Host Response

Question 1

Recepter on the NK cell that binds to the MHC molecule on normal cell

Answer 1

Inhibitory receptor

Question 2

Leukocyte interferon, produced in large quantities by plasmacytoid dendritic cells and is not host specific

Answer 2

INF-Alpha

Question 3

When is gene silencing used?

Answer 3

Cells can utilize this mechanism to disrupt virus replication through production of RNAi that are complementary to specific viral genes

Question 4

Antigenic Plasticity

Answer 4

Rapid changes in the structure of the viral antigen, may be the result of mutation, reassortment or recombination

Question 5

(RNA/DNA) viruses are stronger inducers of Interferons

Answer 5

RNA

Question 6

Possess potent antiviral, immunomodulating and anti-cancer properties

Answer 6

Interferons

Question 7

NK cells recognize what molecules on healthy cells that keeps them from becoming activated

Answer 7

MHC Class I Molecules

Question 8

Innate immune system responds in what ways when their PPRs are bound by a PAMP

Answer 8

Expression of interferons and inflammatory cytokines

Activation of phagocytic cells, increased production of inflammatory cells

Macrophages begin chemotaxis bringing neutrophils to site of inflammation

Question 9

Interferon

Answer 9

Group of cytokines that are secreted by somatic cells in response to viral infections and to other stimuli

Question 10

Ways in which Host responds to viral infection

Answer 10

Innate immune response

Adaptive immune response

Passive immune response

Question 11

Natural Killer Cells

Answer 11

Large lymphocytes that are defined by their cytoplasmic granules, provide early and non specific resistance against viral infections

Question 12

Virokines

Answer 12

Proteins synthesized by viruses which are homologs of cytokines/interferons

Question 13

Ways that viruses evade host immune system

Answer 13

Antigen plasticity

Antigenic Multiplicity

Negative Cytokine Regulation

Down Regulation of MHC I Pathway

Inhibition of complement activation

Evasion of neutralizing antibodies

Latency

Cell to Cell spread

Inhibition of apoptosis

Question 14

Humoral Immunity

Answer 14

Antibodies may be directed against viral proteins on free virions or against viral proteins expressed on surface of infected cells

Question 15

CD4+ Th Cell mechanism of action

Answer 15

• Th interacts with microbial antigen in phagocyte
• Stimulates the release of cytokines
• Results in activation of macrophages, inflammation and Stimulation of B lymphocytes

Question 16

Cellular immunity is mediated by

Answer 16

T Lymphocytes

Question 17

Immunoregulatory interferon produced by antigen stimulated by T cells and NK cells. Labile at pH of 2 and demonstrates host specificity

Answer 17

Type II Interferon - Interferon Gamma

Question 18

Defense exhibits neither antigen specificity nor memory

Answer 18

Innate Immunity

Question 19

Components of adaptive immunity

Answer 19

Humoral Immune Response

Cellular Immune Response

Question 20

Paracrine

Answer 20

Infected cell secretes IFN which acts on adjacent cells

Question 21

Temperature of the nasal passages

Answer 21

33C

Question 22

Gene Silencing

Answer 22

Cells utilize small, interfering RNA molecules (iRNA) to silence genes as a means of regulating normal developmental and physiological processes and potentially to interfere with virus replication

Question 23

Interferons are inactivated by what route of administration

Answer 23

Oral

Question 24

Innate immunity provides critical line of defense against viral infections because:

Answer 24

Constantly present

Operational immediately

Available for the first few days after viral infection

Question 25

Temperature of the alveoli

Answer 25

37C

Question 26

Fibroblast interferon secreted by virus-infected fibroblast, generally host species specific

Answer 26

INF - Beta

Question 27

Granulocytosis

Answer 27

Presence in peripheral blood of increased number of granulocytes

Question 28

Pathogen Associated Molecular Patterns

Answer 28

Macromolecues present in viruses and other microbes, but not on host cells

Question 29

Antiviral effects of antibodies

Answer 29

Reduced damage to host from inflammatory response Generation of oxidants Immunomodulation Opsonization Activation of complement Virus and toxin neutralization Antibody dependent cell cytoxicity Direct antimicrobial activity

Question 30

Perforin

Answer 30

Produce pore in plasma membrane

Question 31

Activation of the complement system causes

Answer 31

Opsonization Chemotaxis Lysis Agglutination

Question 32

How do viruses evade neutralizing antibodies

Answer 32

Produce large amounts of soluble protein to soak up antibody Variation in viral antigens Production of antibodies capable of neutralization Slow production of antibodies

Question 33

Antibody dependent cell mediated cytotoxicity

Answer 33

Antibodies bind to viral antigens expressed on surface of host cells, host cells are destroyed by phagocytosis or by complement mediated cytolysis

Question 34

Virus Neutralization

Answer 34

Neutralizing antibodies prevent virus attachement and entry into host cells, bind viral capsid or host envelope

Question 35

Viroceptors

Answer 35

Virus encoded proteins that are homologous to the receptor for cytokines, secreted cytokine receptor homolog bind to cytokines and serve as competitive antagonists

Question 36

Autocrine

Answer 36

infected cell secretes the INF that acts on same cell triggering apoptosis

Question 37

Opsonization

Answer 37

Coating of virions with antibodies, antibody coated virion is recognized and phagocytosed by macrophages and sometimes by neutrophils

Question 38

How do type I interferons inhibit virus replication

Answer 38

* Activate latent ribonuclease - RNAase L * RNAase L degrades viral RNA * Synthesis of Mx proteins that bind and trap nucleocapsid and inhibit virus assembly

Question 39

Adaptive Immunity

Answer 39

Antigen specific, responses take time to develop and is mediated by lymphocytes that possess surface receptors that are specific to each pathogen

Question 40

Pattern Recognition Receptors

Answer 40

Surface receptors that recognize specific pathogen associated molecular patterns.

Question 41

Mucocilliary Blanket

Answer 41

Layer of mucous produced by goblet cells that is kept in continuous flow by the coordinated beating of cilia on the luminal surface of the epithelial cells that line the nasal mucosa and airways

Question 42

Antigen Multiplicity

Answer 42

Antigenic varients with little or no cross reactivity

Question 43

Granzyme

Answer 43

Proteins that initiate apoptosis

Question 44

At least three interferons have been identified, recently discovered. Expressed in response to viral infections and activation of toll-like receptors. Primary function as immuno regulator

Answer 44

Type III Interferon

Question 45

Major classes of interferons based on antigenic and chemical differences

Answer 45

Type I Type II Type III

Question 46

Roles of type I interferons

Answer 46

Inhibit virus replication Activate NK cells Increase expression of MHC-1 Stimulate differentiation of monocytes into dendritic cells Maturation of dendritic cells Memorty T cell proliferation

Question 47

CD8+ Tc Cell mechanism of action

Answer 47

* Tc cell interaction with infected cell containing microbial antigen * Killing of infected cell

Question 48

Humoral immunity is mediated by

Answer 48

Antibodies released from B lymphocytes

Question 49

Immunocomplex formation

Answer 49

Clumping of viruses, reduces the number of viral particles avilable for cell invasion

Question 50

Cytoplasmic granules of NK cells contain

Answer 50

Perforin Granzyme