CHEMOTACTIC RESPONSES OF HAGFISH (VERTEBRATA, AGNATHA) LEUKOCYTES

The chemotactic responses of hagfish leucocytes were tested using a va riety of chemoattractants. Leucocyte migration was significantly enhan ced by purified mammalian complement anaphylotoxin (C5a) and LPS-activ ated hagfish plasma. Checkerboard analyses confirmed that the response s of leucocytes to both of these chemoattractants were directed along concentration gradients (chemotaxis) and did not result from accelerat ed random movement (chemokinesis). Chemotaxis was undertaken by leucoc yte fractions that were enriched in granulocytes, the predominant phag ocytic cells of hagfish. The data suggest that chemotactic mechanisms may have been conserved during evolution to such a degree that mammali an chemoattractants can bind and activate chemotactic receptors on hag fish leucocytes. Moreover, hagfish appear to express plasma proteins t hat are structurally and functionally homologous to mammalian compleme nt anaphylotoxins.