ObjectiveBlood monocytes are known to pomyslnaszycie.com express endothelial-like genes during co-culture with endothelium.In this study, the time-dependent change in the phenotype pattern of primary blood monocytes after adhering to endothelium is reported using a novel HLA-A2 mistyped co-culture model.Methods and resultsFreshly isolated human PBMCs were co-cultured with human umbilical vein endothelial cells or human coronary arterial endothelial cells of converse human leukocyte antigen A2 (HLA-A2) status.This allows the tracking of the PBMC-derived cells by HLA-A2 expression and assessment of their phenotype pattern over time.PBMCs that adhered to the endothelium at the start of the co-culture were predominantly CD11b+ blood monocytes.
After 24 to 72 hours in co-culture, the endothelium-adherent monocytes acquired endothelial-like properties including hellfire sloe gin the expression of endothelial nitric oxide synthase, CD105, CD144 and vascular endothelial growth factor receptor 2.The expression of monocyte/macrophage lineage antigens CD14, CD11b and CD36 were down regulated concomitantly.The adherent monocytes did not express CD115 after 1 day of co-culture.By day 6, the monocyte-derived cells expressed vascular cell adhesion molecule 1 in response to tumour necrosis factor alpha.Up to 10% of the PBMCs adhered to the endothelium.
These monocyte-derived cells contributed up to 30% of the co-cultured cell layer and this was dose-dependent on the PBMC seeding density.ConclusionsHuman blood monocytes undergo rapid phenotype change to resemble endothelial cells after adhering to endothelium.