Peripheral Blood Mononuclear Cells of Alzheimer's Disease Patients Control CCL4 and CXCL10 Levels in a Human Blood Brain Barrier Model

Abstract

These findings highlight the interest of a BBB model in order to explore chemokine production. For the first time, results showed that PBMCs from patients with AD can control the production of CCL4 and CXCL10 in a human BBB model.

Differential chemokine expression under the control of peripheral blood mononuclear cells issued from Alzheimer’s patients in a human blood brain barrier model

“…Studies analysing the chemotactic crosstalk occurring at the BBB between peripheral cells, actors of the BBB and the parenchyma brain during AD are lacking. We conducted a previous study in order to analyse the production of five chemokines known to be implicated in the pathogenesis of AD in a human BBB model, and also to assess whether PBMCs from AD patients could impact chemokine production [ 35 ]. This work showed that BBB models are valuable tools to explore chemokine production and that PBMCs from AD patients at a moderate stage could influence CCL4 and CXCL10 production in this human BBB model.…”

“…Blood sample were transferred into 10 mL BD Vacutainer ® tube. Then, PBMCs were isolated using a Ficoll Histopaque-1077 density gradient and cultured as previously described [ 27 , 28 ]. PBMCs were seeded at 500,000 cells/500 μL of complete culture medium (RPMI 1640 medium completed with 10% of newborn calf serum, 1% of PS and 10% of PHA at 20 μg/mL) in 12-well plates for 24 hours, and then transferred in the upper side of insert of the BBB model in direct contact with hCMEC/D3 cells.…”

“…In most studies, the PBMCs are either stimulated by PHA, lipopolysaccharide (LPS) or β-amyloid peptide (Aβ). We chose the PHA as a mitogen as in our previous studies [ 27 – 30 ] and those of several authors to consider comparisons on chemokine levels [ 31 – 33 ].…”

“…The assembly of the human BBB model followed a very strict chronology as already described in our previous study [ 35 ]. Indeed, U87 cells were seeded first (D-1) at a density of 10 000 cells/well in 12-well plates (named as U87w in this study), and at the same time on the bottom side of each insert at the density of 3200 cells/insert (called as U87i ).…”

“…Previously, we published a work using the same experimental conditions with PBMCs from AD patients at a moderate stage with Mini Mental State Examination (MMSE) score between 10 and 20. Results showed that PBMCs can modify the chemokine signature at the BBB level and in particular greatly increase the levels of CCL4 and CXCL10 in endothelial and abluminal cells mimicking BBB [ 27 ], highlighting the role of immune system in the onset of AD by disturbing the chemokine expression. But this study did not include control patients.…”