Effects of Granulocyte-Macrophage Colony-Stimulating Factor and Tumor Necrosis Factor Alpha on Trypanosoma cruzi Trypomastigotes
AUTOR(ES)
Fontt, Elizabeth Olivares
FONTE
American Society for Microbiology
RESUMO
We have previously shown that the addition of exogenous granulocyte-macrophage colony-stimulating factor (GM-CSF) to nonactivated mouse peritoneal macrophages (MPM) limits Trypanosoma cruzi infections in vitro (E. Olivares Fontt and B. Vray, Parasite Immunol. 17:135–141, 1995). Lower levels of infection were correlated with a higher level of production of tumor necrosis factor alpha (TNF-α) in the absence of nitric oxide (NO) release. These data suggested that GM-CSF and/or TNF-α might have a direct parasitocidal effect on T. cruzi trypomastigotes, independently of NO release. To address this question, T. cruzi trypomastigotes were treated with recombinant murine GM-CSF (rmGM-CSF), recombinant murine TNF-α (rmTNF-α), or both cytokines in a cell-free system. Treatment with rmGM-CSF but not rmTNF-α caused morphological changes in the parasites, and most became spherical after 7 h of incubation. Both cytokines exerted a cytolytic activity on the trypomastigotes, yet the trypanolytic activity of rmTNF-α was more effective than that of rmGM-CSF. Viable rmGM-CSF- and rmTNF-α-treated parasites were less able to infect MPM than untreated parasites, and this reduction in infectivity was greatest for rmGM-CSF. Treatments with both cytokines resulted in more lysis and almost complete inhibition of infection. The direct parasitocidal activity of rmTNF-α was inhibited by carbohydrates and monoclonal antibodies specific for the lectin-like domain of TNF-α. Collectively, these results suggest that cytokines such as GM-CSF and TNF-α may directly control the level of T. cruzi trypomastigotes at least in vitro and so could determine the outcome of infection in vivo.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=108261Documentos Relacionados
- Granulocyte-macrophage colony-stimulating factor: involvement in control of Trypanosoma cruzi infection in mice.
- Specific human granulocyte-macrophage colony-stimulating factor antagonists.
- Modulation of Mycobacterium lepraemurium growth in murine macrophages: beneficial effect of tumor necrosis factor alpha and granulocyte-macrophage colony-stimulating factor.
- Granulocyte-Macrophage Colony-Stimulating Factor in Staphylococcus aureus-Induced Arthritis
- Activity of Voriconazole Combined with Neutrophils or Monocytes against Aspergillus fumigatus: Effects of Granulocyte Colony-Stimulating Factor and Granulocyte-Macrophage Colony-Stimulating Factor