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Liang C, Xu Y, Zheng D, Sun X, Xu Q, Duan D. RNAi-mediated silencing of HLA A2 suppressed acute rejection against human fibroblast xenografts in the striatum of 6-OHDA lesioned rats. J Neuroimmunol 2016; 297:28-37. [PMID: 27397073 DOI: 10.1016/j.jneuroim.2016.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/11/2016] [Accepted: 05/02/2016] [Indexed: 02/06/2023]
Abstract
Major histocompatibility complex class l (MHC I) molecules play a role in determining whether transplanted cells will be accepted or rejected, and masking of MHC I on donor cells has been found useful for immunoprotection of neural xenografts. In the present study, primary human embryonic lung fibroblasts (HELF), HELF treated with lentivirus-mediated small interfering RNAs (siRNAs) targeting human leukocyte antigen A2 (HLA A2, MHC I in humans) (siHELF), and rat embryonic lung fibroblasts (RELF) were stereotaxically grafted into the striatum of 6-hydroxydopamine lesioned rats to explore whether knockdown of HLA A2 could reduce host immune responses against xenografts. Before lentiviral infection, the cells were transduced with retroviruses harboring tyrosine hydroxylase cDNA. Knockdown of HLA A2 protein was examined by Western blotting. The immune responses (the number of CD4 and CD8 T-cells in the brain and peripheral blood), glial reaction, and survival of human fibroblasts were quantitatively evaluated by flow cytometry and immunohistochemistry at 4d, 2w, and 6w post-graft. Animal behaviors were assessed by counting apomorphine-induced rotations pre- and post-grafts. It was shown that a lower level of HLA A2 was observed in siHELF grafts than in HELF grafts, and knockdown of HLA A2 decreased rat immune responses, as indicated by less remarkable increases in the number of CD8 and CD4 T-cells in the brain and the ratio of CD4:CD8 T-cells in the peripheral blood in rats grafted with siHELF. Rats grafted with siHELF exhibited a significant improvement in motor asymmetry post-transplantation and a better survival of human fibroblasts at 2w. The increasing number of activated microglia and the decreasing number of astrocytes were found in three groups of rats post-implantation. These data suggested that RNAi-mediated knockdown of HLA A2 could suppress acute rejection against xenogeneic human cell transplants in the rat brain.
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Affiliation(s)
- Caixia Liang
- Department of Neurobiology, Beijing Center of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Laboratory of Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Yunzhi Xu
- Department of Neurobiology, Beijing Center of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Laboratory of Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Deyu Zheng
- Department of Neurobiology, Beijing Center of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Laboratory of Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Xiaohong Sun
- Department of Neurobiology, Beijing Center of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Laboratory of Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Qunyuan Xu
- Department of Neurobiology, Beijing Center of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Laboratory of Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Deyi Duan
- Department of Neurobiology, Beijing Center of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Laboratory of Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
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