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Innate immunity Innate immunity Part overview of innate immunity Part innate immune cells Part functions of innate immun ity

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Page 1: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Innate immunityInnate immunity

Part overview of innate immunityⅠ Part innate immune cellsⅡ Part functions of innate immunityⅢ

Page 2: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

1. definition of innate immunity

protection against infections that relies on the mechanisms that exist before infection and are capable of rapid response to pathogens .

.Innate immunity is the first line of defence against infection

Page 3: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 4: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

2.Characteristics

   set up at birth    non –specific    hereditable no immune memory Little individual difference

Innate immunity

Page 5: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

3.Composition

Barriers

Humoral factors

Cells

----Phagocytes (neutrophils, macrophages)

natural killer cells(NK)

Page 6: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

1)  Barriers mechanical defense: skin & mucous membrane Anatomic barrier

.blood-brain barrier, .blood-placental barrier . Blood – thymus barrier

Biological barrier: normal flora

Page 7: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

2)  humoral factors complement l

ysozyme Cytokine

Page 8: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

3)Cells of the innate immunity NK cells

Phagocytes: neutrophils monocytes, macrophages

Others: DC, basophils, mast cells eosinophils, γδT cells, B1 cells,NKT cells

Page 9: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Hematopoietic Stem Cell

Page 10: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 11: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Part innate immune cells Ⅱ-----Immunocytes participating in innate immunity

Phagocytes (Macrophage)

NK cells

Other cells

Page 12: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

2. Natural killer( NK )cells in innate immunity

Concept : large lymphocytes which can directly kill tumor cells and virus-infected cells without induction of antigens

Page 13: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Source: Bone marrow, exist mainly in peripheral blood, spleen and liver.

Characteristics : contain cytotoxic substances functions: 1) Fighting infection and cancer killing virus infected cells and tumor cells 2) Immunoregulation secreting INF-γ

Natural killer cells (NK)

Page 14: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

1). Recognition

(1). Direct recognition receptors Recognizing tumor cell and virus- infected cell

(2). FcR Recognizing Ab-bound target cell

Page 15: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

(1). Direct recognition receptors

HLA I molecules recognizing receptors

Non-HLA I molecules recognizing receptors

Page 16: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

(1). Direct recognition receptors HLA I molecules recognizing receptors

1 ) killer immunoglobulin-like receptor KIR2DL, KIR2DS; KIR3DL, KIR3DS 2 ) killer lectin-like receptor CD94/NKG2A, CD94/NKG2C

recognize the MHC-I molecules on normal cells in normal condition, transduce inhibitory signals t

o inhibit the killing effect of NK cell.

Page 17: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

(1). Direct recognition receptors

1 ) natural cytotoxicity receptors,NCR )

NKp30,NKp44,NKp46 2 ) NKG2D

recognize the ligands on virus-infected cells and some tumor cells

----transduce active signals to kill target cells

Page 18: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Normal condition:HLA I molecules recognizing receptors (KIR,KLR) inhibition effect > activation effect ----- killing effect of NK cell is inhibited Abnormal condition: Non-HLA I molecules recognizing receptors (NCR NKG2D)Activation effect > inhibition effect -----NK cells kill target cells

Page 19: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

(2). FcR Recognizing Ab-bound target cell

ADCC

Page 20: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

2. The mechanisms of killing

perforin and granuzymePerforin: creates pores in target cell membranesgranzymes : enzymes which enter through perforin pores and induce apoptosis of target cells.

Fas-FasL pathway

Page 21: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

NK cell

Target cell

Page 22: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 23: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 24: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Source: Bone marrow, exist mainly in peripheral blood, spleen and liver.

Characteristics : contain cytotoxic substances

functions: 1) Fighting infection and cancer killing virus infected cells and tumor cell

s 2) Immunoregulation secreting INF-γto enhance immune respo

nse

Natural killer cells (NK)

Page 25: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Monocyte/ macrophage

Page 26: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Macrophages are 5- to 10-fold larger than monocytes and contain more organelles, especially lysosomes

Mononuclear phagocytes

Page 27: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 28: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

  Process of phagocytosis

Recognization

Endocytosis

Killing and digestion

Page 29: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Macrophages are 5- to 10-fold larger than monocytes and contain more organelles, especially lysosomes

Mononuclear phagocytes

Page 30: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

1) Recognition

(1) pattern recognition receptors(2) Opsonic receptor

Page 31: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Recognition(1) pattern recognition receptors----- pathogen associated molecular patte

rn, PAMP PAMP:distinct structures or components that are common for many pathogens e.g. LPS, proteoglycan, N-formylated peptides, double RNA of viruses et al.

Page 32: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Pattern recognition receptors, PRRthe receptors that can recognize pathogen associated molecular patterns, locating on the surface of macrophages

e.g. mannose receptor, scavenger receptor, CD14, Toll like receptors et al.

Page 33: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
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(2) Opsonic receptor

FcR the receptor for Fc region of Ab

CR the receptor for complement component,C3b/4b

Page 36: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 37: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 38: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

2) Endocytosis

Page 39: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Activated macrophages kill phagocytosed microbes by producing microbicidal molecules in phagolysosome

Oxygen-dependent system. Oxygen-independent system:

---Low pH(3.5-4) , Lysozyme

3) killing and digestion

Page 40: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

oxygen-dependent system:

reactive oxygen intermediates, ROIs

NADPH+ O2 O2- ,OH- , H2O2 ,

1O2

reactive nitrogen intermediates, RNIs:

inducible nitric oxide synthase, NO

oxygen-independent system

Low PH (3.5-4.0), lysozyme

Digestion by various types of enzymes in phagocytes

Page 41: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 42: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 43: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Functions of monocyte/macrophage

•Phagocytosis

•Induction of inflammation

•Presentation of antigen

Page 44: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity

Part III functions of innate immunity

1. Fighting infection

2. Taking part in adaptive immunity1)Innate immunity initiates adaptive immunity Presenting antigensExpressing B7 2)Innate immunity regulats adaptive immunit

yC3dReleasing cytokines

Page 45: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity
Page 46: Innate immunity Part Ⅰ overview of innate immunity Part Ⅱ innate immune cells Part Ⅲ functions of innate immunity