Linking Apative + Innate

Question 1

What does the cell to cell interaction between T cell and APC (antigen presenting cell) ensure

Answer 1

Correct T cell is activated

Question 2

What are types of APC (antigen presenting cell)

Answer 2

-dendritic cells (DC)
-macrophages
-B cells

Question 3

What is the difference between class 1 MHC and class 2

Answer 3

Class 1 - present intra-cellular Ag on all nucleuated cells
Class 2 - present extra-cellular Ag only on professional APC

Question 4

What is MHC

Answer 4

Major histocompatibility complex

Question 5

What is the MHC complex complied of

Answer 5

-T cell receptor - contact residue peptide
-peptide in between T cell receptor and MHC

Question 6

How are MHC genes expressed

Answer 6

Có dominantly expressed = alleles inherited from both parents expressed equally

Question 7

What is MHC haplotype

Answer 7

Set of MHC alleles present on each chromosome

Question 8

What does tissue typing require in regards to MHC

Answer 8

MHC molecules (haplotypes) need to match to high degree between host and donor

Question 9

features of the extra-cellular Ag (antigen)

Answer 9

-presented by MHC class II
-T helper (Th) cells + regulatory T (Treg) cells
-only see Ag presented in MHC class II - express on CD4 surface
-coordinate immune responses

Question 10

Features of the intra-cellular Ag

Answer 10

-presented by MHC class I
-cytotoxic T + cell/lymphocytes (CTL)
-only see Ag presented on MHC class I - express CD8 on surface
-killed cells infected with intracellular pathogens

Question 11

What is the role of CD4

Answer 11

Stabilises TCR interactions with MHC class II

Question 12

What is the role of CD8

Answer 12

Stabilises TCR interactions with MHC class I

Question 13

Features of DCs (dendritic cells)

Answer 13

-present in all barrier tissues
-immune sentinels
-express PRRs
-do not kill

Question 14

What are the roles of DCs (dendritic cells)

Answer 14

-scan for infection (via PRRs)
-sample environmental antigens
-take Ag to lymph nodes to talk with T cells

Question 15

What is the first signal required for T cells to activate

Answer 15

Signal 1 tells the T cell that it recognises the Ag presented by the DC

Question 16

What is the second signal required for T cells to activate

Answer 16

(Co-stimulation Danger)
-danger signals (PAMPs) up-regulate B7 (CD80/86) on APC
-B7 signals to the T cell via CD28

Question 17

Features of the T-dependant Ab response

Answer 17

-full effector functions
-can switch isotype
-affinity maturation - can increase its affinity for Ag

Question 18

Features of T-independent Ab response

Answer 18

-limited effector functions
-no isotype switching
-no affinity maturation
-stimulated by repeating epitopes
-against carbohydrates or non-proteins

Question 19

How does the B cell work as APC

Answer 19

-B cell presents Ag it recognises to the Th cell
-if Th cell recognises it - means Ag is from a pathogen
-cell gives permission to B cell to respond to

Question 20

How does immune memory relate to activation of T and B cells

Answer 20

-memory T and B cells easier to activate
-memory T cells activated by more APC types (not just DC)
-memory T cell patrol tissue - focusing on location of last infection = dont need to activate LN