Major Histocompatibility Complex

Question 1

a.k.a. Human Leukocyte Antigen

Answer 1

Major Histocompatibility Complex (MHC)

Question 2

Where are MHCs are coded and found?

Answer 2

Short Upper Arm of Chromosome 6 at band 21

Question 3

Three Classes of MHCs

Answer 3

Class I

Class II

Question 4

Three principal Loci of Class I

Answer 4

HLA-A
HLA-B
HLA-C

Question 5

What region is Class II genes located?

Answer 5

D region

Question 6

Loci of D region

Answer 6

HLA-DP
HLA-DQ
HLA-DR

Question 7

Class of MHC that codes for complement and cytokines

Answer 7

Class III

Question 8

Both present in all nucleated cells and APCs

Answer 8

Class I

Question 9

Primary functions of MHCs

Answer 9

1. Graft rejection
2. Tolerance induction (Discriminate self from non-self component)
3. Activation of Adaptive Immunity
4. Presentation of antigen

Question 10

A marker/molecule in the surface of the cell that aid in the presentation of ANTIGEN, also determines the HISTOCOMPATIBILITY of transfusion/graft

Answer 10

Major Histocompatibility Complex

Question 11

True or False. Class I molecules presents antigen to CD4+ cells

Answer 11

False. Class I - CD8+

Question 12

Functions of Class I molecules:

Answer 12

1. Tolerance induction to discriminate self from non-self especially during graft rejection
2. Presentation of antigen
3. Watchdogs of viral, tumor, and certain parasitic antigens

Question 13

True or False. Class II molecules recognizes CD8+

Answer 13

False. Class II - CD4+

Question 14

True or False. Class II are found in APCs only.

Answer 14

True.

Question 15

Enumerate APCs

Answer 15

B lymphocytes
Macrophages
Dendritic Cells
Monocytes

Question 16

This refers to selection/ discriminate self and non-self antigens during maturation of lymphocytes which cells act against or not against self antigens and Graft rejection

Answer 16

Tolerance Induction

Question 17

Most highly polymorphic

Answer 17

HLA-DR

Question 18

What complement proteins are coded by Class III genes?

Answer 18

C2
C4a, C4b
Factor B

Question 19

True or False. Class III also codes for cytokines, like tumor necrosis factor (TNF)

Answer 19

True.

Question 20

MHC Genes & Diseases.

B27

Answer 20

Ankylosing spondylitis

Reiter’s Disease

Question 21

MHC Genes & Diseases.

HLA-DR3, HLA-DR4

Answer 21

Type I DM

Question 22

MHC Genes & Diseases.

HLA-DR4

Answer 22

Rheumatoid arthritis

Question 23

MHC Genes & Diseases.

HLA-DR5

Answer 23

Chronic Lymphatic Leukemia

Question 24

Refers to a transplant or tissue or organ

Answer 24

GRAFT

Question 25

True or False. For transfusion to be successful and not react, MHC molecules should NOT match between the donor and recipient (histocompatible)

Answer 25

False. For transfusion to be successful and not react, MHC molecules SHOULD MATCH between the donor and recipient (histocompatible)

Question 26

Types of Transplantation

Answer 26

Autograft Isograft Allograft

Question 27

Isograft/Autograft

Answer 27

Transfer of tissue/organs from one part of the body to another on the same person.

Question 28

Graft between genetically different recipient and donor of the same species "Donor-Recipient' (one person to another person)

Answer 28

Allograft

Question 29

Graft between individuals of different species (e.g., pig heart valve to a human heart)

Answer 29

Xenograft

Question 30

Organs which can be Transplanted (11)

Answer 30

``` blood vessels bone bone marrow cornea heart kidneys liver lung middle ear pancreas skin ```

Question 31

True or False. • Graft rejection is primarily a T cell function, with some assistance from antibodies

Answer 31

True

Question 32

Time required for Hyperacute rejection happens?

Answer 32

within MINUTES - HOURS

Question 33

Hyperacute rejection is mediated by?

Answer 33

ANTIBODY MEDIATED

Question 34

Where does Hyperacute rejection usually happens?

Answer 34

In o anti-A–related or anti-B–related antibodies to the ABO blood group systems

Question 35

When does Acute Rejection happens after transplant?

Answer 35

weeks (7-21 days)

Question 36

Mechanism of Acute Rejection

Answer 36

T-cell and APC mediated

Question 37

How does acute rejection occur?

Answer 37

due to HLA incompatibility and the possibility of damage to antibody-coated cells through antibody-dependent, cell-mediated cytotoxicity (ADCC)

Question 38

True or False. Chronic Rejection happens months (3 months) to years

Answer 38

True. Later than 3 months

Question 39

Mechanism in Chronic rejection

Answer 39

Cell mediated

Question 40

It results to a slow but continual loss of organ function over MONTHS or YEARS and disturbance of host-graft tolerance

Answer 40

Chronic Rejection

Question 41

GVHD

Answer 41

Graft Versus Host Disease

Question 42

Graft rejection based on the transfusion of • immunocompetent T lymphocytes from a donor to an immunodeficient recipient usually present in BONE MARROW transplant which the donor cells attacks all the cells of the host/recipient

Answer 42

GVHD

Question 43

When does acute GVHD develops

Answer 43

First 3 months of transplantation

Question 44

Process during transplant which it lowers the body’s immune system in order for the body not to immediately reject or directly interfere with the rejection response

Answer 44

Immunosuppression

Question 45

Purpose of Immunosuppression

Answer 45

1. Induction (intense immunosuppression in the initial days after transplantation) 2. Maintenance of transplant 3. Reversal of established rejection

Question 46

Chain Structure - Class I

Answer 46

a chain | B2 microglobulin

Question 47

Class I chain structure involve in the folding of a chaina

Answer 47

b2 microglobulin

Question 48

3 domains of a chain

Answer 48

alpha 1 alpha 2 alpha 3

Question 49

alpha chain domain that reacts with CD8+

Answer 49

alpha 3

Question 50

alpha chain domain that binds to antigen for recognition

Answer 50

alpha 1 | alpha 2

Question 51

Most immunogenic organ

Answer 51

Bone Marrow

Question 52

Least Immunogenic Organ

Answer 52

Cornea

Question 53

Principle in HLA-Phenotyping

Answer 53

Complement dependent lymphocytotoxicity

Question 54

Test in HLA Phenotyping

Answer 54

Microlymphocytotoxicity test

Question 55

Vital dye usqed in HLA Phenotyping

Answer 55

Trypan Blue + Eosin Y

Question 56

Positive result in HLA Phenotyping

Answer 56

(+) Dead Stained Cells

Question 57

In HLA Phenotying, purifued T cells are used for ______________, and purified B cells are used for ______________.

Answer 57

In HLA Phenotying, purifued T cells are used for CLASS I TYPING, and purified B cells are used for CLASS II TYPING.