Phorbol myristate acetate inhibits HeLa 229 invasion by Bordetella pertussis and other invasive bacterial pathogens.
AUTOR(ES)
Ewanowich, C A
RESUMO
The microfilament inhibitors cytochalasins B and D have been traditionally used to indirectly evaluate the requirement for actin in the uptake of invasive bacterial pathogens by nonprofessional phagocytes. Through their effects on microfilaments, both cytochalasins also impart profound alterations in cellular morphology and surface topology, which likely interfere with adherence. Alterations affecting adherence would complicate interpretation of the effect of cytochalasins on entry alone. As an alternative to cytochalasins, the effect of the tumor promoter phorbol myristate acetate (PMA) was examined for its effects on uptake of several invasive bacterial pathogens by HeLa 229 cells. In this communication, PMA was shown to induce a similar change in HeLa cell actin distribution, but, in contrast to cytochalasins B and D, PMA had no significant effect on gross cell morphology. The modified actin distribution was shown to reduce internalization of Bordetella pertussis, Yersinia pseudotuberculosis, Shigella flexneri, and Salmonella hadar in a dose-dependent manner at concentrations ranging from 1 to 1,000 ng/ml. The magnitude of reduction at a PMA concentration of 1,000 ng/ml was greater than the reduction elicited by cytochalasin B at 2.5 micrograms/ml but was less than that elicited by cytochalasin D at 2.5 micrograms/ml. Mezerein, a functional analog of PMA, caused a similar dose-dependent reduction in uptake of B. pertussis, whereas an inactive analog of PMA, alpha-4-phorbol-12,13-didecanoate was without effect on invasion. Binding studies further reveal that pretreatment of HeLa cells with PMA or mezerein did not significantly impair the ability of B. pertussis to adhere, in contrast to cytochalasins B and D, which caused a marked reduction in adherence.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=313638Documentos Relacionados
- Invasion of HeLa 229 cells by virulent Bordetella pertussis.
- A new assay for invasion of HeLa 229 cells by Bordetella pertussis: effects of inhibitors, phenotypic modulation, and genetic alterations.
- Bordetella parapertussis invasion of HeLa 229 cells and human respiratory epithelial cells in primary culture.
- Interaction of Chlamydia trachomatis organisms and HeLa 229 cells.
- Quantitation of HeLa cell monolayer invasion by Shigella and Salmonella species.