BIOL 445 Chapter 5

BIOL 445 Chapter 5 - -Positive and Negative Selection of...

Info iconThis preview shows pages 1–16. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 5 - The Development of T Lymphocytes -T cells develop in the thymus
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1. Immature T cells are known as thymocytes 2. Remember, thymus is a primary lymphoid organ and does not act like a lymph node, etc. 3. By the age of 30, thymus atrophies and is not very productive 4. The architecture of the thymus allows for all the maturation processes
Background image of page 2
- The two lineages of T cells arise from a common thymocyte progenitor - Cells that fail to make productive rearrangements die by apoptosis and are phagocytosed by MO
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
- Production of a T-cell receptor beta chain leads to cessation of beta-chain rearrangement…
Background image of page 4
…a nd to expression of CD4 and CD8
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
- Successful recombination of beta chain leads to double positive thymocytes -Unsucessful beta chain rearrangements can be rescued
Background image of page 6
- T-cell receptor alpha chain genes can undergo several successive rearrangements
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
- Cells expressing particular gamma/delta receptors arise first in embryonic development
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 12
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 14
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 16
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: -Positive and Negative Selection of the T-cell repertoire T-cells that can recognize self-MHC molecules are positively selected in the thymus-Bone marrow transplants display existence of positive selection-Bone marrow transplants MUST have HLA similarities or antigen cannot be presented-Positive selection controls expression of the CD4 or CD8 co-receptor-Rearrangement of the alpha-chain stops once a cell has been positively selected-T cells specific for self-antigens are removed in the thymus by negative selection-Dendritic cells in the cortico-medullary junction display self-antigens-T-cells undergo further differentiation in secondary lymphoid tissues after encounter with antigen-T cells are involved in a variety of malignant diseases-Summary of Positive Selection-Summary of Negative Selection-Again, protein product determines start/stop of gene expression...
View Full Document

Page1 / 16

BIOL 445 Chapter 5 - -Positive and Negative Selection of...

This preview shows document pages 1 - 16. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online