Hematopoiesis – the formation and development of red and white blood cells.

1. Cells/Organs of the Immune System Hematopoiesis – the formation and development of red and white blood cells. Hematopoietic stem cells (HSC) – the cell type from which all lineages of blood cells arise.

2. Cells of the Immune System Leukocytes– White blood cells Myelocytes–macrophage, neutrophil, eosinophil,basophil Leukocytes – B, T and NK cells From Larsson and Karlsson (2005)

4. Cells of the Immune System Larsson and Karlsson (2005)

5. Cells of the Immune System Homeostasis - The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.

6. Cells of the Immune System Examples of apoptosis LM SEM

7. Myeloid cells Dendritic cell

8. Mononuclear phagocytes • Endocytosis takes material into a cell within vesicles that bud inward from the plasma membrane.

9. Mononuclear phagocytes

10. Granulocytic cells Neutrophil

11. Cells of the Immune System Lymphocytes: T cells B cells Natural killer cells

12. Cells of the Immune System Lymphocyte fate following antigen activation:

13. Recall: Jerne, Talmadge& Burnet – clonalselection theory

14. B lymphocytes (B cells)

15. T lymphocytes (T cells) T reg cell

16. NK Cells •Natural killer cells – distinct from T and B cells due to lack of an antigen binding receptor, similar in function to TCcells.

17. Dendritic cells