INFECTION OF RATS WITH HTLV-1 - A SMALL-ANIMAL MODEL FOR HTLV-1 CARRIERS

A human T-cell line producing human T-cell leukemia virus type 1 (HTLV-1), MT-2, was injected intravenously into female F344 rats aged 5 weeks to make HTLV-1 carrier rats. Antibody against HTLV-1 was detected at the 5th week after MT-2 injection, and its titer reached a high plateau which continued from the 15th to the 27th week. The antibodies were against p19, p24, p28 and p53 of HTLV-1 antigens from MT-2 cells. The gag, pX and LTR nucleotide sequences of HTLV-1 provirus were demonstrated by using polymerase chain reaction (PCR) in the peripheral-blood mononuclear cells of 3 rats at the 44th week and 2 at the 66th to 68th week out of 8 F344 rats injected with MT-2 cells. Quantification of the HTLV-1 proviral sequence revealed that 30 to 60 molecules were present in 10(5) peripheral-blood mononuclear cells, indicating that the rats were chronically infected with HTLV-1. HTLV-1-infected rats could serve as a small-animal model for studying the Pathophysiological state of HTLV-1 carriers and also that of HTLV-1 infection on various HTLV-1-related diseases, including adult T-cell leukemia and HTLV-1-associated myelopathy.