Contribution of monocytes Siglec-1 in stimulating T cells proliferation and activation in atherosclerosis

Atherosclerosis. 2012 Sep;224(1):58-65. doi: 10.1016/j.atherosclerosis.2012.06.063. Epub 2012 Jul 3.


Objective: Atherosclerosis (AS) is widely accepted as an inflammatory disease and monocytes are particularly important in inflammatory immune responses. As an important biomarker of monocytes activation, Siglec-1 is highly expressed on circulating monocytes and atherosclerotic plaques of coronary artery disease (CAD) patients, but the exact role of Siglec-1 has not been elucidated.

Methods: M-CSF, INF-α, IFN-γ, TNF-α and ox-LDL alone or in combination were used to stimulate Siglec-1 expression on monocytes, whereas small interfering RNA (si-RNA) or blocking antibody was used to down-regulate Siglec-1. Meanwhile, the role of Siglec-1 in chemokines secretion was determined. Then monocytes from CAD patients or healthy controls were cocultured with CD4+ or CD8+ T cells from a third healthy individual, and lymphocyte proliferation and activation were determined.

Results: All the stimuluses could enhance Siglec-1 expression on monocytes in a dose-dependent manner, and M-CSF could synergistically stimulate Siglec-1 expression with ox-LDL. Moreover, the secretion of MCP-1, MIP-1α and MIP-2 were enhanced when Siglec-1 was up-regulated and down to normal level when Siglec-1 was blocked. More importantly, increased Siglec-1 expression on monocytes was related to the increased T cell proliferation and pro-inflammatory cytokines secretion in CAD patients. However, down-regulation of Siglec-1 could attenuate proliferation and activation of cocultured CD4+ and CD8+ T cells.

Conclusion: Siglec-1 can promote chemokines and pro-inflammatory cytokines secretion and influence the inflammatory process of AS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Atherosclerosis / immunology
  • Cell Proliferation
  • Coronary Artery Disease / immunology
  • Humans
  • Mice
  • Monocytes / immunology*
  • Sialic Acid Binding Ig-like Lectin 1 / physiology*
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism


  • Sialic Acid Binding Ig-like Lectin 1