type II secretion system in intracellular replication; Gene expression by intracellular L. pneumophilia; Impact of intracellular replication on the host cell.