L16-17

Question 1

Main defense against extracellular bacteria

Answer 1

opsonizing antibody and phagocytosis (esp for encapsulated bacteria), neutralizing antibody, complement

Question 2

Encapsulated bacteria

Answer 2

hydrophilic capsule prevents phagocytosis unless opsonizing antibody + C3b are used to engulf bacteria

Question 3

What complement molecule helps phagocytose encapsulated bacteria

Answer 3

C3b

Question 4

neutropenic patients susceptible to

Answer 4

infections with extracellular pathogens

Question 5

Splenectomized patients are susceptible to

Answer 5

sepsis (encapsulated bacteria)

Question 6

Neutralizing antibody

Answer 6

inhibits attachment to receptors on host cells

Question 7

Ig Deficiency patients are susceptible to

Answer 7

infections with extracellular pathogens

Question 8

IgA defends

Answer 8

mucosal surfaces from infections

Question 9

Anti-toxin antibodies

Answer 9

bind and neutralize toxin molecules by inhibiting them from binding to specific host cell receptors

Question 10

endotoxins

Answer 10

LPS

Question 11

Endotoxin is produced by

Answer 11

gram negative bacteria

Question 12

Endotoxin structure

Answer 12

Lipid A core, highly variable carbohydrate side chains

Question 13

Endotoxin vaccine?

Answer 13

no cannot be made into a toxoid due to stable Lipid A structure

Question 14

Secondary immunity to endotoxin?

Answer 14

NO, highly variable structure will not recognized from another infection

Question 15

Endotoxin triggers

Answer 15

alternative complement pathway

Question 16

LPS is an exogenous pyrogen producing:

Answer 16

IL-1, TNF-alpha, IL-6

Question 17

TLR4

Answer 17

PRR that binds CD14-LBP-LPS to induce macrophage response

Question 18

Exotoxin is produced by

Answer 18

gram negative bacteria or gram positive bacteria

Question 19

Exotoxin structure

Answer 19

distinct receptors, little variance, neutralizing antibodies are effective

Question 20

Tetanus

Answer 20

disease doesn’t always lead to immunity because toxins cause disease long before inducing an antibody response

Question 21

Exotoxin vaccine

Answer 21

yes, toxoid

Question 22

Superantigens

Answer 22

exotoxin capable of inducing large quantities of cytokines, by binding HLA class II molecules at non-binding site and activate all T cells with TCR allele

Question 23

Immunity to intracellular bacteria

Answer 23

CD4 producing IFN-gamma

Question 24

IFN-gamma

Answer 24

restricts protein synthesis by decreasing a.a. pool
decreased membrane fluidity to prevent entrance
NO production for bacterial toxicity
altered cell metabolism to inhibit bacterial growth
increased HLA Class I
activation of macrophages

Question 25

Macrophage stimulation occurs by

Answer 25

IFN-gamma, LPS, TNF-alpha

Question 26

Macrophage characteristics

Answer 26

increased vacuolization, increased respiratory burst, increased C3b and Fc receptors, increased HLA Class I and II expression, increased metabolism

Question 27

CTL role in intracellular infection

Answer 27

delayed response after activation with IL-2, NK cells first responders

Question 28

Obligate intracellular pathogens drive immune response towards

Answer 28

Th2 (antibody response) to slow Th1 response, they may also lay dormant until immune response wains

Question 29

Humoral response to extracellular viral proteins

Answer 29

neutralizing antibody, opsonizing antibody (detrimental by providing entrance), classical complement pathway, or ADCC

Question 30

Cellular immunity to intracellular viral proteins

Answer 30

NK cells (KIRS: lack of self HLA Class I), CTL, IFN-gamma

Question 31

IFN-gamma's role in viral infection

Answer 31

restricts protein synthesis by decreasing a.a. pool decreased membrane fluidity to prevent entrance production of enzymes for destruction up regulation of HLA expression

Question 32

Virus adaptation to evade immune response

Answer 32

``` block IFN activation pathway Block HLA molecule expression block complement activation Mutate themselves induce immune suppression ```

Question 33

Protozoan parasite immunity

Answer 33

humoral protects from extracellular pathogens | CMI protects from intracellular pathogens

Question 34

Parasitic helminths causes production of

Answer 34

IgE (allergy like symptoms) and eosinophilia

Question 35

Parasitic helminths causes release of

Answer 35

IL-4, IL-5, and suppress IL-2 and IFN-gamma

Question 36

Septic shock syndrome mediators

Answer 36

LPS, gram-positive peptidoglycan, f-met-leu-phe, 5'-mCPG, superantigens

Question 37

Septic shock syndrome effects

Answer 37

circulatory collapse, DIC, hemorrhagic necrosis

Question 38

By-stander immune pathology

Answer 38

damage to surrounding normal tissue

Question 39

Autoimmunity

Answer 39

sharing of molecular structures may give way to cross-reactivity to host, Strep causing heart valve destruction called rheumatic fever

Question 40

IgA, IgG, IgM

Answer 40

humoral response to virus, neutralization

Question 41

IgG and IgM

Answer 41

humoral response to virus, opsonization

Question 42

IFN-gamma

Answer 42

cellular response, induces anti-viral state