Chapter 8

Leukocyte Differentiantion Antigens and

Cell Adhesion Molecules

Contents

Part Ⅰ Membrane molecules of immune cell Part Ⅱ Definition of leukocyte differentiation antigen and CD Part Ⅲ Definition, classification and functions of adhesion molecules Part Ⅳ Clinical application of CD and adhesion molecules

PartⅠ Membrane molecules of immune cell

Receptors: TCR, BCR, CR, CKR, FcRClassⅠand classⅡ MHC moleculesCD molecules: CD1~339Cell Adhesion Molecules

PartⅡ Definition of leukocyte differentiation antigen and CD

Leukocyte differentiation antigen: Cell surface molecules expressed (or disappeared) during different developmental and differential phases, activation or inactivation process of blood cells.

PartⅡ Definition of leukocyte differentiation antigen and CD

Leukocyte differentiation antigen

CD: cluster of differentiation.

The same differentiation antigen recognized by different monoclonal antibody from different lab are called CD.

CDs which take part in T cell recognition, adhesion and activation

CDs which take part in B cell recognition, adhesion and activation

PartⅢ Definition, classification and functions of adhesion molecules

Ⅰ. Definition

Cell adhesion molecules (CAMs) are cell surface proteins involved in the interaction of cell-cell or cell-extracellular matrix.

CAMs take effect by the binding of receptor and ligand.

Ⅱ. Classification

Integrin familySelectin family Immunoglobulin (Ig) superfamilyCadherin family Mucin-like familyOther adhesion molecules

1. Integrin family

Integrins consist of α and β chains.According to β subunits, Integrins are divided

into eight groups: β1- β8VLA-4(Very Late Antigen-4)------VCAM-1

LFA-1(Lymphocyte Function-associated Antigen-1)------ICAM-1,2,3

MAdCAM-1 (Mucosal Addressin Cell Adhesion Molecule-1) TSP-1 ((Thrombospondin 一 1):凝血酶敏感蛋白一 1

Integrin and platelet aggregation

(Karp, 2001)

Integrins promote immune response

2. Selectin family

Selectins consist of one peptide chain.The three family members include: E-

selectin, L-selectin, and P-selectin.

3. Ig superfamily(IgSF)

The structure of these adhesion molecules resemble that of Ig.

CD4, CD8, CD2(LFA-2), CD58(LFA-3), VCAM-1, ICAM-1,2,3

4. Cadherin family

E-cadherin------ Epithelia cell N-cadherin------ Nerve cell P-cadherin-------Placenta

5. Mucin-like family CD34, GlyCAM-1(glycosylation dependent

cell adhesion molecule-1) PSGL-1(P-selectin glycoprotein ligand-1)

6. Other adhesion molecules CD44

Ⅲ. Functions

1. Participate in development and differentiation of immune cells

CD2----LFA-3

LFA-1----ICAM-1

-------Participate in development and maturation of thymocytes.

2.Participate in immune response and regulation

3. Participate in the adhesion of leukocyte and vascular endothelial cell during inflammation.

4. Participate in lymphocyte homing Lymphoid stem cell migrate to central

lymphoid organs.Mature lymphocyte migrate to peripheral

lymphoid organsRecirculation of lymphocytesLymphocyte migrate to the sites of

inflammation

5. Participate in regulation of apoptosis

• Integrins inhibit cell apoptosis

What should you know by the What should you know by the end of this lecture?end of this lecture?

Definition of leukocyte differentiation

Antigen,CD and adhesion moleculesClassification and function of adhesion

molecules