Applied Immunology

Question 1

Naturally Acquired immunity:
ACTIVE?

Answer 1

Antigens enter the body naturally; body produces antibodies and specialized lymphocytes

Question 2

Naturally Acquired immunity:
PASSIVE?

Answer 2

Antibodies pass from mother to fetus via placenta or to infant in the mother’s milk.

Question 3

Artificially Acquired immunity:
ACTIVE?

Answer 3

Active: Antigens are introduced in vaccines; body produces antibodies and specialized lymphocytes

Question 4

Artificially Acquired immunity:
PASSIVE?

Answer 4

Preformed antibodies in immune serum introduced into body by injection

Question 5

Two artificial methods of immunity?

Answer 5

Active and passive immunization

Question 6

Active immunization:

Answer 6

• Administration of antigens so patient actively mounts a protective immune response

Question 7

Passive immunization:

Answer 7

• Individual acquires immunity through the transfer of antibodies formed by immune individual or animal

Question 8

History of immunization:

Answer 8

– Chinese noticed children who recovered from smallpox did not contract the disease again
– They infected children with material from a smallpox scab to induce immunity
• This process known as variolation
– Variolation spread to England and America but was stopped because of risk of death

Question 9

– 1796 – Edward Jenner discovered

Answer 9

cowpox was similar to smallpox

Question 10

– 1879 – Louis Pasteur developed

Answer 10

a vaccine against Pasteurella multocida

Question 11

Antibody transfer was developed when it

Answer 11

was discovered that vaccines protected through the action of antibodies

Question 12

Pastuer’s research:

Answer 12

• Avian cholera (caused by bacteria not virus) was a common zoonotic disease
• Discovered attenuated pathogen accidentally
• Went on to make other vaccinations

Question 13

Active immunization:
Vaccine types

Answer 13

Attenuated (live) vaccines (weakened)
– Use pathogens with reduced virulence
– Can result in mild infections
– Active microbes stimulate a strong immune response
– Can provide contact immunity

Question 14

Active immunization:
Vaccine types

Answer 14

• Inactivated vaccines
– Whole-agent vaccines (safer, bacteria is dead)
- Subunit vaccines

Question 15

Microbes don’t provide many

Answer 15

antigenic molecules to stimulate the immune response
– Often contain adjuvants (additives)

Question 16

Active Immunization
– Vaccine types
• Toxoid vaccines

Answer 16

– Chemically or thermally modified toxins used to stimulate immunity
– Useful for some bacterial diseases
– Stimulate antibody-mediated immunity
– Require multiple doses because they possess few antigenic determinants (not strong enough=need boosters)

Question 17

• Active Immunization
– Vaccine types
• Combination vaccines

Answer 17

-Administration of antigens from several pathogens • Vaccines using recombinant gene technology
– Attempts to make vaccines more effective, cheaper, safer
– Variety of techniques used to improve vaccines

Question 18

• Active Immunization
– Vaccine safety
• Problems associated with immunization:

Answer 18

– Mild toxicity most common
– Risk of anaphylactic shock
– Residual virulence from attenuated viruses
– Allegations that certain vaccines cause autism, diabetes, and asthma
» Research has not substantiated these allegations

Question 19

• Passive Immunotherapy

Administration of antiserum containing:

Answer 19

Preformed antibodies

Question 20

Passive immunotherapy:

Immediate protection against

Answer 20

recent infection or ongoing disease

Question 21

Passive immunotherapy:
Antisera have several limitations

Answer 21

• Contain antibodies against many antigens
• Can trigger allergic reactions called serum sickness
• Viral pathogens may contaminate antisera
• Antibodies of antisera are degraded relatively quickly
-limitations are overcome through development of hybridomas

Question 22

What is hybidoma?

Answer 22

Myeloma cells fused with plasma cells that make the antibodies

Question 23

Immune testing: serology

Answer 23

Antibody-Antigen Immune Testing: Study and diagnostic use of antigen antibody interactions in blood serum

Question 24

Two categories of immune testing

Answer 24

– Direct testing
• Looking for presence of antigens
– Indirect testing
• Look for antibodies that have formed against antigens

Question 25

What determines which test is chosen? Direct vs indirect?

Answer 25

Test is chosen based on the suspected diagnosis, cost, and speed with which a result can be obtained

Question 26

Precipitate reactions:

Answer 26

Involve soluble antigens with antibodies

Question 27

Agglutination Reactions Involve:

Answer 27

particulate antigens and antibodies Antigens may be: – On a cell (direct agglutination) – Attached to latex spheres (indirect or passive agglutination) Negative means no antigen on RBC

Question 28

• Agglutination occurs due to the

Answer 28

cross-linking of antibodies with particulate antigens

Question 29

Agglutination is the

Answer 29

clumping of insoluble particles, whereas precipitation involves the aggregation of soluble molecules These reactions are easy to see and interpret with the unaided eye

Question 30

Hemagglutination:

Answer 30

the agglutination of RBC, can be used to determine blood type

Question 31

Hemagglutination involves

Answer 31

agglutination of RBCs.

Question 32

Viral hemagglutination inhibition tests for:

Answer 32

antibodies by the antibodies' ability to inhibit the agglutination (clumping) of red blood cells by the viral hemagglutinin.

Question 33

Neutralization reactions:

Answer 33

Eliminate the harmful effect of a virus or exotoxin

Question 34

Labeled antibody tests:

Answer 34

– Uses antibody molecules linked to some “label” that enables them to be easily detected – Used to detect either antigens or antibodies

Question 35

Labeled Antibody Tests • The Complement Fixation Test

Answer 35

– Based on generation of membrane attack complexes during complement activation – Detect presence of specific antibodies in an individual’s serum – Can detect antibody amounts too small to detect by agglutination

Question 36

Labeled Antibody Tests – Fluorescent antibody tests

Answer 36

• Use fluorescent dyes as labels • Fluorescein is one dye used in these tests • Fluorescein-labeled antibodies used in two types of tests –Direct fluorescent antibody tests –Indirect fluorescent antibody tests

Question 37

Labeled Antibody Test – ELISA

Answer 37

• Stands for enzyme-linked immunosorbent assay • Uses an enzyme as the label – Reaction of enzyme with its substrate produces colored product • Commonly used to detect presence of antibodies in serum

Question 38

Labeled Antibody Test – ELISA

Answer 38

• Antibody sandwich ELISA – Modification of the ELISA technique – Commonly used to detect _________ – It is “sandwiched” between two antibody molecules

Question 39

Labeled Antibody Test – ELISA • Advantages of the ELISA

Answer 39

– Can detect either antibody or antigen – Can quantify amounts of antigen or antibody – Easy to perform and can test many samples quickly – Plates coated with antigen and gelatin can be stored for later testing

Question 40

Labeled Antibody Test • Western blot test

Answer 40

– Technique to detect antibodies against multiple antigens – Advantages over other tests – Can detect more types of antibodies – Less subject to misinterpretation

Question 41

Recent Developments in Antibody- Antigen Immune Testing (COVID & pregnancy tests)

Answer 41

– Simple immunoassays that give results in minutes – Useful in determining a preliminary diagnosis – Immunofiltration and immunochromatography are most common

Question 42

• Recent Developments in Antibody- Antigen Immune Testing -immunofiltration:

Answer 42

• Rapid ELISA that uses antibodies bound to membrane filters rather than polystyrene plates – Membrane filters have large surface area » Assay quicker to complete

Question 43

Recent Developments in Immune Testing – Immunochromatography

Answer 43

• Very rapid and easy-to-read ELISAs • Antigen solution flows through a porous strip and encounters labeled antibody • Visible line produced when antigen-antibody immune complexes encounter antibody against them • Used for pregnancy testing and rapid identification of infectious agents

Question 44

Serological Tests Precipitation:

Answer 44

Soluble antigens

Question 45

Serological Tests Agglutination:

Answer 45

Particular antigens

Question 46

Serological Tests Hemagglutination:

Answer 46

Agglutination of RBCs

Question 47

Serological Tests Fluorescent-antibody technique:

Answer 47

Antibodies linked to fluorescent dye

Question 48

Serological Tests Complement fixation:

Answer 48

RBCs are indicator

Question 49

Serological Tests Neutralization:

Answer 49

Inactivates toxin or virus

Question 50

Serological Tests ELISA:

Answer 50

enzyme/substrate complex is the indicator