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Chapter 8 Leukocyte Differentiantion Antigens and

Cell Adhesion Molecules

Contents  PartⅠ Membrane molecules of immune cell  PartⅡ Definition of leukocyte differentiation antigen and CD  PartⅢ Definition, classification and functions of adhesion molecules  PartⅣ Clinical application of CD and adhesion molecules

PartⅠ Membrane molecules of immune cell Receptors: TCR, BCR, CR, CKR, FcR ClassⅠand classⅡ MHC molecules CD molecules: CD1~339 Cell 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 family Selectin family Immunoglobulin (Ig) superfamily Cadherin family Mucin-like family Other adhesion molecules

1. Integrin family Integrins consist of α and β chains. According to β subunits, Integrins are divided into eight groups: β1- β8 VLA-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: Eselectin, 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 organs Recirculation of lymphocytes Lymphocyte migrate to the sites of inflammation

5. Participate in regulation of apoptosis • Integrins inhibit cell apoptosis

What should you know by the end of this lecture? Definition of leukocyte differentiation Antigen,CD and adhesion molecules Classification and function of adhesion molecules