1. Lymphocytes Cell Surface Markers
Immunology
Lymphocytes Cell Surface Markers

2. Introduction
Dendritic
cell
B cell
T cell
Monocyte
NK cell
NKT cell
T h
T c
So, how these cells can be differentiated from each other? Cell surface markers

3. Cell surface markers
• Usually proteins expressed on the surface of the cell and help in differentiation of different groups of the immune cells
• Usually given the designation of (CD) which means: cluster of designation or differentiation together with appropriate number e.g. CD19, CD3 , CD4

4. Introduction
CD3
CD14
CD56
CD56
DRC
IgD
IgM
Dendritic
cell
B cell
T cell
Monocyte
NK cell
NKT cell
CD19
CD20
CD3
CD3
CD3
T h
T c
CD8
CD4
- These markers may not be specific (shared). i.e. differentiation of one group of cells may require more than one marker

5. Techniques Immuno-histochemical staining Flowcytometry ELISA
Western blotting

6. Flowcytometry
9.4%
CD56
CD3

7. Immuno-histochemical staining
Used for the staining of cell markers
Applied to identify the distribution of antigens (Ags) in the tissues
2 types:
Immuno-fluorescent
Immuno-enzymatic
Involve the addition of specific antibodies (monoclonal Abs) which bind to their target Ags in the tissues, but in order for the reaction to be visible , it should be coloured.
Green spots
Red or brown spots

8. Immuno-histochemical staining
Sandwich
Indirect P P P
Direct P

9. Lymphocytes cell markers
Thymus
Tonsil
Lymph nodes
Spleen
Blood
Bone marrow

10. Tonsil: Histology 1ry follicle • • • • • IFA Cortex Mantle zone • •
Germinal centre
Dendritic cells
Medulla
- Majority of lymphocytes in the follicles are of B type
- Majority of lymphocytes in the IFA are of T type

11. B cell markers : IgM 1ry follicles : Many cells are positive
M.Z: Many cells are positive
G.C: Meshwork staining
- IFA : few cells are positive

12. B cell markers: IgD 1ry follicles : Many cells are positive
M.Z: Many cells are positive
G.C: Few cells are positive
- IFA : few cells are positive
Ring-like appearance

13. T cell markers: CD3 or CD4 1ry follicles : Few cells are positive
M.Z: Few cells are positive
G.C: Few cells are positive
- IFA : Majority of cells are positive (2/3 of the cell population)
CD3 can not be differentiated from CD4 from this slide

14. T cell markers: CD8 1ry follicles : Few cells are positive
M.Z: Few cells are positive
G.C: Few cells are positive
- IFA : Minority of cells are positive (1/3 of the cell population)

15. DRC marker
- Meshwork staining in the germinal centre of the 2ry lymphoid follicles.