Immunoregulatory function and expression of OKT17 antigen of adult T-cell leukemia cells.

Research was carried out on neoplastic T-cells taken from 10 cases of Japanese adult T-cell leukemia (ATL) in regard to their immunoregulatory activity on pokeweed mitogen (PWM)-driven immunoglobulin (Ig) production and their differentiation antigens. ATL cells were reactive with OKT3, OKT4 and OKT11 in most cases; however, the ATL cells from one case did not react with OKT11 nor formed E-rosettes. ATL cells of three cases were reactive with OKT8 as well as OKT4. In six cases, the ATL cells were reactive with OKT17 and coincidentally displayed suppressor activity on Ig production. The cells of the remaining four cases did not have such reactivity with OKT17 or suppressor activity. Moreover, the OKT17(+) ATL cells from one case sorted by FACS 440 demonstrated suppressor activity, while the OKT17(-) ATL cells did not. These results indicated that ATL cells with suppressor activity had OKT3(+), OKT4(+), OKT17(+) phenotype.