1. Lymphocyte Development and Antigen Receptor Gene Rearrangement Chapter 8

3. Stages of lymphocyte maturation

4. Pluripotent stem cells give rise to distinct B and T lineages

5. Epigenetics, MicroRNAs, and Lymphocyte Development Many nuclear events in lymphocyte development are regulated by epigenetic mechanisms Epigenetics refers to mechanisms that control gene expression (as well as gene rearrangement in developing lymphocytes) that go beyond the actual sequence of DNA in individual genes The mechanisms that make genes available or unavailable in chromatin are considered to be epigenetic mechanisms including DNA methylation on certain cytosine residues that generally silences genes, post-translational modifications of the histone tails of nucleosomes (e.g., acetylation, methylation, and ubiquitination

6. Checkpoints in lymphocyte maturation

7. Positive and negative selection during lymphocyte maturation

8. REARRANGEMENT OF ANTIGEN RECEPTOR GENES IN B AND T LYMPHOCYTES

9. Germline organization of human Ig loci

10. Domains of Ig and TCR proteins [V(D)J Recombination]

11. Germline organization of human TCR loci

12. Diversity of antigen receptor genes

13. V(D)J recombination

14. Transcriptional regulation of Ig genes

15. Sequential events during V(D)J recombination

17. Junctional Diversity

18. B LYMPHOCYTE DEVELOPMENT

19. Stages of B cell Maturation

20. Ig heavy and light chain gene recombination and expression

21. Pre-B cell and pre-T cell receptors

22. B lymphocyte subsets

23. Co-expression of IgM and IgD

24. MATURATION OF T LYMPHOCYTES

25. Stages of T cell maturation

26. Maturation of T cells in the Thymus

27. TCR α and β chain gene recombination and expression

28. CD4 and CD8 expression on thymocytes and positive selection of T cells in the thymus

29. γδ T Lymphocytes In fetal thymuses, the first TCR gene rearrangements involve the γ and δ loci The diversity of the γδ T cell repertoire is theoretically even greater than that of the αβ T cell repertoire Paradoxically, however, the actual diversity of expressed γδ TCRs is limited because only a few of the available V, D, and J segments are used in mature γδ T cells, for unknown reasons