Bacteroides spp.(7), Clostridium spp.(8), Pseudomonas virulence factor of the organism. Key words: T. pallidum; broblasts; interstitial collagenase. aeruginosa (9), Treponema denticola (10–12), Treponema vincentii (13), were found to produce various colla-(Accepted March 18, 2002.) genases that are thought to be important virulence factors. The collagenases produced by the bacteria are Acta Derm Venereol 2002; 82: 174–178. presumed to release amino acids necessary for bacterial growth and/or to destroy natural defensive tissue barrier Kee Yang Chung, Department of Dermatology, Yonsei University College of Medicine, CPO Box 8044, Seoul in order to facilitate bacterial spread (5). Further degradation of collagen from activation of latent mam-120-752, Korea. Email: kychung@ yumc. yonsei. ac. kr malian collagenases by bacterial proteinases has also been suggested to be another mechanism by which Since its discovery almost a century ago, Treponema bacteria can manifest their pathogenicity (14–16). As T. pallidum has been found to lack a well-defi ned pallidum (T. pallidum) has evaded numerous attempts to discover its pathogenic features. Although the T. pal- secretory apparatus (2), our goal was to determine whether T. pallidum could induce production of enzymes lidum genome has recently been sequenced (1), the expectation that the analysis could open the door to from other sources that can degrade the surrounding connective tissue. Since the most abundant component understanding the pathogenic mechanism of this enigmatic organism has not yet been realized. Possible of the dermis is type I collagen, we have stimulated human dermal fibroblasts in culture with T. pallidum virulence factors include a family of 12 potential membrane proteins and several putative hemolysins but the in order to find out whether this could directly influence the synthesised matrix metalloproteinase-1 genome contains neither the orthologs for any wellknown virulence factors nor the secretory apparatus(MMP-1). needed to deliver virulence factors into the host environment (2). MATERIAL AND METHODS One of the virulence mechanisms of a pathogenic organism is to invade or destroy tissues in order to