Mutations in GBA1, the gene encoding glucocerebrosidase, are common genetic risk factors for Parkinson disease (PD). While the mechanism underlying this relationship is unclear, patients with GBA1-associated PD often have an earlier onset and faster progression than idiopathic PD. Previously, we modeled GBA1-associated PD by crossing gba haploinsufficient mice with mice overexpressing a human mutant α-synuclein transgene (SNCAA53T), observing an earlier demise, shorter life span and faster symptom progression, although behavioral testing was not performed. To assess whether gba+/−//SNCAA53T mice exhibit a prodromal behavioral phenotype, we studied three cardinal PD features: olfactory discrimination, memory dysfunction, and motor function. The longitudinal performance of gba+/−//SNCAA53T (n = 8), SNCAA53T (n = 9), gba+/− (n = 10) and wildtype (n = 6) mice was evaluated between ages 8 and 23 months using the buried pellet test, novel object recognition test and the beam walk. Fifteen-month-old gba+/−//SNCAA53T mice showed more olfactory and motor deficits than wildtype mice. However, differences between gba+/−//SNCAA53T and SNCAA53T mice generally did not reach statistical significance, possibly due to small sample sizes. Furthermore, while gba haploinsufficiency leads to a more rapid demise, this might not result in an earlier prodromal stage, and other factors, including aging, oxidative stress and epigenetics, may contribute to the more fulminant disease course.

No abstract

HIV persists in infected individuals despite effective antiretroviral therapy due to the rapid establishment of a latent HIV reservoir, mainly composed of quiescent memory CD4+ T cells1–3. The mechanisms governing the formation of the latent reservoir remain poorly understood. It is commonly assumed that entry of HIV into latency is a rare and random event associated with sporadic infection of effector T-cells transitioning to a memory phenotype4–8. Using human primary CD4+ T cell models, we show instead, that HIV infection itself triggers a strong transcriptomic remodeling that results in activation of a quiescence program, including downregulation of cellular proliferation and metabolic pathways. This transcriptional program is initiated by KLF2, a key regulator of quiescence, along with activation of the p53 pathway and downregulation of MYC. Loss and gain of function studies confirmed that KLF2 and p53 signaling are responsible for the downregulation of MYC and proliferation pathways, and consequently, proviral transcriptional silencing. Thus, HIV infection per se, enhances the formation of the latent reservoir in T-cells, ensuring viral persistence in infected individuals. These findings identify a new and unexpected mechanism for the formation of the latent HIV reservoir, and broaden the repertoire of strategies through which viruses can control the host cell to their advantage.

No abstract