IL-4 MODULATES THE EXPRESSION OF SECRETORY LEUKOCYTE PROTEASE INHIBITOR (SLPI) ON EPITHELIAL CELL LINES

COSTA, MARÍA JULIETA; AMIANO, NICOLÁS; GUERRIERI, DIEGO; MAFFIA, PAULO; TATEOSIAN, NANCY; CHULUYAN, H. EDUARDO

Cordoba, Argentina

Congreso; 7º congreso de la Asociacion Latinoamericana de Inmunologia; 2005

ABSTRACTSecretory leukocyte protease inhibitor (SLPI) is a serpin of 11,7 kDa and it belongs to the family of four disulfide core proteins characterized by whey acid protein (WAP) motif. This protease has been shown to inhibit human neutrophil elastase, trypsin, cathepsin G and chymiotrypsin. SLPI prevents potential injurious effects of proteolytic enzymes released from inflammatory cells. The gene encoding SLPI seems to be modulated at both transcriptional and translational levels, by proinflammatory cytokines such as IL-1 and TNFa. The aim of this work was to study the modulation of the expression of SLPI by IL-4. For this purpose, Hela and A549 cell lines were grown and treated with IL-4 (2 ng/ml) overnight. Following, the supernatant was removed and total RNA was extracted from cells to perfom RT-PCR.  The transcriptional level of SLPI on Hela, was increased by around 50 %. The expression of SLPI in the supernatant of IL-4-treated cells (20-0,002 ng/ml) was also quantified by ELISA. Results showed that IL-4 caused a dose-dependent increase of SLPI, with a threshold IL-4 concentration of 200 pg/ml (control: 153 ± 22 ng/ml; 200 pg/ml IL-4: 236 ± 18 ng/ml; p<0.05, n=4). Same results were obtained with A549 cell line. These results indicate that IL-4 may be a significant regulatory signal for SLPI secretion on epithelial cells.