Downloaded from www.microbiologyresearch.org by IP: 54.159.222.200 On: Tue, 17 May 2016 11:33:05 Genomic and biological characterization of aggressive and docile strains of lymphocytic choriomeningitis virus rescued from a plasmid- based reverse-genetics system Minjie Chen, 1 3 Shuiyun Lan, 1 3 Rong Ou, 1 3 Graeme E. Price, 1 34 Hong Jiang, 1 Juan Carlos de la Torre 2 and Demetrius Moskophidis 1 Correspondence Demetrius Moskophidis dmoskophidis@mcg.edu 1 Center for Molecular Chaperones/Radiobiology and Cancer Virology, Medical College of Georgia, Augusta, GA 30912, USA 2 Molecular Integrative Neuroscience Department (MIND), The Scripps Research Institute, La Jolla, CA 92037, USA Received 20 September 2007 Accepted 14 February 2008 Arenaviruses include several causative agents of haemorrhagic fever disease in humans. In addition, the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) is a superb model for the study of virus–host interactions, including the basis of viral persistence and associated diseases. There is little understanding about the molecular mechanisms concerning the regulation and specific role of viral proteins in modulating arenavirus–host cell interactions either associated with an acute or persistent infection, and associated disease. Here, we report the genomic and biological characterization of LCMV strains ‘Docile’ (persistent) and ‘Aggressive’ (not persistent) recovered from cloned cDNA via reverse genetics. Our results confirmed that the cloned viruses accurately recreated the in vivo phenotypes associated with the corresponding natural Docile and Aggressive viral isolates. In addition, we provide evidence that the ability of the Docile strain to persist is determined by the nature of both S and L RNA segments. Thus, our findings provide the foundation for studies aimed at gaining a detailed understanding of viral determinants of LCMV persistence in its natural host, which may aid in the development of vaccines to prevent or treat the diseases caused by arenaviruses in humans. INTRODUCTION The family Arenaviridae includes 23 recognized members that have been classified into two phylogenetically distinct but related groups called the Old World and New World complexes. Arenaviruses are zoonotic pathogens that include several aetiological agents of fatal haemorrhagic fever in humans, including the Lassa, Junin, Machupo, Guanarito and Sabia viruses (Emonet et al., 2006). They are rodent-associated viruses, with the single exception of Tacaribe virus, which infect bats and their geographical distribution is determined by the range of the reservoir species. The worldwide distribution of LCMV reflects its ubiquitous natural reservoir, Mus musculus. In contrast, other arenaviruses are endemic to specific geographical regions including SubSahara West Africa (Lassa virus) and South America (Junin, Machupo, Guanarito and Sabia viruses). Human infections occur from inhalation of aerosolized virus or by direct contact with contaminated material (Damonte & Coto, 2002; Jay et al., 2005; Peters, 2002). Despite the intense study of arenavirus biology since the isolation of the first family member, LCMV, in the 1930s, there is not much understanding of the molecular determinants of arenavirus-induced disease in humans and animals. Arenaviruses are enveloped viruses with a bi-segmented negative-strand RNA genome consisting of a small (S) and a large (L) segment with approximate sizes of 3.4 and 7.2 kb, respectively (Meyer et al., 2002; Romanowski & Bishop, 1985). Each RNA segment has an ambisense coding strategy, encoding two proteins in opposite orientation separated by an intergenic region (IGR). The S RNA directs synthesis of the nucleoprotein (NP) (ca. 63 kDa) and two mature virion glycoproteins, GP1 (40– 46 kDa) and GP2 (35 kDa), derived from post-trans- lational cleavage of a precursor polypeptide, GP-C (75 kDa). GP1 and GP2 make up the spikes on the virion envelope. GP1 mediates the virus interaction with its host cell receptor, identified as a-dystroglycan for Lassa and Old 3These authors contributed equally to this work. 4Present address: Office of Cellular, Tissue and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, 1401 Rockville Pike HFM 730, Rockville, MD 20852-1448, USA. Supplementary material is available with the online version of this paper. Journal of General Virology (2008), 89, 1421–1433 DOI 10.1099/vir.0.83464-0 0008-3464 G 2008 SGM Printed in Great Britain 1421