1-40 β-amyloid protein fragment modulates the expression of CD44 and CD71 on the astrocytoma cell line in the presence of IL1β and TNFα

The modulation of CD44, VCAM-1 and CD71 expression was analysed by flow cytometry in the 1321N1 astrocytoma cell line in the presence of interleukin-1β (IL1β), tumour necrosis factor-α (TNFα) and 1-40 or 25-35 β-amyloid (Aβ) fragments. The percentage of 1321N1 astrocytoma cell line expressing these markers increased significantly after treatment with TNFα or IL1β. The presence of Aβ 1-40 fragment, alone or in combination with IL1β, induced an increase in the percentage of cells expressing CD44, but not VCAM-1. However, the concomitant presence of Aβ 1-40 fragment and of IL1β or TNFα caused an increase in the percentage of CD71 positive cells. In contrast, the shorter Aβ 25-35 fragment was always inactive. These results indicates that Aβ 1-40 fragment, in association with cytokines, can activate this astrocyte-derived cell line and add further elements in favour of the hypothesis that β-amyloid can act as immunological mediator.