Fig 4.

Regulatory function of ILT2 after HPV immunization. (A) PBMCs from 23 healthy volunteers were obtained before (T0) and 15 days after the first (T1, day 15) and third (T2, day 195) quadrivalent HPV (type 6/11/16/18) vaccine doses. Cells were loaded with CFSE and incubated for 72 h in the presence of the quadrivalent HPV (type 6/11/16/18) vaccine and with the addition (empty bars) or not (black bars) of the agonistic HP-F1 anti-ILT2 or an isotype-matched MAb (gray bars). Then, the percentage of divided cells was determined by flow cytometry analysis, as stated in Materials and Methods. Data correspond to the arithmetic mean and SD. *, P < 0.05, two-way repeated measures analysis of variance. (B) PBMCs from the same individuals whose data are represented in panel A were incubated for 72 h in the presence of quadrivalent HPV (type 6/11/16/18) vaccine and with the addition (empty bars) or not (black bars) of the agonistic HP-F1 anti-ILT2 or an isotype-matched MAb (gray bars). Then, cell nuclei were stained with propidium iodide and analyzed for DNA content by flow cytometry. Data correspond to the arithmetic mean and SD. *, P < 0.05, two-way repeated measures analysis of variance.