I&d Antigen Recognition By Lymphocytes

Front 1

What is the function of the immune system?

Back 1

Recognise and dispose of invading microbes

Front 2

What are the three main specific recognition structures involved in adaptive immune responses?

Back 2

Antibody
T-cell receptor (TCR)
MHC (major histocompatibility complex) class I and class II molecules

Front 3

The three main specific recognition structures are able to bind a ______. The binding is covalent/non-covalent. Reversible, and obeys the laws of mass action

Back 3

Bind to a ligand. Non-covalent

Front 4

Binding of the recognition structures involves which bonds/forces? (4)

Back 4

van der Waal's
Electrostatic forces
Hydrophobic interactions
Hydrogen bonding

Front 5

What is the name for the transmembrane version of the antibody molecule?

Back 5

The antigen on B cells (BCR)

Front 6

Detail the structure of an antibody molecule:

Back 6

Two identical heavy (H) and two identical light (L) chains held together by disulphide bonds. Each polypeptide chain comprises a variable (V) and constant (C) region.

Front 7

What are Ig-alpha and Ig-beta involved in?

Back 7

Cell signalling, they are associated with the cell surface antibody of B cells

Front 8

What classes of antibody do naive B cells express as membrane receptors?

Back 8

IgM and IgD

Front 9

Is IgM monomeric or pentameric?

Back 9

Monomeric (monomer)

Front 10

What is the antigen receptor molecule on T lymphocytes composed of?

Back 10

A TCR alpha-beta polypeptide heterodimer

Front 11

Where are T cells that use two different polypeptide chains as their receptor found?

Back 11

Associated with epithelial surfaces

Front 12

Do the TCR alpha-beta or TCR gamma-sigma vary their AA sequence? What is the significance of this?

Back 12

Yes. Allows different antigens to bind to either the antibody molecule or the T cell receptor

Front 13

Can TCR recognise antigen shape directly?

Back 13

No, it has to be processed into short peptides and then presented to the TCR in association with peptide-holding molecules on antigen presenting cells

Front 14

What are the two major types of MHC molecules?

Back 14

Class I and class II

Front 15

Where are class I MHC molecules found?

Back 15

All nucleated cells in the body

Front 16

Where are class II MHC molecules present?

Back 16

A limited number of specialised 'professional' antigen presenting cells (IDCs, macrophages and B cells)

Front 17

What is Beta-2 microglobulin used for?

Back 17

Essential for correct folding and surface expression of MHC class I molecule

Front 18

What do the class I and class II grooves of MHC consist of Alpha helix and beta pleated sheet wise?

Back 18

Two alpha-helices and a beta-pleated sheet floor

Front 19

What can MHC molecules be thought of?

Back 19

Providing the 'shop window' for the cell to display any foreign antigens it has to the T cells

Front 20

Class I MHC molecules mainly present what kind of antigen?

Back 20

Endogenous (Having an internal cause or origin) antigen e.g. viruses

Front 21

MHC class II molecules mainly bind peptides derived from exogenous antigens taken in by endocytosis or phagocytosis from outside the cell T/F

Back 21

T

Front 22

What are the three pathways of antigen processing for presentation to T cells?

Back 22

Endogenous pathway, exogenous pathway, Cross presentation (learn these)

Front 23

What is the proteasome?

Back 23

A protein complex in cells containing proteases; it breaks down proteins that have been tagged by ubiquitin

Front 24

What is the name for arms of the antibody?

Back 24

FAB (fragment antigen binding)

Front 25

Which amino acid is important in disulphide bonds?

Back 25

Cystine

Front 26

What is the difference between inter and intra sulphide bonds on an antibody?

Back 26

Inter - between two heavy or two light chains

Intra - between different chains

I think! 1631161110

Front 27

What is an epitome?

Back 27

Part of the antigen that the antibody recognises and attaches to. There can be many on one antigen

Front 28

What is another name for the hypervariable region?

Back 28

The Complimentary determining regions (CDR)

Apparently slightly different

Front 29

What is the hypervariable region or CDR?

Back 29

A small region at the tip of the protein is extremely variable, allowing millions of antibodies with slightly different tip structures, or antigen binding sites, to exist :)

Front 30

What is Major Histocompatibility Complex (MHC)?

Back 30

A genetic system that allows large proteins in immune system cells to identify compatible or foreign proteins

Front 31

What is the MHC for humans?

Back 31

HLA (Human leukocyte antigen)

Front 32

What is HLA?

Back 32

The major histocompatibility complex (MHC) in humans. The immune system uses the HLAs to differentiate self cells and non-self cells. Any cell displaying that person's HLA type belongs to that person (and therefore is not an invader).

Front 33

What is the MHC in mice?

Back 33

H-2