Immunohistochemistry and in situ hybridization of T-cell acute lymphoblastic leukemia-associated antigen 1 in human brain tissues

One of the proteins belonging to the transmembrane 4 superfamily, T-cell ac ute lymphoblastic leukemia-associated antigen 1 (TALLA1), behaves like a po tential tumor-associated antigen, Furthermore, its mRNA is expressed in nor mal brain, We examined here the histochemical localization of the protein a nd its mRNA in human brain tissues. Both nonneurological and Alzheimer dise ase (AD) brains showed astroglial staining for the TALLA1 molecule. In AD b rain tissues, globular dystrophic neurites were positively stained. In dama ged white matter showing leukoaraiosis by CT scan there was varicose axonal staining with the anti-TALLA1 antibody. In situ hybridization histochemist ry using a RNA probe demonstrated neuronal expression of the mRNA, These re sults suggest that TALLA1, like amyloid precursor protein or chromogranin A , is produced in neurons and transported by axonal flow.