Chemoattractant Receptors of Neonatal Polymor‐phonuclear Leukocytes: Lack of Modulation of the Receptors by Membrane Modifier

To analyze a defect(s) in chemotactic responsiveness of human neonatal polymorphonuclear leukocytes (PMN), PMN functions and their chemoattractant receptor properties were examined using N-formylmethionyl-leucyl-phenylalanine (FMLP). Amphotericin B (AmB) is known to affect human PMN membrane and to alter cellular functions. Although the AmB treatment decreased the FMLP binding and cellular movement in adult PMN, there were no such changes in neonatal PMN. Kinetics studies of 3H-FMLP binding to PMN, furthermore, indicated the poor internal transportation of the chemoattractant into neonatal PMN. These abnormalities, which are related to the chemoattractant receptors, may explain in part the defective chemotaxis of neonatal PMN.