Detection of neuronal tissue from brain grafts with anti-Thy-1.1 antibody

Abstract

Grafting of neural tissue has been used to investigate the ability of central nervous system (CNS) axons to elongate into peripheral nerve grafts^1,2; to investigate the growth characteristics of material transplanted within the CNS^3,4; and to determine if grafts producing amines or peptides can replace a natural^5,6 or experimentally induced depletion^7,8 of these biogenic molecules. In such experiments donor tissue has been distinguished from host by injection into graft cells of horseradish peroxidase^1,2 or radioactive leucine⁹ or by detecting biogenic molecules in the grafted tissue with antibodies^6–8. All these methods have limitations and a technique which allows identification of the total neuronal cell output from transplanted tissue would be a powerful tool in delineating host–graft interactions. Polymorphic cell-surface antigens have not previously been exploited as markers. The Thy-1 antigen is an abundant glycoprotein of neurones and in the mouse exists in two allotypic forms called Thy-1.1 and Thy-1.2. We now show that tissue from Thy-1.1-positive animals grafted into Thy-1.1-negative brains can be clearly identified in cryostat sections using an anti-Thy-1.1 monoclonal antibody conjugated with peroxidase. We have used the method to study grafts from normal fetal mice which correct a developmental deficiency when transplanted into hpg mutant mice.