Exudative neutrophils. Modulation of microbicidal function in the inflammatory microenvironment
J. Yee, B. Giannias, B. Kapadia, L. Chartrand and N. V. Christou
Department of Surgery, Royal Victoria Hospital, McGill University, Montreal, Quebec.
OBJECTIVE: To determine whether the inflammatory microenvironment primes
neutrophils for increased microbicidal activity. DESIGN: In vitro studies
of host defense were performed on surgical patients. SETTING: A tertiary
care, university hospital. PATIENTS: A volunteer sample of hospitalized
preoperative, noninfected surgical patients. INTERVENTION: Exudative
neutrophils were collected from skin-blister chambers and functionally
compared with circulating neutrophils. METHODS: Flow cytometry was used to
evaluate directly neutrophil microbicidal activity (using fluoresceinated
Candida albicans), formyl-methionyl-leucyl-phenylalanine (fMLP)-induced
superoxide production (using 123 dihydrorhodamine), and surface expression
of CD11b, CD16, and the fMLP receptor. In vitro tumor necrosis factor alpha
was used to determine the possibility and extent of further priming in both
circulating and exudative neutrophils. RESULTS: Exudative polymorphonuclear
neutrophils have enhanced microbicidal activity, superoxide production, and
expression of CD11b, CD16, and the fMLP receptor. Exogenous tumor necrosis
factor was able to prime circulating neutrophils but did not further
augment superoxide production in exudative neutrophils. CONCLUSION: The
microbicidal activity of neutrophils is enhanced after exudation and is
associated with neutrophil priming. The inability of exogenous tumor
necrosis factor to further augment superoxide production after exudation
suggests that this priming has been maximized.
