Bacteria recovered from dental pulp induce apoptosis of lymph node cells.
Apoptosis is critical in the pathogenesis of several infectious diseases. The induction of apoptosis was assessed in mouse lymph node cells by four bacteria recovered from infected human dental pulp: Gemella morbillorum, Clostridium butyricum, Fusobacterium nucleatum and Bifidobacterium adolescentis. Smaller lymph nodes and smaller numbers of cells were observed after experimental dental pulp infection with C. butyricum, suggesting that this bacterium induces cell death. Apoptosis was evaluated by determination of cell ploidy and detection of DNA degradation in cells cultured with killed bacteria. Paraformaldehyde-killed C. butyricum and heat-killed G. morbillorum induced substantial cell death, while F. nucleatum and B. adolescentis induced cell death at lower levels. No bacterial preparations induced apoptosis in cells from mice genetically deficient for tumour necrosis factor receptor p55 (TNFRp55), implicating this receptor directly or indirectly as a mediator in the process. It was concluded that apoptosis may be induced during periapical lesions of pulpal origin.
Ribeiro-Sobrinho
A P
AP
Dental School1, Department of Biochemistry and Immunology/ICB2 and Department of Microbiology/ICB3, Universidade Federal de Minas Gerais (UFMG), CP 486, 30161-970, Belo Horizonte, Brazil 4Department of Microbiology - Institute of Microbiology 'Professor Paulo de Góes', UFRJ, Rio de Janeiro, Brazil.
Rabelo
F LA
F
Dental School1, Department of Biochemistry and Immunology/ICB2 and Department of Microbiology/ICB3, Universidade Federal de Minas Gerais (UFMG), CP 486, 30161-970, Belo Horizonte, Brazil 4Department of Microbiology - Institute of Microbiology 'Professor Paulo de Góes', UFRJ, Rio de Janeiro, Brazil.
Figueiredo
C Bo
CB
Dental School1, Department of Biochemistry and Immunology/ICB2 and Department of Microbiology/ICB3, Universidade Federal de Minas Gerais (UFMG), CP 486, 30161-970, Belo Horizonte, Brazil 4Department of Microbiology - Institute of Microbiology 'Professor Paulo de Góes', UFRJ, Rio de Janeiro, Brazil.
Alvarez-Leite
J I
JI
Dental School1, Department of Biochemistry and Immunology/ICB2 and Department of Microbiology/ICB3, Universidade Federal de Minas Gerais (UFMG), CP 486, 30161-970, Belo Horizonte, Brazil 4Department of Microbiology - Institute of Microbiology 'Professor Paulo de Góes', UFRJ, Rio de Janeiro, Brazil.
Nicoli
J R
JR
Dental School1, Department of Biochemistry and Immunology/ICB2 and Department of Microbiology/ICB3, Universidade Federal de Minas Gerais (UFMG), CP 486, 30161-970, Belo Horizonte, Brazil 4Department of Microbiology - Institute of Microbiology 'Professor Paulo de Góes', UFRJ, Rio de Janeiro, Brazil.
Uzeda
M
M
Dental School1, Department of Biochemistry and Immunology/ICB2 and Department of Microbiology/ICB3, Universidade Federal de Minas Gerais (UFMG), CP 486, 30161-970, Belo Horizonte, Brazil 4Department of Microbiology - Institute of Microbiology 'Professor Paulo de Góes', UFRJ, Rio de Janeiro, Brazil.
Vieira
L Q
LQ
Dental School1, Department of Biochemistry and Immunology/ICB2 and Department of Microbiology/ICB3, Universidade Federal de Minas Gerais (UFMG), CP 486, 30161-970, Belo Horizonte, Brazil 4Department of Microbiology - Institute of Microbiology 'Professor Paulo de Góes', UFRJ, Rio de Janeiro, Brazil.
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D003782:Dental Pulp / Q000382:microbiology*; D003786:Dental Pulp Cavity / Q000382:microbiology; D008198:Lymph Nodes / Q000166:cytology* / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains
D004269:DNA, Bacterial