<prompt> Chemotaxis is mediated by-HistamineLeukotriene B4 and C5aLeukotriene C4 and C3aBradykinin  <response>: Chemotaxis is unidirectional locomotion of leukocytes towards the site of injury, oriented along a chemical gradient. This chemical gradient is created by substances called chemoattractants chemotactic agents, which may be exogenous bacterial products or endogenous C5a, LTB-4, IL-I, TNF, IL-8. C5a is the most powerful chemo-attractant chemokine REF: ROBBINS pathology 10th edition 