This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology Pa 2 ( Hybridoma Technology, Complement Pathways, Interferon, Structure and Functions of Immune Cells ), Subject name: Microbiology
IL-2 is secreted by - 
Select and explain. 
A. CD4 lymphocytes, B. CD8 cells, C. Macrophages, D. Neutrophils
A: CD4 lymphocytes
Answer: A: CD4 lymphocytes 
Explanation: Option 1 IL-2 (Previously called T-cell growth factor) is a protein produced mainly by helper T 1 cells. It is a major T-cell growth factor. It stimulates both helper and cytotoxic T cells to grow. It also promotes the growth of B cells and can activate natural killer (NK) cells and monocytes. IL-2 acts on T cells in an autocrine fashion. Activation of T cells results in expression of IL-2R and the production of IL-2. Option 2, 3, 4 IL-1: Produced by all nucleatedcells (Mainly by APCs such asMacrophages, monocytesdendritic cell, B-cells andendothelial cell). IL-6: TH 2 cells, macrophages IL-8: Macrophages, endothelial cells IL-12: Macrophages