| Title |
Interactions of Mycobacterium avium subsp. paratuberculosis with murine macrophages: Intracellular survival and modulation of macrophage functions. |
| Author(s) |
Goethe R1,
Kuehnel MP1,
Darji A2,
Weiss S2,
Rohde M2,
Gerlach GF1,
Valentin-Weigand P1.
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| Institution(s) |
1 Department of Microbiology and Infectious Disease, College of Veterinary Science, Hannover, Germany and 2 Department of Cell Biology and Immunology, National Research Center for Biotechnology, Braunschweig, Germany.
|
| Source |
Sixth International Colloquium on Paratuberculosis
|
| Section |
7:
Immunology And Pathogenesis
|
| Abstract |
Murine macrophages were infected in vitro with M. avium subsp. M. paratuberculosis, strain 6783. Samples were taken at different time points up to 10 days to study intra-cellular fate of the bacteria by electron and confocal laser scanning microscopy. Results revealed that mycobacteria were taken up efficiently within 30 min. p.i. and persisted intracellularly in phagosomes for the whole infection period. Bacterial uptake and persistence was associated with a time dependent modulation of the expression of several cytokine and transcriptional control genes as determined by RT-PCR. Expression of the genes for IL-1ß, IL-6, GM-CSF and IL-12 was significantly enhanced, starting at 2 h p.i. and remaining up to 72 h p.i.. Interestingly, expression of the genes for TNFI and c-fos was not or only slightly modified. Mycobacterial persistence also resulted in a suppressed presentation of exogenously added antigen haemagglutinin (HA) as analyzed by measuring IL-2 production of HA specific T-cells. Reduced antigen presentation seemed to be caused by reduced processing of HA and was not accompanied by any alterations of the expression of MHCII and co-stimulatory molecules B7.1 and B7.2.
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