the innate immune system

Question 1

what are Erythrocytes and Megakaryocytes

Answer 1

Red blood cells and the giant cells which produce platelets

Question 2

what are Erythrocytes and Megakaryocytes produced from

Answer 2

from the Megakaryocyte and Erythroid progenitor

Question 3

describe Monocytes and Macrophages

Answer 3

A ‘jack of all trades’ cell

Phagocytosis and Antigen presentation

Produced from the Monocyte progenitoor

Question 4

describe Granulocytes

Answer 4

Contain specific cytotoxic granules for pathogen killing

They each have different specialities

Produced from the Granulocyte progenitor cell

Question 5

Granulocyte/Macrophage Colony are cytokines that regulate what

Answer 5

the differentiation, proliferation, activity, and survival of many of the myeloid cells

Question 6

what is a cytokine

Answer 6

small peptide signalling molecule

Question 7

name the 3 Granulocyte/Macrophage Colony members

Answer 7

GM-CSF
M-CSF
G-CFS

Question 8

describe the GM-CSF Granulocyte/Macrophage Colony member

Answer 8

Secreted as a monomeric glycoprotein

Receptor a heterodimer made up of an α and a β chain, the β-chain being the signal transducer

• Both the ⍺ and the β chain have low affinity for GM-CSF alone, but together they have a high affinity
• The β-chain can combine with the α-chain of the IL-3 and IL-5 receptors

Question 9

describe the M-CSF Granulocyte/Macrophage Colony member

Answer 9

Exists in 3 biologically active dimers (soluble, cell-associated, and extracellular matrix anchored)

Receptor is a homodimer, with the extracellular domain having Ig-like domains. The intracellular domain has an ITAM.

Question 10

describe the G-CSF Granulocyte/Macrophage Colony member

Answer 10

Secreted as a monomeric glycoprotein

The receptor is a single transmembrane protein that forms a homodimer when G-CSF binds.

Question 11

explain The GM-CSF receptor complex

Answer 11

The GM-CSF/GM-CSF receptor complex comprises a hexamer composed of two binary complexes of GMCSF and GMR⍺ bound to a single βc homodimer.

The βc homodimer forms an arch connecting one GM-CSF/GMR⍺ binary complex to a second identical complex

Question 12

what does Assembly of the active GM-CSF receptor complex initiate and how

Answer 12

signalling through JAK2 transphosphorylation, an event triggered following dodecamer complex formation

Question 13

explain what the Assembly of the active GM-CSF receptor complex that initiates signalling through JAK2 transphosphorylation, an event triggered following dodecamer complex formation leads to

Answer 13

This leads to an activation of the JAK/STAT and MAPK pathways that signal for cell proliferation and the PI3K/Akt pathways that promote cell survival

MAPK repression of Bim and IKK repression of Puma also serve to promote cell survival by preventing Bax/Bak activation although the mechanism, whereby cytokine signalling triggers IKK function, remains unknown

Signalling molecules bound to the cytoplasmic domain of GMRa such as SLAP, p85, IkKβ, GRAP, Lyn, and Src are also essential for GM-CSF receptor signalling although their mechanisms of action and how they integrate with the βc/JAK2 signalling axis remain to be elucidated

Question 14

describe the development of the phagosome

Answer 14

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