Open AccessMannheimia haemolytica leukotoxin‐induced increase in leukotriene B 4 production by bovine neutrophils is mediated by a sustained and excessive increase in intracellular calcium concentration
Author(s) -
Cudd Laura,
Clarke Cyril,
Clinkenbeard Kenneth
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00432-4
Subject(s) - leukotriene b4 , calcium , intracellular , calcium in biology , chemistry , leukotriene c4 , leukotriene , microbiology and biotechnology , biochemistry , biology , immunology , inflammation , organic chemistry , asthma
Isolated bovine neutrophils were used to study the relationship between the duration and magnitude of the Mannheimia haemolytica leukotoxin‐induced increase in intracellular calcium concentration and leukotriene B 4 synthesis. In contrast to recombinant human C 5a , which caused a transient, small increase in intracellular calcium concentration and no effects on leukotriene B 4 synthesis, exposure of neutrophils to leukotoxin resulted in a rapid, sustained, large increase in intracellular calcium concentration, followed by leukotriene B 4 synthesis. This leukotoxin‐induced response was similar to those produced by the calcium ionophore, A23187, and phorbol myristate acetate, which also caused significant leukotriene B 4 production. Manipulation of the duration and magnitude of leukotoxin‐ and A23187‐induced intracellular calcium concentration increase confirmed that a high and sustained intracellular calcium concentration was necessary to stimulate production of leukotriene B 4 , which is believed to play an important role in the pathogenesis of pulmonary M. haemolytica infection.