Wondershare EdrawMind
마인드 맵 갤러리 Medical Immunology—Immune Tolerance Mind Map
- 76
Medical Immunology—Immune Tolerance Mind Map
This is an article about medical immunology - immune tolerance mind map, the formation of immune tolerance, immune tolerance mechanism, immune tolerance and clinical practice, etc.
2023-11-09 12:23:41에 편집됨
- 추천 사항
- 개요
Immune tolerance
The development of immune tolerance
Immune tolerance caused by exposure to antigens during embryonic and neonatal stages
Immune tolerance caused by acquired antigen exposure
Antigenic factors
Antigen dose
Low band tolerance and high band tolerance
The antigen dose is too low → not enough to activate T cells and B cells
The antigen dose is too high → Inducing apoptosis of responding cells/Inducing regulatory T cells → Inhibiting immune response
B cell tolerance and T cell tolerance
T vs B cells
The amount of antigen required for T cell tolerance is smaller than that of B cells
Occurs quickly (peak within 24 hours)
Lasts for a long time (months to years)
specific
High-dose TI antigen → induce B cell tolerance
Low dose/high dose TD antigen → induce B cell tolerance
Low dose/high dose TD antigen → induce T cell tolerance
Antigen type and dosage form
Protein monomers are not easily taken up by APC and presented to T cells → T cells cannot assist B cells in producing corresponding antibodies.
Protein monomer adjuvant → easily absorbed by APC to induce normal immune response
Antigen immunity pathway
Tolerance level: oral administration > intravenous injection > intraperitoneal injection > intramuscular injection > subcutaneous and intradermal injection
Oral—separation tolerated
Make intestinal CD4 T cells produce TGF-B and IL-4→Induce B cells to produce IgA to exert local immune effects on the mucosa, and induce Treg to lead to systemic immune tolerance.
Antigen persists
T cells that are simply repeatedly stimulated by self-antigens without costimulatory signals provided by activated APC → prone to apoptosis
Antigenic epitope characteristics
Tolerogenic epitope
body factors
age and developmental stage
Embryonic stage>Neonatal stage>Adult animals
Physiological state
Antigen induction immunosuppressant
genetic background
immune tolerance mechanism
central tolerance
Establishment of T cell central tolerance
clone cleanup
The TCR expressed by SP binds with high affinity to the self-antigen peptide-MHC expressed by TEC (thymic epithelial cells) or thymic DC → apoptosis
Some autoreactive T cells bind to the corresponding self-antigen → develop into Tregs
autoantigen
Autoantigens commonly found in cells of various tissues in the body
Tissue-specific antigens (TSAs) expressed by specific tissues
autoimmune regulatory factor (AIRE)
Establishment of B cell central tolerance
peripheral tolerance
clone cleanup
High level of antigen→T cells are repeatedly reactivated→Upregulate the expression of Fas and ligand FasL→Apoptosis
High level of antigen → extensive cross-linking of B cell receptors → loss of auxiliary signals provided by T cells → B cell apoptosis
immune neglect
Low self-antigen expression level/low affinity to TCR or BCR → unable to effectively activate corresponding T and B cells
Clonal incapacitation or inactivation
T cells express TCR and recognize the antigen peptide-MHC presented by immature DC to produce the first signal → no IL-12 and cannot produce the second signal → clonal incompetence
B cells lose T cell help → cannot be effectively activated
The role of immune regulatory cells
Tregs
nTreg naturally arises in thymocyte development
Cell-to-cell contact → inhibition
Peripherally induced iTreg
Secretion of TGF-B and IL-10→Inhibition
Antigens at immunoprivileged sites do not elicit an immune response under physiological conditions
Immune tolerance and clinical
induce immune tolerance
Antigen administered orally or intravenously
Use allosteric peptide ligands
block costimulatory signals
induce immune deviation
Using cytokines to induce Th1/Th17 deviation towards Th2
Bone marrow and thymus transplant
Adoptive infusion of suppressive immune cells
Break immune tolerance
checkpoint blocking
CTLA-4 and PD-1 blocking antibodies
Activate costimulatory signals
Inhibit Treg cells
Enhance the functions of DC
Rational use of cytokines and their antibodies