Lymphocytes in the Immune Response

35 Lymphocytes in the Immune Response Tcells B cells Null Cells (NK,K) Description...

35 Lymphocytes in the Immune Response Tcells B cells Null Cells (NK,K) Description Small lymphocyte small lymphocyte Large lymphocyte % of Total Circulating :::: 80% 5 - 15% 5 - 15% Lymphoid cells T cell receptor Surface lmmunoglobulin No TCR Surface Receptor (lgD or lgM) No surface (TCR-1 or TCR-2) Complement Receptors immunoglobulin CO2+ : Rosette with SRBCs CD3+ : Associated with TCR CDl9+ Surface Markers CD16+ CD4+ : T Helper cell CD20+ CD8+ : T cytotoxic/ CD56+ CO2!+ regulatory cells CD4: Release cytok:ines Become memory cell Evolve into plasma cells Important in killing virus Function(s) CD8: Become Cytotoxic which secrete antibody infected cells and CD4 or CD8: Interact with Become memory cell tumor cells B cells Natural Killer cells - cytotoxic without MHC restriction Immune response against viral Antibodies neutralize Killer cells - Antibody Primary Immune infections and tumors toxins, activate Dependent Cellular Protection Important in delayed complement, and Cytotoxicity (ADCC) hypersensitivity reactions act as opsonins Important in killing virus infected cells and tumor cells Normal T cell : B cell Ratio = 8 : 1 Normal T helper : T regulatory Ratio = 2 : l AIDS Patient Inverse T helper : T regulatory Ratio = l : 2 Characteristics of T&B Lympb.ocytes Calculate T and B Cell Populations 2. Monoclonal Antibodies a. Can be u sed to differentiate T and B cells by detecting cell surface markers (CD markers) with flow cytometry, ELISA or immunofluorescence