Resistance to Superinfection of Vero Cells Persistently Infected with Junin Virus

ELLENBERG PAULA, EDREIRA MARTÍN AND SCOLARO LUIS

ARCHIVES OF VIROLOGY

Año: 2004 vol. 149 p. 507 - 522

0304-8608

Two non-virogenic Vero cell lines persistently infected with the arenavirusJunin (JUNV), namedV3 and V7, were characterized with respect to theirresistance to superinfection with homologous and antigenically related viruses.Both lines were refractory to JUNV multiplication and partially resistant to otherarenaviruses. JUNV was able to adsorb and penetrate persistently infected cellsand, although V3 and V7 were able to support synthesis of antigenomic senseviral RNA, protein production of superinfecting virus was totally blocked. Thisresistance was not mediated by defective interfering particles but rather by a“cell-associated factor” that could be cell to cell transmitted. Prolonged thermaltreatment of V3 and V7 abrogated expression of the viral nucleoprotein (N) andturned persistently infected cells permissive to JUNV multiplication. Thermaltreated cells cultured at 37 ◦C resumed the expression of N in association to therecovery of resistance. Results strongly suggest a correlation between the presenceof the viral nucleoprotein and superinfection exclusion.