Up-regulation of adhesion molecule expression and induction of TNF-alpha on vascular endothelial cells by antibody against human parvovirus B19 VP1 unique region protein.
BACKGROUND
Human parvovirus B19 infection has been frequently described as a cause or trigger of various autoimmune diseases. In previous studies, we have postulated the association among human parvovirus B19 (B19)-VP1 unique region (VP1u), production of anti-beta2-glycoprotein I (anti-beta2GPI) antibody and anti-phospholipid syndrome (APS)-like autoimmunity. However, the precise role of B19-VP1u in induction of APS is still obscure.


METHODS
To further elucidate the pathogenic roles of VP1u in B19 infection and autoimmunity, we examined the effect of anti-B19-VP1u IgG antibodies on endothelial cells that is recognized to play crucial roles in APS. Human vascular endothelial cells, ECV-304, were incubated with various preparations of purified human or rabbit IgG. The activation of endothelial cells and production of cytokines were assessed by flow cytometry and ELISA, respectively.


RESULTS
Purified IgG from rabbits immunized with recombinant B19-VP1u proteins can up-regulate ICAM-1 (CD54), VCAM-1 (CD106), E-selectin (CD62E), MHC class II (HLA-DR, DP, DQ) molecule expression, and TNF-alpha production in endothelial cells as compared to those endothelial cells cultured with control IgG. Additionally, significantly increased phosphorylated-P38 mitogen-activated protein kinase (P38 MAPK) and iNOS were observed in both human anti-beta2GPI IgG and rabbit anti-B19-VP1u IgG treated-ECV-304 cells, respectively.


CONCLUSIONS
These experimental results imply that antibodies against B19-VP1u play important roles in the immunopathological processes as well as human anti-beta2GPI IgG that leads to development of APS by involving p38 phosphorylation and iNOS activation. It could provide a clue in understanding the role of anti-B19-VP1u antibodies in APS manifestations.
Tzang
Bor-Show
BS
Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung, Taiwan, Republic of China.
Tsai
Chun-Chou
CC
Chiu
Chun-Ching
CC
Shi
Jing-Yu
JY
Hsu
Tsai-Ching
TC
D000818:Animals; D036022:Capsid Proteins / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology* / Q000821:virology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010322:Parvoviridae Infections / Q000276:immunology; D016732:Parvovirus B19, Human / Q000276:immunology*; D010766:Phosphorylation; D011817:Rabbits; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D036022:Capsid Proteins; D015815:Cell Adhesion Molecules; D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha; C095547:capsid protein VP1, parvovirus B19; D052247:Nitric Oxide Synthase Type II; D048051:p38 Mitogen-Activated Protein Kinases