CHEMOTACTIC RECEPTOR FOR VAL(ALA)-GLY-SER-GLU ON HUMAN EOSINOPHIL POLYMORPHONUCLEAR LEUKOCYTES

Preferential eosinophil chemotactic activity is an in vitro and in vivo property of eosinophil chemotactic factor of anaphylaxis (ECF-A), a mixture of 2 peptides composed of Val-Gly-Ser-Glu and Ala-Gly-Ser-Glu, isolated from extracts and anaphylactic diffusates of human lung tissue. Purified native and synthetic ECF-A share with the synthetic N-formyl methionyl peptides such features as in vitro activity in nanomolar amounts, high dose inhibition of effect and a requirement for hydrophobic amino acid residues. The capacity of the substituents of ECF-A, Val-Gly-Ser, Ala-Gly-Ser and Gly-Ser-Glu to modulate eosinophil chemotaxis permitted a preliminary functional characterization of an eosinophil surface receptor. The activity, specificity and structural characteristics of the active tetrapeptides suggest that distinct interactions of the peptide with a stereospecific receptor on the eosinophil surface is required for chemotactic movement.