Other types of cells involved in the innate immunity:
Dendritic cell Eosinophil granulocyte Basophilic granulocyte Mast cell
三. Innate effector molecules and their main function
（二） Blood-brain barrier （三） blood –fetus barrier
二. Cells involved in innate immunity and their functions Phagocute Natural killer cells γδ T cells NKT cells B1 cells
Phagocytes
Biological functions
Anti-infection Anti-tumor: directly contact and fuse with the tumour cell membrane ; cytotoxic substance, proteinase, cytolysin, TNF-α,ADCC mediated by tumor specific antibody Antigen processing and presentation Immunoregulation
一. Tissue barriers and their effection
（一）The skin and mucosal surfaces provide protective barriers against infection Physical barriers: epithelial, cilia, mucus Chemical barriers: lactic acid, unsaturated fatty acid, gastric acid Biological barriers: microorganisms
3. γδ T cell
Distributions: epithelia, mucosa surface markers: γδTCR, CD2/3/16/25/45, LFA-1，DN Molecular recognition: Narrow spectrum of antigen recognition：HSP, CD1 complex, viral proteins (VP) The same group of cells express only one kind of γδTCR : same specificity of antigen recognition—response to common antigen Biological Function: anti-infection in skin and mucosa, anti-tumor, immunoregulation
Recognized molecules
Corresponding carbohydrate and phosphatide LPS Antigens entrapped by C3b Antigens specially bound by IgG PAMP
Phagocytes Biological functions
Oxygen-dependent killing mechanisms
acid pH, lysozyme , lactoferrin, cationic protein, elastase
Secretion of factors
Released in appropriate or large quantities Cytokines：TNF-α, IL-1, IL-6, IL-8, IL-12, MCP-1 Inflammation mediators：prostaglandin E, LTB4, PAF, phosphatidase, peroxidate → Local inflammatory reaction（TNF-α、IL-1、 LTB4） → Fever and acute phase reaction（CRP、MBL） → Immunoregulation（IL-1、IL-6、IL-12）
Antimicrobial and cytotoxic activity
Oxygen-dependent, Oxygen-independent
Secretion of factors
Cytokines, Inflammantory mediators
Antigen presentation
Intrinsic, Extrinsic
Phagocytes
Biological functions
surface receptors of phagocytes
Mannitol, fucose, phosphatide receptor CR3, CR4 , CD14 C3bR FcγR Toll-like receptor scavenger
2. NK Cells
PBMC, Spleen
Large amount of azurophil granule in the cytoplasma Kill the target cells directly with no needs of preactivation surface markers:CD3-, CD56＋, CD16＋
（三） Defensin （四） Lysozyme （五） β-Lysin
Section 2 Phases of innate immune response
Transient phase of innate immune response Early phase of innate immune response Induction Phase of adaptive immune response
Section I Tissue,cells and molecules of the innate immune system
Innate Immunity
Acquired Immunity
Native Immunity
Adaptive Immunity
Nonspecific Immunity
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NK cells
Molecular recognition: killer activatory receptor(KAR) killer inhibitory receptor(KIR) KAR KAR recognize cell carbohydrate ligands →ITAM→transduce activation signals KIR The extracellular region of KIR recognize MHC-I of self cells →ITIM→ transduce inhibitory signals Regulation of NK cell killing effect by two receptors
4. NKT cells
Distribution:liver, bone marrow, thymus surface marker: NK1.1, TCR-CD3 complex molecular recognition Narrow spectrum of antigen recognition ：CD1 complex， without MHC restriction Biological function: anti-infection, anti-tumor, involved in immunoregulation by secreting cytokines
Cells in innate immunity and their functions
一. Tissue,cells and molecules of the innate immune system 二.Phases of innate immune responses 三.Characteristics of innate immune response and its relationship with adaptive immune response
NK cells
Biological Functions Anti-infection：lysis, IFN-γ and TNF-β Anti-tumor： directly contact and fuse with tumour cells membrane ADCC mediated by tumor specific antibodies Immunoregulation
Specific Immunity
Species development, formed evolutionally Possess from the time of birth，react rapidly ， Non-specific anti-infection immunity, also involved in specific immunity
（一）complement system
（二）Cytokines 1. Cytokines to induce anti-viral ability 2. Cytokines to induce and promote Inflammatory reactions 3. Cytokines to induce and enhance anti-tumor abilities
1. phagocytes
Mononuclear phagocyte system
neutrophils