THE THOMSEN-FRIEDENREICH (TF) ANTIGEN - A CRITICAL-REVIEW ON THE STRUCTURAL, BIOSYNTHETIC AND HISTOCHEMICAL ASPECTS OF A PANCARCINOMA-ASSOCIATED ANTIGEN

Within the family of blood-group related carbohydrate antigens the Tho msen-Friedenreich (TF) antigen (or T antigen) is an outstanding member by attracting scientific interest for more than 65 years and by havin g retained its significance as object of current biomedical research; in particular, as a pancarcinoma-associated antigen. In accordance wit h its constant or even growing attraction scientists have searched for specific reagents which would allow the unambiguous and sensitive det ection of the Thomsen-Friedenreich antigen on cells or tissues. While at the beginning, immunohistochemical work on TF antigen expression wa s restricted by the limited specificity of plant lectins (peanut lecti n) a significant progress has been possible since the introduction of the hybridoma technique. The respective monoclonal antibodies display distinct fine specificities and cellular staining patterns in immunohi stochemistry and have contributed to controversial discussions on the organ-characteristic and tumor-associated expression of the TF antigen in some organs. It is the aim of this survey to summarize in the cont ext of its structural and biosynthetic aspects the current knowledge o n the tissue expression of the TF antigen as based on the use of peanu t agglutinin and monoclonal antibodies and to discuss the findings wit h regard to their biomedical relevance, in particular, with emphasis o n their value in tumor diagnosis.