Current HIV/AIDS Reports

, Volume 9, Issue 1, pp 52–63 | Cite as

The HIV-1 Env Protein: A Coat of Many Colors

  • Kathryn Twigg Arrildt
  • Sarah Beth Joseph
  • Ronald Swanstrom
The Science of HIV (AL Landay, Section Editor)


HIV-1 is completely dependent upon the Env protein to enter cells. The virus typically replicates in activated CD4+ T cells due to viral entry requirements for the CCR5 coreceptor and for high surface levels of the CD4 receptor. This is the case for the transmitted virus and for most of the virus sampled in the blood. Over the course of infection, the env gene can evolve to encode a protein with altered receptor and coreceptor usage allowing the virus to enter alternative host cells. In about 50% of HIV-1 infections, the viral population undergoes coreceptor switching, usually late in disease, allowing the virus to use CXCR4 to enter a different subset of CD4+ T cells. Neurocognitive disorders occur in about 10% of infections, also usually late in disease, but caused (ultimately) by viral replication in the brain either in CD4+ T cells or macrophage and/or microglia. Expanded host range is significantly intertwined with pathogenesis. Identification and characterization of such HIV-1 variants may be useful for early detection which would allow intervention to reduce viral pathogenesis in these alternative cell types.


Human immunodeficiency virus HIV Envelope Env gp160 gp120 gp41 Tropism Macrophage Monocyte Receptor CD4 Coreceptor CCR5 R5 CXCR4 X4 Transmission Evolution Entry 


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Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Kathryn Twigg Arrildt
    • 1
  • Sarah Beth Joseph
    • 2
  • Ronald Swanstrom
    • 3
  1. 1.Department of Microbiology and ImmunologyUniversity of North Carolina at Chapel HillChapel HillUSA
  2. 2.Lineberger Comprehensive Cancer CenterUniversity of North Carolina at Chapel HillChapel HillUSA
  3. 3.Department of Biochemistry and BiophysicsUniversity of North Carolina at Chapel Hill, CB#7295 Lineberger Comprehensive Cancer CenterChapel HillUSA

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