Question

What are the different ways in which HIV-1 can be transmitted across the blood-brain barrier (BBB)?

1) Migration of infected cells across the BBB
2) Cell-free HIV-1 particle migration across BBB
3) Transmission of virus by Infected BMVECs
4) All of the above

Answer 1

HIV-1 can cross the blood-brain barrier through the migration of infected cells, cell-free virus particles, and possibly infected brain microvascular endothelial cells (BMVECs), making all the provided options correct.

Step-by-step explanation:

The different ways in which HIV-1 can be transmitted across the blood-brain barrier (BBB) are indeed diverse. According to recent studies, the mechanisms include:

• Migration of infected cells across the BBB: This involves infected leukocytes (white blood cells) such as monocytes and T cells moving across the barrier in a 'Trojan-horse' fashion, carrying the virus into the central nervous system.
• Cell-free HIV-1 particle migration across BBB: Viral particles themselves may cross the BBB without directly infecting the BBB cells, although this is less understood.
• Transmission of virus by infected BMVECs: Brain microvascular endothelial cells (BMVECs), which make up the BBB, could potentially be infected and transmit the virus across the barrier.

Thus, the transmission of HIV-1 across the blood-brain barrier can be summarized as 'All of the above' options provided in the question, embracing a multi-faceted approach of viral entry into the central nervous system.