Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2012 Mar 9;335(6073):1188-93.
doi: 10.1126/science.1217550.

Natural SIV hosts: showing AIDS the door

Ann Chahroudi  1 , Steven E Bosinger, Thomas H Vanderford, Mirko Paiardini, Guido Silvestri
Affiliations
Review

Natural SIV hosts: showing AIDS the door

Ann Chahroudi et al. Science. .

Erratum in

  • Science. 2012 Apr 27;336(6080):413

Abstract

Many species of African nonhuman primates are naturally infected with simian immunodeficiency viruses (SIVs) in the wild and in captivity. In contrast to HIV-infected humans, these natural SIV hosts typically do not develop AIDS, despite chronic infection with a highly replicating virus. In this Review, we discuss the most recent advances on the mechanisms of protection from disease progression in natural SIV hosts, with emphasis on how they differ from pathogenic HIV/SIV infections of humans and rhesus macaques. These mechanisms include: (i) resolution of immune activation after acute infection, (ii) restricted pattern of target cell infection, and (iii) protection from mother-to-infant transmission. We highlight the areas that should be pursued in future studies, focusing on potential applications for the treatment and prevention of HIV infection.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Mechanisms responsible for the low immune activation and lack of disease progression in SIV-infected natural hosts
The main immunological and virological features contributing to the lack of chronic immune activation and their key consequences resulting in protection from AIDS in natural SIV hosts are depicted.
Figure 2
Figure 2. Proposed mechanisms of target cell restriction in natural host species
(A) In pathogenic hosts such as RMs, activation of CD4+ T cells typically leads to robust surface expression of the HIV/SIV co-receptor CCR5, providing targets for infection and viral replication. Infection is distributed within both effector memory cells (Tem) and central memory cells (Tcm). Infection and disruption of the Tcm pool has been demonstrated to disrupt CD4+ T cell homeostasis in vivo (53). (B) Upon transition from naïve CD4+ T cells to memory cells, AGMs lower the surface expression of the CD4 molecule on a subset of CD3+CD4−CD8αlow lymphocytes that exhibit CD4+ T cell function and are infected by SIV at a lower frequency than naïve or memory CD4+ cells (58). AGMs also exhibit lower levels of CCR5 expression on CD4+ T cells than non-natural hosts (57). (C) Multiple, non-mutually exclusive mechanisms modulating SIV tropism have been described in SMs: (i) Upon activation, SM CD4+ Tcm cells maintain low levels of CCR5 relative to CD4+ Tem cells, resulting in significantly decreased levels of SIV infection (30); (ii) SMs have high levels of CD3+CD4−CD8− “double-negative” lymphocytes that exhibit T helper function, providing a potential surrogate for CD4+ T cells that is resistant to infection (60); (iii) Approximately 7% of captive SMs are homozygous for CCR5 mutations that abrogate surface expression, although these animals can be infected with SIV (59). Photo credit: S.E.B. and K.D. Mir.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Worobey M, et al. Island biogeography reveals the deep history of SIV. Science. 2010 Sep 17;329:1487. - PubMed
    1. VandeWoude S, Apetrei C. Going wild: lessons from naturally occurring Tlymphotropic lentiviruses. Clinical Microbiology Reviews. 2006 Oct;19:728. - PMC - PubMed
    1. Hahn BH, Shaw GM, De Cock KM, Sharp PM. AIDS as a zoonosis: scientific and public health implications. Science. 2000 Jan;287:607. - PubMed
    1. Letvin NL, et al. Induction of AIDS-like disease in macaque monkeys with T-celltropic retrovirus STLV-III. Science. 1985 Oct 4;230:71. - PubMed
    1. Silvestri G. Nonpathogenic SIV infection of sooty mangabeys is characterized by limited bystander immunopathology despite chronic high-level viremia. Immunity. 2003 Mar;18:441. - PubMed

Publication types

MeSH terms