First Aid, Chapter 4 Laboratory Tests, Lymphocyte Function: Cell proliferation, cytokine production, and cytotoxicity Flashcards

1
Q

What is the cell marker on all T cells?

A

CD3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the cell marker on all CD4 T lymphoctes (helper)?

A

CD3 CD4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the cell marker on all CD8 T lymphoctes (cytotoxic)?

A

CD3 CD8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the cell marker on activated CD4 cells?

A

CD4 HLA-DR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the cell marker on activated CD8 cells?

A

CD8 HLA-DR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the cell marker on naive T lymphocytes?

A

CD45RA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the cell marker on activated T lymphocytes?

A

CD45RO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the cell marker on double-negative T lymphocytes?

A

CD4-CD8-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the marker on γδ T lymphocytes?

A

CD4-CD8-γδ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the marker on T regulatory cells (highly expressed); activated T cells

A

CD3 CD25

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which cells respond to recall antigens, ie antigen-specific T lymphocyte proliferation? Is prior exposure required?

A

Activated and memory T cells. Prior exposure is required.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which cells respond to mitogens - ie polyclonal T lymphocyte proliferation (mitogen)? Is prior exposure required?

A

Naive, activated, and memory. Prior exposure is required.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are antigens used for antigen-specific T lymphocyte proliferation assays?

A
CMV 
Tetanus 
VZV antigens 
HIV antigens 
gp 120, p24 
Candida
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are some mitogens uised in polyclonal T lymphocyte proliferation assays?

A

Cell surface signaling:
Phytohemagglutinin (PHA) Pokeweed mitogen (PWM) Concanavalin A (ConA) anti-CD3 antibody

Bypass proximal signaling: Phorbol ester (PMA) 
Calcium ionophore (Ionomycin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is costimulation needed for antigen-specific T-lympohcyte proliferation (recall antigen) assays or polyclonal T lymphocyte proliferation (Mitogen) assays?

A

No, but for antigen-specific T lymphocyte proliferation (recall antigen) assays, antigen presenting cells are required.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Summarize how lymphocyte proliferation assays (LPA) stimulation index works? What is the equation for stimulation index?

A
  • Cells are incubated in culture for a week. On day 3 after mitogen stimulation, and on day 6 for antigens specific T lymphocyte-specific stimulation, radioactive [3H] (tritiated) thymidine is added and is incorporated into the newly synthesized DNA of the dividing cells.
  • The amount of radioactivity incorporated into the DNA of each culture well is measured in a scintillation counter and is proportional to the number of proliferating cells. In the absence of proliferation of defective lymphocytes, less radioactivity is detected.
  • The readout is measured in counts per minute (cpm).
  • Note that pokeweed mitogen also has B-cell proliferation activity along the Tcell proliferation capacity.

Stimulation Index (SI) = (cpm Mitogen / cpm background Unstimulated)

Net counts or cpm = (cpm Mitogen – cpm background Unstimulated)

17
Q

How does in vitro T-lymphocyte proliferation assay by flow cytometry work?

A

Peripheral blood mononuclear cells (PBMCs) are labeled with a proliferation tracking fluorescent dye (carboxyfluorescein diacetate succinimidyl ester, CFSE) and stimulated with appropriate mitogens for 4 days. Flow cytometric evaluation of T-cell proliferation is shown in Figure 4-13.

Upon stimulation and following proliferation of dividing T cells, there is a dilution of CFSC. This will lead to its decreased concentration. In the absence of proliferation of defective lymphocytes, there will be no decrease of fluorescence detected by the machine given the absence of dilutional effect.

18
Q

What are uses for delayed type hypersensitivity testing? What pathogens are those who have lack of DTH response susceptible to? What percentage of the general healthy population experiences anergy? What testing should this population undergo? What can happen with rapid repeat testing?

A
  • Delayed-type hypersensitivity (DTH) is a cost-effective and widely available method to screen for cell-mediated immunity (antigens used may be a number of recall antigens, candida, tetanus, tricophyton, etc).
  • It assess integrity of cell-mediated immunity. Those who have a lack of response are susceptible to intracellular pathogens such as viruses, protozoa, fungi, and parasites.
  • DTH can montior progrssion of acquired immunodeficiency such as HIV, anergy indicated disease progression.

-

19
Q

Describe how the mantoux test is done and interpreted. What are the antigens used?

A

1) 0.1 ml antigen injected (bevel up) ID, volar aspect of arm, bleb 7-10mm, antigens 3 cm apart
2) wait 48-72 hours
3) Area of induration > 5mm? If yes, than intact cell-mediated immunity.

4) If not >5mm, then Deficient cell-mediated immunity or lack of exposure to tested antigen anergy:
- pregnancy
- extremes of age
- cancer
- surgery
- stress
- hemodialysis
- corticosteroid treatment
- anticoagulant treatment
- DM
- liver disease
- Down syndrome

Antigens used:
C. albican
Trichophyton
Tetanus
Mumps
20
Q

In flow cytometry, how are B cells measured?

A

By their cell surface markers, CD19 and CD20.

21
Q

What B cells is CD19 and CD 20 expressed on?

A
  • CD19 is part of the CD19, CD21, CD81 coreceptor complex and functions to amplify B-lymphocyte receptor-generated signals. CD19 is expressed on early B-lymphocyte progenitors up until the B-lymphocyte plasmablast stage of differentiation.
  • CD20 is expressed on pre-B lymphocytes and B-lymphocyte blasts, but are not seen in early B lymphocytes or plasma cells.
22
Q

What cells are absent in XLA?

A

In patients with X-linked agammaglobulinemia (XLA), Bruton agammaglobulinemia tyrosine kinase (BTK) is absent in B lymphocytes and monocytes. CD19+ B lymphocytes are absent.

23
Q

What cells are low or absent in CVID?

A

IgD+CD27+ (unswitched memory) and IgD-CD27+ (Switched memory) cells. Only B cells present are naive IgD+CD27-.

24
Q

Which mitogens stimulate T cells?

A

Pokeweed, phytohemagglutinin, and concanavalin A

25
Q

Which mitogens stimulate B cells?

A

Pokeweed, LPS, and SAC (Staph Aureus Cowan I)

26
Q

How is B cell proliferation measured using a lymphocyte proliferation assay? How is the stimulation index expressed? How are immunoglobulins secreted by the B cells measured?

A

B-lymphocyte proliferation can also be measured by the lymphocyte proliferation assay. Whole blood or peripheral blood mononuclear cells (PBMCs) are cultured with mitogens [i.e., Staphylococcus aureus Cowan I (SAC), anti-IgM, pokeweed mitogen (PWM), and tetanus toxoid] for up to a week.

A stimulation index is generated by measuring the amount of [H]3 thymidine incorporated into DNA and expressed as:

  • [counts per minute of stimulated wells] / [counts per minute of control wells]
  • [counts per minute of stimulated wells] – [counts per minute of control wells]

B-lymphocyte secretion of immunoglobulins in cell culture supernatants after stimulation can be determined by ELISA or ELISPOT.

27
Q

What immunizations are protein vaccines? Do they need T lymphocyte help? What ages can they be used in?

A
  • Diptheria and tetanus.
  • Yes, they need T lymphocyte help.
  • Protein vaccines can be used in all ages.
28
Q

What immunizations are conjugated polysaccharide vaccines? Do they need T lymphocyte help? What ages can they be used in?

A
  • Haemophiuls influenzae Prevnar
  • Yes, they need T lymphocyte help.
  • Can be used in all ages.
29
Q

What immunizations are unconjugated polysaccharide vaccines? Do they need T lymphocyte help? What ages can they be used in?

A
  • Neisseria meningitides Pneumovax
  • no, do not need T lymphocyte help.
  • can only be used in ages > 2 years to induce a response
30
Q

Where are CD107a found? What does presence and absence of CD107a indicate?

A

The granules of NK cells coat in the interior with CD107a. Expression of CD107a on the surface of an NK cell is indicative of degranulation. Absence of CD107a on the surface suggests failure of degranulation.

31
Q

What enzymes can be used to determine cytotoxic cell function?

A

In Vitro NK or CD8 T Lymphocyte Cytotoxicity—Perforin and granzyme B expression in NK and CD8 T lymphocyte can be used to determine cytotoxic cell function (Figure 4-17). Perforin and granzyme B expression in cytotoxic lymphocytes and NK cells. Deficient expression can be seen in patients with hemophocytic lymphohistiocytosis (HLH). (