Membrane-type matrix metalloproteinases in mice intracorneally infected with Pseudomonas aeruginosa.

PURPOSE: To establish the presence of membrane-type matrix metalloproteinases (MT-MMPs) in the cornea and their expression in naive and immunized mice intracorneally infected with Pseudomonas aeruginosa.

METHODS

Naive (unimmunized) and immunized C57BL/6J mice were infected with P. aeruginosa, and gene expression of MT-MMPs were detected by RT-PCR. Immunoblot analysis and immunostaining were also used to characterize the MT-MMP response in both sets of animals.

RESULTS

Expression of MT1-MMP, MT2-MMP, and MT3-MMP (MMP 14, 15, and 16) was detected by RT-PCR and immunoblot analysis. Of the three MT-MMPs detected, MT1-MMP exhibited the greatest expression at protein levels. In general, a bell-shaped curve was obtained for each of the MT-MMPs in naive mice, but all of them showed much less expression in the immunized mice. MT1-MMP was localized in the epithelial tissue of the cornea, whereas MT2-MMP and MT3-MMP were mainly found in the interface between the epithelium and substantia propria.

CONCLUSIONS

MT1-MMP was detected and expressed to a greater extent in naive mice than MT2-MMP and MT3-MMP. Peak expression of all three MT-MMPs showed a good correlation with the overall inflammatory response.