Influenza A virus infection modulates the expression of type IV collagenase in epithelial cells

We investigated the effect of influenza A/Beijing/353/89 (H3N2) virus infec tion on the expression of type TV collagenase in two different types of epi thelial cell. Depending on the cell line infected, the viral infection caus ed changes in the expression of type IV collagenase. The expression of matr ix metalloproteinase-9 (MMP-9; 92 kDa) but not of matrix metalloproteinase- 2 (MMP-2; 72 kDa) was stimulated in Vero cells. In MDCK cells, the MMP-2 pr oduction increased with the virus infection. According to the enzymatic act ivity revealed with zymography, the MMP-9 promoter activity rose by a facto r of over 1788 in influenza A virus-infected Vero cells but not in MDCK cel ls. The tissue inhibitor of metalloproteinase, TIMP-1, had increased slight ly (2.3-fold) in Vero cells 48 hours after the infection, but in MDCK cells , influenza A virus had no effect on the TIMP-1 expression. In conclusion, the MMP-9 and -2 expression by influenza A virus infection are modulated at transcriptional level, depending on the epithelial cell line.