When macrophages in the lung are infected with an intracellular bacterium, such as Mycobacterium tuberculosis, they are activated by the interactions of their pattern recognition receptors with the microbe. These activated macrophages will then:
A) Migrate to the marginal sinus of the draining lymph node to activate naive CD4 T cells
B) Increase their phagocytic properties to scavenge dead and dying neighboring cells
C) Migrate to the liver where they will remove dying cells from the blood
D) Migrate to the red pulp of the spleen where they will remove immune complexes from the circulation
E) Up-regulate MHC class II and B7 molecules to amplify CD4 T cell responses in the lung

Question

Quizplus · Accepted Answer

When macrophages are activated by intracellular bacteria, they up-regulate MHC class II and B7 molecules to amplify CD4 T cell responses, which helps to further activate the immune system against the infection. The other choices are not relevant to the activation of macrophages in the lung against intracellular bacteria.

When Macrophages in the Lung Are Infected with an Intracellular