This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Virus infected cell is killed by - 
Select and explain. 
A. Interferons, B. Macrophages, C. Neutrophils, D. Autolysis
B: Macrophages
Answer: B: Macrophages 
Explanation: Ans. is 'b' i.e., Macrophages "Protein in Toll family (TLR 1-9) can be expressed on macrophages, dendritic cells and B cells as well as on a variety of non-hematopoietic cell types including respiratory epithelial cell. Upon ligation, these receptors activate a series of intracellular events that lead to the killing of bacterial and virus infected cells as well as to the recruitment and ultimate activation of antigen-specific T and B lymphocytes". . Interferons do not kill the virus infected cells. They act on other cells of same species, rendering them refractory to viral infection.