Acta Vet. Brno 2008, 77: 377-385

https://doi.org/10.2754/avb200877030377

Local and Systemic Up-regulation of TNFα, IL-1β and IL-6 in Mice Intratracheally Inoculated with Porphyromonas gingivalis

Z. Pavlica1, A. Nemec1, A. Nemec-Svete1, D. Eržen2, D. A. Crossley1, M. Petelin3

1Veterinary Faculty, Small Animal Clinic, University of Ljubljana, Slovenia
2University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia
3Department for Oral Medicine and Periodontology, Faculty of Medicine, University of Ljubljana, Slovenia

Received November 7, 2007
Accepted April 14, 2008

The objective of the study was to find whether a single intratracheal inoculation with live Porphyromonas gingivalis ATCC 33277 influences local and systemic inflammatory and immune responses in mice.Twelve-week-old BALB/c mice were intratracheally inoculated with 2.9 × 109 CFU P. gingivalis ATCC 33277 diluted in 40 μl sterile phosphate buffer (treated group) or with sterile PBS (control group). The animals were sacrificed 2, 6, 24, 72 and 168 h after inoculation. TNFα, IL-1β, IL-6 and total protein concentrations were measured in the serum, lungs and kidneys. Six hours after P. gingivalis inoculation, TNFα concentration was significantly increased in serum (p = 0.02) and kidneys (p = 0.04), but in the lungs TNFα production was enhanced already 2 h (p < 0.0001) after inoculation, reaching the peak after 6 h (p < 0.0001). The IL-1β concentration was also significantly increased in serum after 2 h (p = 0.006), remaining significantly elevated up to 3 days (p ≤ 0.0001) after inoculation. In lungs IL-1β levels were significantly increased 6 and 24 h (p < 0.0001) and in kidneys 24 h (p < 0.0001) and 168 h (p = 0.01) after inoculation. The IL-6 concentration was significantly increased in serum after 72 and 168 h (p < 0.0001). However, IL-6 was significantly increased in lungs after 6 h (p < 0.0001), remaining elevated until 72 h and in kidneys 2 and 6 h (p < 0.0001) after inoculation. Significantly increased total protein concentration was detected in kidneys 6 and 24 h (p < 0.0001) after inoculation. These results suggest that a single intratracheal inoculation with P. gingivalis stimulates the local and systemic inflammatory and immune response, as shown by increased tissue and serum levels of proinflammatory cytokines.