What types of cells are good targets for natural killer cells and why?
A. Bacterial cells because they contain LPS
B. Gram positive cells because they contain LTA
C. Antigen presenting cells because they have high levels of costimulatory molecules
D. Endothelial cells in inflamed tissues because they have high levels of adhesion molecules
E. Virally infected cells because they have low levels of class I MHC
Answer: E