FIG 5.

Lymphocyte infiltration in the brain of HHV-6A-infected mice. CD46-cyt2 mice (A and F), CD46ge mice (B and C), and wild-type littermates (D and E) received a single i.c. injection of purified HHV-6A or mock infection solution (E) in the right brain hemisphere. Three weeks after injection, mice were perfused with PBS and brains were collected and frozen. Coronal brain sections were fixed and analyzed by immunofluorescence using CD3 (green) (A to E) or CD19-specific (red) (F) antibodies. Cell nuclei were stained with DAPI (blue). Sections were observed at a magnification of ×100, and infiltrates are presented in inserts at higher magnification (×400). Images of the left (A and C to F) or right (B) lateral ventricle (v) areas are presented. (G) Summary of immunohistofluorescence observations. Brain slides from wild-type or CD46-cyt1, CD46-cyt2, and CD46ge mice (grouped as CD46), injected with HHV-6A, mock infection solution, or left uninjected, were analyzed for the presence of CD3⁺ and CD19⁺ cells. Data are presented as the number of brains for which CD3⁺ or CD19⁺ infiltrating cells was observed out of the total number of brains analyzed. nd, not done. (H) Two sections from each brain presented in panel G were used for quantification of CD3 fluorescent signal density. Images from the right lateral ventricle region were analyzed, and CD3 signal density (fluorescent area out of the total area analyzed) was determined using Image J software. Each point corresponds to the average value of 2 sections analyzed from one brain. Means ± standard errors for each group are presented, and statistical analysis was performed using Mann-Whitney test.