Related Experiment Video
Updated: Jul 17, 2026

Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes
Published on: May 31, 2018
The macrophage chemotactic activity of Streptococcus agalactiae and Streptococcus iniae extracellular products (ECP)
Phillip H Klesius1, Joyce J Evans, Craig A Shoemaker
1Aquatic Animal Health Research Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Auburn, AL 36830, USA. pklesius@ars.usda.gov
Abstract:
The ability of Streptococcus agalactiae and Streptococcus iniae to attract macrophages of Nile tilapia (Oreochromis niloticus) was investigated. The extracellular products (ECP) from S. agalactiae and S. iniae were tested in vitro for macrophage chemotaxis using blind-well chambers. The macrophages were obtained from the peritoneal cavity 4-5 days after intraperitoneal injection of squalene. Both macrophage chemotactic and chemokinetic activities were demonstrated using the S. agalactiae ECP. However, only chemotactic activity was shown for S. iniae ECP. High-pressure liquid chromatography fractionation revealed that semi-purified S. agalactiae and S. iniae ECPs had estimated molecular weights of 7.54 and 19.2kDa, respectively. The prominent chemotactic activities of ECP from S. agalactiae and S. iniae are likely to be involved in the proinflammatory responses of macrophages to S. agalactiae and S. iniae infections.
Related Concept Videos
Chemotaxis in E. coli
Differentiation of Common Myeloid Progenitor Cells
Immune Surveillance by NK Cells and Phagocytes
Natural Killer Cells: The Fast Responders
NK cells are large granular lymphocytes found in the blood and lymphatic system. These...
Chemotaxis and Direction of Cell Migration
Determinants of Bacterial Pathogenicity and Virulence

