The involvement of proteins of DNA double-strand breaks repair systems of Mycobacterium tuberculosis in the infection of human macrophages
-
1
Institute of Medical Biology, Polish Academy of Sciences, Poland
Objectives: Double-strand breaks repair systems as non-homologous end-joining (NHEJ) and homologous recombination (HR) are important for the Mycobacterium tuberculosis (Mtb) survival in vitro. We determine the involvement of proteins Ku, ligase D (crucial for NHEJ system) and RecA (major for HR) in the Mtb intracellular survival.
Methods: MtbH37Rv mutants with inactivated genes: ku, ligD (Δku/ligD), recA (ΔrecA) or ku, ligD, recA (Δku/ligD/recA) were obtained using the technique of gene replacement based on the process of homologous recombination. Intracellular growth of bacteria and antimicrobial activities of macrophages: nitric oxide (NO) and reactive oxygen species (ROS) production were examined. The involvement of EKR1/2 signalling pathway in the response of macrophages to Mtb infection was also assessed.
Results: We found that Δku/ligD/recA mutant grew significantly weaker inside the macrophages than wild-type and the rest of mutants. Inhibition of ERK1/2 pathway in macrophages caused the increased intracellular growth of Δku/ligD/recA. Δku/ligD/recA and ΔrecA mutants, but not wild-type or Δku/ligD, stimulated NO and ROS production. Nevertheless, inhibition of ERK1/2 signalling pathway blocked NO and ROS production by macrophages infected with Δku/ligD/recA or ΔrecA. Only the triple mutant did not disturb the phosphorylation of ERK1/2 proteins induced by phorbol ester.
Conclusion: Both NHEJ and HR systems are important for the survival of Mtb inside human resting macrophages. The RecA protein affect the bactericidal activity of macrophages. We suggest that HR repairing pathway can be one of the virulence factor of Mtb.
Research co-financed by the European Regional Development Fund under the Operational Programme Innovative Economy, grant POIG.01.01.02-10-107/09.
Keywords:
Mycobacterium tuberculosis,
DNA double-strand breaks,
human macrophages,
ERK1_2 pathway,
Intracellular survival
Conference:
15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013.
Presentation Type:
Abstract
Topic:
Host-pathogen interactions
Citation:
Szulc
I,
Brzezinska
M,
Klink
M,
Brzostek
A,
Kielbik
M,
Sulowska
Z and
Dziadek
J
(2013). The involvement of proteins of DNA double-strand breaks repair systems of Mycobacterium tuberculosis in the infection of human macrophages.
Front. Immunol.
Conference Abstract:
15th International Congress of Immunology (ICI).
doi: 10.3389/conf.fimmu.2013.02.00381
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
15 Mar 2013;
Published Online:
22 Aug 2013.
*
Correspondence:
Ms. Izabela Szulc, Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland, iszulc@cbm.pan.pl