Identification by DNA microarray of genes involved in Candida albicans-treated gingival epithelial cells.

Background: Oral epithelial cells significantly influence host inflammatory responses against Candida albicans in oropharyngeal candidiasis. Pro-inflammatory cytokines function as an early innate immune system mediator during C. albicans infection in oral epithelial cells. We sought to elucidate the pattern of the molecular mechanisms governing the human gingival epithelial cells (HGECs) to C. albicans infection likely involve multiple converging signal transduction pathways.

Materials And Methods: Primary HGECs were cultured with C. albicans ATCC90029. Total RNA was extracted after 8 h of infection and monitored mRNA levels using Affymetrix GeneChip (Human Genome U133 plus 2.0 Array, 48 000 genes). GeneChip data was analyzed by GeneSpring software and Ingenuity Pathway Analysis system. Reverse transcription polymerase chain reaction (RT-PCR), real-time RT-PCR and immunohistochemistry were used to investigate gene expression changes.

Results: The differentially expressed genes represented functions as diverse as immune response and inflammatory disease. IL-8, ICAM-1 and Cox-2 showed a greater than two fold change in expression relative to those in control cells. Altered mRNA levels in GeneChip analysis were confirmed by RT-PCR and real-time RT-PCR. Stronger immunoreactivity against ICAM-1 and Cox-2 was also observed in the infection with C. albicans in rat gingival epithelium. We have identified differential gene expression up-regulated or down-regulated with the up-regulation of IL-8 in C. albicans-treated cells.

Conclusion: These findings indicate that the molecular mechanisms underlying the IL-8 response of HGECs to C. albicans infection likely involve multiple converging signal transduction pathways.