Characterization of virus-like particles from a psoriatic patient with respect to the possible presence of particle-associated RNA and RNA-directed DNA polymerase.

Subcellular particles resembling retroviruses with respect to their morphology, density, and protein composition, and which are present in the urine of a psoriatic patient have been analysed for the presence of high-molecular-weight polyadenylated RNA and RNA-directed DNA polymerase activity. Neither RNA-directed DNA polymerase activity nor high-molecular-weight polyadenylated RNA was detected in preparations containing the purified virus-like particles. This was the case even when the amount of particles analysed exceeded by a factor of 50 or more the amount of avian myeloblastosis virus in which both polymerase activity and RNA were detected.