CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

oncogenic isoforms. Significant WT1 upregulation is also noted upon treatment with sodium butyrate of de novo KSHV infected HuARLT-1 and HUVEC E4 endothelial cells. Using the iSLK-BAC16 and HUVEC E4, we also demonstrate that upon WT1 knockdown during lytic reactivation, there is noted further increase in vFLIP, LANA, and K8.1 viral gene expression. Conclusion: These findings suggest that both latent and lytic KSHV infection upregulate WT1 expression. Furthermore, given the findings that WT1 knockdown during lytic reactivation leads to marked upregulation of viral gene expression, our data suggests that WT1 may play a complex role in regulating these two phases of infection that we are exploring further in ongoing studies. Saliva Kaposi Sarcoma Herpesvirus Levels as a Diagnostic Marker of Visceral Kaposi Sarcoma Matthew Witterholt , Tishiya Carey, Kathryn Lurain, Ralph Mangusan, Anaida Widell, Irene Ekwede, Vickie Marshall, Nazzarena Labo, Kyle Moore, Wendell Miley, Romin Roshan, Elena M. Cornejo Castro, Denise Whitby, Robert Yarchoan, Ramya Ramaswami National Cancer Institute, Bethesda, MD, USA Background: Kaposi sarcoma (KS), an HIV-associated malignancy, is caused by Kaposi sarcoma herpesvirus (KSHV). KS commonly affects the skin but can also lead to symptomatic visceral manifestations in the pulmonary and gastrointestinal (GI) tracts; it requires invasive procedures such as bronchoscopy or endoscopy for diagnosis. We assessed the outcomes of patients (pts) with visceral KS and evaluated the saliva KSHV viral load (VL) as a diagnostic marker. Methods: We conducted a retrospective study of pts with a history of KS from the HIV and AIDS Malignancy Branch who underwent bronchoscopy and/ or endoscopy/colonoscopy for symptoms concerning pulmonary and GI KS between 2005-2023. Diagnosis of pulmonary KS was based on imaging and visualization of large airway lesions consistent with KS on bronchoscopy. GI KS was confirmed with a biopsy following diagnostic procedures. KSHV VL DNA was quantified in saliva and peripheral blood using primers for the KSHV K6 gene, while cell number was calculated using human endogenous retrovirus 3 primers. Receiver operator curves were created to observe sensitivity and specificity of KSHV saliva VL to diagnose visceral KS among pts with visceral KS symptoms. Overall Survival (OS) was estimated using Kaplan-Meier analysis from date of KS diagnosis to death or last follow-up. Results: Sixty pts (57 with HIV diagnosis, 77% on antiretroviral therapy, median (med) HIV VL of 87 copies/mL and CD4 T cell count of 125 cells/µL) underwent procedures to identify visceral KS. Twenty-six had either pulmonary or GI KS (pulmonary= 8, GI= 18), 15 had both GI and pulmonary KS, and 19 had skin KS without visceral KS. Of those with any visceral KS, 51.2% had other concurrent KSHV-associated disorders. The med KSHV VL in the saliva among those with visceral KS was 1 (IQR: 1, 67566) copy/10 6 cells and was 767 (IQR: 629, 8455) copies/10 6 cells in the peripheral blood. A saliva KSHV VL level of > 190 copies/10 6 cells had a sensitivity of 46%, specificity of 76%, and a positive likelihood ratio of 2 for predicting the presence of visceral disease among symptomatic pts. Median OS in pts with skin KS only was not reached, was 9.2 years in pts with GI or pulmonary KS, and 2.6 years in pts with both GI and pulmonary KS (P=0.009, Figure 1). Conclusion: Despite well controlled HIV among pts with KS, the presence of visceral KS impacts overall survival. Saliva KSHV VL may be a useful tool to aid in diagnosis of visceral KS in limited-resource settings.

underlying pathophysiology. Proteomics facilitate biomarker discovery and may help identify biological mechanisms. Methods: We analyzed data from 1050 PLHIV with transient elastography measurements from the 2000HIV cohort, a Dutch multi-center study amongst virally suppressed PLHIV (NCT03994835). Proteomics was available (Olink® Explore, 2367 proteins) from 1036 individuals (98.7%). Differentially expressed proteins (DEP) were compared between PLHIV with and without liver steatosis (controlled attenuation parameter ≥ 248 dB/m) and with and without liver fibrosis (liver stiffness measurement ≥ 7.0 kPa) using a limma model. We stratified by BMI group (lean [BMI < 25 kg/m 2 or < 23 kg/m 2 in PLHIV from Asian descent] vs. overweight/obese PLHIV [other BMI]). Functional pathways from the GO biological processes, KEGG and Reactome libraries enriched with DEP were identified using Metascape. DEP were correlated to HIV-specific characteristics and antiretroviral therapy (ART). Results: Plasma proteome of PLHIV with steatosis or fibrosis were altered from those without steatosis or fibrosis, respectively. DEP in PLHIV with steatosis were enriched in metabolic pathways, whereas DEP in PLHIV with fibrosis were enriched in interleukin-10 (IL-10) signaling, cell-adhesion, and amino acid metabolism. More DEP (n = 27) were identified in lean PLHIV with versus those without steatosis compared to overweight/obese PLHIV (n = 15), and only four DEP were shared between lean and overweight/obese PLHIV, i.e. IGFBP2, GHR, AFM, and the novel protein IGSF9. IGSF9 was also DE in PLHIV with fibrosis. Especially in lean PLHIV, multiple DEP were associated with HIV-characteristics including HIV duration and CD4 nadir and current ART (NNRTI and INSTI). Conclusion: PLHIV with steatosis and fibrosis have an altered plasma proteome including upregulation of proteins involved in metabolism, cell-adhesion and IL-10 signaling. Steatosis signatures differed between lean and overweight/ obese PLHIV. Furthermore, our findings indicate involvement of HIV-specific factors in the pathogenesis of lean NAFLD, and we discovered the potentially novel NAFLD biomarker IGSF9.

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Poster Abstracts

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WT1 Upregulation by Lytic Induction of Kaposi Sarcoma Herpesvirus Ayana E Morales 1 , Yun Yeong Jang 1 , Ruby Gumenick 1 , Ariene Ouedraogo 1 , Shaun Hinds 2 , Lesly Morocho 2 , Ethel Cesarman 1 1 Weill Cornell Medicine, New York, NY, USA, 2 Cornell University, Ithaca, NY, USA Background: Kaposi Sarcoma herpesvirus (KSHV or HHV8) is the etiologic agent of Kaposi sarcoma and is associated with Multicentric Castleman disease and Primary effusion lymphoma. KSHV demonstrates two different phases of infection in the host: latent and lytic which are both essential to KSHV pathogenesis. The viral protein regulator or transcription activator (RTA) is required for the latent to lytic switch. In previous work, we have demonstrated that de novo KSHV latent infection and in particular vFLIP upregulates Wilms' Tumor 1 (WT1) expression along with its oncogenic isoforms known to have various functions contributing to tumorigenesis. The expression and functions of WT1 have not been explored during lytic KSHV infection. Methods: Cell culture models of latent and lytic KSHV infection were utilized, including iSLK-BAC16 cells latently infected with KSHV as well as HuARLT-1 and HUVEC E4 endothelial cells that were infected with KSHV. iSLK-BAC16 cells, which express RTA under a doxycycline-inducible promoter, were treated with sodium butyrate and doxycycline 2ug/ml for lytic reactivation. HuARLT-1 and HUVEC E4 were treated with sodium butyrate to induce the lytic program. WT1 siRNA was transfected in the iSLK-BAC16 and HUVEC E4 model systems using Lipofectamine RNAiMAX. Results: Here we have found that upon induction of lytic reactivation of KSHV infected iSLK-BAC16 cells, WT1 is upregulated significantly and in particular

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