IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Alemán, M.
Right arrow Articles by Sasiain, M. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Alemán, M.
Right arrow Articles by Sasiain, M. C.
Infection and Immunity, September 2004, p. 5150-5158, Vol. 72, No. 9
0019-9567/04/$08.00+0     DOI: 10.1128/IAI.72.9.5150-5158.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Mycobacterium tuberculosis Triggers Apoptosis in Peripheral Neutrophils Involving Toll-Like Receptor 2 and p38 Mitogen Protein Kinase in Tuberculosis Patients

Mercedes Alemán,1 Pablo Schierloh,1 Silvia S. de la Barrera,1 Rosa M. Musella,2 María A. Saab,2 Matías Baldini,2 Eduardo Abbate,2 and María C. Sasiain1*

Departamento de Inmunología, Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina,1 División de Tisioneumonología, Hospital F. J. Muñiz, Buenos Aires, Argentina2

Received 16 April 2004/ Returned for modification 18 May 2004/ Accepted 2 June 2004

Polymorphonuclear neutrophils (PMN) exposed to Mycobacterium tuberculosis display bactericidal responses and produce inflammatory proteins. This PMN-mediated inflammatory response is regulated by an activation of the apoptotic program, which collaborates to avoid tissue injury. In vitro, circulating PMN from patients with tuberculosis (TB) show an increased spontaneous apoptosis, and M. tuberculosis-induced activation accelerates the PMN apoptosis. In this study, we evaluated the mechanisms involved in spontaneous and M. tuberculosis-induced apoptosis. We demonstrate that apoptosis of PMN is not induced by lipoarabinomannan or by a whole-cell lysate of M. tuberculosis and that neither tumor necrosis factor alpha nor CD11b, CD14, and Fc{gamma} receptors are involved. Apoptosis of PMN from patients with active TB (TB-PMN) is induced by the interaction with the whole M. tuberculosis via Toll-like receptor 2 (TLR2), and, in contrast to spontaneous apoptosis, it involves the p38 mitogen-activated protein kinase (MAPK) pathway. These results correlate with a high expression of phosphorylated p38 (p-p38) in circulating TB-PMN and with the ability of M. tuberculosis to induce in vitro the expression of p-p38 in PMN. Therefore, when the bacterial burden is low, TB-PMN could be detecting nonopsonized M. tuberculosis via TLR2, leading to the activation of the p38 MAPK pathway, which in turn would induce PMN activation and apoptosis. This mechanism needs further confirmation at the site of infection.


* Corresponding author. Mailing address: Inmunología, Academia Nacional de Medicina, Pacheco de Melo 3081 (1425) Buenos Aires, Argentina. Phone: 5411-48055695. Fax: 5411-48039475. E-mail: msasiain{at}hematologia.anm.edu.ar.

Editor: D. L. Burns


Infection and Immunity, September 2004, p. 5150-5158, Vol. 72, No. 9
0019-9567/04/$08.00+0     DOI: 10.1128/IAI.72.9.5150-5158.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2004 by the American Society for Microbiology. All rights reserved.