Fig. 2
From: The cytokine network involved in the host immune response to periodontitis
The cytokine network in the pathogenesis of periodontitis. In this figure, the effects of cytokines in the host immune response are shown at the level of intercellular interactions. Briefly, well-established pro-inflammatory cytokines from IL-1, IL-6 and TNF families are secreted by host periodontal cells and immunocytes after stimulation by pathobionts, which activates and recruits specific immune cell subsets and causes direct tissue damage. Then, naive T cells and B cells differentiate into mature T cells or plasma cells under the action of specific cytokines and further activate or promote other effector cells, such as osteoclasts and neutrophils, which exert pro-inflammatory or anti-inflammatory effects by secreting cell-specific cytokine clusters. Among these cell subsets, Th1 and Treg cells mainly act as protectors, while Th2/B and Th17 cells exert complex effects that may lead to tissue destruction or protection under certain circumstances (full lines: the effect of cytokines on cells and the interactions between cells; dashed lines: the secretion of cytokines)
