A composition comprising intact killed bacterial cells that contain a therapeuticnucleic acid, a drug or a functional nucleic acid is useful for targeted deliveryto mammalian cells. The targeted delivery optionally employs bispecific ligands,comprising a first arm that carries specificity for a killed bacterial cell surfacestructure and a second arm that carries specificity for a mammalian cell surfacereceptor, to target killed bacterial cells to specific mammalian cells and tocause endocytosis of the killed bacterial cells by the mammalian cells. Alternatively,the delivery method exploits the natural ability of phagocytic mammalian cellsto engulf killed bacterial cells without the use of bispecific ligands.
