Exam 1: Cellular Innate Immunity

Question 1

Sentinel cells (5)

Answer 1

Dendritic cells

Eosinophils

Neutrophils

Macrophages

Innate lymphoid cells

Question 2

Neutrophils

Answer 2

Derived from bone marrow

Polymorphonuclear

“Neutral” cytoplasm granules

Most are sequestered in liver, spleen, bone marrow, lungs
Rapid response to invaders

First cell line of defense

Phagocytic cell

Question 3

Stages of neutrophils adhesion and migration (4)

Answer 3

1. Rolling
2. Adherence
3. Emigration
4. Chemotaxis

Question 4

Phagocytosis

Answer 4

Neutrophil activation by CXCL-8, C5a, leukotriene B4

Neutrophils migrate to high chemokines concentration

Opsonins: mannose binding lectin, fibronectin, complement, antibodies

Question 5

Neutrophil extracellular traps (NETs)

Answer 5

DNA strands

NET captures and kills bacteria

Neutrophils can kill bigger microorganisms

NET prevents microorganism spread

Question 6

Ingestion

Answer 6

1. Microorganism is engulfed
2. Phagosome
3. Microorganism destruction

Question 7

Macrophages

Answer 7

Derived from bone marrow

Sentinel cells

Produce cytokine and chemokines

Main role in inflammation and tissue repair

Migrate from blood vessels to tissues

increased and sustained phagocytic activity compared to neutrophils

Bacterial activity by ROS and nitric oxide synthesis

Macrophage extracellular traps (METs) - similar to NETs

Macrophage polarization - M1 and M2

Question 8

Pro-inflammatory cytokines (3)

Answer 8

IL-1

IL-6

TNF-a

Question 9

Macrophage polarization

Answer 9

M1 - host defense –> inflammation and mechanisms of defense

M2 - suppress inflammation –> tissue repair

When M1 or resting macrophages are in contact with: IL-4, IL-10, IL-13 – can differentiate in to M2

Question 10

Chronic inflammation

Answer 10

Persistent infection, persistent inflammation

Continuous M2 polarization

Increased fibroblast proliferation

Increased collagen deposition

These lead to granuloma (area of inflammation)