Immune reactions/responses

Question 1

The state when an immune cell matures but does not respond to antigens is called _______.

Answer 1

anergy

Question 2

What molecule causes transplant rejection reactions?

Answer 2

foreign MHC on the transplant

Question 3

Which class MHC protein has two polypeptides and an alpha and beta chain?

Answer 3

MHC II

Question 4

Which cells have MHCI on their surface?

Answer 4

all cells except RBCs

Question 5

Which class MHC proteins is the main determinant of organ rejection?

Answer 5

MHC II

Question 6

What is the role of MHC II?

Answer 6

presents non-self antigens

Question 7

What are two mechanisms of antigenic shift?

Answer 7

DNA re-arrangement, and RNA segment re-arrangement

Question 8

Is transplant rejection reversible?

Answer 8

yes, with immunosupressive drugs (e.g. cyclosporin).

Question 9

Which cells have MHC II? (3)

Answer 9

macrophages, monocytes, dendritic cells (“professional antigen presenting cells”)

Question 10

All nucleated cells have which type of MHC protein?

Answer 10

MHC 1

Question 11

What are the three MHC II genes?

Answer 11

DP, DQ, DR

Question 12

What is antigenic variation?

Answer 12

when pathogens changes their proteins (surface, flagellar, etc) so that they can escape the immune systems antibodies)

Question 13

Endotoxins are members of a larger category of molecules called

Answer 13

pathogen-associated molecular patterns (PAMPs)

Question 14

pattern recognition receptors (PRRs)
Function and examples

Answer 14

function: to recognize PAMPs and alert MOs to initiate inflammatory response
Example: Toll-like receptors (TLRs) like TLR4 and CD14

Question 15

Activation of C3a leads to

Answer 15

↑ Histamine release and vasodilation

Question 16

Activation of C3b leads to

Answer 16

opsonization of bacteria

Question 17

C5b complement protein induces the formation of

Answer 17

MAC, a collection of proteins that form pores in bacterial cell membranes to cause cell lysis.

Question 18

Activation of ↑ C5a function

Answer 18

(Neutrophil chemotaxis) → Neutrophilic inflammatory infiltration

Question 19

Damaged endothelial cells release ___ leading to ___

Answer 19

Bradykinin, NO release -> Vasodilation

Question 20

How do endotoxins induce disseminated intravascular coagulation (DIC)?

Answer 20

Endothelial damage causes activation of Extrinsic clotting factors

Question 21

____ is characterized by severe hemorrhage and failure of the adrenal glands. common cause?

Answer 21

Waterhouse-Friderichsen syndrome, increased bleeding due to DIC from Neisseria meningidits

Question 22

SIRS + bacterial ifxn + refractory hypotension
Another clinical finding of this condition?

Answer 22

septic shock
May also have lactic acidosis

SIRS + bacterial ifxn = sepsis