Immune response of human umbilical vein endothelial cell to recombinant hemagglutinin protein of influenza virus

Abstract

Objective To investigate the innate immunity of cultured human umbilical vein endothelial cells (HUVEC) after recombinant hemagglutinin (HA) protein of influenza virus innoculation. Methods HUVECs were divided into four groups: control, H9N2 viral particle, recombinant H3HA and recombinant H5HA. After 24 h of innoculation, the supernatant of the culture was extracted and the HUVECs were lysed. The levels of cytokine in HUVEC were measured by real-time PCR and ELISA. Results The mRNA and protein expression of IFNB1 and the mRNA expression of CCL5 and IFITM3 in HUVECs of HA (H3HA and H9HA) innoculated group did not show significant difference compared to control (IFNB1 mRNA and protein expression of H3HA group, P=0.051, 0.839; IFNB1 mRNA and protein expression of H9HA group, P=0.127, 0.561; CCL5 mRNA expression of H3HA and H9HA croups, P=0.314, 0.429; IFITM3 mRNA expression of H3HA and H9HA croups, P=0.530, 0.269). The mRNA expression of CCL5 and IFITM3 in HUVECs of H9N2 viral particle innoculated group increased significantly compared to control (P=0.022, 0.047). Conclusions These results suggest that recombinant HA alone did not trigger innate immunity in HUVEC, but viral particle could activate endothelial innate immunity. Key words: Influenza virus; Recombinant hemagglutinin protein; Human umbilical vein endothelial cell; Innate immunity