Innate Immunity Presented by Lalita Tearprasert, MD. March25, 2016

1. Lalita Tearprasert; MD.
Innate Immunity
1

2. Outline
• Overview of innate immunity
• Microbial pattern recognition by innate immunity
• Phagocytosis
• Inflammatory responses
• Antiviral responses
• Innate instruction of adaptive immune response
2

3. 3
Overview of Innate Immunity
• First line of defense against microbes
• Exist before exposure to microbes
• Found in Plants, Insects, Vertebrates
• 3 Essential function
1.) Initial response to microbes
2.) Eliminate damaged cells and initiate the
process of tissue repair
3.) Stimulates adaptive immune response
• 2 Major type of responses
1.) Inflammation
2.) Antiviral defense Kuby Immunology 7th edition.
Abbas 8th Edition Innate Immunity, 51-86.
Liu A.et al. Middleton's 8th Edition, 1-19.

4. 4 Kuby Immunology 7th edition.
Innate VS Adaptive

5. 5 Kuby Immunology 7th edition.
1.
2.
Component of innate immunity
1. Anatomical barrier
- Physical barriers
- Chemical barriers
2. Cell
- Phagocytic cells
- Dendritic cell
- NK cells, ILC
3. Soluble proteins
- Complement
- Cytokines, Chemokines
- Anti-microbial substances
3.

6. 6
1.) Anatomical barriers
• Enzyme
• Antimicrobial
peptides (AMPs)
• pH
• Skin
• Mucosal &
Glandular tissues
• Mechanical :Cilia
Kuby Immunology 7th edition.

7. 7
2.) Cellular Response (Recognized pathogen by receptors : PRRs)
3.) Soluble proteins
• NK cell
- Viral infected cell
- Malignancy
• Phagocytic cells
-Macrophage, Neutrophil
" Phagocytosis "
• Dendritic cell
>> Activated adaptive
immune response
• Cell activation
>> Inflammation
>> Antiviral defense
Kuby Immunology 7th edition.

8. 8
Microbial pattern recognition by
innate immunity

9. 9
Cellular
response
• Innate immune system recognizes
- PAMPs (Pathogen-associated molecular pattern)
: molecular structures of microbial pathogen
that required for survival
- DAMPs (Damage-associated molecular pattern)
: result of cell damage by infections
• Cellular receptors : PRRs (Pattern recognition receptors)
Abbas 8th Edition Innate Immunity, 51-86.

10. 10
PAMPs
1.) Produced only by microbes, not by their hosts
2.) PAMP structures are usually fundamental to the integrity,
survival, and pathogenicity of the microorganisms
3.) Shared by entire classes of pathogens
Kuby Immunology 7th edition.
Liu A.et al. Middleton's 8th Edition, 1-19.
Abbas 8th Edition Innate Immunity, 51-86.

11. 11
PRRs
Abbas 8th Edition Innate Immunity, 51-86.

12. 12
• Structure: Several families of protein
• Location: Expressed on many effector cells
esp. most importantly on the professional APC
(Macrophages, Dendritic cells, and B cells)
1.) Transmembrane PRRs
2.) Cytosolic PRRs
• Functions: 3 classes
- Secreted PRRs
- Endocytic PRRs
- Signaling PRRs
Janeway C.et al. NEMJ 2000. 343(5), 338-44.
Liu A.et al. Middleton's 8th Edition, 1-19.
Principle functions of PRRs
1.) Opsonization
2.) Activation of complement
3.) Phagocytosis
4.) Activation of proinflammatory signaling pathways
5.) Induction of apoptosis

13. 13
1.) Secreted PRRs
Liu A.et al. Middleton's 8th Edition, 1-19.

14. 14 Liu A.et al. Middleton's 8th Edition, 1-19.
AMPs
Defensins & Cathelicidins

15. 15
Collectins
Mannose-binding lectin (MBL)
Janeway C.et al. 5th Edition.
Abbas 8th Edition Innate Immunity, 51-86.

16. 16
Pentraxins
C-reactive protein (CRP)
Fujita Y. et al. Clinical Chemistry 57:10, 1398–1405 (2011).

17. 17
2.) Endocytic PRRs
Mannose receptors (CD206)
• C - Type Lectin Receptors
• Recognized carbohydrates (Mannose)
- Bacterial, Fungus, Parasite
• Expressed on Macrophage
• Phagocytosis, NF-kB activation
Kuby Immunology 7th edition.
Janeway C.et al. 5th Edition.
Liu A.et al. Middleton's 8th Edition, 1-19.

18. 18
Scavenger receptors
Kuby Immunology 7th edition.
Janeway C.et al. 5th Edition.
Liu A.et al. Middleton's 8th Edition, 1-19.
• Recognize Lipoproteins on gram +
and gram - bacteria
• Eliminated old & apoptotic cells
• Expressed on Macrophage
• Phagocytosis, NF-kB activation

19. 19
4 Major classes of Signaling PRRs
1.) Toll-like receptors (TLRs) : Transmembrane PRRs
2.) C-Type Lectin Receptors (CLRs): Transmembrane PRRs
3.) NOD-like receptors (NLRs) : Cytosolic PRRs
4.) Retinoid acid–inducible gene
(RIG)-like receptors (RLRs) : Cytosolic PRRs
Zaru R.Pattern Recognition Receptors (PRRs)
3.) Signaling PRRs

20. 20
Toll-like receptors (TLRs)

21. 21
• Germany, 1980
• Drosophila fruit fly embryos
• " Toll " = Weird
• Regulation of embryonic development
• Cytoplasmic domain of Toll prot.
: homologous to IL-1 in vertebrate
" Toll-like receptors (TLRs) "
Kuby Immunology 7th edition.

22. 22
Structure of TLRs
Kuby Immunology 7th edition.
• Transmembrane
- LLR domain
- TIR domain
LxxLxLxxN

23. 23
13 TLRs
D. De Nardo. Cytokine 74 (2015) 181–189.
TLR 1-9 : Human & mouse
TLR 10 : Human
TLR 11 : Mouse

24. 24
Cellular location of TLRs
Abbas 8th Edition Innate Immunity, 51-86.

25. 25 Kuby Immunology 7th edition.
Plasma membrane
1/2, 2/6, 4, 5, 11
Endosomes/ Lysosomes
membrane
3, 7, 8, 9, 13

26. 26
TLRs signaling pathways
1.) MyD88-dependent pathway
- All TLR except TLR3
2.) TRIF-dependent pathway
- TLR 3, 4
1.)
2.)
NEMO

27. 27 Liu A.et al. Middleton's 8th Edition, 1-19.
TLR4

28. 28
• UNC-93B : multiple-transmembrane-spanning protein in ER
- required for endosomal localization & proper function
of TLRs 3,7,8,9
- unknown mechanism
- genetic def. in UNC-93B >> viral infections
esp. Herpes simplex encephalitis
Abbas 8th Edition Innate Immunity, 51-86.

29. 29
Defect affecting TLR signaling
1.) MyD88 defect
2.) IRAK4 defect
3.) NEMO defect
4.) UNC93B defect
5.) TLR3 mutation
Esther van de Vosse. et al. Lancet Infect Dis 2009; 9: 688–98.
Wong T. et al. Curr Opin Allergy Clin Immunol 2013,13:607–613.

30. 30
NEMO
• Autosomal recessive
• Severe, life-threatening
infections with pyogenic
bacteria
• Invasive bac.
- S. Pneumoniae
- S. Aureus
- P. Aeruginosa
Esther van de Vosse. et al. Lancet Infect Dis 2009; 9: 688–98.
MyD88 Defect
& IRAK4 Defect

31. 31
NEMO
• Broad immune dysfunction
• X-linked gene (IKBKG)
1.) Amorphic
2.) Hypomorphic
• Gram +, Gram -
esp. S. Pneumoniae
Esther van de Vosse. et al. Lancet Infect Dis 2009; 9: 688–98.
NEMO defect

32. 32
• Amorphic (More common)
Female: Incontinentia pigmenti
Male: Lethal
• Hypomorphic
Female: Carrier
Male: Ectodermal dysplasia
with immunodeficiency
Esther van de Vosse. et al. Lancet Infect Dis 2009; 9: 688–98.

33. 33
TLR3 defect
& UNC93B defect
• Childhood Herpes Simplex
Encephalitis
• TLR3 : AD, AR
(required to induce
Type 1 IFN to protect
HSV-1 in CNS)
• UNC-93B : AR
Wong T. et al. Curr Opin Allergy Clin Immunol 2013,13:607–613.

34. 34
Nucleotide-binding oligomerization
domain-like receptors (NLRs)

35. 35
• Cytosolic PRRs
• Recognized - PAMPs & DAMPs
- Stress/ Damage signal
• Similar to the TLRs : linked to signal transduction
• NLR family : 23 Members
Abbas 8th Edition Innate Immunity, 51-86.
Liu A.et al. Middleton's 8th Edition, 1-19.
Chen et al.Annu. Rev. Pathol. Mech. Dis. 2009.4:365-98.
NOD-Like Receptors (NLRs)

36. 36
Structure of NLRs
• 3 Domains
- C-terminal Leucine-rich repeat domain (LRR)
- Central nucleotide binding & Oligomerization
>> NACHT, NOD, NBD
- N-terminal Effector binding domain (EBD)
>> CARD, PYD, BIR
Abbas 8th Edition Innate Immunity, 51-86.
Liu A.et al. Middleton's 8th Edition, 1-19.
Chen et al.Annu. Rev. Pathol. Mech. Dis. 2009.4:365-98.

37. 37 Saxena and Yeretssian. Frontiers in immunology. July 2014.
NLRs subfamily

38. 38
NOD
• Member of CARD domain containing NOD family
• NLRC subfamily
• Expressed on several cell types
: Mucosal epithelial cells, Phagocytes
• Response to bacterial cell wall peptidoglycans
• 2 Groups
- NOD 1 (CARD4)
- NOD 2 (CARD15)
Abbas 8th Edition Innate Immunity, 51-86.
Liu A.et al. Middleton's 8th Edition, 1-19.
Nature Reviews Immunology 14, 9–23 (2014)

39. 39 Chen et al.Annu. Rev. Pathol. Mech. Dis. 2009.4:365-98.
NOD Response to
bacterial cell wall peptidoglycans
- NOD 1 : iE-DAP
- NOD 2 : MDP

40. 40
NOD 1
• Recognizes Diaminopimelic acid (DAP) derived mainly from
gram-negative bac. peptidoglycans
Abbas 8th Edition Innate Immunity, 51-86.
Liu A.et al. Middleton's 8th Edition, 1-19.
NOD 2
• Recognizes Muramyl dipeptide (MDP) derived both
gram-negative & gram-positive bac. peptidoglycans
• Highly expressed in intestinal Peneth cells
• Mutations : Crohn disease
(Bac. overgrowth --> chronic inflammation)
• Gain-of-function : Blau's syndrome (systemic inflammatory disease)

41. 41 Ramanan D. et al. Immunity 2014, (41), 311-324.

42. 42
HS Jin, et al.
Journal of Bacteriology and Virology 2014, 44(3), 215-25.
NLRs signaling pathways
1.
2.
3.
CARD9 NEMO

43. 43
Inflammasome
Kuby Immunology 7th edition.
H. Kumar et al. International Reviews of Immunology, 30:16–34, 2011.
• Large protein complex that activates caspase-1 to generate IL-1
• Containing
1.) NLR subfamily
- NLRP 1
- NLRP 3
- NLRC 4/ IPAF
2.) Non-NLR/ Adaptor protein
Ex. ASC, AIM2
3.) Caspase-1 (inactivate)

44. 44
Variety stimuli activated Inflammasome
Abbas 8th Edition Innate Immunity, 51-86.
NLRP3 Inflammasome
- Monocyte
- Macrophage
- Neutrophils
- DC
- Lymphocyte

45. 45
Cryopyrin-associated periodic syndrome
(CAPS)
NLRP 3 mutation >> Auto-inflammatory disease
• Muckle-Wells syndrome
• CINCA
• Familial cold autoinflammatory syndrome
Kuby Immunology 7th edition.
H. Kumar et al. International Reviews of Immunology, 30:16–34, 2011.

46. 46
C-Type Lectin Receptors (CLRs)

47. 47
• Plasma membrane receptors
- monocytes, macrophages, dendritic cells, neutrophils,
B cells, and T-cell subsets
• Recognize carbohydrate components of fungi,
mycobacteria, viruses, parasites, and some allergens
(peanut and dust mite proteins)
• Human : 15 CLRs that function as PRRs
• Most recognize sugar moieties
- mannose --> mannose receptor, DC-SIGN
- fucose --> Dectin-2, DC-SIGN
- glucans --> Dectin-1
Kuby Immunology 7th edition.

48. 48
Kuby Immunology 7th edition.
Janeway's Immunobiology. 2012.
• CLRs functions : Variety function
- Signaling
- Phagocytosis

49. 49 Kuby Immunology 7th edition.
CLRs signaling pathways

50. 50
Chronic Mucocutaneous Candidiasis
(CMCC)
• Dectin-1 defect
(recognized B-glycan
in cell wall of candida)

51. 51
RIG-Like Receptors (RLRs)

52. 52
• Soluble PRRs
• Sensors of viral infection ex. Influenza, Measles
• Recognize the RNA viruses in the cytoplasm of infected cells
--> induce inflammatory cytokines and type I interferons
• 3 Members : CARD-containing RNA helicase
1.) RIG-I
2.) MDA5
3.) LGP2
Kuby Immunology 7th edition.
H. Kumar et al. International Reviews of Immunology, 30:16–34, 2011.

53. 53 Kuby Immunology 7th edition.
Signaling of RLRs

54. 54
H. Kumar et al.
International Reviews of Immunology, 30:16–34, 2011.

55. 55
Phagocytosis

56. 56 Kuby Immunology 7th edition.
1.) Direct : PRRs rec.
• Macrophage, Neutrophil, DC : Tissue
• Monocyte : Blood

57. 57
Kuby Immunology 7th edition.
Janeway's Immunobiology. 2012.
Abbas 8th Edition Innate Immunity, 51-86.

58. 58
" Opsonization " (to make it tasty)
- recognition of soluble proteins that have
bound to microbial surfaces
- Soluble prot. = Opsonin
2.) Indirect : Opsonin rec.
Major opsonin 1.) Lectin
2.) C3b
3.) IgG
Kuby Immunology 7th edition.

59. 59

60. 60
Inflammatory response

61. 61 Kuby Immunology 7th edition.
Acute Phase : Local inflammatory response

62. 62
• Phase
- Acute : Local inflammation followed by healing
- Chronic : Long- term, not resolved
• Hallmarks of a localized inflammatory response
: Redness, Swelling, Warm, Pain
- Vasodilatation >> Warm, Redness
- Increased Vascular permeability >> Swelling
Kuby Immunology 7th edition.
Abbas 8th Edition Innate Immunity, 51-86.

63. 63
Acute Phase Response proteins
(APRs)
• Normally found in blood at low concentrations
• Secreted from hepatocyte of liver following
stimulation by proinflammatory cytokines
(TNF-alpha, IL-1, IL-6)
• Function as "opsonin"
• Ex. - C-reactive protein (CRP)
- Mannose-binding lectin (MBL)
- Serum amyloid protein (SAP)
- Complement factor
- Fibrinogen
Kuby Immunology 7th edition.

64. 64 Abbas 8th Edition Innate Immunity, 51-86.
Local & Systemic actions of cytokines in inflammation

65. 65
Antiviral response

66. 66
• Major way : Induce expression of type 1 interferons
>> Inhibit viral replication
• Type 1 interferons : IFN-alpha, IFN-beta
- Encoded by gene on chromosome 9
- most important in viral defense : IFN-alpha
(from Plasmacytoid DC & Mononuclear phagocytes)
• Most potent stimuli : Viral nucleic acid (DNA, RNA)
• Type 1 interferons receptors : IFNAR1, IFNAR2
(All nucleated cells)
Abbas 8th Edition Innate Immunity, 51-86.

67. 67
Induction of Type 1 Interferons
Abbas 8th Edition Innate Immunity, 51-86.

68. 68
Action of Type 1 interferons

69. 69
Innate Instruction of Adaptive
Immune Response

70. 70 Abbas 8th Edition Innate Immunity, 51-86.
Stimulation of adaptive immunity
by innate immunity
" Two-Signal hypothesis "

71. 71 Janeway C.et al. NEMJ 2000. 343(5), 338-44.

72. 72 Kuby Immunology 7th edition.

73. 73
Interleukin-12/interferon-gamma axis
Wong T. et al. Curr Opin Allergy Clin Immunol 2013,13:607–613.
• Mendelian susceptibility to
mycobacterial disease (MSMD)
7 Autosomal
- IRF8
- STAT1
- IL12B, IL12RB1 (40%)
- IFNGR1 (XL) , IFNGR2
- TYK2
Susceptible to
- Mycobacterium tuberculosis
- Salmonella

74. 74 Liu A.et al. Middleton's 8th Edition, 1-19.
1.
2.
3.
4.
5.

75. 75
Thank you