Macrophages 2 Flashcards

1
Q

What is the difference in the lysosome of a macrophage compared to a neutrophil?

A

There is no myeloperoxidase in macrophage which makes it less effective

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

What does the macrophage have that the neutrophil does not?

A

Lipases
* This is why TB is taken care of by the macrophage (it has a thick membrane which is broken down by the lipases)

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

What are the 2 main functions of MHCII on the surface of a macrophage with foreign antigen?

A
  • It presents the antigen to the rest of the immune system
  • It lets the immune system know that the macrophage is self (otherwise the immune cells would try to kill it)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Interferon gamma via Th1 cells on macrophages results in 3 actions by the macrophage

A
  • Increased phagocytosis
  • Increase antigen presentation
  • Increased digestion via lysosomal enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Function of cytokines secreted by macrophages
IL1

A

Increases fever

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

Function of cytokines secreted by macrophages
IL6

A
  • Pro inflammatory cytokine
  • Increases liver secretions of acute phase proteins (CRP, complement, coagulation system, cirruloplasmin, etc.)
  • Stimulates B lymphocytes to produce Ab
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

4 steps (protection) of an acute infection (like a cut)

A
  • Skin
  • Macrophages (langerhans cells)
  • Neutrophils –> IL3 (bone marrow), GM CSF, M CSF, G CSF
  • Increased macrophages after about 8 hours (because of signal from neutrophils)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Function of cytokines secreted by macrophages
IL8

A

Signal to attract neutorphils for acute inflammatory reaction

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

Function of cytokines secreted by macrophages
IL12

A

Acts on T0 and converts it to Th1 (which secretes IL2 which activates cytotoxic T cell and IFN gamma which stimulates the macrophage)

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

Function of cytokines secreted by macrophages
IL10

A

Acts on Th1, inhibiting it which will then allow Th2 to be more activie (it stimulates B cells which make Ab)

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

Function of cytokines secreted by macrophages
TNF alpha

A
  • Secreted after priming by gamma interferon
  • Helps release cytokines for inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Function of cytokines secreted by macrophages
TGF Beta (Tumor Growth Factor)

A
  • Causes apoptosis of many cells (T cells important especially)
  • Decreases neutrophil and monocyte activation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Function of cytokines secreted by macrophages
MIP (Macrophage Inflammatory Proteins)

A
  • CCL3 PMN cell recruiter and activator
  • CCL4 Monocyte recruiter
    (CC = Cysteine-Cysteine chemokine)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What enzymes do macrophages have?

A
  • NADPH Oxidase
  • SOD
  • Lipases (Neutrophils don’t have these) - Used to kill TB
  • Don’t have MPO (Neutrophils do have these)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What 3 CD proteins are on the surface of macrophages?

A
  • CD14 (Works with TLR2 and TLR4)
  • CD31 (for neutrophil health check)
  • CD11b
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What receptors are on the surface of macrophages?

A
  • Gamma Interferon
  • C3b and IgG (both opsonins -
  • TLR2 and TLR4 (PRRR)
17
Q

What is TGF beta?

A

It is a multifunctional protein that plays a crucial role in regulating cell growth, differentiation, proliferation, and survival.

18
Q

What types of cells produce TGF beta?

A

TGF-beta is produced by many different cell types in the body, including immune cells, epithelial cells, and fibroblasts

19
Q

How to Macrophages become resident cells of tissue?

A
  • They adhere to cells via integrins
20
Q

What do integrins do once the macrophage is connected to tissue?

A

They activate TGF beta

21
Q

What does TGF beta do once its activated by integrins (attached to macrophages)?

A
  • It binds to TGF beta receptors on the macrophage which then downregulates the macrophage’s phagocytosis and its production of cytokines
  • The macrophage then sits on the tissue and waits for an invader
22
Q

How is a quiescent macrophage (attached to tissue cells) reactivated?

A

It contacts a bacterial LPS (or a virus) via TLR and CD14

23
Q

What are clusters of differentiation (CDs)?

A
  • They are proteins on the surface of a cell.
  • These proteins, which are also called antigens or markers, are important for our immune system as they help identify different types of cells, such as white blood cells, and allow them to interact with each other.
24
Q

What happens once a macrophage is attached to a bacteria/virus via TLR and CD14?

A
  • Actin is released: –> Decreased integrin attachment
  • TGF beta is decreased
  • Macrophage becomes active