MOLECULAR ASPECTS OF POLIOVIRUS BIOLOGY WITH A SPECIAL FOCUS ON THE INTERACTIONS WITH NERVE-CELLS

Poliovirus (PV), the pathogenic agent of paralytic poliomyelitis, is t he prototype of the picornavirus family. Although paralytic poliomyeli tis has been nearly totally eradicated in most industrialized countrie s, PV continues to be an important public health problem in many devel oping countries. Moreover, in industrialized countries, two current co ncerns are the occurence, albeit at a very low frequency, of vaccine-a ssociated paralytic poliomyelitis, due to the genetic instability of t he attenuated oral PV strains in vaccinees, and the emergence of a neu ro-muscular pathology in many survivors of the acute disease, called t he post-polio syndrome. PV has been targeted by the World Health Organ ization for world-wide eradication in the coming decade and continues to be the subject of intensive research. The advances made in the mole cular biology of PV, taken together with the development of new animal and cell models, have permitted a new look at a key step in the patho genesis of poliomyelitis, i.e. the interactions between PV and nerve c ells. These aspects of PV biology are developed in this review accordi ng to three themes: (i) the PV host range; (ii) the molecular determin ants of PV neurovirulence and attenuation; and (iii) the persistence o f PV in nerve cells, which has proven to be an interesting new domain in the field of PV research.