Characterization of tumor-associated antigens on human oral squamous cell carcinomas using monoclonal antibody 3F8E3

Tumor associated antigen (TAA) on oral squamous cell carcinoma (SCC) was characterized using the monoclonal antibody (MAb) 3F8E3. Flow cytometric analysis revealed a varying degree of reactivity of MAb 3F8E3 to TAA on oral tumor cells. Pretreatment of SCC cells with pronase and trypsin annulled the reactivity of MAb 3F8E3. Sodium metaperiodate (NaIO4) and neuraminidase marginally enhanced the binding of 3F8E3 on oral SCC cells. The studies indicate that the TAA recognized by MAb 3F8E3 on oral tumors is a protein moiety. On Western blotting MAb 3F8E3 showed reactivity to proteins with a molecular weight of 60-66 kDa on oral tumor lysates. MAb 3F8E3 reacted strongly to recombinant human hsp60 and 70 in ELISA. The results suggest that MAb 3F8E3 may react to an epitope expressed on a family of heat shock proteins.