FIGURE 4.

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.