Th1/Th2

CD4 T-cells can be subdivided into Th1, Th2, Th17, and Treg subsets on the basis of their pattern of cytokine production. Protective Th1-related cytokines (Interleukin (IL)-2 and interferon (IFN)-γ) are involved in cellular immune responses. Th2-related cytokines (IL-4 and IL-10) are associated with humoral immunity and anti-inflammatory properties. However, these arise in a later period of periodontitis and are involved in the chronic progression of the disease. Th17 was identified as cells that recruited neutrophils and macrophages to participate and amplify the inflammatory reaction.

Th1/Th2 Cytokine