Relationship between respiratory burst and adhesiveness capacity in elderly polymorphonuclear cells.

Polymorphonuclear cell (PMN) activation was assessed in 30 aged donors, in terms of either adherence to different substrates or superoxide anion (O2-) generation by adhering and suspended cells in response to several agonists. Results showed that PMN in suspension from elderly individuals displayed a phorbol 12-myristate 13-acetate (PMA)-triggered O2- responsiveness which overlapped that seen in the younger counterpart, while a significant decrease of respiratory burst was observed in the presence of formyl-methionyl-leucine-phenylalanine (FMLP). Moreover, in spite of a normal nylon fiber adhesiveness, aged individuals exhibited a reduced PMN adherence to foetal calf serum (FCS)-coated plastic surfaces by using either PMA or FMLP as stimulant. However, elderly adhering cells produced higher amounts of O2- than homologous neutrophils in suspension. Cell pretreatment with anti-CD11b, anti-CD11c and anti-CD18 antibodies led to a further inhibition of PMN adhesion to FCS-coated plates. By contrast, under the same experimental conditions, O2- generation from adhering cells was reduced by using anti-CD18 antibody only. Altogether, these findings provide additional evidence for an imbalance of PMN-mediated functions in the elderly.