LACK OF IL-10 AND IL-13 PRODUCTION BY HUMAN POLYMORPHONUCLEAR NEUTROPHILS

The ability of polymorphonuclear neutrophils (PMN) to produce and rele ase numerous pro-inflammatory cytokines is now established and play an important role in triggering and maintaining the inflammatory respons e. We studied the autocrine downregulation of this process by investig ating the potential production by human PMN of two major anti-inflamma tory cytokines, interleukin 10 (IL-10) and IL-13. The authors' PMN pur ification methods based in part on immunomagnetic depletion, allows th e elimination of all cells known to produce those two cytokines, A wid e range of activation conditions were tested and kinetic studies were done. IL-10 and IL-13 proteins mere not detected in culture supernatan ts or cell lysates of PMN from 13 healthy volunteers. This was confirm ed by the absence of IL-10 and IL-13 mRNA expression, as shown by RT-P CR, Human PMN thus seem unable to produce or release two of the most p otent anti-inflammatory cytokines, IL-10 and IL-13. This could partly account for the persistence of local inflammation, where PMN are the m ain infiltrating cells. (C) 1998 Academic Press Limited.