|
|
||||||||

Departments of
*
Pathology and
Biochemistry, University of Pennsylvania School of Dental Medicine, Philadelphia, PA 19104
We have previously shown that Actinobacillus actinomycetemcomitans produces an immunosuppressive factor that is encoded by the cdtB gene, which is homologous to a family of cytolethal distending toxins (Cdt) expressed by several Gram-negative bacteria. In this study, we report that the cdt locus in A. actinomycetemcomitans is composed of five open reading frames, designated orf1, orf2, cdtA, cdtB, and cdtC. The deduced amino acid sequences of the five open reading frames are highly conserved among A. actinomycetemcomitans strains 652, Y4, 29522, and HK1651. There is also strong homology with the Cdt proteins of Haemophilus ducreyi (8791%), but only partial homology with that of Campylobacter jejuni and Escherichia coli (2948%). Analysis of A. actinomycetemcomitans mRNA by RT-PCR suggests that the two small open reading frames upstream of cdtA are coexpressed with cdtA, cdtB, and cdtC. We next utilized a series of plasmids that express various combinations of the cdt genes to determine their requirement for expression of immunoinhibitory activity. Cell extracts of E. coli transformed with each of the plasmids were tested for their capacity to induce G2 arrest in the cell cycle of PHA-activated human T cells. These experiments suggest that expression of cdtB alone is sufficient to induce G2 arrest in human T cells, but do not exclude the possibility that cdtC also contributes to cell cycle arrest. The implications of our results with respect to the function of the individual Cdt proteins are discussed.
This article has been cited by other articles:
![]() |
M. Handfield, H.V. Baker, and R.J. Lamont Beyond Good and Evil in the Oral Cavity: Insights into Host-Microbe Relationships Derived from Transcriptional Profiling of Gingival Cells J. Dent. Res., March 1, 2008; 87(3): 203 - 223. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. M. Schaeffer, M. L. Schmidt, and D. R. Demuth Induction of Aggregatibacter actinomycetemcomitans leukotoxin expression by IS1301 and orfA Microbiology, February 1, 2008; 154(2): 528 - 538. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Shenker, M. Dlakic, L. P. Walker, D. Besack, E. Jaffe, E. LaBelle, and K. Boesze-Battaglia A Novel Mode of Action for a Microbial-Derived Immunotoxin: The Cytolethal Distending Toxin Subunit B Exhibits Phosphatidylinositol 3,4,5-Triphosphate Phosphatase Activity J. Immunol., April 15, 2007; 178(8): 5099 - 5108. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Wang, J. Orvis, D. Dyer, and C. Chen Genomic distribution and functions of uptake signal sequences in Actinobacillus actinomycetemcomitans. Microbiology, November 1, 2006; 152(Pt 11): 3319 - 3325. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Ueno, M. Ohara, T. Kawamoto, T. Fujiwara, H. Komatsuzawa, E. Oswald, and M. Sugai Biogenesis of the Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin Holotoxin. Infect. Immun., June 1, 2006; 74(6): 3480 - 3487. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Shenker, D. R. Demuth, and A. Zekavat Exposure of Lymphocytes to High Doses of Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin Induces Rapid Onset of Apoptosis-Mediated DNA Fragmentation Infect. Immun., April 1, 2006; 74(4): 2080 - 2092. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Ge, Y. Feng, M. T. Whary, P. R. Nambiar, S. Xu, V. Ng, N. S. Taylor, and J. G. Fox Cytolethal Distending Toxin Is Essential for Helicobacter hepaticus Colonization in Outbred Swiss Webster Mice Infect. Immun., June 1, 2005; 73(6): 3559 - 3567. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Heywood, B. Henderson, and S. P Nair Cytolethal distending toxin: creating a gap in the cell cycle J. Med. Microbiol., March 1, 2005; 54(3): 207 - 216. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Shenker, D. Besack, T. McKay, L. Pankoski, A. Zekavat, and D. R. Demuth Induction of Cell Cycle Arrest in Lymphocytes by Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin Requires Three Subunits for Maximum Activity J. Immunol., February 15, 2005; 174(4): 2228 - 2234. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. S. Tan, G. Ong, and K. P. Song Introns in the Cytolethal Distending Toxin Gene of Actinobacillus actinomycetemcomitans J. Bacteriol., January 15, 2005; 187(2): 567 - 575. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Ohara, E. Oswald, and M. Sugai Cytolethal Distending Toxin: A Bacterial Bullet Targeted to Nucleus J. Biochem., October 1, 2004; 136(4): 409 - 413. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Saiki, T. Gomi, and K. Konishi Deletion and Purification Studies to Elucidate the Structure of the Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin J. Biochem., September 1, 2004; 136(3): 335 - 342. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Ohara, T. Hayashi, Y. Kusunoki, M. Miyauchi, T. Takata, and M. Sugai Caspase-2 and Caspase-7 Are Involved in Cytolethal Distending Toxin-Induced Apoptosis in Jurkat and MOLT-4 T-Cell Lines Infect. Immun., February 1, 2004; 72(2): 871 - 879. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Shenker, D. Besack, T. McKay, L. Pankoski, A. Zekavat, and D. R. Demuth Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin (Cdt): Evidence That the Holotoxin Is Composed of Three Subunits: CdtA, CdtB, and CdtC J. Immunol., January 1, 2004; 172(1): 410 - 417. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Deng and E. J. Hansen A CdtA-CdtC Complex Can Block Killing of HeLa Cells by Haemophilus ducreyi Cytolethal Distending Toxin Infect. Immun., November 1, 2003; 71(11): 6633 - 6640. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Mitchell, L. Gao, and D. R. Demuth Positive and Negative cis-Acting Regulatory Sequences Control Expression of Leukotoxin in Actinobacillus actinomycetemcomitans 652 Infect. Immun., October 1, 2003; 71(10): 5640 - 5649. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. B. Lee, D. C. Hassane, D. L. Cottle, and C. L. Pickett Interactions of Campylobacter jejuni Cytolethal Distending Toxin Subunits CdtA and CdtC with HeLa Cells Infect. Immun., September 1, 2003; 71(9): 4883 - 4890. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. P. Fong, L. Gao, and D. R. Demuth luxS and arcB Control Aerobic Growth of Actinobacillus actinomycetemcomitans under Iron Limitation Infect. Immun., January 1, 2003; 71(1): 298 - 308. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. HENDERSON, M. WILSON, L. SHARP, and J. M. WARD Actinobacillus actinomycetemcomitans J. Med. Microbiol., December 1, 2002; 51(12): 1013 - 1020. [Full Text] [PDF] |
||||
![]() |
L. A. Svensson, P. Henning, and T. Lagergard The Cytolethal Distending Toxin of Haemophilus ducreyi Inhibits Endothelial Cell Proliferation Infect. Immun., May 1, 2002; 70(5): 2665 - 2669. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Henderson Oral bacterial disease and the science of cellular conversation J R Soc Med, January 2, 2002; 95(2): 77 - 80. [Full Text] [PDF] |
||||
![]() |
K. P. Fong, W. O. Chung, R. J. Lamont, and D. R. Demuth Intra- and Interspecies Regulation of Gene Expression by Actinobacillus actinomycetemcomitans LuxS Infect. Immun., December 1, 2001; 69(12): 7625 - 7634. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.J. AHMED, L.A. SVENSSON, L.D. COPE, J.L. LATIMER, E.J. HANSEN, K. AHLMAN, J. BAYAT-TURK, D. KLAMER, and T. LAGERGARD Prevalence of cdtABC genes encoding cytolethal distending toxin among Haemophilus ducreyi and Actinobacillus actinomycetemcomitans strains J. Med. Microbiol., October 1, 2001; 50(10): 860 - 864. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Lewis, M. K. Stevens, J. L. Latimer, C. K. Ward, K. Deng, R. Blick, S. R. Lumbley, C. A. Ison, and E. J. Hansen Characterization of Haemophilus ducreyi cdtA, cdtB, and cdtC Mutants in In Vitro and In Vivo Systems Infect. Immun., September 1, 2001; 69(9): 5626 - 5634. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. C. Hassane, R. B. Lee, M. D. Mendenhall, and C. L. Pickett Cytolethal Distending Toxin Demonstrates Genotoxic Activity in a Yeast Model Infect. Immun., September 1, 2001; 69(9): 5752 - 5759. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Akifusa, S. Poole, J. Lewthwaite, B. Henderson, and S. P. Nair Recombinant Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin Proteins Are Required To Interact To Inhibit Human Cell Cycle Progression and To Stimulate Human Leukocyte Cytokine Synthesis Infect. Immun., September 1, 2001; 69(9): 5925 - 5930. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Shenker, R. H. Hoffmaster, A. Zekavat, N. Yamaguchi, E. T. Lally, and D. R. Demuth Induction of Apoptosis in Human T Cells by Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin Is a Consequence of G2 Arrest of the Cell Cycle J. Immunol., July 1, 2001; 167(1): 435 - 441. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Cortes-Bratti, E. Chaves-Olarte, T. Lagergard, and M. Thelestam Cellular Internalization of Cytolethal Distending Toxin from Haemophilus ducreyi Infect. Immun., December 1, 2000; 68(12): 6903 - 6911. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Cortes-Bratti, C. Karlsson, T. Lagergard, M. Thelestam, and T. Frisan The Haemophilus ducreyi Cytolethal Distending Toxin Induces Cell Cycle Arrest and Apoptosis via the DNA Damage Checkpoint Pathways J. Biol. Chem., February 9, 2001; 276(7): 5296 - 5302. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |