Week 2 Study Questions

Question 1

Explain the term ‘inflammaging’

Answer 1

• Inflammaging: An increase in chronic low grade inflammation
• This response includes pro and anti-inflammatory cytokines
• Pro-inflammatory: IL-6, IL-1β and TNF
• Anti-inflammatory: IL-10, TGFβ
• Many factors can contribute to inflammaging, including pro-inflammatory cytokines, viruses/bacteria, unbalanced diet, cellular senescence etc.

Question 2

List 3 key functions of DCs that are altered during aging

Answer 2

• Antigen uptake and presentation
• Migration
• IL-12 release
• Numbers of DCs are still preserved with age

Question 3

Which cell types are altered in lymph nodes during aging?

Answer 3

• Decreased T cells and T cell trafficking
• Decreased follicular DCs
• Increase in M2 macrophages
• Infiltration of neutrophils
• Impaired DC trafficking possibly
  These lymph node changes lead to a reduced ability to mount an effective immune response

Question 4

Briefly describe how CMV leads to T cell immunosenescence

Answer 4

• A persistent CMV infection, although asymptomatic, can exhaust T cells more from a younger age, in comparison with an individual who does not have a CMV infection

Question 5

List 3 characteristics associated with a healthy immune response in the elderly

Answer 5

• High neutrophil function
• CMV seronegative
• Well-preserved NK cell cytotoxicity

Question 6

List 3 products that M1 macrophages can secrete

Answer 6

M1 macrophages are anti-microbial and anti-tumour

They secrete:

• Th1 cytokines
• INFy
• TNFa

Question 7

Resident macrophages in the brain are called?

Answer 7

Microglia

Question 8

Macrophages can originate from?

Answer 8

• Can be tissue-resident, and develop early during embryogenesis
• Can also be monocyte derived and develop from bone marrow -> monocyte in blood -> macrophage

Question 9

Why is origin important for disease processes?

Answer 9

• The origin of the macrophage is important in determining what the disease process
• e.g. adipose tissue associated macrophages lead to obesity, diabetes and insulin resistance
• e.g. intestinal macrophages can lead to inflammatory bowel disease

Question 10

Name a pathological process where macrophages play a beneficial role

Answer 10

• Macrophages are beneficial in wound healing, viral infections and helminth infections

Question 11

Role of M1 macrophages in cancer

Answer 11

• Cancer-related inflammation recruits monocytes -> macrophages
• M1 are recruited and become “tumour-educated” M2 in response to
  tumour-derived factors e.g. IL-10, CCL2, TGF-β

Question 12

Role of M2 macrophages in cancer

Answer 12

• Tumours often have hypoxic regions, which promote M2 macrophages, and they stimulate angiogenesis via release of vascular endothelial growth factor (VEGF)