Abstract
Secretory Leukocyte Proteinase Inhibitor (SLPI) is an antiinflammatory peptide that blocks the activity of serine proteases, primarily the neutrophil elastase. In an attempt to direct the activity of SLPI on inflamed sites, a chimera consisting of the transglutaminase II substrate domain of trappin 2 (cementoin), and the mature SLPI protein was constructed. Cell attachment and biological activity were compared between SLPI and this chimera. By using whole cell ELISA, fluorescence microscopy and flow cytometry assays we observed that the cementoin-SLPI fusion protein (FP) but not SLPI attached to a human lung epithelial cell line and monocytes. A maximum attachment was achieved 15 min after FP was added to the cell cultures. In an elastase activity assay, we observed that FP retained its antiprotease activity and that at equimolar amount of proteins, FP was more efficient than SLPI in the inhibition. Both, FP and SLPI inhibits IL-2-induced lymphocyte proliferation, however, lower amounts of FP were required to achieve this inhibition. Furthermore, FP binds to mycobacteria and maintained the bactericidal activity observed for SLPI. Overall, these results show that this new chimera is able to attach to the cell surfaces retaining and improving some biological activities described for SLPI.
Highlights
Secretory Leukocyte Proteinase Inhibitor (SLPI) and ELAFIN are low molecular weight endogenous serine proteases inhibitors[1]
We showed by different techniques that this fusion protein (FP), but not SLPI, was able to attach to the cellular surface of the human lung cell line A549 and monocytes
Untreated or TNF-α-treated A549 cells were in vitro cultured with FP or SLPI and their binding to the cell surface was examined in a whole cell ELISA assay
Summary
SLPI and ELAFIN are low molecular weight endogenous serine proteases inhibitors[1]. They are produce by epithelial cells and they are found in mucosal fluids including lung, digestive and genital systems[2,3,4]. Some myeloid cells may produce them[5] These serpins can control excessive proteolysis due to the action of neutrophil serine proteases such as elastase, cathepsin G and proteinase-36. We have previously reported that a fusion protein (FP), consisting of the N-terminal domain of Trappin-2 (cementoin) and mature SLPI, protected the corneal from a noxa, preventing the development of a serious corneal abscess in rats[16]. This effect was not observed when SLPI was administered to the rats. We showed that FP retained and increased some biological activities described for SLPI
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
