Immunohistochemistry for FTL in human brains. Two different FTL antibodies were used
and they showed similar results. A goat polyclonal antiserum (A, C, D)
highlighted immunostained structures with astrocyte and microglial features, as well
as what looked like intracellular inclusions. A mouse monoclonal anti-FTL antibody
(B) showed similar changes as the polyclonal antiserum. Areas indicated
with the yellow arrows are shown at higher magnification (insets), depicting FTL
immunostained structures with histomorphologic features of inclusion bodies. The cell
types stained by the FTL antibodies, even in diseased brains, appeared mostly
nonneuronal. Hippocampus from 1 brain with HS-Aging/CARTS was stained (92-year-old at
death; (C) to allow better discrimination of cell types, and showed both
glial and neuronal (inset) immunostaining. In brains of nondemented subjects (D), FTL
antibodies showed relatively sparse staining of cells with quiescent-type microglial
and astrocyte morphology. Scale bars: A = 15 μm; B,
C = 30 μm; D = 60 μm.