Previous Article | Next Article ![]()
Infection and Immunity, October 2003, p. 5598-5604, Vol. 71, No. 10
0019-9567/03/$08.00+0 DOI: 10.1128/IAI.71.10.5598-5604.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.
Division of Oral Immunology,1 Division of Periodontology and Endodontology,2 Division of Oral Microbiology, Department of Oral Biology, Tohoku University Graduate School of Dentistry, Sendai 980-8575,3 Department of Immunology and Medical Zoology, Kagoshima University Graduate School of Medicine, Kagoshima 890-8544, Japan4
Received 28 May 2003/ Returned for modification 8 July 2003/ Accepted 21 July 2003
It has recently been shown that human salivary glands constitutively express CD14, an important molecule in innate immunity, and that a soluble form of CD14 is secreted in saliva. The concentration of CD14 in parotid (a serous gland) saliva was comparable to that in normal serum and 10-fold the amount in whole saliva, although the physiological function of saliva CD14 remained unclear. Actinobacillus actinomycetemcomitans is a periodontopathic bacterium and is able to invade oral epithelial cells. The present study showed that upon exposure to live A. actinomycetemcomitans Y4 for 2 h, human oral epithelial HSC-2 cells produced interleukin-8 (IL-8) for a further 24 h and whole saliva augmented the production induced by A. actinomycetemcomitans Y4. Parotid saliva showed a more pronounced effect on the production of IL-8 than whole saliva. Neither saliva preparation itself had IL-8-inducing activity. Parotid saliva exhibited antibacterial activity against a low concentration of A. actinomycetemcomitans Y4, but recombinant CD14 did not show the activity. The internalization of A. actinomycetemcomitans Y4 into HSC-2 cells was inhibited by cytochalasin B, indicating that the process was actin dependent, and depletion of CD14 from parotid saliva inhibited the invasion and, as a consequence, inhibited production of IL-8. Furthermore, human recombinant CD14 augmented invasion and IL-8 production. These results suggest that saliva CD14 promoted the invasion of oral epithelial cells by A. actinomycetemcomitans and consequently augmented the production of IL-8, playing an important role in innate immunity in the oral cavity.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»