5: Cellular innate immunity: mast cells, eosinophils, basophils, ILCs, NK cells

Question 1

what are immune cells functions during inflammation?

Answer 1

attract effector cells from the blood to sites of infection
pathogen destruction
tissue damage repair

Question 2

what cells play a role in innate and adaptive immunity?

Answer 2

mast cells, esoinophils, basophils

Question 3

what is the common property of mast cells, eosinophils, and basophils?

Answer 3

they all contain cytoplasmic granules filled with various inflammatory and antimicrobial mediators AND are involved in immune responses that protect against helminths and reactions that cause allergic diseases

Question 4

where are mast cells most abundant?

Answer 4

skin and mucosal epithelia (TISSUE ONLY)

Question 5

what happens upon activation of mast cells?

Answer 5

release many potent inflammatory mediators that defend against helminthic parasites or cause symptoms of allergic diseases

Question 6

what inflammatory mediators are stored in the cytoplasm of mast cells?

Answer 6

histamine and inflammatory lipid mediators

Question 7

how does histamine cause inflammation?

Answer 7

promotes changes in the blood vessels

Question 8

what can mast cells release besides histamine and inflammatory lipid mediators?

Answer 8

cytokines

Question 9

mast cells express high-affinity plasma membrane receptors for which antibody?

Answer 9

IgE

Question 10

what leads to mast cell activation?

Answer 10

antigen binding to the antibodies on the cell surface of the mast cell

Question 11

what is the most important vasoactive molecule released by mast cells and baosphils.

Answer 11

histamine

Question 12

what induces vascular leakage, bronchoconstriction, and intestinal hypermotility (components of the immediate immune response)?

Answer 12

amines and lipid mediators

Question 13

chemokines released by basophils and mast cells result in the recruitment of?

Answer 13

blood leukocytes

Question 14

where are basophils most commonly found?

Answer 14

in the blood circulation and may be recruited to some inflammatory sites

Question 15

basophils are considered what>

Answer 15

blood granulocytes (similar in structure/function to mast cells)

Question 16

eosinophils’ cytoplasmic granules contain enzymes that are harmful to what?

Answer 16

cell walls of parasites

Question 17

where do eosinophils reside?

Answer 17

in the blood circulation and may be recruited to tissues AND normally present in peripheral tissues

Question 18

in what peripheral tissues are eosinophils found?

Answer 18

mucosal linings of the respiratory, GI, and genitourinary tracts

Question 19

what is the function of innate lymphoid cells?

Answer 19

act as effector cells to amplify signals delivered by innate recognition

Question 20

where do innate lymphoid cells develop?

Answer 20

in the bone marrow from the common lymphocyte progenitor (same site that gives rise to B and T lymphocytes and NK cells)

Question 21

how are ILCs grouped?

Answer 21

by the cytokines they produce

Question 22

can innate lymphoid cells (ILCs) destroy pathogens?

Answer 22

no, only activate cytokines

Question 23

what is the important role of ILCs?

Answer 23

they initiate inflammatory responses at barrier surfaces in response to infectious organisms

Question 24

what is the role of group 1 ILCs?

Answer 24

provide resistance to viruses, intracellular bacteria and parasites by producing TNK and IFN gamma

Question 25

what is the role of group 2 ILCs?

Answer 25

provide resistance to helminth parasites by producing IL-4,5,9,13

Question 26

What is the role of group 3 ILCs?

Answer 26

provide resistance to extracellular bacteria by producing lymphotoxin (LT), TNF, IL-17A, IL-22

Question 27

what are the properties of NK cells?

Answer 27

granular lymphocytes
non-phagocytic
not antigen specific
no surface immunoglobulin

Question 28

where are NK cells found?

Answer 28

high concentration in spleen, liver, uterus, and peripheral blood

Question 29

what is the lifespan of a NK cells?

Answer 29

7-10d

Question 30

what is the primary function of NK cells?

Answer 30

non-specifically kill tumors or virally-infected cells, AND secrete cytokines

Question 31

what cells can secrete cytokines?

Answer 31

any immune cell

Question 32

what cells are the first line of defense to viruses and when do they peak?

Answer 32

NK cells; 3 d

Question 33

what are the three methods of killing pathogens employed by NK cells?

Answer 33

natural cytotoxicity
cytotoxic cytokines
anti-body dependent cell-mediated cytotoxicity

Question 34

what is natural cytotoxicity (NK cells)?

Answer 34

releasing of granules after binding to the ligand of a host cell causing it to die

Question 35

what is cytotoxic cytokines (NK cells)?

Answer 35

NK cells respond to IL-12 produced by macrophages and secrete IFN gamma which activates the macrophages to kill the phagocytosed microbes

Question 36

what is anti-body dependent cell-mediated cytotoxicity (NK cells)?

Answer 36

the Fc receptors on NK cells can bind IgG and trigger the release of cytotoxic granules on tumor cells or virus infected cells

Question 37

when are NK cells involved in an infection?

Answer 37

early

Question 38

what receptors on NK cells allow them to detect if a cell is infected or healthy?

Answer 38

inhibitory receptor (healthy)
activating receptor (infected)

Question 39

what immunoglobulin is of central importance in allergic reactions?

Answer 39

IgE binds to specific Fc receptors on mast cells to activate them