The HIV-1 Matrix Protein p17 Does Cross the Blood-Brain Barrier

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Human immunodeficiency virus type 1 (HIV-1)-associated neurocognitive disorder (HAND) remains an important neurological manifestation in HIV-1-infected (HIV) patients. Furthermore, detection of the HIV-1 matrix protein p17 (p17) in the central nervous system (CNS) and its ability to form toxic assemblies in the brain have been recently confirmed. Here, we show for the first time, using both an in vitro blood-brain barrier (BBB) model and in vivo biodistribution studies in healthy mice, that p17 can cross the BBB. There is rapid brain uptake with 0.35%  0.19% of injected activity per gram of tissue (IA/g) 2 min after administration, followed by brain accumulation with 0.28%  0.09% IA/g after 1 h. The interaction of p17 with chemokine receptor 2 (CXCR2) at the surface of brain endothelial cells triggers transcytosis. The present study supports the hypothesis of a direct role of free p17 in neuronal dysfunction in HAND by demonstrating its intrinsic ability to reach the CNS.
This study was supported in part by Associazione Italiana per la Ricerca sul Cancro (AIRC) grant 20108 (to A.C.) and by the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement 828774 (to M.C.)