Interleukin-2 is Present in Human Blood Vessels and Released in Biologically Active Form by Heparanase
Interleukin-2 (IL-2) is a multifaceted cytokine with immunostimulatory and immunosuppressive properties. Our laboratory recently demonstrated that the availability of IL-2 is regulated, in part, by association with perlecan, a heparan sulfate proteoglycan. Given the abundance of perlecan in blood vessels, we asked whether IL-2 is present in vessel walls. Our results indicate that IL-2 is associated with endothelial and smooth muscle cells within the human arterial wall. This IL-2 is released by heparanase, and promotes the proliferation of an IL-2-dependent cell line. Given the presence of IL-2 in human arteries, we asked whether the large vessels of IL-2-deficient mice were normal. The aortas of IL-2-deficient mice exhibited a loss of smooth muscle cells, suggesting that IL-2 may contribute to their survival. In their entirety, these results suggest a here-to-fore unrecognized role of IL-2 in vascular biology, and have significant implications for both the immune and cardiovascular systems.
Miller, J. D.,
Clabaugh, S. E.,
Smith, D. R.,
Stevens, R. B.,
& Wrenshall, L. E.
(2012). Interleukin-2 is Present in Human Blood Vessels and Released in Biologically Active Form by Heparanase. Immunology and Cell Biology, 90 (2), 159-167.