First Aid, Chapter 2 Cells Involved in Immune Responses, Basophils

Question 1

What are the least common circulating granulocytes?

Answer 1

Basophils

Question 2

What are basophils important in?

Answer 2

They are important in the late phase of IgE-mediated disease.

Question 3

Describe basophils nuclei. How big are they?

Answer 3

Have bilobed nuclei and are 10–14μm in size.

Question 4

Where do basophils mature?

Answer 4

bone marrow

Question 5

Where are basophils predominantly found?

Answer 5

Found primarily circulating in blood; also in bronchoalveolar lavage (BAL) from late-phase reactions.

Question 6

What cytokine is important for basophil expansion/differentiation? What receptor is found on the basophil related to this cytokine?

Answer 6

Have CD123 (IL-3 receptor) and IL-3 is important for their expansion/differentiation.

Question 7

What mediators do basophils release

Answer 7

Release preformed mediators (

Question 8

What mediators do basophils release 10-30 minutes after activation?

Answer 8

Produce and release lipid-derived mediators (~10–30 minutes) after activation via the arachidonic acid pathway responsible for late allergic reactions (e.g. LTC4).

Question 9

What mediators do basophils release minutes to days after activation?

Answer 9

Produce and release cytokines and chemokines (minutes to days) (e.g. IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, GM-CSF, TNFα, MCP-1, MIP-1α, RANTES (CCL-5), and PAF).

Question 10

Compared to mast cells, which mediators do basophils produce little to none of?

Answer 10

Unlike mast cells, basophils do not produce (or produce very little) tryptase, chymase, carboxypeptidase, heparin, PGD2, and LTB4.