IL-22 regulation of functional gene expression in salivary gland cells

Microarray analysis using the HumanHT-12 v4 Expression BeadChip was utilized to determine the biological function of IL-22. The data indicate an extensive effect of IL-22 on many major molecular functions including activation of antimicrobial genes and downregulation of immune-associated pathways. Functional studies performed in-vitro using human salivary gland cells treated with IL-22 indicated a direct effect of IL-22 on cell cycling, specifically reducing cellular proliferation at the G2-M phase by activation of STAT3. Total RNAs were obtained from salivary gland cells stimulated with recombinant IL-22 for 45 minutes. Differential expression analyses were conducted using the LIMMA package from the Bioconductor project. MTT assay, flow cytometry and western blotting were used to identify the function of IL-22 on human salivary gland cells.