Prolongation of functional life-span of neutrophils by recombinant verotoxin 2.
OBJECTIVE
Verotoxin-producing Escherichia coli (VTEC) strains of serotype O157 : H7 have been implicated in a wide spectrum of diseases, including blood diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). To further explore the pathological role of verotoxin (VT) in HUS and other VTEC associated diseases, we investigated the effects of recombinant verotoxin 2 (rVT2) on the biological activity of neutrophils.


METHODS
The technique of flow cytometry, a fluorescent probe 2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF/AM), and the assay of reduced cytochrome c to detect superoxide production were used in this study.


RESULTS
gammaVT2 significantly inhibited spontaneous apoptosis in neutrophils. Neutrophils with prolonged survival due to gammaVT2 maintained various biological functions, such as the expression of adhesion molecules (shading CD62L and raising CD11b/CD18), adherence to human umbilical vein endothelial cells (HUVECs), and generation of superoxide (O(2)(-)).


CONCLUSIONS
Prolongation of the functional life-span of neutrophils by gammaVT2 may accelerate inflammatory responses at sites of inflammation. This may play a crucial role in neutrophil-mediated tissue injury in HUS and other VTEC-associated diseases.
Liu
Jiajia
J
Central Laboratory, Luzhou Medical College, China. jiajialiu163@163.com
He
Tao
T
He
Yanzheng
Y
Zhang
Zhongjie
Z
Akahoshi
Tohru
T
Kondo
Hirobumi
H
Zhong
Sen
S
D017209:Apoptosis / Q000187:drug effects; D002448:Cell Adhesion; D004730:Endothelium, Vascular / Q000166:cytology; D006801:Humans; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D011994:Recombinant Proteins / Q000633:toxicity; D022641:Shiga Toxin 2 / Q000633:toxicity*; D013481:Superoxides / Q000378:metabolism
D011994:Recombinant Proteins; D022641:Shiga Toxin 2; D013481:Superoxides