Antigen presentation

Question 1

what are b cells activated by

Answer 1

antigens

Question 2

what happens when dendritic cells report on infections at distant sites

Answer 2

they deliver different kinds of information to T cells in lymph nodes.
once activated, effector T cells can engage with other cells that are presenting the same peptide e.g. macrophages, activated B cells or host cells infected with intracellular pathogens (such as viruses)

Question 3

immature dendritic cells

Answer 3

decrease co-stimulatory molecules
decrease MHC II expression
decrease secretion of proinflammatory cytokines
increase phagocytotic capactiy
decrease CCR7 expression
decrease glycolysis

Question 4

mature dendritic cells

Answer 4

increase co-stimulatory molecules
increase MHC II expression
increase secretion of pro-inflammatory cytokines
decrease phagocytotic capacity
increase glycolysis

Question 5

what do class I and II MHC present antigen to

Answer 5

CD4 and CD8 respectively

Question 6

macrophages and B cells bind to what peptide and is presented to which cells

Answer 6

binds to MHC class II and is presented to CD4 t cells

Question 7

where is the alpha chain encoded

Answer 7

in the MHC on chromosomes and if folded into three domains, 1,2,3

Question 8

how is the alpha chain inserted into the cell membrane

Answer 8

by a transmembrane domain followed by a short stretch of hydrophilic cytoplasmic tail.

Question 9

which alpha domain contains the binding cite for the t cell CD8

Answer 9

alpha 3 domain, it is invariant

Question 10

what do the alpha 1 and 2 domain form

Answer 10

it forms the antigen binding pocket

Question 11

in the MHC class I, where is the beta domain encoded

Answer 11

on chromosome 15

Question 12

how many alpha chains are there in MHCII

Answer 12

alpha 1 and 2, transmembrane domain

Question 13

how many beta chains are there in MHC II

Answer 13

beta 1 and 2 domain

Question 14

where does CD4 bind to

Answer 14

beta 2 domain

Question 15

what does alpha 1 and beta one form

Answer 15

the antigen binding site/ pocket

Question 16

which MHC complex allows for longer peptide chains to bind

Answer 16

MHC II the alpha 1 and beta 1 domain is open

Question 17

what is MHC restriction

Answer 17

refers to the requirement that T cells recognize antigenic peptides only when they are presented in the context of self-MHC molecules. In other words, T cells are specific not only for the antigenic peptide they recognize but also for the MHC molecule presenting that peptide

Question 18

what is cross presentation

Answer 18

the presentation of extracellular antigens on class I MHC, an important exception to the “rule” that only intracellular antigens appear on class I MHC

Question 19

what are follicular dendritic cells

Answer 19

they are in lymphoid follicles and capture and store opsonised antigens on their cell surface.