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Flashcards in T & B Cells and MHC Deck (24):
1

Define HLA

Human Leukocyte Antigen - a gene complex responsible for encoding the MHC

2

Define MHC

Major Histocompatibility Complex - allows the acquired immune system to recognise foreign molecules

3

What do T cells derive from

Bone marrow stem cells

4

Where do T cell precursor cells arrive after leaving the bone marrow and how long do they spend here?

The thymus
7-21 days

5

What happens to the T cell precursor cells to facilitate their change into T cells

Differentiation & Proliferation

6

What percentage of thymocytes (lymphocytes within the thymus) die in the thymus?

Over 95%

7

What are CD4 & CD8 examples of?

Glycoproteins that are found on the surface of immune cells
Cell surface markers

8

What type of cell surface marker is dramatically affected in HIV?

CD4

9

What is the primary reason that T cells die before becoming useful?

Lack of 'positive selection' - i.e. the T cells don't see the MHC so no need to respond to anything, so die

10

When do T cells become auto-reactive?

Negative selection, i.e. the T cells see the MHC too well

11

What must occur in order for a T cell to recognise and bind to an antigen?

MCH MUST BIND TO TcR

12

What is the actual function of the MHC?

To present the antigen for recognition

13

On what cells is MHC Class 1 expressed?

All cells apart from neural tissue & RBCs (lesser concs)

14

On what cells is MHC Class 2 expressed?

Limited to specialised antigen presenting cells & immune cells

15

By which cells is MCH Class 1 recognised by?

CD8 T cells

16

By which cells is MHC Class 2 recognised by?

CD4 T cells

17

What is the length of the protein (antigen) that binds to MHC class 1

9 aa's long

18

What is the length of the protein (antigen) that binds to MHC class 2?

15-20 aa's long

19

Where does MCH class 1 mainly pick up peptides (antigens) from?

INTERNAL CONTENTS OF CELLS

20

Where does MCH class 2 mainly pick up peptides (antigens) from?

DERIVED FROM EXTERNAL SOURCES

21

Where does MHC class 1 pick up peptides (antigens)?

Endoplasmic reticulum

22

Where does MHC class 2 pick up peptides (antigens)?

Endosomes

23

who da best?

u da best!

24

What does polymorphic mean?

Occurs in multiple forms