Lymphocytes

1. KUVEMPU UNIVERSITY SEMINAR ON IDENTIFICATION O LYMPHOCYTES AND THEIR SUBSETS IN BLO By : Poornima R. 1 ST M.Sc. Biotechnology

2. INTRODUCTION Lymphocytes are formed by hematopoetic stem cells.

3. Their common functions are 1. NK Cells: Usually have cytotoxic activity against a wide range of tumor cells and also against some cells infected with viruses. 2. T-Lymphocytes They identify and bind to antigenswhich are bound to MHC complex,a self antigen on the surface of T-cells. 3. B-Lymphocytes Produce antibodies against a given antigen.The Abs act as receptors .

4. These cells are identified in blood depending on the CD antigens [cluster of differentiation] expressed characteristically, but not uniquely, by the cells of certain lineage and certain stage of their differentiation. Examples Cd45RA and CD62L identify naive T-cells CD45RO identifies memory B-cell CD16 and CD56 idntify NK cells

5. Identification: Monoclonal antibodies for unique CD regions is synthesised and incubated with aliquotes of blood sample. Flow cytometry is used to identify and count the cells using an automated fluorescence activated cell scanner which measures the fluorescence generated by each labelled cell. Cells are aspirated into the machine and surrounded by a sheath fluid, which forcs the cells to flow through a chamber in single file past a beam laser and light sensor.

6. Light emitted by the excited fluorescent dye on the cell surface is detected by the sensor and analysed by computer softwares .

7. In total lymphocyte count 60% to 70% is that of CD3 + T-cell B-cells make upto ‹10 % Remaining are NK cells.

8. REFERENCE Kuby immunology by Clinical immunology by Rabindra Narain Clinical immunology by Chapel,Haeney,Misbah and Snowden