Immunology and Serology

Question 1

Immunity

Defense Systems

Answer 1

1. Nonspecific / Innate Immunity
2. Specific / Acquired Immunity

Question 2

Define

Nonspecific / Innate Immunity

Answer 2

Protective mechanisms that repel all microoganisms equally and in the same manner

Question 3

Nonspecific / Innate Immunity

Categories

Answer 3

• Species resistance
• Mechanical and chemical barriers
• Inflammatory response
• Interferon
• Complement

Question 4

Define

Species Resistance

Answer 4

Genetic ability of a particular species to defend itself against certain pathogens
* Ex: dogs can’t get FeLV and cats can’t get canine distemper

Question 5

Mechanical and Chemical Barriers

Answer 5

First Line of Defense

Question 6

Body’s Mechanical Barriers

Answer 6

Skin and Mucous Membranes
* respiratory, intestinal, or urinary tract linings
* needs to be healthy to be effective
* poor quality if inflamed, ulcerated, or broken/cut

Question 7

Body’s Chemical Barrier

Answer 7

Stomach acid, sebum, mucus, and enzymes
* inhibit or destroy pathogens that get through unhealthy mechanical barrier

Question 8

Inflammatory Response

Answer 8

Second Line of Defense
* damage to area causes tissue to release enzymes (mediators)

Question 9

Signs of Inflammation

Answer 9

• Heat
• Redness
• Swelling
• Pain
• Loss of function - secondary to others

Question 10

Interferon

Answer 10

Produced by cells invaded by viruses
* interferes with virus’ ability to replicate within the host cell
* can be activated by acquired immune system

Question 11

Complement

Answer 11

Produces small holes in cell wall
* leads to rupture or lysis of pathogen
* can be activated by acquired immune system

Question 12

Define

Specific / Acquired Immunity

Answer 12

Third Line of Defense
* Formation of antibodies to attack specific pathogens
* Done by lymphocytes

Question 13

T-Lymphocytes

Answer 13

Cell-mediated response
* interact directly with pathogens - destroy/render it incapable of causing disease
* faster response than B-cells

Question 14

T-Lymphocyte Production

Answer 14

Produced in bone marrow
* matures in thymus

Question 15

T-Lymphocytes in Thymus

Answer 15

T-cells learn to recognize antigens that are unique to animal’s own cells
* known as self-recognition

Question 16

Memory T-cells

Answer 16

Remember the pathogen for future insults

Tm

Question 17

B-Lymphocytes

Answer 17

Humoral Response
* produce antibodies in response to specific antigen stimulation

Question 18

B-Lymphocyte Production

Answer 18

Produced and mature in the bone marrow
* immature cells covered in receptors for specific antigens

Question 19

Memory B-Lymphocytes

Answer 19

Remember antigen for future infections

Question 20

Antibody Functions

Answer 20

• Opsonization
• Neutralization
• Agglutination
• Complement Activation

Question 21

Opsonization

Answer 21

Antibody binds to pathogen
* marks pathogen for phagocytosis

Question 22

Neutralization

Answer 22

Antibody binds to pathogen
* renders pathogen harmless

Question 23

Agglutination

Answer 23

Antibody-Antigen binding
* forms large clumps
* makes them more obvious to immune cells

Question 24

Complement Activation

Answer 24

Antibody binds with pathogen
* pokes small holes in cell wall
* leads to rupture or lysis of pathogen

Question 25

Antibody Types

Answer 25

• IgG
• IgM
• IgA
• IgE

Question 26

IgG

Answer 26

Most abundant

Question 27

IgM

Answer 27

• Largest antibody
• First to respond to antigen

Question 28

IgA

Answer 28

Prevents attachment of pathogens to mucosal surfaces
* intestinal
* respiratory
* urogenital

Question 29

IgE

Answer 29

Important in allergic and parasitic responses

Question 30

Passive Immunity

Answer 30

Antibodies formed in one animal are given to another animal
* provides said animal with protection again disease
* lasts for only a short time, eventual susceptibility to disease

Question 31

Passive Immunity Examples

Answer 31

• In utero via placenta
• Newborns drinking colostrum within 24 hours
• IV infusion of antibody rich plasma (for foals)

Question 32

Active Immunity

Answer 32

Animal’s own immune system encounters pathogens and makes antibodies to them
* natural exposure leading to possible disease
* vaccines which are noninfectious forms of pathogen

Question 33

Type I Hypersensitivity

Answer 33

• Immediate reaction
• IgE response
• Ex: atopy and anaphylactic shock

Question 34

Type II Hypersensitivity

Answer 34

• IgG or IgM response
• Antibodies directed to attack own cells
• Ex: anemia or thrombocytopenia

Question 35

Type III Hypersensitivity

Answer 35

Immune-complex disease
* antibodies and antigens form complexes
* deposited into blood vessels
* ex: lupis and kidney (glomerulous)

Question 36

Type IV Hypersensitivity

Answer 36

T-cell mediated disease
* Delayed response
* Ex: type 1 diabetes, rheumatoid arthritis

Question 37

Serology

Answer 37

Detection and measurements of antibodies or antigens
* requires serum (clotted prior)
* tests evaluated for sensitivity and specificity

Question 38

Sensitivity

Answer 38

Ability of a test to identify those infected as positive
* low sensitivity = more false negatives (infected identified as negated)

Question 39

Specificity

Answer 39

Ability of a test to identify those healthy as negative
* low specificity = more false positive (healthy test as positive)