MBC - Inflammation

Question 1

General

Answer 1

Protective biological process to remove damaged cells and clear threats (ie infections and toxins), can occur in any vascularized tissue involves cells at site damage + recruitment of immune cells + fluid + molecular components from circulation

Question 2

Initiation

Answer 2

Initiated when cellular damage (non-apoptotic cell death) leads to release damage associated molecular patterns (DAMPs) or body detects pathogen AMPs (PAMPs),

Question 3

Signalling by cells in damaged tissue

Answer 3

Cells in damaged tissue secrete range of signals to induce inflammation (molecules that alter structure of nearby blood vessels, chemokines to promote recruitment of immune cells to clear source of inflammatory signal and eventual resolution and repair of tissue)

Question 4

Types (basic)

Answer 4

Majority acute, mainly neutrophils recruited, chronic inflammation if acute isn’t enough (other immune cells including adaptive ones are recruited, can lead to repetitive inflammation rounds = scarring and loss of tissue function

Question 5

Definition

Answer 5

Non-specific response to cellular injury to remove injury cause and consequence

Question 6

Causes

Answer 6

• Pathogens, allergens, autoantigens, physical damage, extreme temperatures
• Diseases = infection, autoimmunity, hypersensitivity, trauma, fibrotic disease, cancer

Question 7

Cell types involved

Answer 7

Epithelial, endothelial, neutrophils, macrophages, lymphocytes, eosinophils, mast cells

Question 8

Acute

Answer 8

• Change in local blood flow -> structural changes in microvasculature -> recruitment/accumulation of immune cells and proteins
• Vasodilators = especially from mast cells, histamine and nitric oxide
• Vascular changes = increased permeability + dilation + reduced flow + plasma leakage (antibodies, protein, barrier, leukocyte migration)
• Exudate = fluid protein and cells that have seeped out of blood vessel, separation between inflamed and healthy tissue

Question 9

Cell recruitment (immune)

Answer 9

Signals at damage site, chemokines diffuse out to form gradient, leukocytes with complementary chemokine receptors migrate towards chemokine source (ie chemokine = CXCL8 (IL-8), receptors = CXCR1 and CXCR2 (g-coupled 7-transmembrane proteins), cell type = neutrophils)