Title
Monocyte-astrocyte networks and the regulation of chemokine secretion in neurocysticercosis
Date Issued
01 September 2005
Access level
open access
Resource Type
journal article
Publisher(s)
American Association of Immunologists
Abstract
Neurocysticercosis, caused by infection with larval Taenia solium, is a major cause of epilepsy worldwide. Larval degeneration, which is symptomatic, results in inflammatory cell influx. Astrocytes, the most abundant cell type and major cytokine-producing cell within the CNS, may be important in orchestrating inflammatory responses after larval degeneration. We investigated the effects of direct stimulation and of conditioned medium from T. solium larval Ag (TsAg)-stimulated monocytes (CoMTsAg) on neutrophil and astrocyte chemokine release. CoMTsAg, but not control conditioned medium, stimulated astrocyte CCL2/MCP-1 (161.5 ± 16 ng/ml), CXCL8/IL-8 (416 ± 6.2 ng/ml), and CXCL10/IFN-γ-inducible protein (9.07 ± 0.6 ng/ml) secretion after 24 h, whereas direct astrocyte or neutrophil stimulation with TsAg had no effect. There was rapid accumulation of CCL2 and CXCL8 mRNA within 1 h, with somewhat delayed expression of CXCL10 mRNA initially detected 8 h poststimulation. Neutralizing anti-TNF-α inhibited CoMTsAg-induced CCL2 mRNA accumulation by up to 99%, causing total abolition of CXCL10 and up to 77% reduction in CXCL8 mRNA. CoMTsAg induced maximal nuclear binding of NF-κB p65 and p50 by 1 h, with IκBα and IκBβ decay within 15 min. In addition, CoMTsAg induced transient nuclear binding of AP-1, which peaked 4 h poststimulation. In NF-κB blocking experiments using pyrrolidine dithiocarbamate, CoMTsAg-induced CCL2 secretion was reduced by up to 80% (p = 0.0006), whereas CXCL8 was inhibited by up to 75% (p = 0.0003). In summary, the data show that astrocytes are an important source of chemokines following larval Ag stimulation. Such chemokine secretion is NF-κB dependent, likely to involve AP-1, and is regulated in a paracrine loop by monocyte-derived TNF-α. Copyright © 2005 by The American Association of Immunologists, Inc.
Start page
3273
End page
3281
Volume
175
Issue
5
Language
English
OCDE Knowledge area
Parasitología
Scopus EID
2-s2.0-23844533294
PubMed ID
Source
Journal of Immunology
ISSN of the container
00221767
Sponsor(s)
National Institute of Allergy and Infectious Diseases R03AI042037, U01AI035894
Sources of information: Directorio de Producción Científica Scopus