A clinically applicable technique to study cytoskeletal dynamics in normal and abnormal polymorphonuclear leukocytes isolated from small volume blood samples

• Published in: The American journal of the medical sciences Vol. 308; no. 6; p. 313
• Main Authors: Watts, R G, Gray, B M, Patterson, H S, Tilden, S J, Johnson, Jr, W H, Berkow, R L, Howard, T H
• Format: Journal Article
• Language: English
• Published: United States 01.12.1994
• Subjects: Actins - chemistry; Actins - metabolism; Acute Disease; Bacterial Infections - blood; Cell Movement; Cell Separation; Cell Size; Chemotaxis, Leukocyte - physiology; Chronic Disease; Cytoskeleton - physiology; Flow Cytometry; Humans; Neutrophils - physiology; Neutrophils - ultrastructure; Polymers - chemistry; Polymers - metabolism; Povidone; Reference Values; Silicon Dioxide
• ISSN: 0002-9629
• DOI: 10.1097/00000441-199412000-00002

Shape change and motility of polymorphonuclear leukocytes (PMNs) are essential for host defense and require dynamic reorganizations of microfilamentous cytoskeleton by reversible polymerization of G-actin into filaments (F-actin). Although clinical disorders of actin polymerization are rare, recently described simple methodologies for assaying actin dynamics in PMNs make the technique readily applicable to clinical studies. To develop a clinically useful F-actin assay, the authors investigated the optimal preparation conditions for PMN isolation that resulted in the least in vitro cytoskeletal activation and evaluated the variability in actin dynamics in acutely and chronically infected patients. Basal and chemotactic factor-activated PMN F-actin content was measured by a previously described flow cytometric technique in fixed, permeabilized, NBDphallacidin-stained PMNs isolated by centrifugation in Percoll or Ficoll-Hypaque density gradients or by countercurrent elutriation. F-actin content is expressed as mean fluorescent channel or relative fluorescence intensity. Basal F-actin in PMNs prepared from countercurrent elutriation (mean fluorescent channel = 79.0 +/- 4.5, n = 6) or by Ficoll Hypaque (82.0 +/- 3.5, n = 4) was significantly higher than endotoxin free, Percoll purified PMNs, whether purified in bulk (56.1 +/- 7.9, n = 8) or by the small volume modification applicable to clinical studies (53.3 +/- 8.7, n = 15). Basal Ficoll Hypaque purified PMNs have evidence of shape change, whereas endotoxin free, Percoll purified PMNs are smooth and round and represent the most basal cell equivalent in F-actin content to a circulating PMN.