Effect of mosquito midgut trypsin activity on dengue-2 virus infection and dissemination in Aedes aegypti.
The effect of mosquito midgut trypsins in dengue serotype 2 flavivirus (DENV-2) infectivity to Aedes aegypti was studied. Addition of soybean trypsin inhibitor (STI) in a DENV-2 infectious blood meal resulted in a 91-97% decrease in midgut DENV-2 RNA copies (qRT-PCR analysis). STI treatment also resulted in slower DENV-2 replication in the midgut, less DENV-2 E protein expression, and decreased dissemination to the thorax and the head. A second uninfected blood meal, 7 days after the STI-treated infectious meal, significantly increased DENV-2 replication in the midgut and recovered oogenesis, suggesting that the lower viral infection caused by STI was in part due to a nutritional effect. Mosquitoes fed DENV-2 digested in vitro with bovine trypsin (before STI addition) exhibited a transient increase in midgut DENV-2 4 days postinfection. Blood digestion and possibly DENV-2 proteolytic processing, mediated by midgut trypsins, influence the rate of DENV-2 infection, replication, and dissemination in Ae. aegypti.
Molina-Cruz
Alvaro
A
Department of Microbiology, Immunology and Pathology, and the Arthropod-borne and Infectious Diseases Laboratory, Colorado State University, Fort Collins, Colorado 80523, USA. amolina-cruz@niaid.nih.gov
Gupta
Lalita
L
Richardson
Jason
J
Bennett
Kristine
K
Black
William
W
Barillas-Mury
Carolina
C
D000330:Aedes / Q000201:enzymology* / Q000821:virology*; D000818:Animals; D003716:Dengue Virus / Q000502:physiology*; D005260:Female; D041981:Gastrointestinal Tract / Q000201:enzymology; D010053:Ovary; D012367:RNA, Viral / Q000032:analysis; D013997:Time Factors; D014357:Trypsin / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000378:metabolism; D014779:Virus Replication
D012367:RNA, Viral; D014361:Trypsin Inhibitors; D014357:Trypsin