The Role of IL-12 Family Cytokines in the Pathogenesis of Periodontal Disease: A Therapeutic Approach

BACKGROUND: Periodontal disease is a prevalent chronic inflammatory condition of the tooth-supporting tissues characterized by progressive loss of connective attachment and alveolar bone. The IL-12 cytokine family-comprising IL-12, IL-23, IL-27, and IL-35-plays key yet divergent roles in shaping periodontal immune responses through heterodimeric subunits and distinct JAK-STAT signaling pathways. These cytokines differentially regulate inflammation, microbial interactions, and bone resorption. METHODS: This review integrates experimental and clinical evidence assessing IL-12 family members in saliva, gingival crevicular fluid, and periodontal tissues. Studies examining cytokine expression profiles, their correlation with disease activity, microbial dysbiosis, and treatment response were analyzed. Mechanistic data elucidating how IL-12 family signaling modulates inflammatory cascades and osteoclastogenic pathways were also evaluated. RESULTS: IL-12 and IL-23 predominantly amplify pro-inflammatory responses by promoting Th1/Th17 polarization, enhancing neutrophil recruitment, and driving osteoclastogenesis, thereby linking dysbiotic biofilms to tissue destruction. In contrast, IL-27 and IL-35 exhibit context-dependent immunoregulatory properties, inducing IL-10-mediated anti-inflammatory signaling and expanding regulatory T and B cell compartments to support the resolution of inflammation. Across clinical samples, cytokine levels consistently reflect disease severity and demonstrate modulation following periodontal therapy, underscoring their potential as adjunctive biomarkers. CONCLUSION: Members of the IL-12 cytokine family exert both pathogenic and protective influences in periodontal disease. Therapeutic strategies that suppress IL-12/IL-23-driven inflammation while augmenting IL-27/IL-35-mediated regulation show promise as host-modulatory approaches in periodontal treatment. A deeper understanding of these immunologic dynamics may advance precision-based periodontal therapies.