Intro to Immune

Question 1

a. Humoral immunity

Answer 1

i. Mediated by proteins called antibodies which are produced by cells called B lymphocytes
ii. Cannot gain access to microbes that live and divide inside infected cells
1. Complement, acute-phase proteins, and natural Abs which are generated against Ags derived from normal gastrointestinal microflora rather than being produced in response to an infection.
2. Ex: C-reactive protein
3. Opsonization with CRP promotes the uptake of cells by phagocytes

Question 2

b. Cell-mediated immunity

Answer 2

i. Mediated by T lymphocytes
ii. Activate phagocytes to destroy microbes that have been ingested by the phagocytes into intracellular vesicles
1. Multiple cell types that use a set of specific receptors to recognize and remove pathogens and cellular debris
2. Neutrophils, monocytes, and macrophages are Phagocytes
3. Mast cells, basophils, and eosinophils are essential components host defenses against multiple parasites and allergies
4. Natural Killer (NK) cells play a key role in the elimination of infected and malignant cells, cause destruction by apoptotic mechanisms

Question 3

Natural Immunity

Answer 3

i. Person is exposed to a live pathogen, develops an infection, recovers from the disease, and becomes immune
ii. Takes several weeks to develop, but provides a long lasting protection

Question 4

Artificial (Active) immunity

Answer 4

i. Exposure to killed or attenuated pathogenic microorganisms without contracting an infection
ii. Provides a long lasting protection but takes several weeks to obtain
iii. Used only for prophylactics of infectious diseases

Question 5

Passive Immunity

Answer 5

i. Patient is given someone else’s Abs as a therapeutic treatment of the ongoing infection
ii. Short lived, but helps protect right away

Question 6

Hypersensitivity

Answer 6

i. Result of specific memory is that re-exposure to the same stimulus as well as or instead of eliminating the stimulus, has unpleasant or damaging effects on the body’s own tissues

Question 7

Autoimmune Disease

Answer 7

i. Stimulating a response to the body’s own structures

ii. Attacked as if they are foreign

Question 8

Immune Deficiency

Answer 8

i. Absence of one or more elements of the immune system

ii. Can be congenital or acquired after birth

Question 9

+G-CSF

Answer 9

Myeloblast→basophils, eosinophils, neutrophils (granulocytes)

Question 10

+M-CSF

Answer 10

Monoblast→Monocytes, Dendritic cells

Question 11

T cell Key Markers

Answer 11

CD3, CD4, CD8

Question 12

B cell Key Markers

Answer 12

CD19, CD20

Question 13

NK Cell Key Markers

Answer 13

CD56

Question 14

Macrophage/Monocyte Markers

Answer 14

CD14

Question 15

Phagocytes

Answer 15

i. Neutrophils and macrophages
ii. Ingest and destroy microbes
iii. Steps in response
1. Recruitment of cells to the sites of infection
2. Recognition of and activation by microbes
3. Ingestion of the microbes
4. Destruction of ingested microbes
iv. Secrete cytokines which promote and regulate immune responses

Question 16

Dendritic Cells

Answer 16

1. Originate from monocytes or from IFN
2. Langerhans cells residing in epidermis of the skin is a subset
   vi. Tissue-resident macrophages are long-lived cells derived from a transient hematopoietic progenitors emerging in the yolk sac

Question 17

vi. Mast cells and basophils both contain

Answer 17

1. Histamine, serotonin, heparin
2. cytokines and chemokines
3. basophilic purple granules

Question 18

acute inflammation

Answer 18

o	Tumor (swelling)
o	Rubor (redness)
o	Calor (heat)
o	Dolor (pain)
o	Function laesa (loss of function)

Question 19

What can induce a fever?

Answer 19

TNF, IL-1, IL-6

Question 20

PAMPs

Answer 20

• Indicators of the presence of particular pathogens
• Unique to particular classes of pathogens
• Cannot be altered, suppressed, or hidden from the surface
• No structural similarity with self Ags
• Ex: Porins, Lipoproteins, Liposaccharides, Lipoteichoic acid, teichoic acid, mannoproteins, beta-glycan, lipoarabinomannan

Question 21

IFN alpha/beta

Answer 21

o Block viral replication within host cells
o Induce expression of proteins that interfere with virus replication
o Activates nuclease ribonuclease L which then mediates viral RNA degradation
o Activate NK cells to enhance cytotoxicity

Question 22

Natural killer cells

Answer 22

o Kill virus-infected cells
o Ability is inversely related to expression of MHC class 1 on the target cells
o Recognize ligands on infected cells or cells undergoing other types of stress
o Secrete IFN-gamma so macrophages kill phagocytized microbes

Question 23

Pneumococci microbial evasion

Answer 23

Polysaccharide inhibits phagocytosis

Question 24

Staphylococci microbial evasion

Answer 24

production of catalase, breakdown of reactive oxygen

Question 25

Neisseria meningitidis microbial evasion

Answer 25

sialic acid expression inhibits C3 and C5 convertases

Question 26

Streptococci microbial evasion

Answer 26

blocks binding of C3 to organism and C3b to receptor

Question 27

Pseudomonas

Answer 27

Synthesis of modified LPS that resists peptide antibiotics