Chemotactic competence of neutrophils from neonatal calves. Functional comparison with neutrophils from adult cattle

• Published in: Inflammation Vol. 14; no. 1; p. 109
• Main Authors: Zwahlen, R D, Roth, D R
• Format: Journal Article
• Language: English
• Published: United States 01.02.1990
• Subjects: Aging - blood; Animals; Animals, Newborn - blood; Anti-Inflammatory Agents - pharmacology; Cattle; Cell Migration Inhibition; Chemotaxis, Leukocyte - drug effects; Complement C5a - pharmacology; Hematologic Tests; Lipopolysaccharides - pharmacology; Neutrophils - drug effects; Platelet Activating Factor - pharmacology; Vitamin D-Binding Protein - isolation & purification; Zymosan - pharmacology
• ISSN: 0360-3997
• DOI: 10.1007/BF00914034

Neonates demonstrate an increased susceptibility to infection. Defects in locomotory functions of newborn neutrophils may play a crucial role in this context. We therefore compared the migratory response of newborn (N-PMN) and adult (A-PMN) bovine neutrophils in a microwell filter assay. Stimulation with four different endotoxins (E. coli O128B:4 and O55B:5; S. abortus equi; S. typhimurium), with zymosan-activated plasma (ZAP) and with C5a induced dose-dependent migration of A-PMNs and N-PMNs. Migration of unstimulated cells and of cells stimulated with diluted ZAP or C5a was higher (P less than 0.05) in N-PMNs. Migration of A- and N-PMNs towards C5a was inhibited (P less than 0.001) by preincubation with either a steroidal (122 microM flumethasone) or nonsteroidal (3.3 microM phenylbutazone) antiinflammatory drug. Migratory responses of N-PMNs were inhibited less by SAIDs than were responses of A-PMNs (P less than 0.05); indeed dexamethasone slightly enhanced N-PMN responses towards C5a, and 510 microM flunixin meglumine enhanced C5a-induced migration in both age groups. Endotoxins from E. coli O55:B4, S. abortus equi, and S. typhimurium induced a higher rate of migration (P less than 0.05) in N-PMNs. In contrast to the above findings, measurement of the maximal distance of migration by the leading-front method did not reveal age-related differences. Migration speed of PMNs was lower after stimulation with C5a than with ZAP, but could be restored partly by adding human vitamin D-binding protein (Gc-globulin). The demonstrated hyperirritability of bovine N-PMNs represents a major functional difference to neonatal neutrophils from other species, including man. It may additionally be related to altered PMN functions and neonatal disease susceptibility.