Abstract
An in vitro model for growth and differentiation of the metacestode tissue of the tapeworm Echinococcus multilocularis is described. This model simulates the organotropism of the parasite toward the liver of the intermediate host. In the presence of collagen-embedded primary hepatocytes from rats and humans, which can be kept in culture for 2 to 3 months, the parasitic vesicles grew by exogenous budding and multiplied about 12-fold within 3 weeks. In contrast, without the hepatocytes, the metacestodes rapidly degenerated. Development of protoscolices was seen only in the presence of rat hepatocytes but not in coculture of the metacestodes with hepatocytes of human origin, thus reflecting the in vivo situation during infection of rodents and in alveolar echinococcosis in humans. The experiments indicated that growth of the metacestodes and development of protoscolices depended on soluble low-molecular-weight factors released by the hepatocytes. The in vitro-grown metacestodes did not differ morphologically from the larvae found in infected intermediate hosts, and their infectivity was completely maintained. This report describes the first in vitro model of alveolar echinococcosis and will be the basis for future studies on host-parasite interactions of this important zoonosis.
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- Bader A., Borel Rinkes I. H., Closs E. I., Ryan C. M., Toner M., Cunningham J. M., Tompkins R. G., Yarmush M. L. A stable long-term hepatocyte culture system for studies of physiologic processes: cytokine stimulation of the acute phase response in rat and human hepatocytes. Biotechnol Prog. 1992 May-Jun;8(3):219–225. doi: 10.1021/bp00015a007. [DOI] [PubMed] [Google Scholar]
- Dunn J. C., Tompkins R. G., Yarmush M. L. Long-term in vitro function of adult hepatocytes in a collagen sandwich configuration. Biotechnol Prog. 1991 May-Jun;7(3):237–245. doi: 10.1021/bp00009a007. [DOI] [PubMed] [Google Scholar]
- Dunn J. C., Yarmush M. L., Koebe H. G., Tompkins R. G. Hepatocyte function and extracellular matrix geometry: long-term culture in a sandwich configuration. FASEB J. 1989 Feb;3(2):174–177. doi: 10.1096/fasebj.3.2.2914628. [DOI] [PubMed] [Google Scholar]
- Elsdale T., Bard J. Collagen substrata for studies on cell behavior. J Cell Biol. 1972 Sep;54(3):626–637. doi: 10.1083/jcb.54.3.626. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Furuya K. An established cell line of larval Echinococcus multilocularis. Int J Parasitol. 1991 Apr;21(2):233–240. doi: 10.1016/0020-7519(91)90014-x. [DOI] [PubMed] [Google Scholar]
- Hall H. G., Farson D. A., Bissell M. J. Lumen formation by epithelial cell lines in response to collagen overlay: a morphogenetic model in culture. Proc Natl Acad Sci U S A. 1982 Aug;79(15):4672–4676. doi: 10.1073/pnas.79.15.4672. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hemphill A., Gottstein B. Immunology and morphology studies on the proliferation of in vitro cultivated Echinococcus multilocularis metacestodes. Parasitol Res. 1995;81(7):605–614. doi: 10.1007/BF00932028. [DOI] [PubMed] [Google Scholar]
- Lindsay D. S., Toivio-Kinnucan M. A., Blagburn B. L. Ultrastructural determination of cystogenesis by various Toxoplasma gondii isolates in cell culture. J Parasitol. 1993 Apr;79(2):289–292. [PubMed] [Google Scholar]
- Maya A., Usha S., Jayaraman K., Baba K., Sukumaran M., Balakrishnan A. Interaction of filarial proteins on growth regulation of normal lung epithelial cells in vitro. Cell Biol Int. 1995 Mar;19(3):223–231. doi: 10.1006/cbir.1995.1065. [DOI] [PubMed] [Google Scholar]
- Rodriguez-Acosta A., Girón M. E., Aguilar I. Secretion of macrophage fusion factor (MFF) by schistosome egg granulomas maintained in vitro. Scand J Immunol. 1992 Jun;35(6):633–636. doi: 10.1111/j.1365-3083.1992.tb02968.x. [DOI] [PubMed] [Google Scholar]
- Sakamoto T., Sugimura M. [Studies on echinococcosis. 23. Electron microscopical observations on histogenesis of larval Echinococcus multilocularis]. Jpn J Vet Res. 1970 Sep;18(3):131–144. [PubMed] [Google Scholar]
- Seglen P. O. Preparation of isolated rat liver cells. Methods Cell Biol. 1976;13:29–83. doi: 10.1016/s0091-679x(08)61797-5. [DOI] [PubMed] [Google Scholar]
- Whitfield P. J., Evans N. A. Parthenogenesis and asexual multiplication among parasitic platyhelminths. Parasitology. 1983 Apr;86(Pt 4):121–160. doi: 10.1017/s0031182000050873. [DOI] [PubMed] [Google Scholar]