title: Periodic formation of nascent lamellae is driven by changes in the stable F-actin pool of polymorphonuclear neutrophils after stimulation with chemotactic peptide and cross-linking of CD18 or CD61.
abstract: Cell motility and changes in cell shape are largely powered by actin polymerization and depolymerization. Eight to ten second periodic changes in human polymorphonuclear neutrophil (PMN) shape were detected by video-image analysis of PMN crawling on a surface and by right angle light scattering (RALS) in suspended PMN. However, sustained RALS oscillations in suspended PMN requires pre-treatment with an inhibitor of phosphatidylinositol 3-kinase or an activator of protein kinase C. Here, we show that cross-linking of the beta(2) (CD18) or beta(3) (CD61), but not beta(1) (CD 29) integrins in the presence of a low dose of formyl-Methionyl-Leucyl-Phenylalanine (fMLP) enables similar 8-s periodic RALS oscillations in suspended PMN in response to stimulation with two consecutive doses of chemoattractants. This effect did not appear to be due to increased surface expression of CD18 or CD61. RALS oscillations occurred in phase with 8-s oscillations in the stable F-actin pool and peaks in F-actin correlated with predominance of cells exhibiting a nascent lamella. Thus, simulation of surface attachment by CD18 and CD61 cross-linking after exposure to fMLP in suspended cells supports shape oscillations that are the result of actin-driven cyclic extension/retraction of nascent lamellae at the same frequency as the shape changes previously observed in crawling PMN.
authors.affiliation: Childrens Hospital Los Angeles Research Institute, Childrens Center for Cancer and Blood Diseases, Department of Pediatrics, University of Southern California, Los Angeles 90025-1752, USA.
authors.forename: F J
authors.initials: FJ
authors.lastname: Ibarrondo
authors.forename: M
authors.initials: M
authors.lastname: Torres
authors.forename: T D
authors.initials: TD
authors.lastname: Coates
mesh_terms: D000199:Actins / Q000187:drug effects / Q000378:metabolism*; D015703:Antigens, CD / Q000187:drug effects / Q000378:metabolism*; D018821:CD18 Antigens / Q000187:drug effects / Q000378:metabolism*; D002465:Cell Movement / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002630:Chemotactic Factors / Q000494:pharmacology; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D039661:Integrin beta3; D016023:Integrins / Q000187:drug effects / Q000378:metabolism; D008858:Microscopy, Phase-Contrast; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects; D010980:Platelet Membrane Glycoproteins / Q000187:drug effects / Q000378:metabolism*; D011554:Pseudopodia / Q000187:drug effects / Q000502:physiology*; D012542:Scattering, Radiation; D013997:Time Factors
chemical_list: D000199:Actins; D015703:Antigens, CD; D018821:CD18 Antigens; D002630:Chemotactic Factors; D003432:Cross-Linking Reagents; D039661:Integrin beta3; D016023:Integrins; D010980:Platelet Membrane Glycoproteins