THE IMMUNOLOGICAL EFFECT OF 8-METHOXYPSORALEN AND UVA TREATMENT ON MURINE T-CELL LEUKEMIA

8-Methoxypsoralen (8-MOP) plus long-wavelength UV radiation (UVA, 320- 400 nm) have been used to treat various diseases such as cutaneous T-c ell lymphoma, systemic scleroderma, rheumatoid arthritis and rejection of heart transplants, However, the immunological mechanism of this tr eatment remains unknown, In this report, we investigated the effect of 8-MOP/UVA on the modulation of the immunogenicity of a T-cell leukemi a cell line (RL male 1 cells), The results demonstrated that the stimu lator function of the in vitro 8-MOP/UVA-treated RL3 male 1 cells was enhanced in both RL male 1-specific allogeneic and syngeneic immune re sponses, Furthermore, the enhancement of the immunogenicity of the 8-M OP/UVA-treated RL male 1 cells was found to be strongly associated wit h the increase of intercellular adhesion molecule-1 expression on thes e 8-MOP/UVA-treated tumor cells. Therefore, our findings suggested tha t the alteration of the expression of the immune-related cell surface molecules might be an important effect of 8-MOP/UVA treatment on the e levation of the immunogenicity of the 8-MOP/UVA-treated tumor cells.