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Open Access Short Report

Dendritic Cells Activate and Mature after Infection with Mycobacterium tuberculosis

Adane Mihret12*, Gezahagne Mamo13, Mesfin Tafesse1, Asrat Hailu2 and Shreemanta Parida14

Author Affiliations

1 Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia

2 Faculty of Medicine, Addis Ababa University, Addis Ababa, Ethiopia

3 Faculty of Veterinary Medicine, Addis Ababa, University, Addis Ababa, Ethiopia

4 Max Planck Institute for Infection Biology, Berlin, Germany

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BMC Research Notes 2011, 4:247  doi:10.1186/1756-0500-4-247

Published: 21 July 2011

Abstract

Background

Dendritic cells (DCs) can take up an array of different antigens, including microorganisms which they can process and present more effectively than any other antigen presenting cell. However, whether the interaction between the human DC and Mycobacterium tuberculosis represents a defense mechanism by the invaded host, or helping the invader to evade the defense mechanism of the host is still not clearly understood.

Findings

To analyze the interactions between M. tuberculosis and immune cells, human peripheral blood monocyte-derived immature DCs were infected with M. tuberculosis H37Rv wild type strain and flow cytometry was used to analyse cell surface expression markers. The ability of the M. tuberculosis infected DC to induce T cell proliferation using 5 and 6-carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution technique was also investigated. DCs were found to internalize the mycobacteria and show dose dependent infection and necrosis with different multiplicity of infection. Flow cytometry analysis of cell surface expression markers CD40, CD54, CD80, CD83, CD86 and HLA DR in infected DC revealed significant (p < 0.05) up regulation following infection with M. tuberculosis in comparison to immature DC with no stimulation. Lipopolysaccharide (LPS) from Salmonella abortus equi, a known DC maturation agent, was used as a positive control and showed a comparable up regulation of cell surface markers as observed with M. tuberculosis infected DC. It was revealed that the M. tuberculosis infected DC induced T cell proliferation.

Conclusion

These data clearly demonstrate that M. tuberculosis induces activation and maturation of human monocyte-derived immature DC as well as induces T cell proliferation in vitro.

Keywords:
Dendritic cells; Mycobacterium tuberculosis; T cells; Activation; Flowctometry; CFSE; Proliferation