Y. Gao et Am. Fallon, Immune activation upregulates lysozyme gene expression in Aedes aegypti mosquito cell culture, INSEC MOL B, 9(6), 2000, pp. 553-558
After stimulation with heat-killed bacteria, cultured cells from the mosqui
to Aedes aegypti (Aag-2 cells) secreted an induced protein with a mass of a
pproximate to 16 kDa that cross-reacted with antibody to chicken egg lysozy
me. To investigate whether lysozyme messenger RNA is induced in bacteria-tr
eated cells, we used polymerase chain reaction-based approaches to obtain t
he complete lysozyme cDNA from Aag-2 cells. The deduced protein contained 1
48 amino acids, including a 23 amino acid signal sequence. The calculated m
ass of the precursor protein is 16 965 Da, which is processed to yield a ma
ture lysozyme of 14 471 Da with a calculated pI of 10.1. The lysozyme from
Ae. aegypti shared 50% amino acid identity with lysozymes from Anopheles ga
mbiae and Anopheles darlingi, which in turn shared 70% identity between eac
h other. Northern analysis with the lysozyme cDNA probe showed induction of
a 1.3 kb messenger RNA during the first 3 h after treatment of Aag-2 cells
with heat-killed bacteria, followed by maximal expression 12-36 h after tr
eatment. Southern analysis suggested that the gene likely occurs as a singl
e copy in the genome of Aag-2 cells.