Interleukin-18 Regulations Of Oral Epithelial Cells By Candida Albicans

BACKGROUND:Candida albicans is a parasitic population in the normal oral mucosa, skin, gastrointestinal, respiratory and reproductive tract and other parts of the opportunistic pathogenic fungi, including the mouth of the carrier rate is highest. In recent years, with the wideness use of broad-spectrum antibiotics, cytotoxic drug and immunosuppressive drugs. the increase of AIDS diabetes, cancer patients, the evolve of many therapeutic tools such as organ transplantation and catheter intervention, the host immune function is low or dysbacteriosis, so that the incidence of oral candidiasis is rising rapidly. During the inflammation process, the mucosa as an important natural barrier, epithelial cells also play active roles in mucosal immune responses, including antigen presentation, antimicrobial activity, and the production of multiple cytokines such as IL-1βand the recently described IL-18. Since its discovery, IL-18 has been found to contribute to protective immunity against a variety of pathogens, including Cryptococcus, Leishmania, and Salmonella species and Mycobacterium Tuberculosis. However, on Candida albicans and IL-18 does not have much related research, and IL-18 in the local anti-Candida albicans oral epithelial cells in the mechanism of disease is still not very clear.OBJECTIVE:To investigate the change of interleukin-18(IL-18)in oral epithelial cells(KB cells)infected with the different dimorphism and different density of Candida albicans.METHODS:The different dimorphism of Candida albicans were cultured with in oral epithelial in vitro and the adherent numbers were counted after Gram Staining in 3,6,12,24 hours. ELISA and RT-PCR were applied to determine the levels of IL-18 protein or mRNA expression in the KB cells induced by the phase form and hypha form Candida albicans. The experiments were repeated three times, and the means±standard deviations (SD) were plotted.RESULTS:The functions of C. albicans adherence to oral epithelial cells were time anddose dependent. The transformation of candida from blastospores to hyphae was time dependent.the percentage of the hyphal form rose as time extend. Candida albicans induced the oral epithelial cells secrete more IL-18. Candida albicans and oral epithelial cells induced production of IL-18 protein levels were significantly higher and increased with concentration, The expression of IL-18 was also time dependence, achieve a peak at 12 hours and then appeared downturn, oral epithelial cells was coculture with candida albicans for 12 hours, the expression of IL-18 mRNA was higher than control group.CONCLUSION:1.The functions of C. albicans adherence to oral epithelial cells were time and dose dependent.The actions of C.albicans aherece to oral epithelial cells were specific.2. Candida albicans to oral epithelial cells induced expression of IL-18..3.Candida albicans stimulated oral epithelial cells to produce IL-18 time-dependent 4. Candida albicans is responsible for the production of IL-18 secreted by oral epithelial cells which can be expected to play an important role in the infection and defection with the local oral mucosa.