|
|
||||||||





* Laboratory of Plasma Derivatives, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892;
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, and
Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and
Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605
Cattle and humans are susceptible to infection with the Gram-negative intracellular bacterium Brucella abortus. Heat-killed B. abortus (HKBA) is a strong Th1 adjuvant and carrier. Previously, we have demonstrated that dendritic cells produce IL-12 in response to HKBA stimulation. In the present study, we use knockout mice and in vitro reconstitution assays to examine the contribution of signaling by Toll-like receptors (TLRs) and their immediate downstream signaling initiator, myeloid differentiation protein MyD88, in the activation following stimulation by HKBA. Our results show that HKBA-mediated induction of IL-12p40 and TNF is dependent on the adapter molecule MyD88. To identify the TLR involved in HKBA recognition, we examined HKBA responses in TLR2- and TLR4-deficient animals. TNF responses to HKBA were TLR4 independent; however, the response in TLR2-deficient mice was significantly delayed and reduced, although not completely abolished. Studies using Chinese hamster ovary/CD14 reporter cell lines stably transfected with either human TLR2 or human TLR4 confirmed the results seen with knockout mice, namely TLR2, but not TLR4, can mediate cellular activation by HKBA. In addition, human embryonic kidney 293 cells, which do not respond to HKBA, were made responsive by transfecting TLR2, but not TLR4 or TLR9. Taken together, our data demonstrate that MyD88-dependent pathways are crucial for activation by HKBA and that TLR2 plays a role in TNF, but not IL-12p40 pathways activated by this microbial product.
This article has been cited by other articles:
![]() |
A. V. Carvalho Neta, A. P. R. Stynen, T. A. Paixao, K. L. Miranda, F. L. Silva, C. M. Roux, R. M. Tsolis, R. E. Everts, H. A. Lewin, L. G. Adams, et al. Modulation of the Bovine Trophoblastic Innate Immune Response by Brucella abortus Infect. Immun., May 1, 2008; 76(5): 1897 - 1907. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. C. Macedo, D. M. Magnani, N. B. Carvalho, O. Bruna-Romero, R. T. Gazzinelli, and S. C. Oliveira Central Role of MyD88-Dependent Dendritic Cell Maturation and Proinflammatory Cytokine Production to Control Brucella abortus Infection J. Immunol., January 15, 2008; 180(2): 1080 - 1087. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Copin, P. De Baetselier, Y. Carlier, J.-J. Letesson, and E. Muraille MyD88-Dependent Activation of B220-CD11b+LY-6C+ Dendritic Cells during Brucella melitensis Infection J. Immunol., April 15, 2007; 178(8): 5182 - 5191. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. He, S. Reichow, S. Ramamoorthy, X. Ding, R. Lathigra, J. C. Craig, B. W. S. Sobral, G. G. Schurig, N. Sriranganathan, and S. M. Boyle Brucella melitensis Triggers Time-Dependent Modulation of Apoptosis and Down-Regulation of Mitochondrion-Associated Gene Expression in Mouse Macrophages Infect. Immun., September 1, 2006; 74(9): 5035 - 5046. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Sanakkayala, A. Sokolovska, J. Gulani, H. HogenEsch, N. Sriranganathan, S. M. Boyle, G. G. Schurig, and R. Vemulapalli Induction of Antigen-Specific Th1-Type Immune Responses by Gamma-Irradiated Recombinant Brucella abortus RB51 Clin. Vaccine Immunol., December 1, 2005; 12(12): 1429 - 1436. [Abstract] [Full Text] [PDF] |
||||
![]() |
L.-Y. Huang, K. J. Ishii, S. Akira, J. Aliberti, and B. Golding Th1-Like Cytokine Induction by Heat-Killed Brucella abortus Is Dependent on Triggering of TLR9 J. Immunol., September 15, 2005; 175(6): 3964 - 3970. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Rosenkrands, E. M. Agger, A. W. Olsen, K. S. Korsholm, C. S. Andersen, K. T. Jensen, and P. Andersen Cationic Liposomes Containing Mycobacterial Lipids: a New Powerful Th1 Adjuvant System Infect. Immun., September 1, 2005; 73(9): 5817 - 5826. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. S. Weiss, K. Takeda, S. Akira, A. Zychlinsky, and E. Moreno MyD88, but Not Toll-Like Receptors 4 and 2, Is Required for Efficient Clearance of Brucella abortus Infect. Immun., August 1, 2005; 73(8): 5137 - 5143. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. P. Jimenez de Bagues, A. Gross, A. Terraza, and J. Dornand Regulation of the Mitogen-Activated Protein Kinases by Brucella spp. Expressing a Smooth and Rough Phenotype: Relationship to Pathogen Invasiveness Infect. Immun., May 1, 2005; 73(5): 3178 - 3183. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. H. Giambartolomei, A. Zwerdling, J. Cassataro, L. Bruno, C. A. Fossati, and M. T. Philipp Lipoproteins, Not Lipopolysaccharide, Are the Key Mediators of the Proinflammatory Response Elicited by Heat-Killed Brucella abortus J. Immunol., October 1, 2004; 173(7): 4635 - 4642. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. I. Duenas, A. Orduna, M. S. Crespo, and C. Garcia-Rodriguez Interaction of endotoxins with Toll-like receptor 4 correlates with their endotoxic potential and may explain the proinflammatory effect of Brucella spp. LPS Int. Immunol., October 1, 2004; 16(10): 1467 - 1475. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. P. Jimenez de Bagues, A. Terraza, A. Gross, and J. Dornand Different Responses of Macrophages to Smooth and Rough Brucella spp.: Relationship to Virulence Infect. Immun., April 1, 2004; 72(4): 2429 - 2433. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |