Recombinant lymphocytic choriomeningitis virus expressing vesicular stomatitis virus glycoprotein

Abstract

T he prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) is an important model to study both acute and persistent viral infection, as well as virus-host balance (1) and associated disease (2). Important concepts of immunology (3) and viral pathogenesis (4) have been developed by using the LCMV model. In addition, LCMV provides an excellent system to study basic aspects of the molecular and cell biology of clinically important human pathogens, including Lassa fever virus (LFV) and other arenaviruses causing severe hemorrhagic fever.LCMV is an enveloped bisegmented negative-strand RNA virus. The two genome segments L and S have approximate sizes of 7.2 and 3.4 kb, respectively (5, 6). Each segment uses an ambisense strategy to direct the synthesis of two proteins in opposite orientations, separated by an intergenic region. The S RNA contains the nucleoprotein (NP) and the glycoprotein (GP) precursor (GPC) genes, which are encoded in antigenome and genome polarity, respectively. Posttranslational processing of GPC produces GP-1 and -2 (7) and was recently shown to be mediated by the cellular protease S1P (8). GP-1 and -2 make up the spikes on the virion envelope and mediate cell entry by interaction with the host cell surface receptor. The L RNA segment codes for the virus RNA-dependent RNA polymerase (L) and a small (11-kDa) RING finger protein (Z), whose role in the virus life cycle is poorly understood.The inability to genetically manipulate the virus genome has hampered studies aimed at understanding the molecular and cell biology of LCMV. We have described a LCMV minigenome (MG) rescue system based on the use of reverse genetic approaches (9-11). We have identified NP and L as the minimal transacting viral factors required for virus replication and transcription. Moreover, we found that the viral 5Ј and 3Ј UTR, together with the intergenic region, are sufficient cis-acting signals for RNA synthesis by the LCMV RNA-dependent RNA polymerase. Z was not required for MG transcription and replication and exhibited a dose-dependent inhibitory effect on both processes (12). We have also shown that assembly and budding of LCMV infectious virus-like particles (VLPs) require both GP and Z (10).

Kinetics of protective antibodies are determined by the viral surface antigen

“…Neither LCMV nor rVSV/LCMV-GP induced detectable VSV-IND nAb's because they lacked INDG. All VSV-neutralizing serum samples neutralized rLCMV/INDG in vitro ( Figure 2C), confirming that rLCMV/INDG infectivity was INDG-mediated (18). But neither of the sera collected during this experiment exhibited neutralizing activity against rVSV/LCMV-GP ( Figure 2B) or LCMV-ARM (Figure 2D).…”

“…Infection of mice with either of the two recombinant or WT viruses revealed a critical role for the GP but not for the viral backbone in determining nAb kinetics. ly reported that propagation and peak titers of rLCMV/INDG are reduced when compared with LCMV-ARM (18). In vitro growth curves revealed that rVSV/LCMV-GP was similarly attenuated when compared with VSV-IND ( Figure 1D).…”

“…LCMV-ARM is a triple plaque-purified isolate of ARM CA 1371 (32) obtained originally from M.J. Buchmeier (The Scripps Research Institute, La Jolla, California, USA). Generation of rLCMV/INDG has been described (18). VSV-IND was originally obtained from D. Kolakofsky (University of Geneva, Geneva, Switzerland).…”

“…Experimental infection of mice with the highly cytolytic VSV evokes an early (4 days or less) and potent GP-specific nAb response (16) that prevents lethal myeloencephalitis (17). The recombinant LCMV (rLCMV) expresses the VSV serotype Indiana (IND) GP (INDG) instead of its own GP ( Figure 1, A-C) (18). It is efficiently neutralized by VSV nAb's in vitro but has retained the noncytolytic behavior of LCMV in persistently infected mice.…”

Diseases of the central nervous system caused by lymphocytic choriomeningitis virus and other arenaviruses

“…GPC is transcribed as a single protein and then is posttranslationally cleaved by a host protease S1P to form GP1 and GP2, the virion surface glycoproteins (Beyer et al, 2003;Pinschewer et al, 2003). GP1 mediates attachment of the virus to its cellular target and subsequent receptor-mediated endocytosis (Pasqual et al, 2011).…”