AP-Micro Immunology and Host Defense

Question 1

Which complement pathway is activated by mannose-binding lectin (MBL) recognizing carbohydrate patterns on microbial surfaces?

Accepted Answer

Lectin pathway

Answer

Classical pathway

Answer

Alternative pathway

Answer

Terminal pathway

Question 2

Which leukocyte is the predominant phagocyte recruited first during an acute bacterial infection?

Accepted Answer

Neutrophil

Answer

Macrophage

Answer

Natural killer cell

Answer

Dendritic cell

Question 3

Which toll-like receptor (TLR) recognizes lipopolysaccharide (LPS) from gram-negative bacteria?

Accepted Answer

TLR-4

Answer

TLR-2

Answer

TLR-5

Answer

TLR-9

Question 4

Natural killer (NK) cells preferentially kill target cells that:

Accepted Answer

Lack or downregulate MHC class I

Answer

Overexpress MHC class I

Answer

Overexpress MHC class II

Answer

Express surface IgG

Question 5

Which cytokine is the primary endogenous pyrogen responsible for inducing fever via the hypothalamus?

Accepted Answer

IL-1β

Answer

IL-4

Answer

IL-10

Answer

IL-13

Question 6

Opsonization enhances phagocytosis by coating bacteria with which molecules recognized by phagocyte surface receptors?

Accepted Answer

IgG antibodies and C3b complement fragments

Answer

Antibiotics and lysozyme

Answer

Interferons and defensins

Answer

Collectins and surfactant proteins only