REVERSE-TRANSCRIPTASE AND CORRESPONDING ACTIVITY-BLOCKING ANTIBODY FOR MONITORING SIVSM INFECTION IN MACAQUES

A nonradioactive reverse transcriptase (RT) assay was used to measure RT activity in serum during the viremia peak associated with primary i nfection and for measuring the generation and maintenance of RT activi ty-blocking antibody (RTb-ab) titers during and after seroconversion i n SIV-infected macaques, The RT assay was compared to an antigen captu re immunoassay designed for HIV-2/SIVsm and was found to be approximat ely 40 times more sensitive in detecting SIVsm in serum from infected macaques, The RT assay detected RT activity in serum corresponding to levels from 3 pg/ml. Earliest detection of viral replication using the RT assay was on day 6-8, with a peak at day 10 (up to 8000 pg/ml), Th e earliest detection of RTb-ab was seen on day 17-23, with established RTb-ab titers by day 29, followed by increasing titers of 15,000-120, 000 by day 62-77, The usefulness of RT and RTb-ab for monitoring the c ourse of SIV infection in monkey models is discussed.