Antigen Capture And Presentation: 3/18

Front 1

How do B and T lymph recognize antigens?

Back 1

antigen-specific receptors on surface: BCR and TCR

Front 2

What is an antigen? List examples of soluble molecule and molecules belonging to whole cells:

Back 2

-molecules that are recognized and responded to by cells
-soluble: proteins, polysaccharides, glycoproteins, nucleoproteins
-whole cells: bacteria, protozoa, tumor, virus-infected cells

Front 3

what are two names of the small molecular names to which the cells of adaptive system bind?

Back 3

-epitopes or antigenic determinants

Front 4

What is a difference between a B and a T cell? (Also, what KIND of antigens can T cells only recognize?)

Back 4

-B cell recognize antigen by itself; T cell need MHC
-T cell only recognize protein antigens

Front 5

What are the three types of APC's:

Back 5

-dendritic cells, macrophages, B cells

Front 6

Draw a CTL:APC cell interaction and draw a Th:APC interaction

Back 6

Front 7

Where do APC's and T cells meet?

Back 7

secondary lymph organs (lymph nodes)

Front 8

How do you know that DC is maturing?

Back 8

-upregulation of MHC molecules and expression of costimulation molecules such as B7

Front 9

Define MHC (HLA) and define the 6 types of loci amongst the two classes. Where is class I found and where is class II found?

Back 9

Major histocompatibility complex: human leukocyte antigen complex:


-1: (on all nucleated cells): HLA-A, HLA-B, HLA-C
-2: (on APC's): HLA-DP; HLA-DQ; HLA-DR / only found on antigen presenting cells

Front 10

What are the properties of MHC molecules and genes? (3):

Back 10

1.) co-dominant expression (both parental alleles of each are expressed)
2.) polymorphic genes (many diff. alleles are present in population)
3.) MHC expressing cell types:
class II: professional APCs, macrophages, B cells and class I: all nucleated cells

Front 11

MHC Structure : Draw a picture of MHC1 and show where the CD8 bind and indicate how many aa can fit in between alpha 1/ alpha 2:

Back 11

8-11 aa

Front 12

MHC Structure : Draw a picture of MHC2 and show where the CD4 bind and indicate how many aa can fit in between alpha 1/ beta 1:

Back 12

10-30 aa

Front 13

What is the name of processing of intracellular antigens: (2)
List/ draw steps that involve Class I MHC being loaded with intracellular peptides:

Back 13

-cytosolic or endogenous pathways

-ubiquitinated unfolded protein
-transfer to the ER via TAP (transporter associated with antigen processing, TAP)
-the MHC class I chain is in the ER: has the alpha and beta chain / form stable complexes than transporter to the golgi and then via exocytic vesicle to the membrane

Front 14

What is the name of processing of extracellular antigens? (2)
List the steps involved with a class II MHC being loaded with extracellular peptides:

Back 14

-endocytic or exogenous
-exogenous proteins taken in are fragmented by proteases in ENDOSOME
-endosome fuses with lysozome
-The alpha and beta chains of MHC class II (with invariant chain) synthesized in ER and taken to golgi then exocytic vesicle; --> THEN fuse with lysosome
-invariant chain digested to leave CLIP (class-II associated invariant chain protein)
-HLA-DM takes clip out of the MHC-II

Front 15

What is infection defined as and can it be both extracellular and intracellular?

Back 15

-attachment and entry of pathogen to host
-yes; both intracellular and extracellular

Front 16

Why the separation of class I and class II pathways of antigen processing?

Back 16

-to establish the different versions of T cell effector responses for extracellular and intracellular hosts