Figure 2.

PGE₂ is the DC modulatory molecule of A. sculptum saliva. Bone marrow cells from C3H/HePas mice were differentiated into DCs, seeded at 10⁵ cells/well in 96-well plates and preincubated for 1 h with medium only, with a low molecular weight (LMW) or with a high molecular weight (HMW) fractions of A. sculptum saliva collected by pilocarpine stimulation from female ticks fed on host for 7–9 days. Cells were stimulated with ultrapure LPS (200 ng/mL) and after 6 h, the TNF-α production was evaluated in culture supernatants by ELISA (A). The LMW fraction was fractionated by UFLC (solid black line), eluted with a linear gradient of ACN (2–60% -dashed black line). Each fraction was tested for LPS-induced TNF-α production by DCs (solid red line) (B). PGE₂ concentration was determined in the fractions presenting stronger inhibition of TNF-α (eluted between 49 to 55% of ACN) by ELISA (C). PGE₂ concentration was determined in A. sculptum saliva collected by pilocarpine stimulation from female ticks fed on host for 3, 5, 7, 9, and 11 days (D). ^*p ≤ 0.05 vs. “LPS without fractions” group.