Question

15. Describe how antibodies may stop or prevent the steps of pathogenesis (may have to review chapter 15)

16. would B cell activation occur in a person whose T cells lack TCR or in a person who has no DC (dendritic cells)? Explain

17. Would T cell activation occur in a person who lacks the gene that specifies IL-2, IL-7, IL-15, CD 28 or B7? Explain

Answer 1

15. Antibiotics either kill bacteria or stop them from reproducing by allowing the body's natural defenses to eliminate the pathogens. They take advantage of the difference between the structure of the bacterial cell and the host’s cell.They either prevent the bacterial cells from multiplying so that the bacterial population does not change like blocking the process of building of bacterial cell wall etc.

16. B cell activation would occur as it depends on the specificity of binding resides in the B cell receptor (BCR). Dendritic cells are accessory cells of immune system which processes antigen material and presents it on the cell surface to the T cells of the immune system. So, B cell activation are not dependent on dendritic cells.

17. A number of secondary signals are required to activate T cells in order to provide a response to the threat, which are provided by CD 28. B7 produces costimulatory signals for activation T cells. Activated T cells produce IL-2, IL-7. IL-15 has a pivotal role in T cell activation. So, T cell activation would not occur in a person who lacks these genes.