Genetic basis of viral persistence: single amino acid change in the viral glycoprotein affects ability of lymphocytic choriomeningitis virus to persist in adult mice.
This study has identified a single amino acid change in the viral glycoprotein that profoundly affects the ability of lymphocytic choriomeningitis virus (LCMV) to persist in its natural host. Adult immunocompetent mice infected with a variant of the Armstrong strain, spleen isolate clone 13 (svA/svA), harbor virus for several months and exhibit suppressed T cell responses. In contrast, adult mice infected with a reassortant virus (svA/wtA) that contains the L segment of the spleen variant and the S segment of the parental wt Armstrong, make potent LCMV-specific CTL responses and clear the infection within 2-4 wk. These two viruses, spleen variant clone 13 and the reassortant svA/wtA, are identical in their noncoding regions and show no amino acid changes in any of their viral genes except for one substitution in the glycoprotein. The reassortant virus svA/wtA has a phenylalanine at amino acid residue 260 of the glycoprotein, whereas the spleen variant clone 13 has a leucine at this position. This study constitutes one of the first reports defining the genetic basis of viral persistence at the whole animal level, and identifying a single mutation that markedly increases the ability of a virus to persist in its natural host.
Matloubian
M
M
Department of Microbiology and Immunology, UCLA School of Medicine 90024.
Somasundaram
T
T
Kolhekar
S R
SR
Selvakumar
R
R
Ahmed
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D006023:Glycoproteins / Q000737:chemistry*; D008217:Lymphocytic choriomeningitis virus / Q000235:genetics* / Q000472:pathogenicity; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009154:Mutation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014764:Viral Proteins / Q000737:chemistry*
D006023:Glycoproteins; D014764:Viral Proteins