Int Conf AIDS 1991 Jun 16-21; 7:21 (abstract no. M.A.6) Stevenson M, Bukrinsky MI, Stanwick TL, Dempsey MP; Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE USA
The underlying basis for HIV-1 persistence and latency and the nature of the virus reservoir in the course of AIDS remains unresolved. The large number of cells in infected individuals which harbor proviral DNA is difficult to reconcile with low numbers of productively infected cells suggesting a restricted reservoir where a majority of infected cells are non-permissive to a complete HIV-1 replication cycle. Our previous work in vitro has demonstrated that quiescent T lymphocytes are infectible by HIV-1 with equal efficiency when compared to activated lymphocytes, although the virus life cycle is restricted due to an as yet unidentified block to HIV-1 integration. Importantly, the preintegration complex within quiescent lymphocytes retains full capacity to integrate upon subsequent activation of the infected host cell. These in vitro experiments prompted us to determine whether infected quiescent lymphocytes represent a reservoir for HIV-1 in vivo and whether this reservoir could explain some of the features of viral persistence in AIDS. We have developed a PCR protocol which allows us to distinguish a single copy of the HIV-1 genome and to determine whether viral DNA is in an integrated or unintegrated state. Application of this method to analysis of lymphocytes from a cohort of HIV-1 infected asymptomatic and AIDS individuals demonstrated that a major portion of viral DNA in asymptomatic individuals exists as full length unintegrated HIV-1 genomes. In contrast, the major DNA form in AIDS patients was an integrated provirus. Importantly, in vitro activation of lymphocytes from asymptomatic individuals resulted in efficient integration of viral DNA demonstrating an inducible virus reservoir. Several lines of evidence, including ligation mediated PCR analysis of patient lymphocyte subpopulations depleted of activated cells, specifically identified quiescent T lymphocytes as the source of extrachromosomal HIV-1 DNA. Our data demonstrates the existence of a novel HIV-1 reservoir in infected individuals. The nature of this novel quiescent T lymphocyte reservoir indicates that HIV-1 latency and persistence is governed in part by events prior to proviral integration.
Keywords: AEGIS, HIV-1, Proviruses, DNA, Viral, Virus Replication, Acquired Immunodeficiency Syndrome, Polymerase Chain Reaction, T-Lymphocytes, Lymphocytes, Anti-HIV Agents, DNA Primers, In Vitro, Human, virology, ICA7 910616
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