Fig. 5

Transfusion with isolated blood plasma increases Aβ deposition in Tg2576 mice. Groups of young Tg2576 animals were intravenously challenged with 300 µL of blood cells or plasma obtained from old Tg2576 mice or WT littermates. The number of amyloid plaques in experimental and control animals was counted and expressed as number of plaques per mm² of brain area analyzed (a) and ThS burden was measured as the ThS stained area in relation to the total brain area (cortex and hippocampus) analyzed (b) and expressed as percentage. *P < 0.05, **P < 0.01, ***P < 0.001 based on ANOVA followed by the Tukey’s multiple comparison post hoc test. The dotted line in panels a and b represents the threshold value used to calculate attack rate, i.e. the proportion of individual animals having significantly higher pathology than controls as explained in “Materials and methods” section. The numbers on top indicate the ratio of animals over the threshold/total number of animals in the group. C Levels of inflammatory markers at the experimental endpoint in animals subjected to transfusion with blood fractions. Various inflammatory markers (IL-1β, IL-6, TNFα, MIP-1α, IFN-γ, IL-10 and MCP-1) were measured in PBMC and plasma. Unfortunately none of the markers were observed above the background levels in plasma and only IL-1β, IL-6, TNFα, MIP-1α and IFN-γ were detectable in LPS stimulated PBMC. Statistical analyses showed that blood administration produced a significant increase of the levels of only IL-6. However, no differences were observed between administration of WT or transgenic blood