Genetic, Transcriptome, Proteomic, and Epidemiological Evidence for Blood-Brain Barrier Disruption and Polymicrobial Brain Invasion as Determinant Factors in Alzheimer’s Disease

Carter, Chris J.

Pathogens that have been detected in the AD brain using DNA detection or immunocytochemistry include HSV-1, C. Pneumoniae, B. Burgdorferi, and many other spirochetes [33] [34] [35] , human herpes virus 6 (HHV-6) [36] , the Epstein-Barr virus (EBV) [37] , and Propionibacterium acnes [38] . Bacterial LPS, an immunogenic component of the outer coat of gram-negative bacteria, and E coli K99 (a filamentous fimbrial thread that attaches to other bacteria or host cells) were detected immunocytochemically in brain parenchyma and vessels in all AD (24/24) and control brains (18/18) . K99 levels were greater in AD compared to control brains and K99 was localized to neuron-like cells in AD but not control brains. LPS levels were also greater in AD compared to control brain and LPS colocalized with A␤ in amyloid plaques and around vessels in AD brains [39] . P. gingivalis LPS has also been detected in AD brains postmortem [40] .