10. Differentiation of T cells Flashcards Preview

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Flashcards in 10. Differentiation of T cells Deck (16):
1

Differentiation of T- cells ( and location )

T- cell precursor ( no CD4 , 8, TCell receptor ) in bone marrow --> T cell with CD4, cD8 ( both and T-cell receptor ( cortex of thymus) --> T- cells with TCR an either CD8 or CD4 (medulla of Thymus) -->

CD8Q Cytotxic T cells ( lymph node)
CD4 Q Helper T cells (lymph node

Il-12: TH1
IL-4: Th2
TGF-β + IL-6 : Th14

2

Central tolenance is the

mechanism by which newly developing T cells and B cells are rendered non reactive to self

3

Central tolerance is the

mechanism by which newly developing T cells and B cells are rendered non - reactive to self

4

Central tolerance - T cells - type ( and location)

1 positive selection ---> thimic cortex
2. Negative selection --> thimic medulla

5

T cells positive selection - location and mechanism

LocationQ thymic cortex
T cells expressing TCRs capable of binding surface self -MHC molecules survive

6

T cells negative selection - location and mechanism

location : thymic medulla
T cells expressing TCRs with high affinity for seld antigens undergo apoptosis --> Tissue restricted self antigens are expressed in thymus due to the action of autoimmune regulator (AIRE)

AIRE --> transcription factor --> major proteins from elsewhere in the body (tissue - restricted antigens)

7

Autoimmune regulator ( AIRE ) mutation

Autoimmune poly endocrine syndrome - 1

8

• Describe the process of positive and negative selection of T cells.

Positive selection identifies T cells that recognize MHC, whereas in negative selection, T cells reactive to self antigens apoptosis

9

Th1, Th2, and Th17 cells are specialized descendants of which type of cell?

CD4+ helper T cells

10

Which cytokines induce differentiation of helper T cells to Th1, Th2, and Th17 cells, respectively?

IL-12, IL-4,TGF-β plus IL-6

11

Interleukin12 induces helper T cells to differentiate to____(Th1/Th2) cells as part of____(cellular/humoral) immunity.

Th1; cellular

12

Immature T cells go from bone marrow to the thymic cortex for ____ (positive/negative) selection, becoming ____ (CD4/CD8/CD4+CD8) T cells.

Positive, CD4 plus CD8

13

CD4+ T cells give rise to ____ (helper T/cytotoxic T/NK) cells. CD8+ T cells give rise to ____ (helper T/cytotoxic T/NK) cells.



Helper T, cytotoxic T

14

Interleukin 4 induces helper T-cell differentiation to ____(Th1/Th2) cells as part of ____(cellular/humoral) immunity.

Th2 cells, humoral

15

What are three kinds of cells that cytotoxic T cells kill?

Virus-infected, neoplastic, and donor graft cells

16

• To a culture of T-cell precursors, you add an inhibitor that blocks CD8 expression. Will these cells be able to stave off viruses?

Unlikely, as CD8+ cytotoxic T cells are required to kill virus-infected cells