IFN-β reduces NRP-1 expression on human cord blood monocytes and inhibits VEGF-induced chemotaxis

Type I interferons (IFNs) inhibit angiogenesis, the sprouting of new blood vessels, during tissue development, remodeling, and tumor growth. One of the major targets type I IFNs inhibit are circulating monocytes, which promote vascular development by secreting growth factors, chemokines, and proteases. This study tested the hypothesis that IFN-beta directly inhibits monocyte chemotaxis towards VEGF. We were interested in looking at chemotaxis towards VEGF because VEGF is known to create a pro-angiogenesis environment by acting as a stimulator and chemotactic factor for endothelial cells and monocytes. Here, we demonstrate that IFN-beta, a type I IFN, downregulates neuropilin-1 (NRP-1) expression by human monocytes and inhibits chemotaxis induced by vascular endothelial growth factor (VEGF), a NRP-1 ligand. Together, the data suggest that IFN-beta directly downregulates NRP-1 expression in monocytes, thus inhibiting monocyte chemotaxis toward a VEGF enriched environment.

Automated summary

The study demonstrates that IFN-beta inhibits monocyte chemotaxis towards VEGF by downregulating NRP-1 expression, suggesting a mechanism by which type I interferons suppress angiogenesis by targeting circulating monocytes.