Perhaps the first evidence for an involvement of IL-9 in atherosclerosis was recently reported in the online journal PLoS One by Ida Gregersen and colleagues from the Oslo University Hospital Rikshospitalet, Oslo, Norway.
Interleukin (IL)-9 is a cytokine linked mostly to T helper (Th)2 cell responses and Th2-related conditions such as parasitic helminth infections and allergy/asthma.
New evidence also implicates IL-9 in autoimmunity, heart failure and experimental cardiomyopathy. The major source of IL-9 is T lymphocytes, and particularly the newly defined Th9 cells.
In the PLoS One study the authors found elevated circulating levels of IL-9, and increased IL-9 and IL-9R expression in cells and tissue of patients with carotid and coronary atherosclerosis.
IL-9 is also known to support Th17 cell expansion. As in this study the cytokine potentiated the release of IL-17 in peripheral blood mononuclear cells, and particularly in cells from unstable angina patients, the authors suggest that the effects of IL-9 in atherosclerosis are most likely IL-17-mediated. Of note, recent reseach indicate that the key pro-inflammatory and highly pathogenic cytokine IL-17 contributes to atherosclerosis.
The study suggests that the IL-9 – IL-9R interaction, and the link between IL-9 and IL-17 are probably involved in atherosclerosis development, but this needs further, more detailed investigation.
Source: PLoS One. 2013 Aug 30;8(8):e72769. doi: 10.1371/journal.pone.0072769.
Read More: PLoS One
