Neutrophil Polymorphonuclear Granulocytes

ABSTRACT The entry of antibiotics into phagocytes is necessary for activity against intracellular pathogens. The ability of sanfetrinem, the first member of a new class of antibiotics, to penetrate human polymorphonuclear granulocytes and its consequences upon subsequent phagocytosis and killing of ingested penicillin-resistantStreptococcus pneumoniae have been evaluated. Sanfetrinem penetrated into human polymorphonuclear leukocytes (PMNs) at all concentrations tested, with cellular concentration/extracellular concentration ratios of 6.6 to 5.03 and 4.21 when sanfetrinem was used at 0.25 to 0.5 and 1 μg/ml, respectively, within 30 min of incubation. The uptake was complete within 5 min and was not energy dependent, since it was not affected by cell viability, environmental temperature, or the addition of a metabolic inhibitor. At a concentration of one-half the MIC, sanfetrinem significantly enhanced human PMN phagocytosis and increased intracellular bactericidal activity against penicillin-resistant S. pneumoniae. Following preexposure of PMNs to a concentration of one-half the MIC of sanfetrinem, there was a significant increase in both phagocytosis and killing compared with that for the controls, indicating the ability of sanfetrinem to interact with biological membranes and remain active within PMNs. Preexposure of streptococci to sanfetrinem made penicillin-resistant S. pneumoniae more susceptible to the bactericidal mechanisms of human PMNs than untreated organisms.

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Both IL-1β and TNF-α Regulate NGAL Expression in Polymorphonuclear Granulocytes of Chronic Hemodialysis Patients

Mediators of Inflammation ◽

10.1155/2010/613937 ◽

2010 ◽

Vol 2010 ◽

pp. 1-7 ◽

Cited By ~ 8

Author(s):

Adriana Arena ◽

Giovanna Stassi ◽

Daniela Iannello ◽

Domenica Gazzara ◽

Maria Calapai ◽

...

Keyword(s):

Healthy Subjects ◽

Venous Blood ◽

Chronic Hemodialysis ◽

Clear Cut ◽

Polymorphonuclear Granulocytes ◽

End Of Treatment ◽

Tnf Α ◽

Uremic Patients ◽

Stage Renal Disease ◽

Esrd Patients

Background. NGAL is involved in modulation of the inflammatory response and is found in the sera of uremic patients. We investigated whether hemodiafiltration (HDF) could influence the ability of polymorphonuclear granulocytes (PMGs) to release NGAL. The involvement of interleukin- (IL-)1β and tumor necrosis factor- (TNF-)α on NGAL release was evaluated.Methods. We studied end-stage renal disease (ESRD) patients at the start of dialysis (Pre-HDF) and at the end of treatment (Post-HDF) and 18 healthy subjects (HSs). Peripheral venous blood was taken from HDF patients at the start of dialysis and at the end of treatment.Results. PMGs obtained from ESRD patients were hyporesponsive to LPS treatment, with respect to PMG from HS. IL-1β and TNF-α produced by PMG from post-HDF patients were higher than those obtained by PMG from pre-HDF. Neutralization of IL-1β, but not of TNF-α, determined a clear-cut production of NGAL in PMG from healthy donors. On the contrary, specific induction of NGAL in PMG from uremic patients was dependent on the presence in supernatants of IL-1β and TNF-α.Conclusion. Our data demonstrate that in PMG from healthy subjects, NGAL production was supported solely by IL-1β, whereas in PMG from HDF patients, NGAL production was supported by IL-1β, TNF-α.

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