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
. 2015 Jun;21(3):276-89.
doi: 10.1007/s13365-014-0287-x. Epub 2014 Sep 19.

HIV-1 target cells in the CNS

Affiliations
Review

HIV-1 target cells in the CNS

Sarah B Joseph et al. J Neurovirol. 2015 Jun.

Abstract

HIV-1 replication in the central nervous system (CNS) is typically limited by the availability of target cells. HIV-1 variants that are transmitted and dominate the early stages of infection almost exclusively use the CCR5 coreceptor and are well adapted to entering, and thus infecting, cells expressing high CD4 densities similar to those found on CD4+ T cells. While the "immune privileged" CNS is largely devoid of CD4+ T cells, macrophage and microglia are abundant throughout the CNS. These cells likely express CD4 densities that are too low to facilitate efficient entry or allow sustained replication by most HIV-1 isolates. Examination of CNS viral populations reveals that late in disease the CNS of some individuals contains HIV-1 lineages that have evolved the ability to enter cells expressing low levels of CD4 and are well-adapted to entering macrophages. These macrophage-tropic (M-tropic) viruses are able to maintain sustained replication in the CNS for many generations, and their presence is associated with severe neurocognitive impairment. Whether conditions such as pleocytosis are necessary for macrophage-tropic viruses to emerge in the CNS is unknown, and extensive examinations of macrophage-tropic variants have not revealed a genetic signature of this phenotype. It is clear, however, that macrophage tropism is rare among HIV-1 isolates and is not transmitted, but is important due to its pathogenic effects on hosts. Prior to the evolution of macrophage-tropic variants, the viruses that are predominately infecting T cells (R5 T cell-tropic) may infect macrophages at a low level and inefficiently, but this could contribute to the reservoir.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Successful HAART blocks new infection but does not affect cells already infected with HIV-1. Therefore, the remaining viral production (and viral load) is directly related to the lifespan of the cells infected prior to initiating HAART. In essentially all patients infected with HIV-1, viral load (VL) decays rapidly upon initiation of HAART with a half-life of approximately 1 to 2 weeks in the blood (indicated by the solid red line) and cerebrospinal fluid (CSF; solid blue line), which is consistent with virus produced from infected CD4+ T cells in both compartments. In rare cases, patients will have the same rapid decay of VL in the blood but will have a much slower decay in the CSF (dashed blue line). This indicates that in these patients viruses are being produced in CD4+ T cells in the blood but are being produced by a longer-lived cell, likely perivascular macrophages or microglia, in the CSF.

Similar articles

Cited by

References

    1. Albright AV, Shieh JTC, O'Connor MJ, Gonzalez-Scarano F. Characterization of cultured microglia that can be infected by HIV-1. J Neurovirology. 2000;6:S53–S60. - PubMed
    1. Alexander M, Lynch R, Mulenga J, Allen S, Derdeyn CA, Hunter E. Donor and recipient envs from heterosexual human immunodeficiency virus subtype C transmission pairs require high receptor levels for entry. J Virol. 2010;84:4100–4104. - PMC - PubMed
    1. Antinori A, Arendt G, Becker JT, Brew BJ, Byrd DA, Cherner M, Clifford DB, Cinque P, Epstein LG, Goodkin K, Gisslen M, Grant I, Heaton RK, Joseph J, Marder K, Marra CM, McArthur JC, Nunn M, Price RW, Pulliam L, Robertson KR, Sacktor N, Valcour V, Wojna VE. Updated research nosology for HIV-associated neurocognitive disorders. Neurology. 2007;69:1789–1799. - PMC - PubMed
    1. Archin NM, Margolis DM. Emerging strategies to deplete the HIV reservoir. Curr Opin Infect Dis. 2014;27:29–35. - PMC - PubMed
    1. Archin NM, Liberty AL, Kashuba AD, Choudhary SK, Kuruc JD, Crooks AM, Parker DC, Anderson EM, Kearney MF, Strain MC, Richman DD, Hudgens MG, Bosch RJ, Coffin JM, Eron JJ, Hazuda DJ, Margolis DM. Administration of vorinostat disrupts HIV-1 latency in patients on antiretroviral therapy. Nature. 2012;487:482–U1650. - PMC - PubMed

Publication types