Question

1. True or False: Scavenger and C-type lectin receptors bind pathogens and induce phagocytosis by macrophages.

2. Which of the following is a location of Toll-like receptor (TLR) expression in the cell? a. Plasma membrane b. Mitochondrial membrane c. Cytoplasm d. Nucleus

3. True or False: Between the four different inflammasome complexes, bacterial byproducts and DNA can be recognized to induce inflammation.

4. Pattern recognition receptors that detect viral infections have primarily ___________ expression. 1. Intracellular 2. Extracellular 3. Free receptors in the serum

5. Which of the following is NOT an antimicrobial mechanism in the phagosome following the phagocytosis of a pathogen? a. Acidification b. Release of toxic oxygen-derived products c. Presence of peptides and enzymes d. Fusion with the endoplasmic reticulum

6. True or False: Neutrophil extracellular traps (NETs) make it easier to kill pathogens by other immune cells.

7. The interferon response is important for the innate immune response against viruses because it: 1. Increases MHC class I expression 2. Activates dendritic cells and macrophages 3. Induces production of cytokines and chemokines 4. All of the above

8. Which of the following is not a way NK cells can kill host cells that have been infected with a pathogen? 1. Secreting its granules filled with perforins and granzymes 2. Phagocytosis of the infected cell 3. TRAIL binding Death Receptor 4/5 on the infected cell 4. Sensing the absence of MHC class I expression

9. Which of the following events do not occur during inflammation? 1. Cytokine secretion 2. Chemokine secretion 3. Recruitment of innate immune cells 4. Constriction of blood vessels

10. Cytokines released that have a longer half-life and enter the bloodstream to target distant cells are defined as having ____________________ affect. 1. An autocrine 2. A paracrine 3. An endocrine

Answer 1

1. True. Scavenger receptors generally recognise lipid molecules and facilitates entry of them into macrophages. C tupe lectin receptors in myeloid cells also after recognition of PAMPs induce macrophages.

2. TLRs are either located on plasma membrane or in endosomal compartments.(3,7 and 9)

3. True. Not only bacterial but viral, fungal infections can also be recognised.

4. Intracellular. Mostly the PRRs recognising viral PAMPs are located in subcellular compartments.

5. Macrophages rely on acidification and proteases while neutrophils rely on proteases and toxic oxygen species. So d is false.

6. True. NETs allow neutrophils to kill pathogens without creating damage to host cells.

7. All the options are correct

8. 2 is incorrect. NK cells are non phagocytic cells

9. 4 is correct.

10 . 3 is correct. Autocrine means it will affect same cells and paracrine means affect neighbouring cells.