chapter 5 immunology test 3

which cells can use MHC I

all nucleated cells

which cells can use RAG-1 and RAG-2

B and T cells

polymorphism

multiple alleles across a population

only type of antigen T cells recognize

protein

do TCRs secrete?

no, t cells have effector functions

TCR function

used only to recognize antigen

Fab region of T cell does what

recognition

Fc region of T cell does what

effector function

the two polypeptide chains in T cell receptors

alpha and beta chains

which are the adaptive T cells

alpha-beta T cells

which are the innate T cells

gamma-delta T cells

how many CDRs in a single binding site

6 CDRs. 3 in beta and 3 in alpha

which CDR has the greatest diversity

CDR 3 (junctional diversity)

multiple copies of TCR bind to

multiple copies of Ag

true or false: T cells rearrange the same genes as B cells for their receptors

false

alpha chain contains which segments

V and J

beta chain contains which segments

V, D, and J

how many attempts per cell to get a functional beta chain rearrangement

4 per cell bc 2 per chromosome

what signal for the TCR

CD3 complex and zeta chains

what makes up CD3 complex

• Two CD3ε (epsilon) chains

• One CD3γ (gamma) chain

• One CD3δ (delta) chain

• A ζ (zeta) chain dimer — two zeta chains (ζ–ζ)

lack of function of CD3 delta and CD3 gamma

low TCR expression and impaired signal transduction = immunodefiency

majority of T cells in our body are?

adaptive - alpha-beta t cells

when V to J in the alpha rearranges, what happens to delta?

it gets cut out and it’s gone

do gamma deltas use coreceptors (CD4 and CD8)?

no bc they dont need MHC to present

does gamma delta need the CD3 complex

YES

where does processing take place for MHC 1

proteasome in the cytoplasm and broken peptides are shuttled to the Endoplasmic reticulum

where did loading take place for MHC 1

the ER

how many chains in MHC II

alpha and beta

how many chains in MHC 1

alpha with 3 domains (1, 2, and 3)

which domains makeup the binding group in MHC II

1 and 2

beta 2 microglobulin

invariant chain to every single MHC 1 molecule

do TCRs have variable region domains

yes

does MHC have variable region domain

no because we dont change anything

how do we get diversity in MHC

polymorphism

if its processed in a vesicle called a phagolysozome what MHC is loaded

MHC II

B cells recognize anything what?

outside and native

for t cells to recognize…

they have to have MHC present broken down peptides (inside or outside)

if a peptide isnt loaded, what happens

it cant go to the surface

binding group for MHC II

beta 1 and alpha 1

binding group for MHC I

alpha 1 and alpha 2

intracellular pathogen

virus

extracellular pathogen

bacteria

MHC I is the sampling of which environment

internal

MHC II is the sampling of which environment

external

CD4 T cells recognize which MHC

MHC II

CD8 T cells recognize which MHC

MHC I

TH2 cells do what

stimulate B cells (plasma cells) to make antibody

TH1 cells do what

activate macrophages to phagocytose and kill extracellular pathogens and secrete cytokines and other biologically active molecules to affect the course of the immune response

true or false: CD4 and CD8 are co receptors for T cells

true

how many amino acids are in a sequence in MHC I

8-10 amino acids

how many amino acids are in a sequence in MHC II

10-25 Amino acids

MHC I has what residue and at what term

basic or hydrophobic residue at the C term

MHC molecules have what binding specificity

promiscuous/degenerate

waht does TAP stand for

transporter associated with antigen processing

TAP is a what

heterodimer

TAP-1 and TAP-2

provide a gateway from the cytoplasm into the air for the peptides

chaperones

provide a safe environment for protein folding. keeps proteases out

what does tapasin do

holds the binding room open. also links TAP-1 and TAP-2 to MHC I

bare lymphocyte syndrome is caused by

TAP being nonfuncitonal

only cells that can activate naive cd4 and cd8 cells

dendritic cells

what does CLIP fragment stand for

Class II associated invariant chain peptide

what does the CLIP fragment do

blocks binding groove

true or false: the binding group of MHC II alpha and beta chains have a great deal of specificity

false

HLA-DM deos what

unloads the CLIP and helps load the peptide onto the presenting molecule

HLA DP, DQ, DR

presenting molecules for MHC II

HLA A, B and C are what

MHC I presenting molecules

what cell would a “genius” virus avoid

dendritic cell

cross presentation

only ecxtracellular goes into MHC I

do erythrocytes have a nucleus

no

what are the APCs (antigen presenting cells)

macrophages, dendritic cells, B cells

fully heterozygous, how many MHC presenting molecules

18

MHC II heterozygous, how many MHC presenting molecules

12

MHC I heterozygous, how many MHC presenting molecules

6

alleles

different nucleotide sequence that codes for the same protein

what is the MHC called in humans

HLA complex

what does HLA stand for

Human leukocyte antigen

HLA-E

negative regulator for NK cells

MHC restriction

in order for T cells to recognize the antigen, the MHC has to be specific. both the shape of the MHC, alpha helix and peptide coming together that make up that antigen

haplotype

linked genes. every person inherites 2. one from each parent

AIDS

less than 200 CD4 T cells per microliter