Fatmah M A Naemi1, Vaughan Carter, John A Kirby, Simi Ali. 1. Applied Immunobiology and Transplantation Group, Institute of Cellular Medicine, Medical School, University of Newcastle Upon Tyne, Newcastle Upon Tyne, UK.
Abstract
BACKGROUND: The development of donor-specific human leukocyte antigen (HLA) class I antibodies after organ transplantation is associated with subsequent acute and chronic rejection. The aim of this study was to examine the role of anti-HLA class I antibody in modulating endothelium-leukocyte interaction. METHODS: Human microvascular endothelial cells (HMEC-1) stimulated with HLA class I antibody (W6/32) or allospecific antibodies from sensitized patients (n=6) were examined for activation of transcription factor CREB by Western blotting. Up-regulation of endothelial adhesion molecules and chemokines was measured by flow cytometry and quantitative polymerase chain reaction, respectively. Leukocyte adhesion was evaluated by chemotaxis and in vitro flow-based assays. RESULTS: Treatment of HMEC-1 cells with HLA class I antibody resulted in the phosphorylation of CREB in protein kinase A-dependent pathway. Furthermore, there was a significant increase in the expression of cell surface VCAM-1 (Akt-dependent) and ICAM-1 in Akt-dependent and extracellular signal-regulated kinase-dependent manner (P<0.001). Additionally, exposure to W6/32 antibody induced significant expression of interleukin-6, CXCL8, CXCL10, and CCL5. Knockdown of CREB produced a reduction in W6/32-induced CXCL8 expression (P<0.001). Media from W6/32-treated endothelial cells induced a significant monocyte chemotaxis (P<0.001) and flow-based adhesion assay demonstrated an increase in monocyte adhesion to endothelial cells compared with the control group (P<0.001). Importantly, allospecific antibodies from sensitized patients also activated endothelial CREB and significantly up-regulated VCAM-1, ICAM-1, and CXCL8. CONCLUSION: These findings suggest that donor-specific HLA class I antibodies directly activate endothelial cells leading to an increase in their potential to recruit and bind recipient leukocytes, thereby increasing the potential for allograft inflammation.
BACKGROUND: The development of donor-specific human leukocyte antigen (HLA) class I antibodies after organ transplantation is associated with subsequent acute and chronic rejection. The aim of this study was to examine the role of anti-HLA class I antibody in modulating endothelium-leukocyte interaction. METHODS:Human microvascular endothelial cells (HMEC-1) stimulated with HLA class I antibody (W6/32) or allospecific antibodies from sensitized patients (n=6) were examined for activation of transcription factor CREB by Western blotting. Up-regulation of endothelial adhesion molecules and chemokines was measured by flow cytometry and quantitative polymerase chain reaction, respectively. Leukocyte adhesion was evaluated by chemotaxis and in vitro flow-based assays. RESULTS: Treatment of HMEC-1 cells with HLA class I antibody resulted in the phosphorylation of CREB in protein kinase A-dependent pathway. Furthermore, there was a significant increase in the expression of cell surface VCAM-1 (Akt-dependent) and ICAM-1 in Akt-dependent and extracellular signal-regulated kinase-dependent manner (P<0.001). Additionally, exposure to W6/32 antibody induced significant expression of interleukin-6, CXCL8, CXCL10, and CCL5. Knockdown of CREB produced a reduction in W6/32-induced CXCL8 expression (P<0.001). Media from W6/32-treated endothelial cells induced a significant monocyte chemotaxis (P<0.001) and flow-based adhesion assay demonstrated an increase in monocyte adhesion to endothelial cells compared with the control group (P<0.001). Importantly, allospecific antibodies from sensitized patients also activated endothelial CREB and significantly up-regulated VCAM-1, ICAM-1, and CXCL8. CONCLUSION: These findings suggest that donor-specific HLA class I antibodies directly activate endothelial cells leading to an increase in their potential to recruit and bind recipient leukocytes, thereby increasing the potential for allograft inflammation.
Authors: Xuedong Wei; Nicole M Valenzuela; Maura Rossetti; Rebecca A Sosa; Jessica Nevarez-Mejia; Gregory A Fishbein; Arend Mulder; Jayeeta Dhar; Karen S Keslar; William M Baldwin; Robert L Fairchild; Jianquan Hou; Elaine F Reed Journal: Am J Transplant Date: 2020-05-22 Impact factor: 8.086
Authors: Yuan Liu; Tianfei Lu; Cheng Zhang; Zhengze Xue; Jin Xu; Ronald W Busuttil; Qiang Xia; Ning Xu; Jerzy W Kupiec-Weglinski; Haofeng Ji Journal: Transplantation Date: 2019-08 Impact factor: 4.939
Authors: K Iwasaki; H Hamana; H Kishi; T Yamamoto; T Hiramitsu; M Okad; T Tomosugi; A Takeda; S Narumi; Y Watarai; Y Miwa; M Okumura; Y Matsuoka; K Horimi; A Muraguchi; T Kobayash Journal: Clin Exp Immunol Date: 2020-07-18 Impact factor: 4.330