In Vivo Approaches Reveal a Key Role for DCs in CD4+ T Cell Activation and Parasite Clearance during the Acute Phase of Experimental Blood-Stage Malaria
Figure 7
In vivo and ex vivo analysis of iRBC uptake by splenic DCs during crisis.
(A-D) B6.CD11-YFP mice were i.p. infected with 1 × 106 mCherry-Pc iRBCs. Spleens were analyzed by CIVM after eight days, at a time of day when mature parasite stages predominated. (A) A snapshot shows the subcapsular RP. (B) CIVM 3D animation shows the presence of few mCherry-Pc iRBCs (red) attached to YFP+ cells (green). (C) Percentage of mCherry+ cells in the YFP+ cell population is shown (mean ± SEM). (D) YFP+ cell volume and sphericity are shown. Black, red and blue dots are from three different experiments. Horizontal lines represent mean values and SEM. (E and F) B6 mice were i.p. infected with 1 × 106 Pc iRBCs. At eight days p.i., half of the B6 mice were re-infected i.v. with 1 × 108 purified mature CTV-Pc iRBCs. Spleens were analyzed by flow cytometry after 15 min. (E) Representative contour plots show CTV staining in the CD11c+ cells of Pc-infected mice that were re-infected or not with CTV-Pc iRBCs. CD11c+ cells in the CD3-CD19-DX5-Ter119- cell population were analyzed. Data show the percentages of CTV+ cells in the CD11c+ cell population. (F) The numbers of total and CTV+CD11c+ cells per spleen were calculated from the data obtained in E (means ± SD). (G and H) B6 mice were i.p. infected with 1 × 106 Pc iRBCs or GFP-Pc iRBCs. Spleens were analyzed after eight days, at a time of day when mature parasite stages predominated. (G) Representative contour plots obtained by flow cytometry show GFP staining in CD11c+ cells of mice that were infected with Pc iRBCs or GFP-Pc iRBC. CD11c+ cells in the CD3-CD19-DX5-Ter119- cell population were analyzed. Data show the percentages of GFP+ cells in the CD11c+ cell population. (H) Numbers of total and GFP+CD11c+ cells per spleen were calculated from the data obtained in G. In A and B, the scale bars correspond to 50 µm and 30 µm, respectively. One representative experiment out of three (n = 2) is shown. In C and D, data were obtained using Imaris software. Data from three experiments (n = 2) are shown. In E-H, one representative experiment out of three (n = 5) is shown.