Week 1- Major Histocompatibility Complex Flashcards
Their main function is to bring antigen to the cell surface for recognition by T cells
Major Histocompatibility Complex
T- cell activation will occur only when antigen is combined with?
MHC molecules.
These will produce antibodies, except?
A. B cell
B. T cell
C. Dendritic cell
D. NK cells
C. Dendritic cell
It is considered as an Antigen Presenting Cell.
A. B cell
B. T cell
C. Dendritic cell
D. NK cells
A. B cell
The most potent Antigen Presenting Cell
Macrophages
True or False. Your T cells does not have any capability to recognize the whole antigen.
True. That is why the antigen needs to be process before presenting to T cells.
It is the bridge between innate immunity to adaptive immunity
MHC
They are the ones who will engulf and process the bacteria and present it using Class I and Class II
Antigen Presenting Cell
After presenting the engulfed bacterial compound, what cell will be activated and release cytokines?
CD4 T cell
CD4 T cell will activate what cell?
B Cell
B cell will mature into?
Plasma B cell
What cell will produce antibodies that will try to opsonize/neutralize your antigen.
Plasma B cell
What will happen if there are some malfunctions under your innate and adaptive?
move to diseases already
Other term for Major Histocompatibility Complex (MHC)
Human Leukocyte Antigen (HLA)
These are the gene system which plays a key immunologic role
Major Histocompatibility Complex (MHC) or Human Leukocyte Antigen (HLA)
Which statements are correct?
MHC Play a pivotal role in the development of both humoral and cellular immunity.
Genetic capability to mount on immune response is linked to a group of molecules originally referred to as human leukocyte antigens (HLA) or MHC
Both True
Where does MHC found in Humans?
Found on the short arm of chromosome 6 band 21 (6p21)
What are the 3 categories of MHC?
○ Class I
○ Class II
○ Class III
Molecular basis for T-cell discrimination of self from non-self-antigens
HUMAN LEUKOCYTE ANTIGEN. These are markers or tags that indicate that the specific cell or organ contains a specific antigen that tells if it is a part of the body (self) or not (non-self).
Which statements are correct?
Named by Dausset - German scientist
The reason why they are called Human LeukocyteAntigen is because of the discovery of antibody response to circulating WBCs
Only Second statement is correct.
Daussest is a French scientist
True or False. MHC/HLA gene system is Heteromorphic.
FALSE. MHC/HLA gene system is Polymorphic. to increase the chances of interacting with diverse self and non-self antigens/immunogens. Among all the systems in our body this is the most polymorphic.
What class has alpha chain and one or more genes that code for the beta chain?
ClASS II
What class does gene products are involved in antigen recognition?
Class I and II
Which code for complement proteins and cytokines such as tumor necrosis factor?
Class III
Which are correct?
● HLA-A - 580 different alleles
● HLA-B - 920 alleles
● HLA-C - 315 alleles
Only HLA-A.
● HLA-A - 580 different alleles
● HLA-B - 921 alleles
● HLA-C - 312 alleles
True or False. The MHC system is described as polymorphic because there are so many possible alleles or molecules at each location and there are different subsets and variety of these molecules
True
It is the Alternate forms of a gene that code for slightly different varieties of the same product
Alleles
True or False. An individual inherits two copies of MHC molecules in chromosome 6
TRUE. Remember that we are formed from half of the genes from our mothers and half of our genes from our fathers.
True or False. MHC genes are closely linked, inherited together as a package called a polypeptide.
FALSE. MHC genes are closely linked, inherited together as a package called a HAPLOTYPE
True or Falss. The best organ donors are your parents and future offspring.
FALSE. The best donors are not your relatives vertically. The best donor is your sibling because both of you got 50% from your mother and 50% from your father. There is a high likely chance of 100% HLA typing.
In which chromosome can we find the genes encoding for the most polymorphic system in the human body?
A. Long arm of chromosome 9
B. Short arm of chromosome 9
C. Long arm of chromosome 6
D. Short arm of chromosome 6
D. Short arm of chromosome 6
What class does this belong?
HLA-DP, HLA-DQ, HLA-DR
CLASS II
What class does this belong?
HLA-A, HLA-B, HLA-C
Class I molecules
What class does this belong?
C4a, C2, C4b, TNF
Class III molecules
Which statements are correct?
Class I is expressed by all nucleated cells.
They don’t usually test class I MHC and HLA typing that much because it is not sensitive in liver cells.
BOTH ARE CORRECT.
CLASS I are highest in lymphocyte. Lowest or undetected in hepatocytes, muscle cells, sperm cells, neural cells
Which is expressed the lowest?
HLA-A
HLA-B or
HLA-C
HLA-C. HLA-A and HLA-B are more important, both expressed highest in the cell surface than HLA-C
True or False. MHC Class I is nit expressed by RBC, thrombocytes or platelets.
TRUE
Which statements are correct?
The Class I molecule is a glycoprotein dimer.
It is made up of 2 non-covalently bonded polypeptide chains: ALPHA AND BETA
BOTH ARE CORRECT
Class I Alpha chains are folded into 3 domains. Which is detected by CD8 of T killer cells or cytotoxic T cells?
Alpha 3. Alpha 3 is detected by CD8 of T killer cells or cytotoxic T cells, serves as the anchor.
What are the components of Class I?
Alpha Chain (Alpha 1, Alpha 2 (α1 and α2) and Alpha 3) and β2-microglobulin.
Molecular weight of Class I?
45, 000 kD
In Class I, α1 and α2 serve as antigen binding site and forms the peptide binding cleft/site. How many amino acids does it holds?
8-10 amino acids.
In Class I, which are anchored to the cell membrane?
Alpha 1
Alpha 2
Alpha 3
β2-microglobulin
Alphas 1, 2, and 3 are anchored to the cell membrane, while Beta 2-microglobulin is floating.
Molecular Weight of β2-microglobulin of Class I.
12, 000 kD
Which statements are correct?
Class I β2-microglobulin is non-polymorphic and is freely attached to the alpha chain.
Its main function is to stabilize folded alpha chain – maintains the peptide binding cleft and anchoring towards the cell surface
BOTH TRUE. Alpha chain cannot stand alone, therefore they need a supporter which is β2-microglobulin
Class I β2-microglobulin is coded on what chromosome?
Chromosome 15
In Class I, during the replication of intracellular pathogen, the matabolites of the organism is called
DRiPs (Defective Ribosomal Products)
Its function is to cleave DRiPs in Class I
Proteosome
In Class I. If the proteosomes can cleave your DRiPs into its smaller peptides, then these smaller peptides will now go to?
Endoplasmic reticulum
These chaperone molecules will guide the antigen to the endoplasmic reticulum.
TAP1 and TAP2 (Transporters associated with Antigen Presentation)
Class I.
Inside the endoplasmic reticulum, this will try to synthesize the first part of your class 1 which is your Alpha chain.
ribosome
How any amino acids will proteosome cleave in DRiPs?
8-12 amino acids or peptides
Which statements are correct in Class I?
Ribosome will synthesize the Alpha chain by the presence of calnexin.
The main function of the calnexin is to stabilize the Alpha chain because Beta chain is not synthesized yet.
BOTH TRUE
Class I.
True or False. Ribosome will only produce the Beta chain if calnexin is lost.
FALSE. If calnexin is already there, the ribosome will now produce your Beta chain
Class I.
The main function of Calreticulin and ERp57 is to support Alpha chain and cover Alpha 1 and Alpha2 because we have exogenous antigens.
Their function is to protect the binding site because the binding site of Alpha1 and Alpha 2 should only bind to the pathogen peptides.
OONLT STATEMENT 2 IS CORRECT.
The main function of Calreticulin and ERp57 is to support Alpha chain and cover Alpha 1 and Alpha2 because we have ENDOGENOUS antigens.
Once this molecule stabilizes the endoplasmic reticulum, other molecules will be removed and will then bind your Antigen into your class 1 – Alpha1 and Alpha 2.
TAPASIN. Once Tapasin stabilizes the endoplasmic reticulum, other molecules will be removed and will then bind your Antigen into your class 1 – Alpha1 and Alpha 2.
Class I.
Once binding is done, it is now ready to go out and pass through the _______ to be presented.
Golgi apparatus
