T helper 1 and 2 stimuli induce distinct phenotypes in gingival fibroblasts

Abstract

Objective: Gingival fibroblasts (GFs) can participate in the immune response and play an immune-regulatory role. This study was to evaluate whether GFs can be differently activated and polarized into distinct functional subtypes in response to T helper type 1 (Th1), or Th2 stimuli. Design: Human GFs were stimulated by the Thl cytokine, IFN-gamma, and lipopolysaccharide (LPS), separately or in combination (Thl stimuli), or by Th2 cytokines, IL-4 and IL-13, separately or in combination (Th2 stimuli). mRNA expression of pro-inflammatory cytokines (IL-1 beta, IL-6, IL-12), anti-inflammatory cytokines (IL-4, IL-10, IL-13), chemokines ((C-X-C motif chemokine (CXCL)10, CXCL11, C-C motif ligand 20), molecules involved in antigen presentation ((human leukocyte antigen (HLA)-ABC, HLA-DP, CD74, CD40)), LPS-recognizing components (Toll-like receptor 4, CD14), collagen type 1 (COL1), matrix metalloproteinase (MMP)-1, and inducible nitric oxide synthase (iNOS) and the protein levels of IL-6, CXCL11, CD14, and COL1 accumulated in supernatants were analyzed using real-time PCR and ELISA, respectively. The cell surface levels of the molecules involved in antigen presentation were detected by flow cytometry. Results: Thl stimuli strongly upregulated the expression of diverse cytokines, chemokines, molecules involved in antigen presentation, LPS-recognizing components, MMP-1, and iNOS, whereas Thl stimuli inhibited the expression of COLI. In contrast, Th2 stimuli strongly upregulated the levels of COL1 and IL-4, while the expression levels of the other factors were minimally affected or even inhibited. Conclusion: These results show that GFs can be polarized into functionally distinct subtypes, immune-activating but tissue-destructive GF1 or tissue-reparative GF2, in response to Th1 and Th2 stimuli, respectively.