Antigen Capture & Presentation Flashcards
These antigen presenting molecules are on all nucleated cells.
MHC I
***Also called HLA
These antigen presenting molecules are on professional APCs (DCs, macrophages, B-cells).
MHC II
T-lymphocytes DO NOT recognize antigens in free or soluble forms. They recognize portions of _______ antigens associated with HLA (MHC).
Protein
The total set of MHC/HLA alleles are present on each chromosome. The set of alleles on each chromosome is called an MHC/HLA _________. Encode protein antigens central for immune system to discriminate between self and non-self.
Haplotype
Most humans are heterozygous and have two MHC/HLA haplotypes, one from Mom and one from Dad. Both are expressed simultaneously exhibiting ________ (generates more diversity this way).
Co-dominance
This class of MHC/HLA gene is encoded by three separate gene regions in the locus (HLA-A, HLA-B, HLA-C). They are membrane bound glycoproteins and are expressed on all nucleated cells.
MHC I
What type of T-cells do MHC I bind to?
CD8+ cytotoxic T-lymphcytes (CTLs)
What does MHC I inhibit?
NK cells
(MHC I) Alpha-chain translated into _____ as glycoprotein. Alpha-chain interacts with Beta2 microglobulin. Complex transported to cell surface.
ER
What region are class II MHC/HLA encoded by?
HLA-D (HLA-DP; HLA-DQ; HLA-DR)
What type of T-cells do MHC II bind to?
CD4+ T-lymphocyte
T/F. Only one peptide binds to a molecule of MHC/HLA at any one time, but the same molecule of MHC/HLA has the capacity to bind to multiple peptides.
True
There are _______ in the floors of the peptide-binding clefts that the side chains of the amino acids on the antigen peptides fit into and anchor the peptides in the cleft.
Pockets
These are antigens coded on Y chromosome. They’re associated with acute rejection of male grafts in female recipients.
H-Y
Microbes that enter the body are either:
– Phagocytosed or pinocytosed by APCs in the tissues
– (Enter via the periphery) They are filtered by the lymph and lymphoid tissues
– (In the blood) Filtered by the ________
Spleen
This type of APC can activate naive mature T cells and are in tissues or blood.
DCs
Classical DCs are in all tissues, but __________ DCs are in the blood and tissues. These promote innate anti-viral state.
Plasmacytoid DCs (pDC)
Which class of MHC work against intracellular pathogens and self?
MHC I
What class of MHC work against extracellular pathogens?
MHC II
T/F. Even in the absence of infection, protein degradation and peptide transport occur simultaneously. MHC/HLAs carry peptides derived from normal self-proteins, but normally these do not provoke immune responses.
True
***MHC I carry self proteins
During this, DCs can ingest virally infected or transformed cells and display Ag to CTLs via MHC I.
Cross-Presentation
***Remember, MHC I is usually intracellular. DCs ingested virus from extracellular environment, and displayed to MHC I.
A large number of autoimmune diseases and susceptibility to infectious agents are associated with particular ______ alleles.
HLA
This HLA-associated disease exhibits inflammation of the spine, and is due to the expression of the HLA-B27 allele. This allele can not bind a critical antigenic peptide, allowing it to cause disease.
Ankylosing spondylitis
This HLA-associated disease occurs as a result of Streptococcus pyogenes infection. There is a generation of Abs against the streptococci that cross react with cardiac tissue.
Rheumatic fever
