ENHANCED ENGRAFTMENT OF HTLV-I-INFECTED HUMAN T-CELLS IN SEVERE COMBINED IMMUNODEFICIENCY MICE BY ANTI-ASIALO GM-1 ANTIBODY TREATMENT

The effects of anti-asialo GM-1 antibody (AAGM) treatment on the engra ftment of human T-cell leukemia virus type I (HTLV-I)-infected human T cells in severe combined immunodeficiency (SCID) mice were studied, T he frequency of tumor formation in an HTLV-I-transformed human T-cell line, MT-2 cells, at the site of inoculation was significantly higher in AAGM-treated than untreated mice (P<0.05): 16/18 (89%) and 16/26 (6 2%), respectively, The promotive effect of AAGM treatment on tumor dev elopment was marked in the early stage (less than 3 weeks), suggesting that the immediate reaction of natural killers to the inoculated cell s may be important for the prevention of tumor development, The surfac e phenotypes and clonality of the tumor cells were the same as the MT- 2 cells inoculated, Inoculation of peripheral blood mononuclear cells (PBMC) from one of the 4 adult T-cell leukemia/lymphoma (ATL) patients resulted in the development of tumors in AAGM-treated SCID mice, Howe ver, the surface phenotypes of the cells from these tumors were a mixt ure of B cells and T cells, suggesting that these tumors consisted of Epstein-Barr virus-transformed B cells and HTLV-I-transformed T cells, In addition, HTLV-I was detected by polymerase chain reaction in vari ous organs of the mice inoculated with PBMC from the ATL patient and t he asymptomatic carrier examined, These results suggest that eliminati on of natural killer function by AAGM treatment is important, although such treatment is not always necessary for the engraftment of HTLV-I- infected cells in SCID mice.