NS 1 gene sequences from eight dengue-2 viruses and their evolutionary relationships with other dengue-2 viruses

Abstract

The nucleotide sequences of the NS 1 genes from five Thai and three Sri Lankan dengue-2 viruses were determined by sequencing the viral RNA using synthetic oligonucleotide primers. The results were shown to be similar to four published dengue-2 NS 1 sequences and the classification of these genes was compared with the one obtained for the envelope genes of the same viruses. The classification was similar and showed that the Thai isolates could be divided into two separate groups and that the Sri Lankan isolates were distinct. We found no correlation between disease severity, serological response (1 degree or 2 degrees), or year of isolation and various aspects of NS 1 protein sequence variation; and no particular amino acid changes were correlated with virulence. The sequences were combined with those published and classified elsewhere to provide a comprehensive E/NS 1 gene taxonomy of dengue-2 virus isolates.

Production of dimer-specific and dengue virus group cross-reactive mouse monoclonal antibodies to the dengue 2 virus non-structural glycoprotein NS1

“…Eleven of the MAbs used in this study were unable to react with the NS 1 glycoprotein of this strain in immunoblots. Although the NS1 sequence of PR 159S 1 (Hahn et al, 1988) has been shown to be very different at the amino acid level to other isolates from Jamaica (Deubel et al, 1988), New Guinea (Irie et al, 1989), Malaysia (Fong et al, 1990), Thailand and Sri Lanka (Blok et al, 1991), only one MAb (5H10.3d) in this panel showed strain specificity. Interestingly, 5H10.3d was found to react only with the Puerto Rican dengue 2 virus isolate, PR159 (and its attenuated derivative, PR159S1) which was used to raise this MAb, and a 1987 Taiwan isolate of dengue 2 virus.…”

Microevolution and virulence of dengue viruses

“…It was not until the first sequencing studies that an attempt was made to identify the genetic differences between strains from DF patients and viruses isolated from DHF patients. Comparisons of E gene sequences from 12 serotype 2 viruses showed no correlation between disease severity and specific nucleotides or amino acids (Blok et al, 1989), and a similar conclusion was drawn after comparison of the NS1 gene from eight virus strains (Blok et al, 1991). Subsequent full genome analyses of viruses from patients in southeast Asia also failed to identify specific sites that might determine virulence (Mangada and Igarashi, 1998;Pandey and Igarashi, 2000).…”

Sequences of E/NS1 Gene Junction from Four Dengue‐2 Viruses of Northeastern Thailand and Their Evolutionary Relationships with Other Dengue‐2 Viruses

“…A variety of genetic analyses have been performed by several workers in the past 10-15 years to detect the genetic variability among dengue-2 virus strains; these included Ti RNase-resistant oligonucleotide fingerprinting (Si, 52), cDNA-RNA hybridization (2), antigen signature analysis (34), hybridization using synthetic deoxyoligonucleotide probes (28), restriction enzyme mapping (53) and more recently by nt sequencing (3,4,30,41). Dengue-2 strains could be classified into several topotypes or geographical types by the above mentioned studies.…”