Peripheric Blood Mononuclear Cells (PBMC) and polymorphonuclear leukocytes (PMNL) upregulate Secretory Leukocyte Protease Inhibitor (SLPI) expresión.

28. COSTA, JULIETA; TATEOSIAN, NANCY; AMIANO, NICOLÁS; REITERI, MACARENA1; SÁNCHEZ, MERCEDES; ROMEO, HORACIO; CHULUYAN, EDUARDO.

Buenos Aires

Congreso; First French-Argentine Immunology Congress; 2010

SAI

SLPI is a serpin of 11.7 kDa that belongs to the family of fourdisulfide core proteins characterized by whey acid protein motif.The gene encoding SLPI is modulated at transcriptional andtranslational levels by pro-inflammatory cytokines. However,there is no data if the SLPI expression can be modulated byleukocytes recruited at the inflammation site. Therefore, theaim of this work was to examine the modulation of the SLPIexpression by leukocytes on type II-like alveolar cell line (A549).SLPI was measured by sandwich ELISA in culture cells supenantantof A549, PMNL (resting and LPS-activated), PBMC (restingand IL-2-treated), lymphocyte (resting and IL-2-activated) orcocultures of leukocytes with A549 cells. CS were harvested at18 h of incubation. SLPI (ng/ml) was present in the CS of A549(0.06±0.02), PMNL (0.18±0.06), LPS activated-PMNL (0.54±0.06),PBMC (0.1±0.05), but not in IL-2-treated PBMC, lymphocytes orIL-2-treated lymphocytes. The co-culture of A549 with PMNLor PBMC, but not with LPS-activated PMNL, IL-2-treated PBMC,lymphocyte or IL-2-treated lymphocyte increased SLPI production(A549+PMNL: 0.84±0.21; A549+PBMC: 5.02±0.33, p<0.001and p<0.001). In order to determined whether the increased inSLPI concentration in the co-culture of A549 with PMNL or PBMCwere mediated by soluble factor released by leukocyte, A549cells were cultured with CS derived from PMNL or PBMC. WhenA549 cells were treated with PMNL or PBMC-derived CS, the SLPIsecretion was increased by three fold (p<0.001 and p<0.001). Interestingly,the CS-derived from activated-PMNL or IL-2-treatedPBMC was not able to increase the SLPI secretion. However, ifactivated PBMC were pre-treated with SLPI, the SLPI secretion isrestored. Overall these results demonstrate that epithelial cellssecretion of SLPI may be upregulated by factors released byneutrophils and PBMC, but not lymphocytes or activated leukocytes.