Abstract
During the development and effector phases of the anti-Toxoplasma response, the immunological system of a host is involved in several complex interactions with the endocrine system, and prolactin (PRL) is one of the most important hormones involved in immunoregulation. In this work, the influence of the recombinant human prolactin (rhPRL) on the viability, penetration, and intensity of intracellular proliferation of Toxoplasma gondii BK strain in vitro was evaluated. Using one murine (L929) and two human cell lines (Hs27 and HeLa), no toxic effect of the rhPRL on host cells was found (by determining cellular viability using MTT assay). A similar lack of rhPRL cytotoxic activity was found in the case of the extracellular tachyzoites of T. gondii BK. Replication of parasites in the presence of rhPRL was analyzed first by simultaneous addition of the hormone and the parasites into a microculture of the host cells (treatment during infection). No statistically significant changes in the intensity of parasite proliferation in all used host cells were found for a wide range of the hormone concentrations. However, pre-incubation of the tachyzoites with rhPRL resulted in a significant reduction (up to 36.15%) in the replication abilities of the parasite. Further experiments revealed that in fact, the inhibition of replication was caused by a limited capacity of the parasites to penetrate host’s cells as demonstrated by the reduced number of infected cells.
This is a preview of subscription content, log in via an institution to check access.
References
Barragan A, Sibley D (2003) Migration of Toxoplasma gondii across biological barriers. Trends Microbiol 11:426–430
Benedetto N, Folgore A, Galdiero M, Meli R, Di Carlo R (1995) Effect of prolactin, rIFN-gamma or rTNF-alpha in murine toxoplasmosis. Pathol Biol (Paris) 43:395–400
Benedetto N, Folgore A, Romano-Carratelli C, Galdiero F (2001) Effects of cytokines and prolactin on the replication of Toxoplasma gondii in murine microglia. Eur Cytokine Netw 12:348–358
Ben-Jonathan N, Mershon JL, Allen DL, Steinmetz RW (1996) Extrapituitary prolactin: distribution, regulation, functions, and clinical aspects. Endocr Rev 17:639–669
Berczi I (1994) The role of growth and lactogenic hormone family in immune function. Neuroimmunomodulation 1:201–216
Bole-Feysot C, Goffin V, Edery M, Binart N, Kelly PA (1998) Prolactin (PRL) and its receptors: actions, signal transduction pathways and phenotypes observed in the PRL receptor knockout mice. Endocr Rev 19:225–268
Clevenger CV, Sillman AL, Hanley-Hyde J, Prystowsky MB (1992) Requirement for prolactin during cell cycle regulated gene expression in cloned T-lymphocytes. Endocrinology 130:3216–3222
De Meerschaman F, Rettinger C, Focant C, Boreux R, Pinset C, Leclipteux T, Losson B (2002) Use of a serum-free medium to produce in vitro Neospora caninum and Toxoplasma gondii tachyzoites on Vero cells. Vet Res 33:159–168
Dzitko K, Malicki S, Komorowski J (2008) Effect of hyperprolactinaemia on Toxoplasma gondii prevalence in humans. Parasitol Res 102:723–729
Escobedo G, Roberts CW, Carrero JC, Morales-Montor J (2005) Parasite regulation by host hormones: an old mechanism of host exploitation? Trends Parasitol 21:588–593
Freeman ME, Kanyicska B, Lerant A, Nagy G (2000) Prolactin: structure, function, and regulation of secretion. Physiol Rev 80:1523–1631
Gerlo S, Verdood P, Hooghe-Peters EL, Kooijman R (2005) Modulation of prolactin expression in humans T lymphocytes by cytokines. J Neuroimmunol 162:190–193
Ibars CB, Rodriguez AB, Skwarlo-Sonta K, Lea RW (1997) Mitogenic effect of naturally occurring elevated plasma prolactin on ring dove lymphocytes. Dev Comp Immunol 21:47–58
Kelly PA, Djiane J, Postel-Vinay MC, Edery M (1991) The prolactin/growth hormone receptor family. Endocr Rev 12:235–251
Ortega E, Forner MA, Barriga C (1996) Effect of prolactin on the in vitro phagocytic capacity of macrophages. Comp Immunol Microbiol Infect Dis 19:139–146
Pfefferkorn ER, Pfefferkorn LC (1977) Specific labeling of intracellular Toxoplasma gondii with uracil. J Protozool 24:449–453
Skwarlo-Sonta K (1992) Prolactin as an immunoregulatory hormone in mammals and birds. Immunol Lett 33:105–121
Sun R, Li AL, Wei HM, Tian ZG (2004) Expression of prolactin receptor and response to prolactin stimulation of human NK cell lines. Cell Res 14:67–73
Trott JF, Horigan C, Gloviczki JM, Costa KM, Frekin BA, Farmer C, Hayashi K, Spencer T, Morabito JE, Hovey RC (2009) Tissue-specific regulation of porcine receptor expression by estrogen, progesteron, and prolactin. J Endocrinol 202:153–166
van de Loosdrecht AA, Beelen RHJ, Ossenkoppele GJ, Broekhoven MG, Langenhuijsen MMC (1994) A tetrazolium-based colorimetric MTT assay to quantitate human monocyte mediated cytotoxicity against leukemic cells from cell lines and patients with acute myeloid leukemia. J Immunol Meth 174:311–32
Acknowledgments
This work was supported by The Polish Ministry of Science and Higher Education (grant no. N401 232334).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Dzitko, K., Gatkowska, J., Płociński, P. et al. The effect of prolactin (PRL) on the growth of Toxoplasma gondii tachyzoites in vitro. Parasitol Res 107, 199–204 (2010). https://doi.org/10.1007/s00436-010-1849-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00436-010-1849-3