BIO 312 Immunology Final F16
1. What protein/antigen marker would someone use for flow cytometry /FACS analysis to sort out hematopoietic stem cells?
The best protein to use is CD34 because it is present on all human hematopoietic stem cells, anti-CD34 monoclonal antibodies are often used to separate the hematopoietic stem cells from other bone marrow cells.
2. B-cells and T-cells both have to perform a few “quality control” checks to ensure that a functional cell is produced. Describe in detail the way either a B or T cell does this.
In B-cells the quality control checks are done with a surrogate light chain to make sure that the heavy chain is functional. During the pro-B-cell stage the heavy chain assembles with the surrogate light chain and Igβ. If it is successful, then it shows it forms a functional pre-B-cell and signals to shut down gene rearrangement at the heavy chain. If it cannot do that then the cell will not get the signal to survive and it will die. Next the B-cell generates a light chain gene diversity in pre-B-cells then is checked for its functional B-cell receptor. Without functional B-cell receptor it will not get the signal to survive and will die. 3. What scenario might prompt a B-cell to undergo apoptosis?
The first scenario that will prompt a B-cell to undergo apoptosis is during development in the bone marrow. Either no pre-B-cell receptor or no B-cell receptor functioning the cell will undergo apoptosis because it does not get the signal to