Figure 3. Localization, quantification, and dynamics of sporozoites in the DLN.

Immunofluorescence (IF) images depicting sporozoites and CS protein in the DLNs at various time points after ID inoculation with 1×10⁵ P. berghei CS^5M sporozoites. A. IF images of a DLN 30 minutes post-inoculation. Box 1 and 2 indicate enlarged areas of a DLN montage. Arrowhead denotes a sporozoite in the subcapsular sinus. Subcapsular sinus abbreviated as SCS. Colors of the word labels correspond to the colors of the stains here and throughout. White dotted line demarcates the paracortex. B. IF images of a DLN 1 hour post-inoculation. Box 3 indicates a maximum intensity projection of a 30 μm z stack. Box 4 and 5 are higher magnification images of sporozoites in the DLN 1 hour after ID inoculation. C. Number of sporozoites in whole DLNs at various time points after ID inoculation. The mean from one experiment is shown and is representative of 8 similar experiments. D. IF image of whole parasites interacting with DCs 5 and 8 hours post-inoculation. White dotted line marks boundary between the medullary sinus and LN parenchyma. Box 6 is an enlarged image of a DC-associated sporozoite. E. IF images of CS-positive events in a DLN 8 hours post-inoculation. White dotted line indicates boundary between the medullary sinus and LN parenchyma or the B cell follicle and cortex. Box 7 and 8 are higher magnification images of CS-positive events associated with DCs. F. Number of CS-positive events associated with DCs in the DLNs at 5 and 8 hours post-inoculation. Mean from one experiment is shown and is representative of 2 similar experiments. G. Maximum intensity projection of a 2-photon image from a CD11c-EYFP DLN 5 hours after ID inoculation with 1×10⁵ P. berghei GFP sporozoites (pseudo-colored red). Second-harmonic generation (SHG, capsule); z stack of 30 μm. H. Time course of sporozoite uptake by a DC taken 3 hours after injection by infectious mosquito bites. Time, min:sec. See also S1 and S2 Movies.