2.2

Question 1

specificity

innate immunity

Answer 1

for structures shared by classes of microbes (pathogen-associated molecular patterns) or damaged cells (damaged-asssociaed molecular patterns)

Question 2

specificity

adaptive immunity

Answer 2

for structural detail of microbial molecules (antigens) may recognize nonmicrobial antigens

Question 3

receptors

innate

Answer 3

encoded in germline; limited diversity (pattern recognition receptors)

Question 4

receptors

adaptive

Answer 4

encoded by genes produced by somatic recombination of gene segments; greater diversity

Question 5

distribution of receptors

innate

Answer 5

noncolonal: identical receptors on all cells of the same lineage

Question 6

distribution of receptors

adaptive

Answer 6

colonal: clones of lymphocytes with distinct specificities express different receptors

Question 7

discrimination of normal self and nonself

innate

Answer 7

yes; healthy host cells are not recognized, or they may express molecules that prevent innate immune reactions

Question 8

discrimination of normal self and nonself

adaptive

Answer 8

yes; based on selection against self-reactive lymphocytes; may be imperfect (giving rise to autoimmunity)

Question 9

The two principal types of reaction of the innate immune

system are:

Answer 9

• • Stimulate acute Inflammation.

- - Anti-viral defenses

Question 10

• Stimulate acute Inflammation.

Answer 10

— which is the accumulation of leukocytes,
phagocytic cells, plasma proteins, and
fluid derived from the blood at an
extravascular tissue site of infection or injury.

Question 11

Anti-viral defenses mediated by: (2)

Answer 11

— NK cell-mediated killing of virus-infected cells.
— Interferon α/β (Type I interferons), which are
secreted by virus-infected cells, bind to
receptors on surrounding cells, and induce
an anti-viral state in those cells.

Question 12

Prominent cell-associated Pattern Recognition Receptors and

Sensors of Innate Immunity (3)

Answer 12

Toll-Like Receptors (TLRs).
NOD-like Receptors (NLRs).
RIG-like Receptors (RLRs)

Question 13

NOD-like Receptors (NLRs).

Answer 13

– NLRs are a family of more than 20 different cytosolic proteins that recognize
PAMPs and DAMPs in the cytoplasm and recruit other proteins to form signaling
complexes (such as inflammasomes) that promote inflammation.

Question 14

RIG-like Receptors (RLRs).

Answer 14

– RLRs are cytosolic sensors of viral RNA that respond to viral nucleic acids
by inducing production of the antiviral type I interferons.

Question 15

Components of the Innate Immune Response.

- Epithelial barriers (3)

Answer 15

physical barrier to infection
killing of microbes by locally produced antibiotics
killing of microbes and infected cells by intraepithelial lymphocytes

Question 16

Components of the Innate Immune Response.

- Phagocytes (2)

Answer 16

neutrophils

monocytes/macrophages

Question 17

.Neutrophils. (3)

Answer 17

…Circulating phagocytic cells; Most abundant leukocytes blood.
…First cell type to respond to most infections.
…Live only a few hours in tissues.

Question 18

.Monocytes/Macrophages. (1)

Answer 18

…Blood monocytes differentiate into tissue macrophages

after entering tissues.

Question 19

Macrophages: fxn (2)

Answer 19

Secrete cytokines that induce
inflammation, and ingest and
destroy microbes.

Question 20

Macrophages:

life span

Answer 20

Survive for long time periods in

tissues

Question 21

Components of the Innate Immune Response.

- Dendritic cells (sentinel cells) (2)

Answer 21

…Secrete cytokines.

…Present antigenic peptides to T cells.

Question 22

Components of the Innate Immune Response.
mast cells (4)

Answer 22

…Abundant cytoplasmic granules.
…Present in skin and mucosal epithelium.
…contain vasoactive amines (e.g. histamine).
…cause vasodilation and capillary permeability

Question 23

Components of the Innate Immune Response.

Innate lymphoid cells (2)

Answer 23

…lymphocyte-like cells.

…produce cytokines but lack T cells antigen receptors (TCRs)

Question 24

Components of the Innate Immune Response.

- Complement (1)

Answer 24

…Induce inflammation, opsonize microbes enhancing

their phagocytosis, cause osmotic lysis of microbes.

Question 25

Delivery of neutrophils, macrophages, T
lymphocytes, complement proteins, antibodies,
and acute-phase reactants to the site of
inflammation is due to reversible changes in
blood vessels in the infected or damaged tissue: (3)

Answer 25

– increased blood flow into tissue due to
arteriolar dilation
– increased adhesiveness of circulating
leukocytes to the endothelial lining of venules
– increased permeability of capillaries and
venules to plasma proteins and fluid

Question 26

All these changes are induced by cytokines and
small molecule mediator initially derived from
(2) in response
to stimulation of pathogen-associated molecular
patterns (PAMPs) or damage-associated
molecular patterns (DAMPs).

Answer 26

sentinel cells (resident phagocytic cells) in the
tissue, as well as endothelial cells,

Question 27

Sequence of events in migration of blood leukocytes to sites of infection (4)

Answer 27

The sequence of selectin-mediated rolling, chemokine-dependent integrin-mediated
firm adhesion, and chemokine-mediated motility leads to the migration of blood
leukocytes to the extravascular site of infection.

Question 28

Components of the Innate Immune Response.

- Natural Killer (NK) cells (2)

Answer 28

…Kill virus-infected cells.

…Secrete interferon γ which activates macrophages.

Question 29

inhibitory receptor engaged

Answer 29

NK cell not activated, no cell killing

Question 30

inhibitory receptor not engaged

Answer 30

NK cell activated; killing of infected cell

Question 31

Components of the Innate Immune Response.

- IFN α/β (Type I Interferons) (1)

Answer 31

…Secreted by virus infected cells, induce anti-viral state in
surrounding cells.

Question 32

The major protective innate immune responses to different microbes are:

Extracellular bacteria and fungi

Answer 32

are combated mainly by an acute inflammatory
response, in which neutrophils and monocytes are recruited to the site of
infection, and by the complement system.

Question 33

The major protective innate immune responses to different microbes are:

Intracellular bacteria,

Answer 33

which can survive inside phagocytes, are eliminated when
the microbial killing functions of phagocytes are activated by Toll-like receptors
and other sensors, as well as by cytokines.

Question 34

The major protective innate immune responses to different microbes are:

viruses

Answer 34

Defense against viruses is provided by type I interferons (interferons α and β) and
by natural killer (NK) cells.