The researchers have told the reason why the dengue virus is becoming resistant to therapeutics and vaccines. They have revealed that the dengue virus has the ability to change its shape by mutations in the protein envelope. And this capability allows them to evade the various therapeutics and vaccines.
This study has given insights into the types of therapies that can be used for treating the dengue infection at different stages. And can also give rise to new advances in treatment and vaccine development for dengue disease.
Mutation in the virus’ E protein
Around the world, the dengue virus – DENV2, can affect nearly 400 million people per year. While this virus exists with high prevalence in tropical and subtropical regions. The DENV2 can lead to a varying degree of diseases. That can range from mild dengue fever to severe dengue hemorrhagic fever. And can also cause dengue shock syndrome.
The dengue virus exists as smooth spherical surface particles. And grows at the physiological temperature of the mosquito, that is 29 degree Celsius. But, at human physiological temperature – 37 degrees Celsius – this virus can change into bumpy surfaced particles.
This morph ability can facilitate the virus in evading the immune system of the human host. So, it is important to comprehend this mechanism for the development of vaccines and therapeutics. In this study, the research team has analyzed the laboratory developed strains of DENV2.
And has found that mutations in the E protein of the virus have led to the transformation into bumpy particles. Moreover, these structure changes can make therapeutics and vaccines ineffective against the virus. The journal “PLOS Medicine” has published the findings of this study.
More insight to dengue virus
The research team has also analyzed four DENV2 strains from dengue patients. And observed the structural differences among these strains and the laboratory-adapted viruses. The majority of these clinical strains were maintaining their smooth surface structure at 37 degrees Celsius.
But, at the temperature of a fever – 40 degrees Celsius – all viral strains were showing a bumpy surface. This study has given a new approach for the development of vaccines and treatments for dengue patients. Before dengue infection in a patient, the vaccines that are efficient against the smooth surface virus should be used.
But the type of therapy changes if the patient is showing fever symptoms. In this case, one should implement the treatment methods that are effective against the bumpy surface viruses. This research is the first step in gaining more insight into DENV2. And shows how the dengue virus reacts and adapts to the immunological defenses of the host.
In this study, the team has also used computational modelling approaches. And predicted why proteins from different strains of dengue virus are more or less adaptable to morph from the smooth to bumpy structures.
A better understanding of the interaction between the host and virus can help to develop better vaccines and therapies to prevent or treat dengue infections. And can also play a part in public health outcomes.
The results of the study have also shown that the lab adapted virus may not be a good research model. That may be due to the structural differences with the clinical strains that are isolated from patients. In the future, the team is planning to test other DENV serotypes and find any other possible structural changes.