4a3A and Aa23T immune response to bacterial challenges. (A) qRT-PCR analysis at 3, 6, 9 and 24h after cell challenge with a mixture of heat-killed E. coli and E. faecalis show both early and late phase induction of DEF and TEP in both mosquito species. The time of early phase induction varies between species. Upregulation levels for each gene are similar between the two cell lines. Relative expressions were calculated to PBS-challenged cells and represent the average of 3 biological repeats +/- SE (B) 99% of E. coliis rapidly cleared by Aa23T cell line at 3h post-infection while for 4a3A only about 14% have been killed when compared to the same amount of bacteria incubated in cell-free (CF) medium. The starting amount used in each case was 25µl per well of culture with an OD600 reading of 0.05, which represents approximately 15-18M CFU/ml. I -Set I; II -Set II.