Objective: It has been found that the human major histocompatibility complex class I chain-related antigen A,B (MICA,B), the ligand for NKG2D (an activating receptor of NK cell, CD8+ cell and gammadelta T cell), could be induced by cellular stress. The purpose of this study is to investigate whether Hypoxia/Reoxygenation could upregulate expression of MICA,B gene in human hepatocytes (HL-7702).
Methods: The model of cell hypoxia/reoxygenation was used to mimic ischemia/reperfusion injury (IRI) of graft organ. The human hepatocytes were exposed to hypoxic condition for 15 h under 1% O2, 94% N2 and 5% CO2, then reoxygenated for 2 h, 4 h, 6 h, 12 h and 24 h separately under normal condition. The levels of MICA and MICB mRNA were measured by semi-quantitative RT-PCR. The surface expression of MIC were detected by immunofluorescence with a rabbit polyclonal antibody which is recommended for the detection of MICA,B of human origin simultaneously.
Results: Hpoxia/Reoxygenation increased the levels of MICA,B in hypoxic hepatocytes.
Conclusion: In this article is firstly reported that H/R could increased the levels of MICA,B in human hepatocytes, yet the meachinsm is unknown. The upregulated expression of NKG2D ligand possibly activates NK cells and is hence associated with transplantation.