This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Human Immunodeficiency Virus, Subject name: Microbiology
HIV infects most commonly: 
Select and explain. 
A. CD4+helper cells, B. CD8+cells, C. Macrophage, D. Neutrophil
A: CD4+helper cells
Answer: A: CD4+helper cells 
Explanation: Ans. is 'a' i.e., CD4 Helper cells The receptor for the virus is the CD4 antigen on surface. The cells affected are:- CD4 T Cells (major target).- B lymphocytes.- Monocytes and macrophages.- Langerhans cells in dermis.- Glial cells and microglia in the CNS.- Follicular dendritic cells from tonsils can be infected by HIV without the involvement of CD4.