Lecture 2 - Immunity

Question 1

Immunity

Answer 1

• The protection against infectious disease conferred either by the immune response generated by immunization or previous infection or by other nonimmunologic factors
• body’s ability to resist infection

Question 2

Two Types of Immunity

Answer 2

• Non Specific (Innate)

- Specific (adaptive/acquired)

Question 3

Innate Immunity:

Skin

Answer 3

- Mechanical barrier
Effective because: 
- Largest 
- Skin is selectively permeable 
- Reproduces constantly 
- Produces sebum
- pH of skin is acidic

Question 4

Innate Immunity:

Mucous Membranes

Answer 4

• Cilia in respiratory tract
• pH of the stomach
• Lysosomes in tears

Question 5

Innate Immunity:

Iron Binding Proteins

Answer 5

• Some bacteria require iron for growth
• Lacoferrin (example)
• You then starve the bacteria from iron

Question 6

Innate Immunity:

Phagocytosis

Answer 6

• PMS, monocytes, and macrophages

- Act as a vacuum cleaner

Question 7

Innate Immunity:

Complement (two things they do)

Answer 7

• Set of circulating proteins that do two main things:
  1. Able to bind to antibodies, make the bacteria more opsonized for the immune system
  2. Recognize certain sugars on the cell wall of bacteria, and form a pore, insides of bacteria leaks out and the bacteria dies.

Question 8

Specific Immunity:

Two Subcategories

Answer 8

• Humoral

- Cell Mediated (CMI)

Question 9

Specific Immunity:

Humoral

Answer 9

• Antibody
• Antigen
• Circulating antibodies in the blood

Question 10

Opsonization

Answer 10

When complement binds to antibodies and makes the bacteria more appealing for the immune system

Question 11

DIfference between Innate and Adaptive Immunity?

Answer 11

– Innate: protects against ANY invader, does not discriminate
– Adaptive: directed against one type of invader, dependant on past exposure

Question 12

Where do immune cells come form?

Answer 12

• Bone marrow

Question 13

B-cells

Answer 13

• Make antibodies
• After a signal is sent from T helper two cells
• 1 B-Ceel, one type of bacteria

Question 14

Antibody

Answer 14

• Protein that binds specification to a substance (antigen)
• IGs
• Produced by B-cells upon stimulation from antigen presenting T-cells
• Recognize toxins, capsules, some viral proteins

Question 15

Antigen

Answer 15

• Non self

- Protein, glycoprotein, lipoprotein, polysaccaride

Question 16

Structures that can be antigenic in a bacteria?

Answer 16

• Something on the outside

Question 17

Antibody Binding

Answer 17

• Arm can bind to antigen
• On arm could bind to one antigen on one cell, and another on another cells
• This starts clumping the antigens

Question 18

Antibody composition

Answer 18

• Y part (where binding occurs)

- Bottom part (consistent)

Question 19

Clumping

Answer 19

• Glutamate

- Means there is a positive reactions

Question 20

Antobody

Answer 20

• Ig produced in response to stimulation by antigen and reacting specifically with it
• Distinguish “non self” from “Self”
• Constant and variable region

Question 21

Classes of IG

Answer 21

• IgG
• IgD
• IgA
• IgM
• IgE

Question 22

IgG

Answer 22

• Host defines

- Crosses the placenta and protects the new born

Question 23

IgD

Answer 23

• Role is unknown

Question 24

IgA

Answer 24

• host defence
• Found in secretions (tears saliva, milk ext
• Dimer

Question 25

IgM

Answer 25

- Host defence - Early immune response - Pentamer

Question 26

IgE

Answer 26

- Allergies (hypersensitivity) | - Defends against parasites

Question 27

1st Immune Response

Answer 27

- Ab production triggered on first antigen introduction - Latent period of several days - Circulating antibody detectable after 5-10 days - Antibody in serum is maximum at 21 days (titer), then starts to drop to low levels

Question 28

2nd Immune Response

Answer 28

- Basis for Immunization - Occurs when Ag (NOT Ab) is introduced 2nd, 3rd, 4th time - Lag, rapid Ab increase (2-3 days) - Slow decrease - Booster injection maximize Ab levels

Question 29

Antibody Detection: | Serology Reaction

Answer 29

- Detects presence of Ab in serum sample - Antigen and antibody interact (agglutination) - Antibody titration - Detect unknown microorganisms using known antisera

Question 30

Agglutination

Answer 30

When an antigen and antibody interact

Question 31

CMI: | T-Cells

Answer 31

- NOT antibodies - Helper, suppressive, cytotoxic (killer) generated from memory T- cells - Exposure to antigen induces response form trained T-cells

Question 32

CMI:

Answer 32

Essential for defence against intracellular organism, parasites, tumours, and other foreign cells

Question 33

Disorders of Immunity: | Allergy and Hypersensitivity

Answer 33

- Over reaction to antigens in absence of true infection | - Anaphylaxis

Question 34

Disorders of Immunity: | Auto-immune disease

Answer 34

- Immune system reacts to its own "self" antigens - "auto antibodies" - Type I diabetes, MS, Lupus

Question 35

Disorders of Immunity: | Immunodeficiency states

Answer 35

- Inability to produce antibodies and more disfunction CMI - Congenital, disease, AIDS - HIV destroys T helper cells

Question 36

Disorders of Immunity: | Graft rejection

Answer 36

- NORMAL immune reaction to non self | - Controlled by immune suppressive medication

Question 37

Immunization

Answer 37

- Passive Immunization | - Active Immunization

Question 38

Passive Immunization

Answer 38

– administration of pre-formed antibody against a specific microbial agent – IgG animal origin: short lived, risk of hypersensitivity reaction – IgG human origin: short lived, no risk of reaction – Gamma globulin (IgG): pooled from large grouped of blood donors and has antibodies to many common infections – Hyperimmune globulins (IgG): specific for a particular microbe

Question 39

Active Immunization:

Answer 39

Stimulates immune system by administration of antigen. | LONGER LASTING

Question 40

Active Immunization: | Live Attenuated Vaccines

Answer 40

– Sub-clinical or mild illness mimicking the disease – Local (IgA) and humoral (IgG) immunity – Rapid immunity development – Serious illness in immuno-compromised individuals

Question 41

Active Immunization: | Killed Vaccines

Answer 41

– Antigens without infectivity – May require boosters – Adjuvant with toxoids – Polysaccharide vaccines can be conjugated to protein (see conjugate vaccines)

Question 42

Active Immunization: | Recombinant Vaccines

Answer 42

– DNA recombinant technology – Attenuates microorganism – Hep B vaccine

Question 43

Active Immunization: Adsorbed Vaccines NOTE THE "AD"

Answer 43

– Vaccine mixed with inorganic salt for slower adsorption and longer- lasting immunity – Tetanus, diphtheria

Question 44

Active Immunization: | Conjugate Vaccines

Answer 44

– Designed for poorly antigenic microorganisms | – Conjugate antigen of interest to immunogenic, non-toxic protein – Haemophilus influenzae type b

Question 45

Active Immunization: | Combined Vaccines

Answer 45

– For ease of administration

Question 46

Active Immunization: | Combined Active-Passive Immunization

Answer 46

– Immediate protection after possible exposure to microbe | – Hyperimmune Igs and vaccine injected at DIFFERENT sites – Tetanus, Rabies, Hep B

Question 47

Types of Active Immunization

Answer 47

- Live attenuated vaccines - Killed vaccines (sub-unit vaccines and toxoids) - Recombinant vaccines - Adsorbed vaccines - Conjugate vaccines - Combined vaccines - Combined Active-Passive Immunization

Question 48

Passive Immunization: | IgG animal origin

Answer 48

Short lived, risk of hypersensitivity reaction

Question 49

Passive Immunization: | IgG human origin

Answer 49

Short lived, no risk of reaction

Question 50

``` Passive Immunization: Gamma globulin (IgG) ```

Answer 50

Pooled from large grouped of blood donors and has antibodies to many common infections

Question 51

``` Passive Immunization: Hyperimmune globulins (IgG) ```

Answer 51

Specific for a particular microbe

Question 52

Why Passive Immunization?

Answer 52

- Faster acting | - Short lived