Abstract
An unusual 120-kDa alkaline peptidase contained in a trypomastigote soluble fraction (TSF) of Trypanosoma cruzi is associated with the induction of repetitive Ca2+ transients and subsequent invasion by the parasite of a number of mammalian cell lines, including tissue culture L6E2 myoblasts (B. A. Burleigh and N. W. Andrews, J. Biol. Chem. 270:5172-5180, 1995; S. N. J. Moreno, J. Silva, A. E. Vercesi, and R. Docampo, J. Exp. Med. 180:1535-1540, 1994; A. Rodríguez, M. G. Rioult, A. Ora, and N. W. Andrews, J. Cell Biol. 129:1263-1273, 1995; I. Tardieux, M. H. Nathanson, and N. W. Andrews, J. Exp. Med. 179:1017-1022, 1994). Using single cell spectrofluorometry and whole-cell patch clamping, we show that TSF produces rapid repetitive cytosolic Ca2+ transients (each associated with cell contraction) in primary cardiac myocytes isolated from dogs. The response of myocytes to TSF was dose dependent in that increasing numbers of cells responded to increasing concentrations of TSF. The TSF-induced Ca2+ transients could be obliterated when TSF was heated or treated with trypsin or the protease inhibitor leupeptin. Aprotinin, pepstatin A, and E-64 did not affect TSF activity. The TSF-induced Ca2+ transients and trypomastigote cell invasion could not be inhibited by alpha (prazosin)- or beta (propanolol)-adrenergic blockers or L-type Ca2+ channel blockers (verapamil, nisoldipine, or cadmium) or by removal of extracellular Ca2+. However, inhibition of pertussis toxin-sensitive G proteins and Ca2+ release from the sarcoplasmic reticulum (with thapsigargin or ryanodine) prevented the TSF-induced Ca2+ transients and cell invasion by trypomastigotes. These data suggested that cardiac myocyte pertussis toxin-sensitive G proteins are associated with the regulation of TSF-induced Ca2+ transients and myocyte invasion by trypomastigotes but are independent of Ca2+ entry into the cytosol via L-type Ca2+ channels. The Ca2+ transients are dependent on release of Ca2+ from sarcoplasmic reticulum Ca2+ stores, but this release is not dependent on extracellular Ca2+ or on the classic model of Ca2+ -induced Ca2+ release in cardiac myocytes. Further, subthreshold depolarizations, together with cell contraction as demonstrated by whole-cell patch clamping, occurred with each Ca2+ transient. However, the depolarizations were of magnitude insufficient to generate an action potential, providing further evidence for a lack of dependence on L-type Ca2+ channels and other voltage-dependent channels (Na+ and K+ channels) in the generation of TSF-induced Ca2+ transients. Our findings suggest that primary canine cardiac myocytes respond to TSF and parasite invasion in ways similar to those of the in vitro cell lines studied to date. Since cardiac myocytes are primary targets for T. cruzi in the vertebrate host, our study indicates that TSF may play a role in the pathogenesis of Chagas' disease in humans.
Full Text
The Full Text of this article is available as a PDF (428.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andrews N. W., Colli W. Adhesion and interiorization of Trypanosoma cruzi in mammalian cells. J Protozool. 1982 May;29(2):264–269. doi: 10.1111/j.1550-7408.1982.tb04024.x. [DOI] [PubMed] [Google Scholar]
- Andrews N. W., Hong K. S., Robbins E. S., Nussenzweig V. Stage-specific surface antigens expressed during the morphogenesis of vertebrate forms of Trypanosoma cruzi. Exp Parasitol. 1987 Dec;64(3):474–484. doi: 10.1016/0014-4894(87)90062-2. [DOI] [PubMed] [Google Scholar]
- Bers D. M., Bassani J. W., Bassani R. A. Competition and redistribution among calcium transport systems in rabbit cardiac myocytes. Cardiovasc Res. 1993 Oct;27(10):1772–1777. doi: 10.1093/cvr/27.10.1772. [DOI] [PubMed] [Google Scholar]
- Burleigh B. A., Andrews N. W. A 120-kDa alkaline peptidase from Trypanosoma cruzi is involved in the generation of a novel Ca(2+)-signaling factor for mammalian cells. J Biol Chem. 1995 Mar 10;270(10):5172–5180. doi: 10.1074/jbc.270.10.5172. [DOI] [PubMed] [Google Scholar]
- Callewaert G., Cleemann L., Morad M. Epinephrine enhances Ca2+ current-regulated Ca2+ release and Ca2+ reuptake in rat ventricular myocytes. Proc Natl Acad Sci U S A. 1988 Mar;85(6):2009–2013. doi: 10.1073/pnas.85.6.2009. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Choromanski L., Kuhn R. E. Augmentation of suppressed antibody responses in mice during experimental Chagas' disease by T helper cells activated in a time-dependent mode of immunization. J Protozool. 1990 Sep-Oct;37(5):388–392. doi: 10.1111/j.1550-7408.1990.tb01162.x. [DOI] [PubMed] [Google Scholar]
- Fabiato A. Time and calcium dependence of activation and inactivation of calcium-induced release of calcium from the sarcoplasmic reticulum of a skinned canine cardiac Purkinje cell. J Gen Physiol. 1985 Feb;85(2):247–289. doi: 10.1085/jgp.85.2.247. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- Hall B. F., Webster P., Ma A. K., Joiner K. A., Andrews N. W. Desialylation of lysosomal membrane glycoproteins by Trypanosoma cruzi: a role for the surface neuraminidase in facilitating parasite entry into the host cell cytoplasm. J Exp Med. 1992 Aug 1;176(2):313–325. doi: 10.1084/jem.176.2.313. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huang A. J., Manning J. E., Bandak T. M., Ratau M. C., Hanser K. R., Silverstein S. C. Endothelial cell cytosolic free calcium regulates neutrophil migration across monolayers of endothelial cells. J Cell Biol. 1993 Mar;120(6):1371–1380. doi: 10.1083/jcb.120.6.1371. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jaffe L. F. Classes and mechanisms of calcium waves. Cell Calcium. 1993 Nov;14(10):736–745. doi: 10.1016/0143-4160(93)90099-r. [DOI] [PubMed] [Google Scholar]
- Moreno S. N., Silva J., Vercesi A. E., Docampo R. Cytosolic-free calcium elevation in Trypanosoma cruzi is required for cell invasion. J Exp Med. 1994 Oct 1;180(4):1535–1540. doi: 10.1084/jem.180.4.1535. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Morris S. A., Barr S., Weiss L., Tanowitz H., Wittner M., Bilezikian J. P. Myocardial beta-adrenergic adenylate cyclase complex in a canine model of chagasic cardiomyopathy. Circ Res. 1991 Jul;69(1):185–195. doi: 10.1161/01.res.69.1.185. [DOI] [PubMed] [Google Scholar]
- Morris S. A., Tanowitz H., Factor S. M., Bilezikian J. P., Wittner M. Myocardial adenylate cyclase activity in acute murine Chagas' disease. Circ Res. 1988 Apr;62(4):800–810. doi: 10.1161/01.res.62.4.800. [DOI] [PubMed] [Google Scholar]
- Morris S. A., Wittner M., Weiss L., Hatcher V. B., Tanowitz H. B., Bilezikian J. P., Gordon P. B. Extracellular matrix derived from Trypanosoma cruzi infected endothelial cells directs phenotypic expression. J Cell Physiol. 1990 Nov;145(2):340–346. doi: 10.1002/jcp.1041450220. [DOI] [PubMed] [Google Scholar]
- Nogueira N., Cohn Z. Trypanosoma cruzi: mechanism of entry and intracellular fate in mammalian cells. J Exp Med. 1976 Jun 1;143(6):1402–1420. doi: 10.1084/jem.143.6.1402. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pacioretty L. M., Barr S. C., Han W. P., Gilmour R. F., Jr Reduction of the transient outward potassium current in a canine model of Chagas' disease. Am J Physiol. 1995 Mar;268(3 Pt 2):H1258–H1264. doi: 10.1152/ajpheart.1995.268.3.H1258. [DOI] [PubMed] [Google Scholar]
- Randriamampita C., Tsien R. Y. Emptying of intracellular Ca2+ stores releases a novel small messenger that stimulates Ca2+ influx. Nature. 1993 Aug 26;364(6440):809–814. doi: 10.1038/364809a0. [DOI] [PubMed] [Google Scholar]
- Rodríguez A., Rioult M. G., Ora A., Andrews N. W. A trypanosome-soluble factor induces IP3 formation, intracellular Ca2+ mobilization and microfilament rearrangement in host cells. J Cell Biol. 1995 Jun;129(5):1263–1273. doi: 10.1083/jcb.129.5.1263. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schenkman S., Andrews N. W., Nussenzweig V., Robbins E. S. Trypanosoma cruzi invade a mammalian epithelial cell in a polarized manner. Cell. 1988 Oct 7;55(1):157–165. doi: 10.1016/0092-8674(88)90018-9. [DOI] [PubMed] [Google Scholar]
- Schenkman S., Robbins E. S., Nussenzweig V. Attachment of Trypanosoma cruzi to mammalian cells requires parasite energy, and invasion can be independent of the target cell cytoskeleton. Infect Immun. 1991 Feb;59(2):645–654. doi: 10.1128/iai.59.2.645-654.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schettino P. M., Majumder S., Kierszenbaum F. Regulatory effect of the level of free Ca2+ of the host cell on the capacity of Trypanosoma cruzi to invade and multiply intracellularly. J Parasitol. 1995 Aug;81(4):597–602. [PubMed] [Google Scholar]
- Simon M. I., Strathmann M. P., Gautam N. Diversity of G proteins in signal transduction. Science. 1991 May 10;252(5007):802–808. doi: 10.1126/science.1902986. [DOI] [PubMed] [Google Scholar]
- Tardieux I., Nathanson M. H., Andrews N. W. Role in host cell invasion of Trypanosoma cruzi-induced cytosolic-free Ca2+ transients. J Exp Med. 1994 Mar 1;179(3):1017–1022. doi: 10.1084/jem.179.3.1017. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tardieux I., Webster P., Ravesloot J., Boron W., Lunn J. A., Heuser J. E., Andrews N. W. Lysosome recruitment and fusion are early events required for trypanosome invasion of mammalian cells. Cell. 1992 Dec 24;71(7):1117–1130. doi: 10.1016/s0092-8674(05)80061-3. [DOI] [PubMed] [Google Scholar]
- Thastrup O., Cullen P. J., Drøbak B. K., Hanley M. R., Dawson A. P. Thapsigargin, a tumor promoter, discharges intracellular Ca2+ stores by specific inhibition of the endoplasmic reticulum Ca2(+)-ATPase. Proc Natl Acad Sci U S A. 1990 Apr;87(7):2466–2470. doi: 10.1073/pnas.87.7.2466. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsien R. W., Bean B. P., Hess P., Lansman J. B., Nilius B., Nowycky M. C. Mechanisms of calcium channel modulation by beta-adrenergic agents and dihydropyridine calcium agonists. J Mol Cell Cardiol. 1986 Jul;18(7):691–710. doi: 10.1016/s0022-2828(86)80941-5. [DOI] [PubMed] [Google Scholar]
- Tsien R. Y., Pozzan T., Rink T. J. Calcium homeostasis in intact lymphocytes: cytoplasmic free calcium monitored with a new, intracellularly trapped fluorescent indicator. J Cell Biol. 1982 Aug;94(2):325–334. doi: 10.1083/jcb.94.2.325. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wier W. G., Yue D. T., Marban E. Effects of ryanodine on intracellular Ca2+ transients in mammalian cardiac muscle. Fed Proc. 1985 Dec;44(15):2989–2993. [PubMed] [Google Scholar]