Innate Immunity

Question 1

Components

Answer 1

1. Mechanical Barriers 2. Chemical Barriers 3. Physiological Factors 4. Proteins 5. Cells 6. Influence on induction of Adaptive Immune Response 7. Evasion of Innate Immunity by Microbes

Question 2

Mechanical barriers

Answer 2

Intact Skin: -Simple and Most effective Mucosal Epithelia and Mucus: -Sneezing and coughing -Vomiting and Diarrhea -Critical to be intact Shedding of Infected Cells The Flushing action of Saliva, Tears, Perpiration, Urine

Question 3

Chemical Barriers

Answer 3

Skin: Secretion of Sebum Saliva: Lysozymes and Antiboitics Mucus: Lysozymes and Antibiotics Tears: Lysozymes Defensins: Skin, mucosal epithelial cells, Neutrophils, NK cells Cathelicidins: Neutrophils, skin epithelia, gastrointestina/respiratory mucosa Lactoferrins: Bind to iron, interfering with microbial iron acquisition HcL: secretion in the stomach Bile acids and Salts

Question 4

Physiologic Factors

Answer 4

Body Temperature: Fever response may lead to poor growth of microbes Oxygen Tension: Hinder Growth of Anaerobic Microbes Hormonal Balance: Increase in corticosteroids leads to decrease in inflammatory response leading to increase in infection Age: Children and the elderly are susceptible to disease becuase of suboptimal immune response

Question 5

Effector Proteins

Answer 5

Complement System, Mannose-binding Lectin, C-reactive protein, Cytokines

Question 6

Complement

Answer 6

Killing of mocrobes, opsonization of microbes, activation of leukocytes

Question 7

Mannose-binding Lectin (collectin)

Answer 7

Opsonization of microbes, activation of complement lectin pathway

Question 8

C-reactive Protein (pentraxin)

Answer 8

Opsonization of microbes, Activation of complement

Question 9

Cytokines

Answer 9

Messengerd in the whole body: 1. TNF, IL-1, Chemokines : Inflammation 2. IFN-a, IFN-b : Resistance to viral infection 3. IFN-g : Margrophage activation 4. IL-12 : IFN-g production by NK cells and T cells 5. IL-15 : Proliferation of NK cells 6. IL-10, TGF-b : Control of Inflammation

Question 10

Alarmins

Answer 10

Heparan Sulfate Heat-shock proteins from cell cytoplasm

Question 11

Vasoactive Lipids

Answer 11

Prostaglandins Leukotrienes

Question 12

Steriod Inhibition

Answer 12

Inhibits Phospholipases that convert Damaged tissue/cells ——> Cell Membrane Phospholipids

Question 13

5-lipoxygenase

Answer 13

Converts Arachidonic Acid to Leukotrienes 1. LTB4 : Chemotaxis of blood leukocytes 2. LTC : Increases vascular permeability and smooth muscle Contraction 3. LTD : Increases vascular permeability and smooth muscle Contraction 4. LTE : Increases vascular permeability and smooth muscle Contraction

Question 14

Sentinel Cells

Answer 14

Sense tissue damage and recognize microbes -Induce inflammation -Recruit Blood Leukocytes via cytokines/chemokines -Kill Pathogens 3 cell types: 1. macrophages 2. Dendritic Cells 3. Mast Cells

Question 15

Macrophages

Answer 15

Come from Monocytes -Phagocytosis/killing of pathogen/infected cells -production of cytokines/chemokines tha recruit other inflammatory cells -Antigen presention to T-cells -Survie longer than Neutrophils at site of inflammation and are the dominant effector cells

Question 16

Dendritic cells

Answer 16

1. Capture, process, and present antigens to lymphocytes - Prefessional Antigen Presenting cell (APC) 2. Provide signals aht stimulate T-cells proliferation and differentiation 3. Secrete cytokines and chemokines Subsets: Langerhans cells - Epidermis and mucous membranes Intersitisal DC - Polulate most organs Interdigitating DC - T-cell areas of secondary lymphoid tissues and the thymic medulla Circulatind DC - Blood and Lymph

Question 17

Mast Cells

Answer 17

Secrete Vasoactive Amines, and Inflammatiory Protiens Vasoactive amines -Histamine Serotonin

Question 18

Pathogen-associated Molecular Patterns (PAMPs)

Answer 18

Conserved molecular motifs found only on microbes - Stimulate innate immune respones - Examples: > Virus single or double stranded DNA > Unmethylated CpG DNA sequences in bateria and viruses > Lipopolysaccharides (LPS) on Gram - bacteria > Mannose-Rich oligosaccharides

Question 19

Pattern Recognition Receptors (PRRs)

Answer 19

Detect PAMPs Examples: > Toll-like receptors (TLRs) > Retinoic Acid-inducible Gene (RIG) -1-like > Nucleotide-binding Oligomerization domain (NOD) like receptors (NLR)

Question 20

Soluble Pattern Recognition Receptors

Answer 20

Collectins Foclins Complment Pentraxins

Question 21

PRRs within vesicles

Answer 21

TLR3 TLR7 TLR8 TLR9

Question 22

Cytoplasmic PRRs

Answer 22

Rig-1 NOD-like Peptidoglycan receptors DNA receptors

Question 23

Membrane-Bound PRRs

Answer 23

TLRs Lectins Mannose receptors Lanferins Dectins Scavenger receptors Intergrins

Question 24

Damage-Associated Molecular Patterns (DAMPs)

Answer 24

Products from stressed or injured cells

Question 25

Pleiotropism

Answer 25

One cytokine having multiple effects on diverse cell types

Question 26

Redundancy

Answer 26

Multiple cytokines having the same or overlapping actions

Question 27

Synergy

Answer 27

Two or more cytokines having greater than additive effects

Question 28

Antagonism

Answer 28

One cytokine inhibiting the action of another

Question 29

Evasion of Innate Immunity by Microbes

Answer 29