Lecture 6

Question 1

Monocytes (Circulating Precursors of Macrophage)

Answer 1

1. Numerous, very small azurophilic granules (lysosomes)
2. Circulating precursors of Macrophage
3. Can respond to challenges within the vasculature

Question 2

Monocytes

Answer 2

1. Macrophage (connective tissues; sentinels)
2. Inflammatory Macs: M1 vs. M2 (response to infection )
3. Macrophage (spleen)
4. Alveolar Macrophage (lung alveoli- air space)
5. Kupfer Cells ( liver sinusoid- vascular lumen)
6. Osteoclasts (bone)
7. Microglia

Question 3

M1 vs. M2 Macrophage

Answer 3

1. M1: Killing
2. M2: Healing

Question 4

Macrophage (Multi-Functional Cell Type)

Answer 4

Resident Macrophage
1. Spleen: recycle RBCs
2. Liver: clean up particulates in portal blood
3. Lung: removed inhaled particulate matter
4. Bone: remodel bone

Inflammatory Macrophage: Tissues
1. Destroy invading pathogens
— phagocytosis and digestion
— cytoxic secretions
2. Signal other immune cells via cytokines
3. Present antigens to T-lymphocytes

Question 5

Macrophage (Mechanisms of Pathogen Recognition)

Answer 5

1. Innate Immune Pathway: PAMP-PRR
2. Adaptive Immune Pathway: Antibody Opsonization

Question 6

PAMP (on pathogens)

Answer 6

Pathogen- associated membrane

Question 7

PRR (on innate cells)

Answer 7

Pattern recognition receptor

Question 8

Pathogen Recognition

Answer 8

1. Pathogen-Associated Molecular Patterns
   – classes of pathogens will often express common PAMPS
2. Recognized by Pattern Recognition Receptors
   – highly conserved
   – germline-encoded
   – constitutively expressed
   – broadly expressed
   — in vertebrates and invertebrates

Question 9

Dendritic Cell (A professional Antigen Presenting Cell)

Answer 9

1. Highly branched morphology
2. Reside in peripheral tissues (Sentinel cell)
3. Branches increase the surface area for interactions
4. Continuous sampling of interstitial fluids and tissues for antigens

Question 10

Dendritic Cell (Immature Form)

Answer 10

1. Antigen capture – in the peripheral tissues
2. Internalizes antigens
3. Internalizes via phagocytosis, pinocytosis, and receptor-mediated endocytosis

Question 11

Dendritic Cell (Mature Form)

Answer 11

1. Antigen presentation – in the lymph nodes
2. Minimal capacity for antigen internalization
3. Migrate from tissues to lymphoid organs
4. Process antigens onto the cell surface
5. Present antigens on surface to T-cells