Class I MHC

Question 1

role of MHC class 1

Answer 1

alert CD8+ T cells that the cell is infected by displaying foreign peptide/HLA class I on cell surface

Question 2

MHC class 1 is expressed on

Answer 2

all nucleated cells including APC

Question 3

Nomenclature and isotypes of MHC-class 1

Answer 3

MHC- any species HLA class 1- human leukocyte antigen H2-mouse H2-k, D, L Human HLA class I region HLA - A, B, C

Question 4

normal cells express class 1 isotypes

Answer 4

ABC

Question 5

HLA class 1 in population are

Answer 5

polymorphic, each isotype has several allels in population

Question 6

HLA class 1 exhibits

Answer 6

co-dominant expression with six different stable heterodimers possible

Question 7

HLA class 1 expression is enhance in presence of

Answer 7

IFN gamma

Question 8

Structure of HLA class 1

Answer 8

transmembrane polymorphic polypeptide heavhy chain non covalently associated with smaller non polymorphic chian Beta 2

Question 9

Beta 2 microglubulin does not

Answer 9

bind peptide it is needed for protein folding

Question 10

teritary structure of heavy chian provides

Answer 10

a groove into which peptides of about 10 AA’s binds non covalently

Question 11

antigen processing and presnetiong with HLA class

Answer 11

1. antigens-ubitquitin in cytosol degraded by protesome 2. peptide fragments bind to TAP-1,2 3. Peptide fragments transported into endoplasmic reticulum 4. peptide binds to co-assembled HLA-1/Beta2 microglubulin complex 5. Golgi vesicles containing complexes transported to the cell surface 6. Complexes are released from golgi and fuse with cell membrane 7. HLA-class I/ peptide is now displayed on cell surface

Question 12

expression of HLA class 1 and foreign peptide signals that

Answer 12

the cell is infected.

Question 13

Cross presentation

Answer 13

process by which exogenous antigens normally processed in phagolysosomes and presented on the cell surface with MHC class II, are presented by MHC class 1 to CD8+ instead

Question 14

cross presentation occurs primarily in

Answer 14

dendritic cells.

Question 15

Cross priming

Answer 15

been documented in viral and non viral infections, cross presentation activation of CD8+

Question 16

Epstein Barr Virus

Answer 16

HHV-4- causative agent of mono, inhibits proteasome activity and remains a latent infection

Question 17

Cytomegalovirus

Answer 17

HHV-5- in immunocompromised, may cause numerous disorders (encephalitis, pneumonia, hepatitis, retinitis, or blindness), encodes proteins that redirect newly synthesized calss I MHC molecules from the endoplasmic reticulum back into the cytoplasm for proteasome.

Question 18

Herpes Simplex Virus

Answer 18

HHV-1:2 Produces an immediate early protein that binds to the cytosolic portion of TAP transporter -inhibits TAP mediated translocation of peptides from the cytosol into the ER -remains life long in neurons because they have little MHC1 class molecules.

Question 19

Beta 2 is encoded on

Answer 19

chromosome 15.

Question 20

microorganisms in cytoplasm no enclosed in a vacuole are susceptible to

Answer 20

proteolytic action of proteasome by being targed by ubitquitin

Question 21

MHC class I restriction

Answer 21

CD8+ only recognize cells infected with virus or other pathogen that display antigenic peptide in association with class I MHC molecules on cell surface

Question 22

Polymorphism and MHC class I

Answer 22

distinguising characterisitic, shows allelic heterogneity wihtin the population.

Question 23

CD-1 molecules

Answer 23

glycoproteins that present lipid and glycolipid antigens. to T cells

Question 24

CD1 molecules are structurally similar to

Answer 24

Class 1 MHC because they form a complex with Beta 2

Question 25

procesing and cell surface presentation of CD-1 antigen complex is similar to

Answer 25

Class II MHC

Question 26

five members of CD1

Answer 26

group 1 abc, group 2 de

Question 27

dendritic cells express all

Answer 27

CD1 members

Question 28

all CD1 proteisn have

Answer 28

a group of hydrophobic amino acids in a hydrophobic pocket which they can interact with hydrophobic molecules