CD14 + CD163 + IL-10 + monocytes/macrophages: Pro-angiogenic and non pro-inflammatory isolation,enrichment and long-term secretion profile

Abstract

The establishment of a stable endothelial layer on a biomaterial suture is a well known strategy to achieve hemocompatibility. The endothelialisation is supported by factors as e.g. vascular endothelial growth factor (VEGF), which can be secreted by monocytes/macrophages (mo/mΦ) in an angiogenic milieu. In order to avoid detrimental inflammation triggered by these mo/mΦ, we established a protocol for the generation of alternatively activated macrophages and studied their response towards VEGF-A₁₆₅. We could generate sufficient amounts of these CD14⁺ CD163⁺ IL-10⁺ mo/mΦ from buffy coats(8.6 ± 4.7 × 10⁵ cells/mlbuffy coat). Furthermore, we achieved a VEGF-A₁₆₅ secretion in the nanogram range. The VEGF-A₁₆₅ secretion increased 2.1-fold within 14 days from 7.6 ± 2.2 to 16.1 ± 2.5ng/ml when the cells were grown with a VEGF-A₁₆₅ supplemented (10ng/ml) cell culture medium. Within this time period the secretion levels of other pro-angiogenic growth factors (bFGF, PDGF-BB) and immunomodulatory cytokines (IL-10, IL-12, IL-1ra, TNFα, IFNγ) reached only the picogram range. These results suggest that angiogenically stimulated CD14⁺ CD163⁺ IL-10⁺ mo/mΦ might be useful as a cellular cytokine delivery system supporting endothelialisation of biomaterials without inducing pro-inflammatory effects.