Where does maturation of T lymphocytes take place?
Precursors of T cells migrate from the bone marrow and mature in the thymus. This process is similar to that for B cells, including the sequential rearrangement of antigen receptor gene segments.
How do T cells develop and mature?
T cells are born from hematopoietic stem cells, found in the bone marrow. Developing T cells then migrate to the thymus gland to develop (or mature). T cells derive their name from the thymus. After migration to the thymus, the precursor cells mature into several distinct types of T cells.
Is the site of T-cell development and maturation?
The thymus is the primary site of T cell development, where progenitors from the bone marrow lacking CD4+ and CD8+ coreceptor expression undergo T cell receptor (TCR) rearrangement to generate CD4+CD8+ double positive (DP) thymocytes.
What are the two major goals of T-cell development?
Answer: The two goals are (1) to ensure that all T cells have functional TCR and that (2) autoreactive cells are deleted (self-tolerance in ensured).
What are the main steps of T-cell maturation?
1) Made productive TCR β chain re-arrangement.
What is T-cell development?
T-cell Development • During 3 week development, differentiating T cells pass through stages of development based on surface phenotypes 11. DN= double negative Cell-Surface Molecules •c-Kit: Receptor for stem cell growth factor •CD44: Adhesion Molecule •CD25: Alpha-Chain of the IL-2 receptor 12. TCR is now in the Double Positive (DP) State 13.
When do T cells migrate to the thymus?
• Progenitor T cells migrate to thymus • At about 8th or 9th week of gestation in humans • T cell maturation involves rearrangements of the germ-line TCR genes • In thymus, thymocytes proliferate and differentiate 4. The development of T cells 5. Figure 7-8 part 1 of 2 The cellular organization of the human Thymus
What are the initial responses to activation of T cells?
Initial responses to activation • #1 rule- key cytokine the T cell needs to make is IL-2 • Proliferation. Mostly dependent on IL-2 through an autocrine pathway. • Other cytokines, cytokine receptors will also get produced and lead to effector T cell development (lecture upcoming…)
What determines the magnitude and nature of T cell responses?
• Balance of positive and negative signals determine the magnitude and nature of T cell responses • Challenges: – Which signals are dominant in vivo under different conditions? – How do we use this knowledge to design therapeutic strategies?