Table 2.

Cell types and their role in the pathogenesis of OLP

Cell Type	Role in Pathogenesis
Keratinocytes	Express MHC-I and MHC-II (when stimulated), release inflammatory mediators and undergo apoptosis/pyroptosis
Langerhans cells	Once activated, they migrate from the epithelium to the lymph nodes and present antigens to naive T cells
Dendritic cells	Present antigens to T lymphocytes
Näive T cell	Differentiates into effector subtypes following activation by APCs
Th1	Produces IFN-γ, IL-2 and TNF-α, exacerbating inflammation and promoting TCD8+activation
Th2	Modulates the inflammatory response and contributes to less aggressive forms of OLP
Th17	Secretes pro-inflammatory cytokines, amplifying inflammation and tissue destruction
Treg	Produces IL-10 and TGF-β, regulates inflammation and balances the immune response
TCD8+ cell	Induces keratinocyte apoptosis through perforin/granzyme B release, FasL/Fas interaction and TNF-α signaling
MAIT cell	Produce granzyme B contributing to apoptosis and possibly pyroptosis of keratinocytes
M1 macrophage	Promote chronic inflammation through antigen presentation and secretion of TNF-α and IL-1β
M2 macrophage	Have an anti-inflammatory or pro-reparative function
Mast cells	Amplify inflammation through the release of inflammatory mediators and angiogenic factors. They activate MMP-9 and contribute to the rupture of the basement membrane
Fibroblasts	Promote angiogenesis, induce proliferation and migration of CD4 + T and inhibit their apoptosis