Patchima Sithisarn. The molecular cause of loss of dengue virus infectivity in solution . Master's Degree(Molecular Genetics and Genetic Engineering). Mahidol University. : Mahidol University, 2003.
The molecular cause of loss of dengue virus infectivity in solution
Abstract:
The dengue virus is one of the mosquito-borne viruses, which is classified in the
family Flaviviridae. The dengue viruses consist of four serotypes of Dengue 1 to 4
(DEN1 to 4). At present dengue viral disease is distributed throughout the world and
has become one of the world’s health problems because of ineffective control of
dengue vectors, no specific disease treatment and the absence of dengue vaccine. In a
previous study of dengue virus behavior in solution, it was shown that the dengue
virus lost its infectivity over time in an exponential decay and showed the difference
between prototype strains of each dengue serotype. However, the molecular
mechanism for the loss of dengue virus infectivity in solution is not known. Therefore,
in this study the molecular mechanism of the loss of dengue virus infectivity in
solution was investigated. Factors influencing the rate of the loss of dengue virus
infectivity were determined from the difference in the rate and pattern of loss of
dengue virus serotype 2 infectivity under various solution conditions by using the
standard plaque assay and statistical analysis. In order to determine whether the
structural integrity of the dengue virus particle is involved in the loss of dengue virus
infectivity, the characteristics of the dengue virus particle in solution were determined
by using TEM imaging and RT-PCR technique. The results showed that the rate of
loss of dengue virus infectivity in solution was primarily determined by the pH and
temperature of the viral solution. However, the mechanism for the loss of dengue virus
infectivity is not involved in the loss of virus structural integrity, but rather with viral
aggregation as shown by TEM images and PCR products of dengue viral RNA. The
molecular mechanism for the loss of dengue virus infectivity in solution was proposed
to be an irreversible conformational change of E protein, which caused dengue viral
aggregation and loss of dengue virus infectivity in solution.