Effects of human parvovirus B19 VP1 unique region protein on macrophage responses.
BACKGROUND
Activity of secreted phospholipase A (sPLA2) has been implicated in a wide range of cellular responses. However, little is known about the function of human parvovirus B19-VP1 unique region (VP1u) with sPLA2 activity on macrophage.


METHODS
To investigate the roles of B19-VP1u in response to macrophage, phospholipase A2 activity, cell migration assay, phagocytosis activity, metalloproteinase assay, RT-PCR and immunoblotting were performed.


RESULTS
In the present study, we report that migration, phagocytosis, IL-6, IL-1beta mRNA, and MMP9 activity are significantly increased in RAW264.7 cells by B19-VP1u protein with sPLA2 activity, but not by B19-VP1uD175A protein that is mutated and lacks sPLA2 activity. Additionally, significant increases of phosphorylated ERK1/2 and JNK proteins were detected in macrophages that were treated with B19-VP1u protein, but not when they were treated with B19-VP1uD175A protein.


CONCLUSIONS
Taken together, our experimental results suggest that B19-VP1u with sPLA2 activity affects production of IL-6, IL-1beta mRNA, and MMP9 activity, possibly through the involvement of ERK1/2 and JNK signaling pathways. These findings could provide clues in understanding the role of B19-VP1u and its sPLA2 enzymatic activity in B19 infection and B19-related diseases.
Tzang
Bor-Show
BS
Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung, Taiwan. bstzang@csmu.edu.tw
Chiu
Chun-Ching
CC
Tsai
Chun-Chou
CC
Lee
Yi-Ju
YJ
Lu
I-Jung
IJ
Shi
Jing-Yu
JY
Hsu
Tsai-Ching
TC
D000818:Animals; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000502:physiology*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016732:Parvovirus B19, Human / Q000201:enzymology* / Q000235:genetics / Q000276:immunology*; D010587:Phagocytosis / Q000502:physiology; D010741:Phospholipases A / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D010741:Phospholipases A; D020780:Matrix Metalloproteinase 9