Plasmodium yoelii17XL infection up-regulates RANTES, CCR1, CCR3 and CCR5 expression, and induces ultrastructural changes in the cerebellum

Sarfo, Armah, Irune Ikovwaiza, Adjei, Olver, Singh Shailesh, Lillard, Stiles

Description

Malaria afflicts 300–500 million people causing over 1 million deaths globally per year. The immunopathogenesis of malaria is mediated partly by co mplex cellular and immunomodulator interactions involving co-regulators such as cytokines and adhesion molecules. However, the role of chemokines and their receptors in malaria immunopathology remains unclear. RANTES (Regulated on Activation Normal T-Cell Expressed and Secreted) is a chemokine involved in the generation of inflammatory infiltrates. Recent studies indicate that the degradation of cell-cell junctions, blood-brain barrier dysfunction, recruitment of leukocytes and Plasmodium -infected erythrocytes into and occlusion of microvessels relevant to malaria pathogenesis are associated with RANTES expression. Additionally, activated lymphocytes, platelets and endothelial cells release large quantities of RANTES, thus suggesting a unique role for RANTES in the generation and maintenance of the malaria-induced inflammatory response. The hypothesis of this study is that RANTES and its corresponding receptors (CCR1, CCR3 and CCR5) modulate malaria immunopathogenesis. A murine malaria model was utilized to evaluate the role of this chemokine and its receptors in malaria. Methods The alterations in immunomodulator gene expression in brains of Plasmodium yoelii 17XL-infected mice was analysed using cDNA microarray screening, followed by a temporal comparison of mRNA and protein expression of RANTES and its corresponding receptors by qRT-PCR and Western blot analysis, respectively. Plasma RANTES levels was determined by ELISA and ultrastructural studies of brain sections from infected and uninfected mice was conducted. Results RANTES (p < 0.002), CCR1 (p < 0.036), CCR3 (p < 0.033), and CCR5 (p < 0.026) mRNA were significantly upregulated at peak parasitaemia and remained high thereafter in the experimental mouse model. RANTES protein in the brain of infected mice was upregulated (p < 0.034) compared with controls. RANTES plasma levels were significantly upregulated; two to three fold in infected mice compared with controls (p < 0.026). Some d istal microvascular endothelium in infected cerebellum appeared degraded, but remained intact in controls. Conclusion The upregulation of RANTES, CCR1, CCR3, and CCR5 mRNA, and RANTES protein mediate inflammation and cellular degradation in the cerebellum during P. yoelii 17XL malaria.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2005
• Nombre de lectures: 7
• Langue: English

Extrait

Malaria Journal

BioMedCentral

Open Access Research Plasmodium yoelii17XL infection up-regulates RANTES, CCR1, CCR3 and CCR5 expression, and induces ultrastructural changes in the cerebellum 1 2,32 3 Bismark Y Sarfo, Henry B Armah, Ikovwaiza Irune, Andrew A Adjei, 4 22 Christine S Olver, Shailesh Singh, James W Lillard Jrand 2 Jonathan K Stiles*

1 Address: ParasitologyUnit, Noguchi Memorial Institute for Medical Research, University of Ghana, P.O. Box LG581, Legon, Accra, Ghana, 2 Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, 720 Westview Drive S. W., Atlanta, GA, 30310 3 1495, USA,Department of Pathology, University of Ghana Medical School & KorleBu Teaching Hospital, P.O. Box 4236, Accra, Ghana and 4 Department of Pathology, Colorado State University, Fort Collins, CO, 80523, USA Email: Bismark Y Sarfo  [e-mail]; Henry B Armah  [e-mail]; Ikovwaiza Irune  [e-mail]; Andrew A Adjei  [e-mail]; Christine S Olver  [e-mail]; Shailesh Singh  [e-mail]; James W Lillard  [e-mail]; Jonathan K Stiles*  [e-mail] * Corresponding author

Published: 16 December 2005Received: 23 August 2005 Accepted: 16 December 2005 Malaria Journal2005,4:63 doi:10.1186/1475-2875-4-63 This article is available from: http://www.malariajournal.com/content/4/1/63 © 2005 Sarfo et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract Background:Malaria afflicts 300–500 million people causing over 1 million deaths globally per year. The immunopathogenesis of malaria is mediated partly by co mplex cellular and immunomodulator interactions involving co-regulators such as cytokines and adhesion molecules. However, the role of chemokines and their receptors in malaria immunopathology remains unclear. RANTES (Regulated on Activation Normal T-Cell Expressed and Secreted) is a chemokine involved in the generation of inflammatory infiltrates. Recent studies indicate that the degradation of cell-cell junctions, blood-brain barrier dysfunction, recruitment of leukocytes andPlasmodium- infected erythrocytes into and occlusion of microvessels relevant to malaria pathogenesis are associated with RANTES expression. Additionally, activated lymphocytes, platelets and endothelial cells release large quantities of RANTES, thus suggesting a unique role for RANTES in the generation and maintenance of the malaria-induced inflammatory response. The hypothesis of this study is that RANTES and its corresponding receptors (CCR1, CCR3 and CCR5) modulate malaria immunopathogenesis. A murine malaria model was utilized to evaluate the role of this chemokine and its receptors in malaria. Methods:The alterations in immunomodulator gene expression in brains ofPlasmodium yoelii 17XL-infected mice was analysed using cDNA microarray screening, followed by a temporal comparison of mRNA and protein expression of RANTES and its corresponding receptors by qRT- PCR and Western blot analysis, respectively. Plasma RANTES levels was determined by ELISA and ultrastructural studies of brain sections from infected and uninfected mice was conducted. Results:RANTES (p < 0.002), CCR1 (p < 0.036), CCR3 (p < 0.033), and CCR5 (p < 0.026) mRNA were significantly upregulated at peak parasitaemia and remained high thereafter in the experimental mouse model. RANTES protein in the brain of infected mice was upregulated (p <

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