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The Magic of Lymphocytes. Cells that take the form of lymphocytes. T cells cytotoxic helper cells suppressor cells B cells NK (natural killer) cells Stem cells Possible others pro-mast cells ?? pro-dendritic cells ??.
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The Magic of Lymphocytes
Cells that take the form of lymphocytes T cells cytotoxic helper cells suppressor cells B cells NK (natural killer) cells Stem cells Possible others pro-mast cells ?? pro-dendritic cells ??
small lymphoblast lymphocyte (prolymphocyte)
Small Lymphocytes can Switch back and forth into Lymphoblasts T. SL = small lymphocyte Blast = lymphoblast
An Antibody Molecule An antibody binds to an antigen
The exact position of gene splicing is variable. End of a v segment Beginning of a d segment |G.G.A|C.A.T. ……… T.C.G|T.C.C|G.G.G variable splicing|G.G.A|C.A.G ----------- |T.C.C|G.G.G|G.G.A|C.A. ----------- G|T.C.C|G.G.G|G.G.A|C. ----------- C.G|T.C.C|G.G.G|G.G.A|C.A.G------- T.C.G|T.C.C|G.G.G|G.G.A|------------------ T.C.C|G.G.G
Lymphocytes insert extra nucleotides into their DNA at junction sites in a non-templated manner. |G.G.A|C.A.T. …………… T.C.G|T.C.C|G.G.G |G.G.A|C.A.T|N.N.N|N.N.N|T.C.G|T.C.C|G.G.G
The Clonal Selection Theory Proposes a two stage process for antibody formation.
B stem cellProliferationPre B cells DiversificationB cells Antigen stimulation B cell Lymphoblast o o o o o o o o o o o o o
o o o Activated B lymphoblast Proliferation Differentiation Antibodies o o o o o o Plasma cells B memory cells
B stem cellProliferationPre B cells DiversificationB cells Antigen stimulation B cell Lymphoblast o o o o o o o o o o o o o
The T cell Receptor - is homologous to antibody. - forms by gene rearrangement. - varies from one T cell to another. but it - is always membrane-bound. - binds to peptides fragments of antigens - These must be held on a cell surface by an MHC protein.
Cells that take the form of lymphocytes T cells cytotoxic helper cells suppressor cells B cells NK (natural killer) cells Stem cells Possible others pro-mast cells ?? pro-dendritic cells ??