Cells and Organs of the immune System

A macrophage and bacterium Sept 26, 2002

本章大綱

1. Hematopoiesis (造血 )

2. Cells of the Immune System

3. Organs of the Immune System

Hematopoiesis

Locations of hematopoiesis

Yolk sac fetal liver spleen (3rd to 7th month) bone marrow

Hematopoietic stem cell (HSC)

Lymphoid stem cell

1. T progenitor 2. B progenitor

1. T cell 2. B cell

1. Granulocyte/monocyte progenitor2. Eosinophil progenitor3. Basophil progenitor4. Erythroid progenitor5. megakaryocyte

1. Monocyte, macrophage, neutrophil2. Eosinophil3. Basophil4. Erythrocyte5. platelets

Myeloid stem cell

Pluripotent (self renewal):

cytokines cytokines

cytokines cytokines

Clinical Use of Hematopoietic Stem Cells 1. Providing a functional immune system to individuals with a genetically immunodeficiency.

2. Replacing a defective hematopoitic system with a functional one.

3. Restoring the hematopoitic system of cancer patients after treatment with high doses of chemo- therapeutic agents or radiation.

Autologous : The recipient is also the donor.

Syngeneic : The donor is the identical twin of the recipient.

Allogeneic : The donor and the recipient are not genetically identical within the same species.

Xenogeneic : The donor and the recipient are from different species.

Bone-Marrow Transplantation

Cells for transplantation

Bone-marrow cells

Peripheral blood cells

Umbilical-cord blood cells (Cord Blood)

Stem-cell transplantation

Cells of the Immune System

Normal Adult Blood-Cell Count __________________________________

Cell type Cells/mm3 % ___________________________________________________________________________________________________________________________

Red blood cells 5.0 x 106

Platelets 2.5 x 105

Leukocytes 7.3 x 103

Neutrophil 50 – 70 Lymphocyte 20 – 40 Monocyte 1 – 6 Eosinophil 1 – 3 Basophil < 1 ____________________________________________

- Lymphoid Cells

B lymphocytes, T lymphocytes, Null Cells (natural killer, NK cells)

- Mononuclear Cells

(Lymphoid cells), Monocytes, Macrophages

- Polymorphonuclear Cells (PMN) or granulocytic cells or granulocytes

Neutrophils, Eosinophils, Basophils

- Mast Cells

- Dendritic Cells

Lymphoid Cells

- 20% - 40% of the body’s white blood cells

- 99% of the cells in the lymph

- ~ 1010 - 1012 in the human body

- Circulate in the blood and lymph

- Migrate into the tissue spaces and lymphoid organs

T Lymphocytes: Thymus

B Lymphocytes: Bursa of Fabricius (黏液囊 ) or Bone Marrow

T Lymphocyte Markers

T cell receptor (TCR)CD4/CD8CD28CD45

B Lymphocyte Markers

Immunoglobulin (Ig) B220 (CD45R) MHC Class II CR1 (CD35) & CR2 (CD21) FcRII (CD32) B7-1 (CD80) & B7-2 (CD86) CD40

Fate of antigen-activated small B lymphocytes

Null Cells

- Most are large, granular lymphocytes called natural killer (NK) cells.

- Constitute 5 - 10% of the lymphocytes in human peripheral blood.

- NK T cells

Mononuclear Cells

- Monocytes circulating in the blood

- Macrophages in the tissues

Macrophages are 5- to 10-fold larger than monocytes and contain more organelles, especially lysosomes