1. Innate Immunity
Lecture 2
Presented by :Miss, Ihsan Elrashied
alghad International Collage
For Health Sciences

2. Immune Cells & Blood Components
1.Fluid Part (Plasma)
2.Cellular Part (Cells)
•
Red Blood Cells (RBCs)
•
Whit Blood Cells (WBCs) (Leukocytes)
a.Polynuclear Cells (Granulocytes)
- Neutrophils
- Eosinophils
- Basophiles
a.Mononuclear Cells (Agranulocytes)
- Lymphocytes (T-, B- &NK)
- Monocytes/Macrophages
Origin of Blood & Immune Cells
- All blood cells & platelets are originated from the Stem cell
Origin of Stem cell
- Yolk Sac,
- Fetal Liver &
- Bone Marrow
Types of Stem Cell
•
Myeloid Stem Cell
-It is the origin of all blood cells except lymphocytes
•
Lymphoid Stem Cell
-It is the origin of B- & T-lymphocytes

3. Lymphocyte Population
•B-lymphocytesPlasma cell (B-cell precursor) (Ab producing cell)
•T-lymphocytes
1.T- helper (Th1 & Th2)
(Help all immune cells & secrete cytokines)
1.T-Cytotoxic cell (Tc) (Kill foreign cells)
2.T- Suppressor cell (Ts) (Suppress the immune cell)
3- Non-T & Non-B-cells (NK) (Large granular) cells
(Kill foreign cells)

4. Anatomy of the Immune System
Tissue & Cells of the Immune System
Role of Different Lymphoid Tissue in the Development of the Immune Cells
Types of Lymphoid Organs
1- Primary Lymphoid Organs
2- Secondary Lymphoid Organs
1- Primary Lymphoid Organs
*- These are the Sites for:- Development
- Maturation
- Proliferation
- Education &
- Graduation of Lymphocytes, as:- T- lymphocytes
- B- lymphocytes & - NK cells
*- E.g. - Thymus Gland ~~ T-cell
- Bursa of Fabricious (In Birds) ~~~~ B-Cells
- Payer’s Patches - Bone Marrow ~ B-Cells

5. 2- Secondary Lymphoid Organs
*- These are the sites for:-Lymphocyte response to the Antigen
- The Sites for the Interactions between the Ags & Agsensitive cell (macrophage & lymphocyte)
- This results Immune Reaction & Immune Response
*- Either Humoral &/or Cellular Immune response
*-E.g.-Tonsils
- Spleen
- Lymph Nodes
- Gut associated LT
- Bronchial associated LT

6. Cells of the Immune System (Immune Response)
I- Lymphocytes (20-30% of WBCs)
1- B- Lymphocytes (15-20%)
2- T- Lymphocytes (65-70%)
3- Natural Killer (NK) Large Granular Lymphocytes (15% of total
Lymphocytes)
II- Monocytes /Macrophages (4 - 8% of WBCs)
*- All of these cells are also called Immuno-Competant Cells
Subpopulation of
1- T- Lymphocytes
*- They are Thymus-Dependent Cells.
*- T- cells are developed in Thymus gland
T- Helper (Th) Cells
T- Cytotoxic (Tc) Cells
T- Suppressor (Ts) Cells
T-Effectors (Te) Cells

7. 1- T- Helper (Th) Cells
*- It represents ~ 65% of total T-cells
*- It activates all the immune cells (B-, NK- & Tc) & also activates
non- immune cell
*- It Regulate the immune response (Humoral & Cellular)
*- It Secret different kinds of Cytokines

8. 2- T- Cytotoxic (Tc) Cells
*- It rep represent ~ 35% of total T-lymphocytes
*- It responsible for Specific cytotoxicity of foreign cell
*- It is MHC-I restricted (binding) cell
*- It Kill by Kiss of Death
3- T- Suppressor (Ts) Cells
*- It responsible for suppression or inhibition of immune response (T-h
activity)
4- T-Effectors (Te) Cells
*- It also called T-delayed Hypersensitivity (T-dh)
*- It is a memory T- of cell mediated Immunity
*- When it is activated, it will secrete different types of cytokines
Development of T-Lymphocytes
*- T- Cells are developed in thymus gland by NEGATIVE & POSITVE
Selection

9. *- Stem Cells started to be developed to T-cells as follows:1- Stem Cells
2- Pre-T- Cells (Thy1 + & others -)
3- Immature T- Cells (TCR-, CD3 - & Others +)
4- Negative & Positive Selection of Immature T-cells
(All + & αβTCR +)
5- T-helper cells (CD4 + & CD8 -)
6- T-Cyttotoxic (CD8 + & CD4 -)

10. Functions of Macrophages in immunity
1- Phagocytosis & destruction of bacterial
2- Cytotoxicity by ADCC
3- Cytotoxicity by Non-ADCC
4- Ag- processing & presentation
5- Tissue recognition & wound healing
6- Cytokines Secretion
(IL-1, IL-6, IL-8, IFN-δ,
IFN-β, TNF-α & GM-CSF)

11. The End