Lab 1 (cell markers)

Lymphocytes Cell Surface Markers

Immunology

Introduction

B cell
T cell
Monocyte
NK cell
T h
T c

Dendritic

cell

NKT cell

So, how these cells can be differentiated from each other? Cell surface markers


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

Introduction

B cell
T cell
Monocyte
NK cell
T h
T c

Dendritic

cell

NKT cell

- These markers may not be specific (shared). i.e. differentiation of one group of cells may require more than one marker

IgD
IgM


CD19
CD20

CD3

CD3
CD8
CD4
CD3

CD14

CD56

CD56

CD3
DRC

Techniques

Immuno-histochemical staining
Flowcytometry
ELISA
Western blotting


Flowcytometry

CD3
CD56
9.4%

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

Immuno-histochemical staining

P

P


P
P
Direct
Indirect
Sandwich

Lymphocytes cell markers

Thymus
Tonsil
Lymph nodes
Spleen
Blood
Bone marrow

Tonsil: Histology

•

Medulla

Cortex

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•
•
•
•
•

Germinal centre

Mantle zone

1ry follicle

2ry follicle

Dendritic cells

IFA
- Majority of lymphocytes in the follicles are of B type


- Majority of lymphocytes in the IFA are of T type

B cell markers : IgM

1ry follicles : Many cells are positive

2ry follicles:
M.Z: Many cells are positive
G.C: Meshwork staining

- IFA : few cells are positive

B cell markers: IgD

1ry follicles : Many cells are positive

2ry follicles:
M.Z: Many cells are positive
G.C: Few cells are positive


- IFA : few cells are positive
Ring-like appearance

T cell markers: CD3 or CD4

1ry follicles : Few cells are positive

2ry follicles:
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

T cell markers: CD8

1ry follicles : Few cells are positive

2ry follicles:

M.Z: Few cells are positive
G.C: Few cells are positive


- IFA : Minority of cells are positive (1/3 of the cell population)

DRC marker

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