NK Cells

Question 1

This cell is produced in the bone marrow, found in the peripheral blood system, liver, and spleen, but does not possess receptors produced during gene rearrangement. What cell is this?

Answer 1

NK cell

Question 2

T/F: Natural Killer cells migrate to tissues in large numbers only when an inflammatory reaction is underway.

Answer 2

True

Question 3

While of lymphocytic in appearance, they also contain _______, that kill some virus-infected cells.

Answer 3

Granules

Question 4

What receptors are expressed on NK cells for identification?

Answer 4

CD16, CD56, and a reduction of CD3 receptors

Question 5

In solely bovine species, what receptor is identified on NK cells?

Answer 5

CD335, or NKp46

Question 6

What roles do NK cells possess?

Answer 6

The elimination of tumor, virus-infected, and stressed cells

Question 7

What cytokines are needed for the differentiation of NK cells into LAK cells, or Lymphokine activated killer cells?

Answer 7

IL-2 and IFN gamma

Question 8

What cell is associated with the production of cytokines and chemokines like IFN gamma, TNF alpha, IL-17, and IL-22, MIP-1 alpha, and MIP-1 beta, which have regulatory roles?

Answer 8

Natural Killer cells

Question 9

What difference is noted on the cell membrane of a normal cell, versus one that is cancerous, stressed, or virally infected?

Answer 9

The expression of MHC I is not suppressed in normal cells

Question 10

What roles do the receptors MICA, MICB, Rae-1, and H60, have on cell membranes?

Answer 10

Mark the cell as stressed and for phagocytosis

Question 11

What broad categories are NK cell receptors placed in?

Answer 11

Activating vs. Inhibitory receptors

Question 12

Which of the following signals will be blocked? Activating signals blocking inhibitory signals, or inhibitory signals blocking activating signals in normal cells?

Answer 12

Inhibitory signals blocking activating signals, under normal conditions

Question 13

T/F: An NK cell will only allow a cell to live, if it is recognized as “self” for both the peptide and MHC complex expressed on a cell’s surface.

Answer 13

True

Question 14

In mice, horses, and rats, the NK cell receptors that recognize MHC I molecules are called -?

Answer 14

KLRs, or Killer cell lectin-like receptors

Question 15

In humans, cattle, dogs, cats, and pigs, the NK cell receptors that recognize MHC I molecules are called -?

Answer 15

KIRs, or Killer cell immunoglobulin-like receptors

Question 16

What Natural Killer cell receptor family is associated with CD158?

Answer 16

KIRs, or Killer cell immunoglobulin-like receptors

Question 17

What are some traits associated with KIRs, or Killer cell immunoglobulin-like receptors?

Answer 17

Polymorphic, transmembranous, and they include LILRs, or leukocyte immunoglobulin-like receptors

Question 18

Where are KIRs expressed?

Answer 18

NK cells and subsets of lymphocytes

Question 19

Where are LILRs expressed?

Answer 19

NK cells and several types of leukocytes

Question 20

What is meant by KIRs and KLRs being mutually exclusive, since they both contain both activating and inhibitory receptors?

Answer 20

That they, KIRs and KLRs, can’t both be found within the same individual, organism, etc.

Question 21

NKG2D is an example of what type of receptor? What stress proteins does it recognize?

Answer 21

Killer cell lectin-like receptor, which recognizes MICA, MICB, and ULBP in humans; Rae-1, H60, and MULT1 in rats

Question 22

In ruminants, NKG2D, a KLR receptor, is also expressed on activated -?

Answer 22

Gamma delta T cells

Question 23

What occurs when there is a large presence of stress proteins on cells, in the presence of NKG2D?

Answer 23

NKG2D will bind to these stress receptors, which will lead to an override of inhibitory signals allowing for NK cell cytotoxicity and elimination of that stressed cell

Question 24

A reduction in the presence of antigen: MHC I complexes along a cell will mark it for _________ by NK cells.

Answer 24

Elimination

Question 25

Which of the following is not associated with NK cells? A) Control of hematopoiesis B) ADCC against virally-infected cells C) Activation of macrophages and lysis of stressed cells D) Bactericidal and fungicidal functions

Answer 25

B) ADCC against virally-infected cells

Question 26

What three mechanisms are associated with NK cells for elimination of targeted cells?

Answer 26

- Perforin dependent pathway - CD95/CD95L or Fas/FasL pathway - ADCC or CD16 pathway

Question 27

What occurs in the perforin dependent pathway?

Answer 27

Upon recognition and activation, NK cells secrete perforin which form channels into targeted cells for the entry of cytotoxic granules containing granulysin, NK-lysin, and fragmentin (which activate apoptotic zymogens or inactive enzymes) leading to apoptosis

Question 28

What occurs in the CD95/CD95L or Fas/FasL pathway?

Answer 28

Abnormal cells express the Fas/CD95 receptor, which is recognized and binds to the FasL/CD95L ligand of NK cells, which will then induce apoptosis of the abnormal cell

Question 29

What occurs in the ADCC or CD16 pathway?

Answer 29

The Fc or CD16 receptor of NK cells recognizes and binds to antibodies that are already bound to antigens, which will then initiate cytotoxicity

Question 30

What does ADCC stand for?

Answer 30

Antibody-dependent cellular cytotoxicity

Question 31

T/F: ADCC will only occur if antibodies are present and bound to antigens.

Answer 31

True

Question 32

What cytokines are needed to activate NK cells?

Answer 32

IL-1, IL-2, IL-12, IL-15, IL-18, IL21, and both Type I and II IFNs

Question 33

Upon stimulation by NK cell activating cytokines, what will occur to the NK cell?

Answer 33

It will become a lymphokine activated killer cell, or LAK, which has an increased cytotoxic abilities

Question 34

T/F: FMD in swine will increase the ability to stimulate the conversion of NK cells into LAK cells.

Answer 34

False, FMD and some other viruses have the ability to suppress NK cell cytotoxicity

Question 35

What cytokine is produced by Natural killer cells, and is associated with the activation of phagocytic leukocytes?

Answer 35

IFN gamma

Question 36

While thymic in origin, these cells are similar to NK cells and lymphocytes. They are extremely specific, and express an invariant alpha and beta TCR. What cells are these?

Answer 36

Natural killer T cells

Question 37

A killer cell lectin-like receptor, this receptor is found on NKT cells, which are mostly CD4+ cells that recognize glycolipid antigens on bacterium. What receptor is this?

Answer 37

NK1.1

Question 38

While unable to develop memory, _____ cells are activated by IL-__, and play a role in allergies, antitumor immunity, autoimmunity, and antimicrobial immunity.

Answer 38

NKT cells | IL-15

Question 39

Natural killer dendritic cells are associated with the expression of what NK cell and DC receptors, or markers?

Answer 39

Express NK1.1 (on NK cells) and CD11c (DC marker)

Question 40

What three functions are associated with NK DCs?

Answer 40

The spontaneous lysis of tumor cells, antigen presentation, and the major production of IFN gamma

Question 41

What is needed for the production of IFN gamma by NK DCs?

Answer 41

CpG or TLR9

Question 42

Where can NK DCs be located in the body?

Answer 42

Thymus, spleen, liver, and lymph nodes