Conclusions
Costimulatory pathways are altered in CD4(+)CD28(null) T cells in ACS. We show that the inflammatory and cytotoxic function of CD4(+)CD28(null) T cells can be inhibited by blocking OX40 and 4-1BB costimulatory receptors. Modulation of costimulatory receptors may allow specific targeting of this cell subset and may improve the survival of ACS patients.
Objective
Our aim was to investigate the expression and role of alternative costimulatory receptors in CD4(+)CD28(null) T cells in ACS.
Results
Expression of alternative costimulatory receptors (inducible costimulator, OX40, 4-1BB, cytotoxic T lymphocyte associated antigen-4, programmed death-1) was quantified in CD4(+)CD28(null) T cells from circulation of ACS and stable angina patients. Strikingly, in ACS, levels of OX40 and 4-1BB were significantly higher in circulating CD4(+)CD28(null) T cells compared to classical CD4(+)CD28(+) T lymphocytes. This was not observed in stable angina patients. Furthermore, CD4(+)CD28(null) T cells constituted an important proportion of CD4(+) T lymphocytes in human atherosclerotic plaques and exhibited high levels of OX40 and 4-1BB. In addition, the ligands for OX40 and 4-1BB were present in plaques and also expressed on monocytes in circulation. Importantly, blockade of OX40 and 4-1BB reduced the ability of CD4(+)CD28(null) T cells to produce interferon-γ and tumor necrosis factor-α and release perforin. Conclusions: Costimulatory pathways are altered in CD4(+)CD28(null) T cells in ACS. We show that the inflammatory and cytotoxic function of CD4(+)CD28(null) T cells can be inhibited by blocking OX40 and 4-1BB costimulatory receptors. Modulation of costimulatory receptors may allow specific targeting of this cell subset and may improve the survival of ACS patients.