HIV-1 immune activation induces Siglec-1 expression and enhances viral trans-infection in blood and tissue myeloid cells

Retrovirology. 2015 May 7;12:37. doi: 10.1186/s12977-015-0160-x.


Background: Myeloid cells are key players in the recognition and response of the host against invading viruses. Paradoxically, upon HIV-1 infection, myeloid cells might also promote viral pathogenesis through trans-infection, a mechanism that promotes HIV-1 transmission to target cells via viral capture and storage. The receptor Siglec-1 (CD169) potently enhances HIV-1 trans-infection and is regulated by immune activating signals present throughout the course of HIV-1 infection, such as interferon α (IFNα).

Results: Here we show that IFNα-activated dendritic cells, monocytes and macrophages have an enhanced ability to capture and trans-infect HIV-1 via Siglec-1 recognition of viral membrane gangliosides. Monocytes from untreated HIV-1-infected individuals trans-infect HIV-1 via Siglec-1, but this capacity diminishes after effective antiretroviral treatment. Furthermore, Siglec-1 is expressed on myeloid cells residing in lymphoid tissues, where it can mediate viral trans-infection.

Conclusions: Siglec-1 on myeloid cells could fuel novel CD4(+) T-cell infections and contribute to HIV-1 dissemination in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • CD4-Positive T-Lymphocytes / virology
  • Cells, Cultured
  • HIV-1 / immunology*
  • HIV-1 / physiology*
  • Humans
  • Interferon-alpha / metabolism*
  • Male
  • Myeloid Cells / virology*
  • Sialic Acid Binding Ig-like Lectin 1 / biosynthesis*
  • Up-Regulation*


  • Interferon-alpha
  • Sialic Acid Binding Ig-like Lectin 1