ROLES OF HUMAN AND VECTOR DERIVED PHENOTYPES OF DENV IN CAUSING HUMAN DISEASE- CAN MOSQUITO MEDIATION BE BYPASSED?

Abstract

Rajan Joseph Payyappilly1, Deepa Athilat2

BACKGROUND
Plasma membrane of midgut epithelial cells of the mosquito differs from that of human dendritic cells in composition with respect to protein and lipid content and posttranslational modifications, viz. glycosylation. Virus acquires its envelope from the host cell membrane. Expectedly therefore, such differences are reflected in the construction of its envelope, which may influence virulence. Lipid composition and glycosylation pattern of envelope protein E1 (with important roles in viral entry) are different in the virus grown in insect cell lines and mammalian cells. As consequence, they have 'different modes' of cell entry each with role at different stages in disease course. Virions that initiate primary infection are mosquito derived; but then on, it is a phenotype of human cell origin that multiplies and spreads in the host.
MATERIALS AND METHODS
In a hospital-based yearlong prospective study conducted at our institute, we have tried to highlight (indirectly albeit), all important role of antibody mediated cell infection by DENV in the human host and how it modified disease process.
RESULTS
Mediation of the biological vector thus is required essential in ‘initiation’ of primary infection (emphasising the role of vector control as numero uno strategy for disease control); in the human tissues, thereafter, antibody mediated cell infection seems to take the lead role.
CONCLUSION
Mediation of the biological vector mosquito is required in natural cycle of transmission of DNV from man to man. Unique features of the envelope of 'mosquito derived' virions enabling them to enter human cells nonpermissive to human derived phenotype maybe capitalised and such mechanisms be targeted in designing vaccine or drugs against dengue and besides this emphasises the relative importance of vector control in dengue control.

image