Cytokine mRNA expression in the labial salivary glands of healthy volunteers

OBJECTIVE: To examine the cytokine profile in minor salivary glands of healthy volunteers and examine differential cytokine production from acinar and ductal tissues. STUDY DESIGN: Acinar and ductal elements were isolated by a cell-specific micro-dissection technique from frozen 8 microns sections of minor salivary glands from healthy volunteers. Reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern hybridization using 32P-labeled cytokine gene-specific probes were utilized to detect cytokine mRNA. mRNA transcripts for the Th1 cytokines (IL-2, TNF-alpha, and IFN-gamma), Th2 cytokines (IL-4, IL-6, and IL-10), TGF-beta, actin, and CD3 delta were analyzed in acini, ducts and total tissue sections of minor salivary glands of six healthy controls. RESULTS: Actin, TGF beta and TNF alpha was present in 6/6 acinar, 6/6 ductal, and 6/6 total section samples. IFN gamma was present in 2/6 acinar, 3/6 ductal, and 6/6 total samples. IL-2 was found in 3/6 acinar, 3/6 ductal and 5/6 total sections. IL-6 was found in 1/6 acinar, 0/6 ductal, and 5/6 total sections. IL-10 was found in 3/6 acinar, 3/6 ductal, and 5/6 total sections. IL-4 was present in 0/6 acinar, 0/6 ductal and 1/6 total samples. CD3 delta was present in 6/6 acinar, 5/6 ductal and 6/6 total sections. CONCLUSIONS: These results demonstrate abundant expression of cytokines in healthy minor salivary glands. The production of these cytokines in healthy tissues demonstrates a likely role of supporting normal cellular function.