Immunology Lecture 05,6 Innate Immunity

Front 1

Define innate immunity

Back 1

form of immunity that exist before exposure to pathogens; hard wired, rapid, and recognizes conserved patterns on pathogens

Front 2

4 major characteristics of innate immunity

Back 2

1. Limited repertoire of receptors
2. Ancient system
3. Intimately intertwined with the adaptive immune system
4.Invariant and constant

Front 3

What is the major cellular response of innate immunity

Back 3

Inflammation or the Inflammatory response

Front 4

The 4 players that participate in the generation of inflammation

Back 4

Tissues, Early soluble mediators, cells, other soluble mediators

Front 5

What are the barriers to pathogen entry

Back 5

Physical (External skin and internal mucosa)
Chemical (Fatty acids, Mucus and saliva, Cationic antimicrobial peptides)

Front 6

What are the early soluble inflammatory mediators

Back 6

Bradykinin, Histamine, Complement, Lipid mediators, Platelet activating factor

Front 7

What does bradykinin do

Back 7

Stimulates neutrophil migration, macrophage release of cytokines; induces histamine release; activates complement; vasodilation, pain, edema

Front 8

What does histamine do

Back 8

Bronchoconstriction, vasodilation, pruritis

Front 9

What does complement do

Back 9

Vasodilation, edema, opsonization

Front 10

What do lipid mediators do

Back 10

Cell activation

Front 11

What does platelet activating factor do

Back 11

Neutrophil recruitment and activation

Front 12

What are the three major C' mediated pathways

Back 12

1. Alternative pathway (pathogen surface)
2. Lectin pathway (mannose-binding lectins bind to pathogen surface)
3. Classical (Antibody binds to pathogen antigen)

Front 13

Where are two places C' receptors are found

Back 13

Neutrophils and macrophages. These facilitate uptake by phagocytosis

Front 14

What are the two major biologic functions of C'

Back 14

Opsonization and Chemotaxis

Front 15

Which host cells are involved in innate immunity

Back 15

Neutrophils, Tissue macrophages, mast cells, immature dendritic cells, NK cells, lymphocytes

Front 16

What is the role of neutrophils in innate immunity

Back 16

Most abundant phagocytes, first cells recruited, relatively short lived

Front 17

What is the role of tissue macrophages in innate immunity

Back 17

Mature form of monocytes, can undergo division at inflammatory sites, dominant effector cells of the second stage of the innate immmune response, set the stage for adaptive immunity

Front 18

Discuss Mast cells in innate immunity

Back 18

Located on surfaces (skin, GI tract, respiratory tract, connective tissues); preformed granules of cytokines and histamine; after activation secrete TNF-a, IL-4, IL-5, IL-6, IL-8

Front 19

Which cells are usually first to interact with antigen in the skin and mucosa

Back 19

Immature dendritic cells

Front 20

What do NK cells express

Back 20

Inhibitory receptors that recognize MHC class 1. They are thus activated by target cells lacking MHC class 1

Front 21

What do macrophages and mast cells do upon phagocytosis of pathogens in the tissues?

Back 21

Synthesize and secrete a panel of soluble mediators that play a role in the local stimulation of the localized inflammatory response and also have systemic effects

Front 22

What are the major cytokines

Back 22

IL-1B, TNF-a, IL-6, IL-8, IL-12, Type 1 interferons

Front 23

What does IL-1b do

Back 23

Activates vascular endothelium, induces the acute phase

Front 24

What does Il-8 do

Back 24

Chemotactic cytokine

Front 25

What does TNF-a do

Back 25

Activates vascular endothelium, induces the acute phase response

Front 26

What does IL-6 do

Back 26

Activates lymphocytes and induces the acute phase response

Front 27

What does IL-12 do

Back 27

Activates NK cells leading to cytokine production, especially IFN-g

Front 28

What do Type 1 and a/B interferons do

Back 28

Activate NK cells to kill virus-infected cells

Front 29

What three cytokines induce the acute phase response

Back 29

IL-1B, TNF-a, IL-6

Front 30

What are acute phase proteins (ACP)

Back 30

Soluble plasma proteins secreted by hepatocytes in the liver in response to acute infection

Front 31

What two acute phase proteins enhance the fixation of C' at the pathogen surface

Back 31

C-Reactive protein (binds PC on bacteria)
Mannose-binding protein (MBP)(initiates lectin-binding C' pathway)

Front 32

The process of leukocyte migration to sites of infection is initiated by

Back 32

Activated tissue macrophages and mast cells at the site of infection

Front 33

Activated macrophages and mast cells at the site of infection causes

Back 33

Increased vascular permeability, increases in adhesion molecule expression, secrection of cytokines and chemokines

Front 34

What is the multi-step model of leukocyte migration

Back 34

Rolling of leukocytes on the endothelium, activation of leukocytes, stable adherence to the endothelium, transmigration

Front 35

The process of leukocyte migration to sites of infection is stimulated by

Back 35

Cytokines, especially TNF-a

Front 36

What are Pathogen Associated Molecular Patterns (PAMPS)

Back 36

Conserved molecules produced only by microbes and not by the host organism

Front 37

What are Pattern Recognition Receptors (PRR)

Back 37

A set of germline encoded receptors that recognize PAMPS and thus are specific for non-self structures

Front 38

Name two common PRRs

Back 38

Toll-like Receptors and Seven transmembrane a-helical receptors

Front 39

Name 4 phagocytic receptors

Back 39

Mannose receptors, Scavenger receptors, Fc receptors, Mac-1 (integrin)

Front 40

What are two chemicals used to kill microbes

Back 40

Reactive oxygen intermediates (ROIs) and Nitric oxide (NO)

Front 41

How is NO created in macrophages

Back 41

The inducible Nitric oxide (iNOS) system