Molecular biology and pathogenicity of human and animal parvoviruses

Abstract

The so-called autonomous parvoviruses comprise a wide spectrum of viral agents with quite similar physicochemical and biological properties. Characteristically, they are small, naked, and extraordinarily stable particles made up of only 2-4 structural proteins and a genome of linear, single-stranded DNA consisting of 4500-5600 nts. For replication they depend on cellular helper functions which become available at distinct stages during cellular differentiation (developmentally-dependent functions) and transiently during the phase of DNA synthesis in the mitotic cycle (cell cycle-dependent function(s)) of a susceptible cell. Most of the clinical syndromes induced by parvoviruses therefore can be related to infection of mitotically active cells or tissues at different stages in the development and maturation of the host organism. This view of parvovirus pathogenicity holds true for all animal parvoviruses as well as for the human parvovirus B19.