自身免疫耐受 Layers of self-tolerance Type of tolerance Mechanism Site of action Central tolerance Deletion Editing Bone marrow Physical barrier to Antigen segregation self-antigen access Peripheral organs to lymphoid system (e. g. thyroid, pancreas) Cellular inactivation b Peripheral anergy weak signaling without Secondary lymphoid tissue )-stimulus Regulatory cells Suppression by cytokines, Secondary lymphoid tissue intercellular signals and sites of inflammation Cytokine deviation Differentiation to TH2 cells, Secondary lymphoid tissue limiting inflammatory and sites of inflammation cytokine secretio Clonal deletion Apoptosis post-activation Secondary lymphoid tissue and sites of inflammation自身免疫耐受