TRANSMISSION OF HUMAN T-CELL LEUKEMIA-VIRUS TYPE-I TO SHEEP - ANTIBODY PROFILE AND DETECTION OF VIRAL-DNA SEQUENCES

Lambs were inoculated intraperitoneally with either 1.8 x 10(7) live p eripheral blood cells from an HTLV-I-infected person (five lambs) or w ith 8 x 10(7) live cells from the HTLV-I-producing cell lines MT-2 (fo ur lambs) or C10 MJ (five lambs), Four control lambs were inoculated w ith minimal essential medium supplemented with fetal calf serum, The a nimals were monitored during a period of 24 months, Beginning at 5 to 12 months after inoculation, four of the five lambs inoculated with th e fresh HTLV-I-infected peripheral blood cells began to develop detect able levels of antibodies to a recombinant HTLV-I gp21(env) antigen, a s determined by an enzyme-linked immunoassay (ELISA). The anti-gp21 an tibodies persisted for the remaining observation period, These antibod ies were not detected in the sera from the other sheep, Absorption and blocking experiments demonstrated the specificity of the gp21 reactiv ity, This reactivity was also confirmed by Western blot (WB). With the exception of the serum of an MT-2-inoculated sheep that formed a weak band with p19 by WB, none of the sera of the four gp21-positive sheep or of the other experimental sheep reacted with other structural or r egulatory HTLV-I proteins, as determined by ELISA, WB, and radioimmuno assay, PCR analyses demonstrated the presence of the HTLV-I provirus i n peripheral blood leukocytes of the four sheep showing antibodies to gp21(env), The remaining sheep were negative, PCR analyses failed to d etect BLV sequences in any of the experimental sheep, None of the shee p showed clinical abnormalities during the observation period, The pot ential value of the sheep model for studying atypical virus-host inter actions in infected people is discussed.