Immunology 1.4 C*

Question 1

MIC

Answer 1

MHC class I-related chain

for infected cells that have had their receptors down regulated by viruses, NK cells recognize these and kill the cell.

Question 2

LAD

Answer 2

leukocyte adhesion deficiency

inability of leukocytes to migrate into sites of infection: history of overwhelming infections. often lethal.

early symptom** delayed loss of umbilical cord***

no PMNs and macros in sites of infection.
higher levels in blood.

Question 3

type 1 interferons

Answer 3

antiviral response that results in cells having a higher level of resistance to infection than unactivated cells.

response driven by JAC STAT pathway.

Main effect: resistance of viral replication, and infection.

recognized by NK cells.

immunomodulatory.

Question 4

type 2 interferons

Answer 4

produced by Nk cells. AKA gamma interferon.

Activates Macrophages.

Question 5

what induces liver to produce acute phase proteins?

Answer 5

IL-6

Question 6

acute phase proteins

Answer 6

manose binging lectin,

c- reactive protein

Question 7

c-reactive protein

Answer 7

opsonin, induces phagocytocis

Question 8

C’ functions

Answer 8

opsonization and phagocytocis- binds C3b, recognized by phagocyte, then its eaten.

stimulation of inflammatory reactions- recruits and activates leukocytes by C5a and C3a

complement mediated cytolysis- recruits components, forms pore, osmotic lysis of microbe.

Question 9

C’ tags are permanent

Answer 9

true

Question 10

C3 convertase

Answer 10

cleaves C3 so that it can tag bacteria for destruction.
C3a, part of C3 will then recruit phags

AKA C3bBb

Question 11

covalent likage to substrate

Answer 11

form a covalent bond, permanently marking it.

Question 12

3 ways that complement is activated

Answer 12

Classical - least important.
Lectin - activated by acute phase proteins. has to go to liver first.
Alternative - doesn’t need antibody, most important. first to act.

they all lead to cleavage of C3 to C3a and b. C3b can also cleave C3 to make more C3a

Question 13

C1-9 with 4 out of line.

Answer 13

the classical pathway
lectin pathway doesn’t use C1

alternative activates C3 directly.

Question 14

amplification

Answer 14

C3 cleavage

Question 15

Alternative pathway

Answer 15

main way to activate complement.
C3 cleavage driven by:

Factor B- forms C3bBb complex aka C3 convertase

Factor D- cleaves B when bound to C3b to Ba and Bb

Properdin- stabilizes complexes formed by other factors. positive regulator. accelerator.

Question 16

regulation of C3 activation

Answer 16

Factor H+

Factor I- inhibitor, slows down consumption of C3
^^^ if missing this then you are more susceptible to encapsulated bacteria.

Question 17

C5

Answer 17

initiates assembly of membrane attack complex in solution

activated by C5 convertase, activates terminal part of complement

Question 18

MAC

Answer 18

membrane attack complex.

formed by complement, poly 9 forms the pores.

Question 19

C8 deficiency

Answer 19

recurrent Neisseria infections to to lack of MAC

Question 20

C3 mutations

Answer 20

no complement response!!!!!

severe, recurrent infections

Question 21

C5 mutations

Answer 21

increased complement activation, deplete C3, recurrent infections.

Question 22

C1inh mutation

Answer 22

angioedema

Question 23

MBL

Answer 23

member of the collectin family of proteins
uses specific set of MASP proteases
cleaves C4, then C2.

Question 24

Classical C3 convertase

Answer 24

C4bC2b

Question 25

calssical pathway

Answer 25

utilizes bound antibody

need to bind multiple arms of C1.

Question 26

best antibody for activation of c’

Answer 26

IgM

Question 27

CR1

Answer 27

major activation receptor for macros and PMNs

Question 28

immune complex disease

Answer 28

lack CR1 or liver receptors
inability to clear bloodstream of immune complexes

kidney is site of deposition. Nephritis.

Question 29

regulation of complement

Answer 29

1. specific activation
2. short half life
3. regulation

Question 30

C1 inhibitor

Answer 30

serine protease inhibitor. SERPIN family.

also helps regulate clotting

Question 31

Hereditary HAE

Answer 31

C1 deficiency

Question 32

DAF

Answer 32

decay acclerating factor

cell surface membrane of host, dissociates C2b

Question 33

CD59

Answer 33

inhibits formation of MAC

Question 34

Paroxysmal nocturnal hemoglobinuria

Answer 34

missing CD59

complement induced RBC lysis. via random activation of MACs on RBCs

acquired. CD59 just goes missing.

PIGA - x linked

Question 35

Familial Atypical Hemolytic Uremic Syndrome

Answer 35

associated with lack of control of converts activation.

means complement cascade is always activated.

missing Factor H, factor I, mutation in C3, increased C3 consumption.

Question 36

what is controlled most carefully?

Answer 36

C3 convertase. its generation and stability.

Question 37

which is a most common infection with complement deficiencies?

Answer 37

Neisseria species