A mouse is infected with staphylococcal bacteria through a laceration in the skin of its paw. Dendritic cells are isolated from the tissue at the site of infection, and are incubated together with naïve staphylococcal-specific CD4 T cells. Seventy-two hours later, the proliferation of the CD4 T cells is measured as a readout for T cell activation. Surprisingly, the T cell response is quite poor compared to the response observed when the same T cells are mixed with a comparable number of dendritic cells isolated from the draining lymph node of the infected mouse. A comparison of the dendritic cells isolated from the two different sites would reveal:
A) Much higher levels of MHC and B7 molecules on the lymph node dendritic cells than those from the infected tissue
B) Much higher expression of all TLRs in the lymph node dendritic cells than those from the infected tissue
C) An increased number of MHC class II molecules bearing bacterial peptides on the surface of dendritic cells from the infected tissue than on those from the lymph node
D) Increased phagocytic activity of the lymph node dendritic cells than those from the infected tissue
E) Increased expression of Dectin-1, DEC205, and DC-SIGN on the lymph node dendritic cells than on those from the infected tissue

Question

Quizplus · Accepted Answer

Dendritic cells from the lymph node are more effective at presenting antigens and stimulating T cells due to higher levels of MHC and co-stimulatory molecules like B7, which are crucial for T cell activation.

A Mouse Is Infected with Staphylococcal Bacteria Through a Laceration