Lecture 10: Host Defense II

Question 1

What activates the classical pathways of complement fixation

Answer 1

C1 binding to C-reactive protein on the pathogen surface

Question 2

The classical complement pathways are activated by

Answer 2

• Ab binding to Ag

- C1 reactive protein binding

Question 3

Initial complement component of classical pathway

Answer 3

C1q, C1r, C1s,C4, and C2

Question 4

C3 convertase of classical and lectin

Answer 4

C4bC2b

Question 5

C5 convertase of classical and lectin

Answer 5

C4bC2bC3b

Question 6

Activator of the lectin pathway

Answer 6

Mannan binding lectin (MBL) and MBL-associated serine protease-2 (MASP-2)

Question 7

Initial complement component of lectin pathway

Answer 7

C4, C2

Question 8

Activator of alternative pathway

Answer 8

Contact of microbial cell wall with C3

Question 9

Initial complement component of alternative pathway

Answer 9

C3, factor B, factor D, and properdin

Question 10

C3 convertase in alternative pathway

Answer 10

C3bBb

Question 11

C5 convertase in alternative pathway

Answer 11

C3bBbC3b

Question 12

Biological consequences of complement activation

Answer 12

1. Lysis
2. Opsonization
3. Activation of inflammatory response
4. Clearance of immune complexes

Question 13

Humoral immunity is mediated by

Answer 13

antibodies secreted by antigen-activated B cells and their progeny plasma cells

Question 14

Antigens

Answer 14

1. Induce specific, adaptive immune responses

2. React specifically with the products of the response

Question 15

Paratropes

Answer 15

The part of an antibody which recognizes an antigen, the antigen-binding site of an antibody

A small region of the antibody’s Fab region

Question 16

What have paratropes with a specificity for a single antigenic epitope

Answer 16

Abs, BCR and TCR

Question 17

What recognizes native protein antigens

Answer 17

B-cell receptors

Question 18

TCRs recognize

Answer 18

processed Ag on MHC

Question 19

BCRs and Abs recognize

Answer 19

native Ag without processing or MHC

Question 20

Adaptive immunity

Answer 20

Adaptive, specific immune responses that are induced by exposure to an antigen(s), the response is specific for the inducing antigen(s), and immunologic memory is generated

Question 21

Primary versus secondary humoral immune response

Answer 21

Secondary has a shorter lag phase, greater magnitude, and class-switched IgG