Induction of adaptive immunity Differentiation of Th Cytokines Cell-mediated immunity Humoral immunity Immunological memory Immune effector function
Gene rearranged receptors: TCR/BCR Foreign Ags………. 對外
Adaptive immunity 1. Antigen specificity 2. Diversity 3. Immunological memory 4. Self tolerance Four characteristics
Clonal selection Immune diversity Antigen specificity Diversity Memory Central tolerance Peripheral tolerance
Sites of effector function Primary (Central): Bone marrow 骨髓 Thymus 胸腺 Secondary (Pheripheral): Lymph nodes 淋巴結 Spleen 脾臟 Peyer’s patches
Lymph node distribution in the body
Ag Innate Adaptive ExtracellularPhagocytes B cells Intracellular NK CD8 Tc cells (Altered self) Immunity & Ag location Cytotoxicity CD4 Th Humoral response Cell-mediated immunity (CMI) 1 2
Phagocytes Antigen-Presenting Cells (APC) B/T cells Lymphocyte activation Clonal selection Humoral Imm/CMI Memory Inflammatory site Inflammation Inflammatory site Lymph node Induction of adaptive immunity Dendritic cells (DC)
Lymph node DC T HEV T cell activation
Induction of adaptive immunity Differentiation of CD4 Th Cytokines Cell-mediated immunity Humoral immunity Immunological memory Immune effector function
Naïve, activated, effector Humoral immunityCell-mediated immunity (CMI) Activation Effector
Three signals in naïve T cell activation Priming The activation and differentiation of naïve T cells Costimulation
Professional APC
Ag & MHC presentation pathways DC/Macrophages/B cells Foreign or Self Ag Signal 1
Signal 2 Signal 2 alone
CD4 T cell activation IL2 production Clonal expansion Signal 1+2 IL2R
Professional APC
Lack of signal 2 upon T cell activation Peripheral tolerance
Negative regulation of signal 2 upon T cell activation Peripheral tolerance Inhibition of activated T cells
CD4 T cell differentiation CMI: CD8 T Humoral response Th17 Promote local inflammation
Signal 3: cytokine
Induction of adaptive immunity Differentiation of Th Cytokines Cell-mediated immunity Humoral immunity Immunological memory Immune effector function Effector response
Innate immunity Activation Effector phase
IL6 Chemokines Amplifier of acute Inflammation (local site, BM) Recruitment of neutrophils Activation of macrophages Expression of antimicrobial peptides IL17 Ubiquitous expression of IL17R: fibroblasts, epithelial cells, keratinocytes, etc. Rapid T cell response to infection: Th17 G-CSF GM-CSF
CD4 T cell differentiation CD8 T CMI Humoral immunity
CMI: Macrophages activated by Th1 APC activation
Cytotoxic granules CMI: CD8T cytotoxic response
Membrane effector molecule
Effector T cells
Induction of adaptive immunity Differentiation of Th Cytokines Cell-mediated immunity Humoral immunity Immunological memory Immune effector function Effector response
Effector Th2 cells Humoral immunity: B cell response B cells as APC
Affinity maturation 2. Somatic hypermutation 1. Isotype switching 3. Memory CD4T-dependent:
Effector response CD4 Th17, Th1/ Th2 CD8 Tc B cells
Induction of adaptive immunity Differentiation of Th Cytokines Cell-mediated immunity Humoral immunity Immunological memory Immune effector function
Adaptive immunity
Protective immunity & time Apoptosis of effectors Memory cells:long-lived