CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

Background: HIV infection plays a role in accelerating aging. Limited studies have found cellular senescence can occur in some tissues in HIV-infected individuals. However, it is unclear whether HIV infection can accelerate senescence in the brain partially due to challenges of access to human brain tissues. Here we used the SIV infected rhesus macaque model to determine whether SIV contributes to aging of the brain. Methods: Four groups of rhesus macaques were studied, which included SIVmac251-infected young (Mean 6.65 ± SD 0.94 years) and old aged animals (Mean 20.26 ± SD 3.91 years), and SIV-naïve age-matched animals for comparison. Brain frontal lobes were collected and formalin-fixed paraffin- embedded. Lipofuscin, p16, p21, Cyclin D1 (CCND1), and Caveolin 1 (CAV1) were used as biomarkers of brain cellular senescence, and measured by RNAScope, RT-qPCR, and/or immunohistochemistry. Image data quantification analysis was performed by HALO and ImageJ software. Results: As expected, in healthy SIV-naïve groups, a significantly higher amount of lipofuscin was observed in old animals than young animals. However, interestingly, this age-dependent discrepancy disappeared between groups of young and old animals with SIV infection, although both groups had higher levels of lipofuscin than young uninfected group. Moreover, the increase of lipofuscin was significantly higher in SIV-infected young animals than those age-matched animals without SIV infection, this was not observed between the older groups of animals with or without SIV infection. CAV1 gene expression was significantly increased in the SIV-infected young animals. CCND1 was significantly higher in uninfected older animals than uninfected young animals, but SIV infection of young animals reduced this difference to insignificant. In the young groups, SIV infected animals had a higher expression levels of p21, CCND1, and CAV1 than uninfected cohorts. Conclusion: Our results demonstrate that SIV infection contributes to accelerating brain cellular senescence in young rhesus macaques. Given that senescent cells in the brain contribute to the cognitive decline and neurodegeneration, our findings indicate that they play an important role in the acceleration of brain aging in young hosts and possibly towards to the development of HIV-associated neurocognitive disorders.

including bacterial and fungal smear, acid-fast stain, cryptococcal antigen test, GeneXpert MTB/RIF, Treponema pallidum particle agglutination assay, rapid plasma reagin test, as well as culture of bacteria, fungal organisms and Mycobacterium species. Patients with negative results of all the above- mentioned tests were enrolled and had a mNGS test on CSF. Results: A total of 45 eligible patients were enrolled. The majority of them were middle-aged male with CD4 T cell counts of 75 (2-504) cells/ul. An etiologic diagnosis was identified in 57.8% (26/45) of the study participants. CD4 T cells counts in patients with pathogens detected in CSF by mNGS were significantly lower than that in those without a definite diagnosis [44(2-414) vs 180(5-504) cells/ul, P=0.02]. Among the 26 patients with confirmed CNS infection, pathogens including John Cunningham virus (10), Cytomegalovirus (9), Varicella-zoster virus (4), Toxoplasma gondii (3), Aspergillus (3), Penicillium (2), Torque teno virus 19 (1), Human herpesvirus 8 (1), Methylobacterium (1), Mesorhizobium (1), and Acinetobacter (1) were identified by mNGS. Multiple infections were diagnosed in 11 cases (24.4%). The results of mNGS led to the modification of treatment in 33.3% patients (15/45), while they increased confidence in maintaining original therapy in 24.4% patients (11/45). During a median of 20 days hospitalization, the overall mortality was 2.2% (1/45). 66.7% (30/45) of the patients showed improvement, 28.9% (13/45) stable and 2.2% (1/45) deteriorated, respectively. Conclusion: Our data show that clinical mNGS of CSF represents a helpful tool in the diagnosis of CNS infection among HIV-infected patients. Hisashi Akiyama 1 , Sallieu Jalloh 1 , Seonmi Park 1 , Gustavo Mostoslavsky 1 , Rahm Gummuluru 1 1 Boston University, Boston, MA, USA Background: Chronic immune activation is observed in HIV-1+ individuals on long-term combination antiretroviral therapy (cART) and is thought to lead to HIV-associated non-AIDS complications (HANA) such as neurocognitive impairment. We have recently reported that expression of HIV intron-containing RNA (icRNA) alone in productively infected monocyte-derived macrophages induces proinflammatory responses (PMID 30150664). Hence, in this study, we tested the hypothesis that persistent expression of HIV icRNA in microglia (MG), the brain-resident macrophage, contributes to neuroinflammation. Methods: Monocyte-derived microglia (MDMGs) were derived from CD14+ cells purified from PBMCs. Human iPSC (induced pluripotent stem cell)-derived microglia (hiMG) were generated by co-culturing yolk-sac-derived primitive macrophages and iPSC-neurons. Expression of MG markers such as P2RY12, IBA-1 and TMEM119 was confirmed by qRT-PCR or flow cytometry. Microglia were infected with HIV-1, and extent of viral infection and induction of proinflammatory responses was determined by mRNA analysis (NanoString, qRT-PCR), flow cytometry and ELISA. Results: HIV-1 infection in MDMGs up-regulated expression of ISGs and proinflammatory cytokines such as IP-10 and MCP-1. Treatment of infected MDMGs with raltegravir or a CRM1 inhibitor that blocks Rev–CRM1-dependent nuclear export of HIV-1 icRNA, or infection of MDMGs with Rev-mutant (M10) deficient for icRNA export did not induce IP-10 expression, suggesting that nuclear export of HIV icRNA but not Rev or Tat expression is the trigger for proinflammatory responses in MDMGs. To better mimic the yolk-sac origin of MG, we generated hiMG and found that hiMGs were robustly infected with replication competent CCR5-tropic HIV-1 (YU2). Importantly, establishment of productive infection led to secretion of proinflammatory cytokines IP-10 and MCP-1, which was inhibited upon pre-treatment with raltegravir or CRM1 inhibitor. Interestingly, HIV-infected hiMGs displayed poor phagocytic activity, suggesting that HIV infection negatively impacts homeostatic functions of MG. Conclusion: Collectively, our findings suggest that viral gene expression and nuclear export of HIV icRNA, even in the absence of viral spread, induces proinflammatory responses in microglia and suppresses their homeostatic functions. Since none of the current cART regimens inhibit viral RNA expression, novel strategies are needed to suppress HIV icRNA expression-induced immune activation. 423 ACCELERATING CELLULAR SENESCENCE IN THE BRAIN OF SIV-INFECTED YOUNG RHESUS MACAQUES Fei Wu 1 , Robert Blair 1 , Binhua Ling 1 1 Tulane National Primate Research Center, Covington, LA, USA 422 EXPRESSION OF HIV-1 INTRON-CONTAINING RNA IN MICROGLIA INDUCES INFLAMMATORY RESPONSES

Poster Abstracts

424 CNS HIV BEARS ENVELOPE MARKERS CONSISTENT WITH T-CELL ORIGIN IN THE FACE OF ART Gila J. Lustig 1 , Sandile Cele 1 , Farina Karim 1 , Yashica Ganga 1 , Khadija Khan 1 , Bernadett Gosnell 2 , Mahomed-Yunus Moosa 2 , Rohen Harrichandparsad 2 , Suzaan Marais 2 , Ravindra K. Gupta 3 , Tulio de Oliveira 2 , Katya Govender 1 , John Adamson 1 , Vinod B. Patel 2 , Alex Sigal 1

CROI 2020 147