Induction of leukemic infiltration by allogeneic transfer of HTLV-I-transformed T cells in rabbits.

An HTLV-I-transformed T-cell line from a (B/J x Chbb:HM)F1 rabbit was intravenously inoculated at a dose of 1 x 10(8) cells into B/J and Chbb:HM adult rabbits. All B/J rabbits died or became moribund 6-13 days later, whereas all Chbb:HM rabbits survived without disease symptoms. Marked leukocytosis was observed in Chbb:HM rabbits but not in B/J rabbits, the leukocyte counts in the peripheral blood of the former being 10-30 times the normal level 10 days post-inoculation with most cells being of normal lymphoid appearance. Pathological examination of dead B/J animals revealed leukemic infiltration of abnormal lymphocytes in major organs, the infiltrate being composed of medium-sized lymphoid cells with pan T-cell marker, convoluted vesicular nuclei and frequent mitotic figures. These results indicate that allogeneic transfer of HTLV-I-transformed cells can induce leukemic infiltration under appropriate conditions. Similar leukemic infiltration was observed in major organs of random-bred rabbits 72 h after a similar inoculation of the same cell line. Such adult T-cell leukemia-like disease induced in random-bred rabbits may be useful in studying the mechanism and the prevention of leukemic infiltration.