The invention provides therapeutic compositions that present an artificial repertoire of mammalian pattern recognition receptor (PRR) agonists, so that the pattern of PRR agonists recapitulates a distinct portion of a PRR agonist signature of a mammalian pathogen. The artificial repertoire of PRR agonists may be formulated together in a therapeutic vehicle for combined presentation to an innate immune cell resident in a target tissue in a mammalian host, and the vehicle adapted to deliver the PRR agonists to the target tissue, so as to modulate an immune response.