Immune suppression in HTLV-I carriers: a predictive sign of adult T-cell leukemia.

Suppression of the cellular immune system appears to be a prerequisite for the manifestation of adult T-cell leukemia (ATL). In other words, ATL will develop when impairment of the immune system is caused by the infection of human T-lymphotropic virus type I (HTLV-I). This defect of immune surveillance against virus-infected cells may be a result of the impairment of the function of cytotoxic T-cells (CTLs) specific for the HTLV-I-infected cells. The manifestation of ATL could be predicted by examining the function of CTLs in HTLV-I carriers. A new strategy of prevention and therapy for ATL would include an attempt to restore and fortify the CTL function of the host.