Norman L. Letvin

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Understanding why some people establish and maintain effective control of HIV-1 and others do not is a priority in the effort to develop new treatments for HIV/AIDS. Using a whole-genome association strategy, we identified polymorphisms that explain nearly 15% of the variation among individuals in viral load during the asymptomatic set-point period of(More)
Identification of the transmitted/founder virus makes possible, for the first time, a genome-wide analysis of host immune responses against the infecting HIV-1 proteome. A complete dissection was made of the primary HIV-1-specific T cell response induced in three acutely infected patients. Cellular assays, together with new algorithms which identify sites(More)
Clinical evidence suggests that cellular immunity is involved in controlling human immunodeficiency virus-1 (HIV-1) replication. An animal model of acquired immune deficiency syndrome (AIDS), the simian immunodeficiency virus (SIV)-infected rhesus monkey, was used to show that virus replication is not controlled in monkeys depleted of CD8+ lymphocytes(More)
To extend the understanding of host genetic determinants of HIV-1 control, we performed a genome-wide association study in a cohort of 2,554 infected Caucasian subjects. The study was powered to detect common genetic variants explaining down to 1.3% of the variability in viral load at set point. We provide overwhelming confirmation of three associations(More)
In sexual transmission of simian immunodeficiency virus, and early and later stages of human immunodeficiency virus-type 1 (HIV-1) infection, both viruses were found to replicate predominantly in CD4(+) T cells at the portal of entry and in lymphoid tissues. Infection was propagated not only in activated and proliferating T cells but also, surprisingly, in(More)
Recent studies of human immunodeficiency virus type 1 (HIV-1) infection in humans and of simian immunodeficiency virus (SIV) in rhesus monkeys have shown that resolution of the acute viral infection and control of the subsequent persistent infection are mediated by the antiviral cellular immune response. We comparatively assessed several vaccine vector(More)
The isolation of a T-cell tropic retrovirus from three immunodeficient macaques and one macaque with lymphoma is described. The morphology, growth characteristics, and antigenic properties of this virus indicate that it is related to the causative agent of acquired immune deficiency syndrome in humans (HTLV-III or LAV). This virus is referred to as simian(More)
The utility of the simian immunodeficiency virus of macaques (SIVmac) model of AIDS has been limited by the genetic divergence of the envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) and the SIVs. To develop a better AIDS animal model, we have been exploring the infection of rhesus monkeys with chimeric simian/human immunodeficiency(More)
BACKGROUND Inhibitors of HIV-1 protease produce a rapid decrease in plasma HIV-1 RNA, with concomitant increases in CD4 T-helper lymphocyte counts. The main side-effects of the protease inhibitors currently in use include gastrointestinal disturbances, paraesthesias, hyperbilirubinaemia, and nephrolithiasis. The increasing use of these agents in patients(More)
Potent virus-specific cytotoxic T lymphocyte (CTL) responses elicited by candidate AIDS vaccines have recently been shown to control viral replication and prevent clinical disease progression after pathogenic viral challenges in rhesus monkeys. Here we show that viral escape from CTL recognition can result in the eventual failure of this partial immune(More)