L1: Overview Of Innate And Adaptive Immunity

Front 1

What is an immune response?

Back 1

A combination of mechanisms that depend body against "threats."

Front 2

What constitutes a threat?

Back 2

Something that is non-self.

Front 3

Examples of non-self threats?

Back 3

-Infectious organisms
-Cancer
-Transplanted Tissue
-Parasitic Infections
-Toxins

Front 4

What does the immune system determine self?

Back 4

Normal body constitutes or natural components of an individual.

Front 5

What does the immune system constitute as non-self?

Back 5

Cells or molecules to which the immune system has no exposure during its maturation OR does not normally encounter in the body.

Front 6

What are used to determine whether the molecules encountered are self or non-self?

Back 6

A variety of soluble molecules and cell bound surface receptors.

Front 7

Where does innate immunity originate from?

Back 7

It is the basic resistance to disease that an individual is born with.

Front 8

What is response time of innate immunity?

Back 8

Rapid protection against against microbes because its first line of defense and always "on."

Front 9

When does response appear in innate immunity?

Back 9

Response is in place before foreign challenge (antigen) presents.

Front 10

Does response vary with different antigens?

Back 10

No, same response every time.

Front 11

In innate response does previous exposure have effect on next response?

Back 11

No, same response regardless of of previous antigen exposure.

Front 12

What is the response time of adaptive immunity?

Back 12

Protection develops more slowly.

Front 13

When does adaptive immunity take place?

Back 13

Only after a specific challenge (antigen).

Front 14

What is adaptive immunity responsible for?

Back 14

Resulting products effective only against the specific antigen.

Front 15

What is adaptive immunity's response to repeated exposure?

Back 15

Has enhanced ability to deal with recurring antigen.

Front 16

What is the primary function of innate immunity?

Back 16

Prevents pathogens from establishing themselves.

Front 17

What are the innate anatomic barriers?

Back 17

Skin, mucus membranes, cilia

Front 18

What are innate physiologic variables that block entry?

Back 18

pH (stomach acidity, acid in skin), digestive enzymes, and temperatures.

Front 19

What are the innate biologic barriers?

Back 19

Normal flora

Front 20

Innate immunity secretes what substances?

Back 20

Cytokines, complement, defensins, acute phase proteins.

Front 21

What are the cellular effectors of innate immunity?

Back 21

Dendritic cells, natural killer (NK) cells, macrophages, granulocytes (eosinophils, basophils, and neutrophils).

Front 22

What are cytokines?

Back 22

Secreted proteins that function as mediators of immune reactions.

Front 23

What function requires cytokines?

Back 23

Virtually every aspect of both innate and adaptive immune function requires careful regulation by cytokines.

Front 24

Examples of cytokine Interleukins?

Back 24

IL-1, IL-2

Front 25

Examples of cytokine Interferons?

Back 25

INF-a, IFN-y

Front 26

Examples of cytokine tumor necrosis factor?

Back 26

TNF-a, TNF-b

Front 27

Examples of cytokine colony stimulating factors?

Back 27

M-CSF, G-CSF

Front 28

Examples of cytokine growth factors?

Back 28

EGF and PDGF

Front 29

Examples of cytokine chemokines?

Back 29

Rantes and MIP-1a

Front 30

What are the general properties of cytokines?

Back 30

Cytokines regulate a variety of immune responses.
*Pleiotropism, Redundancy, Synergy, and Antagonism.

Front 31

What are the general actions of cytokines?

Back 31

*Cytokines function to stimulate, inhibit and modify immune responses.
*They function by activation of signal transduction pathways resulting in the generation of transcription factors.

Front 32

What is specific about cells that can respond to cytokines?

Back 32

Cells that are able to respond to cytokines have surface receptors that allow specific cytokines to bind.

Front 33

What chains do cytokine receptors contain?

Back 33

*The ligand-binding subunit of a receptor is referred to as the alpha chain.
*Other signal transducing subunits are named beta chains, or gamma chains.

Front 34

What is important about the Janus kinases (JAKs)?

Back 34

All cytokine receptors are associated with one or more members of the Janus kinases (JAKs), which couple ligand binding to tyrosine phosphorylation of various signaling proteins recruited to the receptor complex.

Front 35

What is significant about signal transducers and activators of transcription (STATs).

Back 35

Among these signaling proteins are unique family of transcription factors named the signal transducers and activators of transcription (STATs).

Front 36

Is native (un-liganded) receptor in complex with a JAK is in what state?

Back 36

It is in an inactive state.

Front 37

What results in juxtapositioning?

Back 37

Receptor dimerization due to ligand binding results in the juxtapositioning of the JAKs.

Front 38

What does aggregation of JAKs result in?

Back 38

Autophosphorylation or cross phosphorylation.

Front 39

What do activated JAKs do?

Back 39

Activated JAKs then phosphorylate receptors on target tyrosine sites.

Front 40

What do phosphotyrosine sites on receptors serve as?

Back 40

They serve as docking sites that allow the binding of other SH2 domain containing signaling molecules such as STATs.

Front 41

What are some examples of signaling molecules such as STATs?

Back 41

Src-kinases, protein phosphatases, Grb2 and phosphatidylinositol 3-kinase (PI3K) can also bind.

Front 42

The bound STAT proteins are what?

Back 42

Phosphorylated

Front 43

What is function of phosphorylated STAT proteins?

Back 43

Phosphorylated STAT proteins dimerize, translocate into the nucleus and affect transcription of specific genes.

Front 44

What is innate complement?

Back 44

A group of serum proteins that are sequentially activated by proteolysis.

Front 45

What produces most of the complement components?

Back 45

The liver produces most of the components which include C1-C9, factorB, factor D, factor H, factor I, and properdin.

Front 46

What are the three different complement cascade pathways that can be initiated?

Back 46

*Antigen-antibody complexes
*Mannose-binding lectin
*Pathogen surface

Front 47

Products of the proteolytic cascade function to?

Back 47

*Promote inflammation and reqruit WBCs
*Opsonize pathogens
*Lyse the pathogens

Front 48

What is the function of opsonizing pathogens?

Back 48

Cover the surface and promote phagocytosis of the pathogen.

Front 49

The classical pathways converge where?

Back 49

C3 convertase

Front 50

What are defensins?

Back 50

*Antibiotic-like peptides secreted by macrophages and intestinal cells.
*Amphipathic molecules that interact with microbial membranes, leading to their disruption.

Front 51

What are acute phase proteins?

Back 51

Serum proteins whose synthesis increases dramatically during inflammation.

Front 52

Acute phase proteins synthesis are induced by?

Back 52

Cytokines which include IL-1, IL-6, and TNF-a

Front 53

When are proteins important in acute phase proteins?

Back 53

Proteins are important in nonspecific defense mechanisms including cell adhesion, migration, proliferation and opsonization.

Front 54

How do cells of the innate system respond to stimuli?

Back 54

They respond in a general fashion to stimuli such as proteins, nucleic acids, carbohydrates, and microbial surface structures.

Front 55

What are the broad range pathogens that are associated with stimuli?

Back 55

*Lipopolysaccharide (LPS), N-formyl methionyl, mannose, flagellin, viral/bacterial nucleic acid.
*PAMPs=pathogen-associated molecular patterns.

Front 56

What is special about opsonin stimuli?

Back 56

They are host-derived proteins that "coat" pathogens.
*Antibodies, complement proteins (C3b), CRP

Front 57

How do innate cells recognize stimuli?

Back 57

*They use pattern recognition receptors (PRRs).
*Receptors are encoded in the germ line and have limited diversity.
*Identical receptors are found on all cells of the same lineage.
*Cells bearing receptors are able to be discriminated btw self and non-self.

Front 58

What are the different cellular effects on the receptor binding innate receptors can have?

Back 58

*Phagocytosis and killing
*Cell migration into tissues
*Prommotion of inflammatory response
*Tissue repair
*Cytokine production

Front 59

What are examples of toll-like receptors?

Back 59

*TLR 1-11
*Specific for different microbial components.
*Promote inflammatory response.

Front 60

What are activated in adaptive immunity?

Back 60

B and T cells are activated against a specific antigen when innate responses are not sufficient to remove the challenge.

Front 61

Why are adaptive responses specific?

Back 61

*Because each B and T cell expresses a unique receptor.
*B and T cell receptors detect subtle differences

Front 62

B and T cell receptors are created by?

Back 62

Somatic recombination of gene segments, which provides greater diversity of receptor than in the innate immune system.

Front 63

What does the antibody titer measure?

Back 63

The amount of antibody in the serum (antibody titer) is often measured to determine exposure specific infectious agents.

Front 64

What is humoral immunity mediated by?

Back 64

Antibodies that are present in the blood, lymph, other body fluids, and tissues.

Front 65

What is humoral immunity critical in defense against?

Back 65

Extracellular pathogens (viruses, bacteria and fungi) and microbial toxins.

Front 66

What is cell-mediated immunity mediated by?

Back 66

Tlymphocytes that produce their effect by direct contact with target cells.

Front 67

Cell-mediated immunity is critical in the defense against?

Back 67

Intracellular pathogens (mycobacteria, fungi and viruses) and tumor cells.

Front 68

Innate immunity specificity is for?

Back 68

Structures shared by classes of microbes("molecular patterns").
*Different microbes but identical mannose receptors.

Front 69

Where are receptors of innate immunity?

Back 69

Encoded in germline; limited diversity.
*Toll-like receptor
*N-formyl methionyl receptor
*Mannose receptor

Front 70

What is the distribution of innate receptors?

Back 70

Nonclonal: identical receptors on all cells of the same lineage.

Front 71

Does the innate system discriminate btw self and non self?

Back 71

Yes,; host cells are not recognized or they may express molecules that prevent innate immune reactions.

Front 72

What is the specificity of adaptive immunity?

Back 72

For structural detail of microbial molecules (antigens); may recognize non microbial antigens.
*Have different microbes with distinct antibody molecules.

Front 73

Where are the adaptive immunity receptors?

Back 73

They are encoded by genes produced by somatic recombination of gene segments; greater diversity.
*TCR are in membranes and bind to Ig.

Front 74

What kind of distribution does adaptive immunity have?

Back 74

Clonal: clones of lymphocytes with distinct specificities express different receptors.

Front 75

Does adaptive immunity discriminate btw self and non-self?

Back 75

Yes; based on selection against self-reactive lymphocytes; may be imperfect (giving rise to autoimmunity).

Front 76

When does immunologic memory develop?

Back 76

Immunologic memory develops after an initial exposure of B and T cells to a specific antigen.

Front 77

What is activation rate of memory cells?

Back 77

Its quicker, so there is a shorter lag time between exposure and production of an adaptive immune response.

Front 78

What does repeated exposure do to memory cells?

Back 78

*Repeated exposure to the same antigen induces a heightened state of immune reactivity.
*Higher antibody production and titers.

Front 79

What is the importance of memory cells and adaptive immunity?

Back 79

This is the basis of our vaccination program.

Front 80

What is the first response to injury/infection?

Back 80

Typically, innate immune mechanisms are the first response to injury/infection, and adaptive immune mechanisms (when necessary) are the second response.

Front 81

What is phagocytosis?

Back 81

An innate mechanism that is optimal in the presence of both complement (another innate component) and antibody (produced during an adaptive response).

Front 82

What activates T cells?

Back 82

Activation of T cells is dependent upon antigen processing by certain innate cells.

Front 83

What can cytokines secreted by Th cells do?

Back 83

They can enhance phagocytic and cytotoxic activities of several innate immune cells.