Expression of Tumor-associated Glycoantigen, Sialyl Lewisa, in Human Head and Neck Squamous Cell Carcinoma and Its Application to Tumor Immunotherapy

The glycoantigen sialyl Lewis^a (sLe^a) is widely expressed on a variety of gastrointestinal tumor cells. Here, we immunohistochemically demonstrated the expression of sLe^a antigen in 54% (7 out of 13) of human head and neck squamous cell carcinoma (H-NSCG) samples. Frequent expression of sLe^a antigen was also demonstrated on a variety of H-NSCC cell lines using flow cytometry. Both CD4⁺ and CD8⁺ T cells, which were activated with immobilized OKT3 monoclonal antibody plus inter-leukin-2, showed augmented cytotoxicity against sLe^a-positive H-NSCC, including autologous tumor cells, on targeting with anti-CD3 x anti-sLe^a bispccific antibody, suggesting that sLe^a antigen is a good target molecule for bispecific antibody-dependent adoptive tumor immunotherapy of human head and neck cancer.