Productively infected cells in HIV-1 CNS infection are a. neurons b. endothelial cells c. oligodendrocytes d. macrophages/microglia e. all of the above

The central nervous system (CNS) contains various cell types, including neurons, endothelial cells, oligodendrocytes, and macrophages/microglia. Each of these cell types has a specific function in the CNS, such as transmitting signals (neurons), forming the blood-brain barrier (endothelial cells), producing myelin (oligodendrocytes), and acting as immune cells in the brain (macrophages/microglia).

Investigate the roles of each cell type in the context of HIV-1 infection to identify which ones are productively infected. a. Neurons: Neurons are the primary functional units in the CNS responsible for transmitting information throughout the body. However, they are not productively infected by HIV-1. b. Endothelial cells: These cells form the blood-brain barrier, which separates the CNS from the blood circulation. They can be affected by HIV-1 but are not productively infected. c. Oligodendrocytes: These cells produce myelin, which insulates neuronal axons. Oligodendrocytes are not productively infected by HIV-1. d. Macrophages/Microglia: Macrophages (found in the brain as microglia) are immune cells responsible for fighting infections. They can be productively infected by HIV-1 and contribute to the spread of the virus in the CNS.

Based on the information from Step 2, it becomes evident that only macrophages/microglia are productively infected by HIV-1 in the CNS. Thus, the correct answer is: d. macrophages/microglia