Question 1
Which of the following statements regarding the cell-mediated immune response is TRUE?
◦ Cytotoxic T lymphocytes do not require antigen presentation to become activated.
◦ Cytotoxic T lymphocytes kill by producing hydrogen peroxide.
◦ Helper T lymphocytes have no role in the activation of cytotoxic T lymphocytes.
◦ Cytotoxic T lymphocytes interact with antibodies that have bound antigen to identify their target.
◦ A single cytotoxic T lymphocyte can kill many target cells.
Question 2
The protozoan that causes malaria is an intracellular parasite of red blood cells (RBCs). An adaptive immune response to this parasite is problematic because
◦ the parasite damages leukocytes along with RBCs.
◦ red blood cells do not produce MHC and, therefore, do not display the fact that they have been infected by presenting antigen.
◦ RBCs never enter lymphoid tissue.
◦ complement cannot effectively destroy RBCs.
◦ RBCs normally produce cytokines necessary for adaptive immune response, which this infection prevents.
Animal cells and the extracellular matrix (ECM)
Mouse lung stained to visualize differentiated epithelial cells and macrophages
Bacterial cells of Staphylococcus aureus
Normal red blood cells.
Human embryonic stem cells forming rosettes, a sign of neural differentiation
X-ray showing pneumonia. Fluid and blood cells fill the lungs