HIV infects most commonly:

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.