This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunity, Subject name: Microbiology
Phagocytosis of mycobacterium tuberculosis by macrophages is mainly mediated by- 
Select and explain. 
A. IL6, B. IL3, C. IL12, D. IFN gamma
D: IFN gamma
Answer: D: IFN gamma 
Explanation: Ans. is 'd' i.e., IFN gamma o Phagocytosis of M tuberculosis of macrophages is a granulomatous inflammation which is induced by IFN-g.o Activated T-cells (helper) produce IFN-g, the major cytokine of granulomatous inflammation.o IFN-g has the following effects:1. It is the most important activator of macrophages.2. It induce granuloma formation by conversion of activated macrophages into epitheliod cells and formation of giant cell.3. Augment the differentiation of T-cells.o Finally there is formation of granuloma induced by IFN-g.