Two mosquito salivary antigens demonstrate promise as biomarkers of recent exposure to P. falciparum-infected mosquito bites

Measuring malaria transmission intensity using the traditional entomological inoculation rate is difficult. Antibody responses to mosquito salivary proteins such as SG6 have previously been used as biomarkers of exposure to Anopheles mosquito bites. Here, we investigate four mosquito salivary proteins as potential biomarkers of human exposure to mosquitoes infected with P. falciparum: mosGILT, SAMPSP1, AgSAP, and AgTRIO. We tested population-level human immune responses in longitudinal and cross-sectional plasma samples from subjects with known P. falciparum infection from low and moderate transmission areas in Senegal using a multiplexed magnetic bead-based assay. AgSAP and AgTRIO were the best indicators of recent exposure to infected mosquitoes, with antibody responses to AgSAP in a moderate endemic area, and to AgTRIO in both low and moderate endemic areas, significantly higher than healthy non-endemic control cohort (p-values = 0.0245, 0.0064, and <0.0001 respectively)..., Multiplex assay
We tested IgG responses to AgSAP, AgTRIO, mosGILT, and SAMSP1 in a magnetic bead-based assay on the Bio-rad Multiplex using the CDC multiplex assay. Plasma samples and controls were diluted 1:400 in assay buffer (PBS, 0.05% Tween20, 0.5% BSA, 0.5% PVA, 0.5% PVP, 0.02% NaN3, 5% casein). For DBS samples, 6 mm punches were eluted in 200 μl of assay buffer 4,34. Since this results in the equivalent of a 1:40 plasma dilution, the eluted DBS were further diluted 1:10 in assay buffer for a final equivalent concentration of 1:400.
Five hundred beads per bead region for each of the four antigens (each antigen has beads in a specific bead region) in 50 μl assay buffer were added to each well, the plate was washed twice in PBS with 0.05% Tween20, and 50 μl of the diluted sample (plasma or DBS) was added. 50 μl of 0.4% biotin-labeled anti-human IgG (Southern Biotech), 0.16% biotin-labeled anti-human IgG4 (Invitrogen), and 1% Streptavidin-PE (Invitrogen) in assay buffer was added to ..., , # Two mosquito salivary antigens demonstrate promise as biomarkers of recent exposure to *P. falciparum*-infected mosquito bites

[https://doi.org/10.5061/dryad.cz8w9gjbj](https://doi.org/10.5061/dryad.cz8w9gjbj)

The data contains multiplex serology data for 4 mosquito salivary antigens (AgSAP, AgTRIO, mosGILT, and SAMSP1) and the Sg6 peptide. Samples were tested in duplicate and the average mean florescent intensity (MFI) was calculated by: MFIave = (MFI1 + MFI2 - MFIblank1 - MFIblank1)/2, where MFI1 and MFI2 represent the sample duplicates and MFIblank1 and MFIblank1 represent the blank duplicates. Positive controls (pooled plasma from Mali and pooled plasma from Kédougou, Senegal) and negative controls (healthy, unexposed US controls) were included on each plate.

ELISA data is also included for AgSAP and AgTRIO. For each plate, the average optical density (OD) of blanks was calculated and subtracted from the OD of the sample. Samples were tested in duplicate and the mean OD was cal...,