Project description:We used ac4C-seq to detedc cellular and KSHV transcripts in iSLK-Puro, iSLK-KSHV, iSLK-KSHV (WT), iSLK-KSHV (ΔNAT10) cells after after doxycycline and sodium butyrate treatment.
Project description:Kaposi sarcoma is the most common cancer in AIDS patients and is typified by red skin lesions. The disease is caused by the KSHV virus (HHV8) and is recognizable by its distinctive red skin lesions. The lesions are KSHV infected spindle cells, most commonly the lymphatic endothelial and blood vessel endothelial cells (LEC and BEC), plus surrounding stroma. The effects of KSHV infection of LECs were assayed using Affymetrix hgu133plus2 chips at 6 and 72 hours post infection. There were n=4 each of lymphatic endothelial cells (LEC) following 6 hours of culture, LEC following 6 hours post KSHV infection, LEC following 72 hours of culture, and LEC following 72 hours post KSHV infection.
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent of primary effusion lymphoma (PEL). All PEL cell lines are infected with KSHV, and 70% are co-infected with Epstein-Barr Virus (EBV). KSHV reactivation from latency requires promoter-specific transactivation by the KSHV Rta protein through interactions with RBP-Jk (CSL), the cellular DNA binding component of the Notch signal transduction pathway. EBV transformation of primary B cells requires EBV nuclear antigen (EBNA)-2 to interact with RBP-Jk to direct the latent viral and cellular gene expression program. Although KSHV Rta and EBV EBNA-2 both require RBP-Jk for transactivation, previous studies have suggested that RBP-Jk-dependent transactivators do not function identically. We have found that the EBV latent protein LMP-1 is expressed in less than 5% of KSHV+/EBV+ PEL cells, but is induced in an Rta-dependent fashion when KSHV reactivates. KSHV Rta transactivates the EBV latency promoters in an RBP-Jk-dependent fashion and forms a ternary complex with RBP-Jk on the promoters. In B cells that are conditionally transformed by EBV alone, we show that KSHV Rta complements a short-term EBNA2 growth deficiency in an autocrine/paracrine manner. Complementaton of EBNA2-deficiency by Rta depends on RBP-Jk and LMP-1, and Rta transactivation is required for optimal growth of KSHV+/EBV+ PEL lines. Our data suggest that Rta can contribute to EBV-driven cellular growth by transactivating RBP-Jk-dependent EBV latency genes. However, our data also suggest that EBNA2 and Rta induce distinct alterations in the cellular proteomes that contribute to growth of infected cells. EREB2-5 cells were transfected and grown in the presence or absence of β-estradiol, as described. Seven days post-transfection, protein extracts were prepared, and 200 ugs. of each were analyzed using the RayBio Human Apoptosis Antibody Array Kit (RayBiotech) as per manufacturers suggestions. The membranes were exposed to autoradiography film for different times to detect the chemiluminescent signals. Images with signals in linear range were quantitated using the program ImageJ [59]. For each membrane, signals from the negative control spots were averaged, and then subtracted from each of the other spots. A signal was considered valid if its value exceeded both its average local background, and the average of all valid negative control values. Valid signals were normalized using the positive control spots (for cellular BID protein). Fold change in signals for each spot were quantitated by dividing by the valid signals for each corresponding spot on the minus β-estradiol membrane. Average fold change, and standard deviation, were calculated for each protein.
Project description:The aging process is characterized by cellular functional decline and increased susceptibility to infections. Understanding the association between virus infection and aging is crucial for developing effective strategies against viral infections in older individuals. Kaposi's sarcoma-associated herpesvirus (KSHV) infection increases the risk of Kaposi's sarcoma, a vascular cancer prevalent among the elderly without HIV infection. However, the relationship between KSHV pathogenesis and cellular senescence remains unknown. Here, we demonstrate that KSHV infectivity is significantly increased in senescent human endothelial cells due to enhanced binding of virions to cell surface. Proteomic analysis identified caveolin-1 and CD109 that promote KSHV infection and were significantly upregulated in senescent cells. In particular, CD109 is expressed on cell surface and directly interacts with KSHV virions to enhance KSHV infection. Knockout of CD109 abolished while overexpression of CD109 promote KSHV binding to cell surface, and infectivity. These results identify CD109 as a novel KSHV entry receptor that enhances KSHV infection in senescent cells, which might in part explain the higher sensitivity of elder subjects to KSHV infection and Kaposi's sarcoma.
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent of primary effusion lymphoma (PEL). All PEL cell lines are infected with KSHV, and 70% are co-infected with Epstein-Barr Virus (EBV). KSHV reactivation from latency requires promoter-specific transactivation by the KSHV Rta protein through interactions with RBP-Jk (CSL), the cellular DNA binding component of the Notch signal transduction pathway. EBV transformation of primary B cells requires EBV nuclear antigen (EBNA)-2 to interact with RBP-Jk to direct the latent viral and cellular gene expression program. Although KSHV Rta and EBV EBNA-2 both require RBP-Jk for transactivation, previous studies have suggested that RBP-Jk-dependent transactivators do not function identically. We have found that the EBV latent protein LMP-1 is expressed in less than 5% of KSHV+/EBV+ PEL cells, but is induced in an Rta-dependent fashion when KSHV reactivates. KSHV Rta transactivates the EBV latency promoters in an RBP-Jk-dependent fashion and forms a ternary complex with RBP-Jk on the promoters. In B cells that are conditionally transformed by EBV alone, we show that KSHV Rta complements a short-term EBNA2 growth deficiency in an autocrine/paracrine manner. Complementaton of EBNA2-deficiency by Rta depends on RBP-Jk and LMP-1, and Rta transactivation is required for optimal growth of KSHV+/EBV+ PEL lines. Our data suggest that Rta can contribute to EBV-driven cellular growth by transactivating RBP-Jk-dependent EBV latency genes. However, our data also suggest that EBNA2 and Rta induce distinct alterations in the cellular proteomes that contribute to growth of infected cells.
Project description:Tan et al. discovered abundant conserved N6-methyladenosine (m6A) modifications on KSHV transcripts during latent and productive infection in different cell types. They also show that m6A readers YTHDF2 and YTHDF3 mediate KSHV replication, and KSHV optimizes both phases of viral replication by reprograming cellular epitranscriptome to regulate distinct signaling pathways.
Project description:MicroRNAs are 19 to 23 nt RNAs that post-transcriptionally regulate gene expression. Human cells express several hundred miRNAs which regulate important biological pathways such as development, proliferation, and apoptosis. Recently, 12 microRNA genes have been identified within the genome of Kaposi’s sarcoma-associated herpesvirus; however, their functions are still unknown. To identify host cellular genes that may be targeted by these novel viral regulators, we performed gene expression profiling in cells stably expressing KSHV-encoded miRNAs. Data analysis revealed a set of 81 genes whose expression was significantly changed in the presence of miRNAs. While the majority of changes were below 2-fold, eight genes were down-regulated between 4- and 20-fold. We confirmed miRNA-dependent regulation for three of these genes and found that protein levels of thrombospondin 1 (THBS1) were decreased >10-fold. THBS1 has previously been reported to be down-regulated in KS lesions and has known activity as a strong tumor suppressor and anti-angiogenic factor, exerting its anti-angiogenic effect in part by activating the latent form of TGF-b. We show that reduced THBS1 expression in the presence of viral miRNAs translates into decreased TGF-b activity. These data suggest that KSHV-encoded miRNAs may contribute directly to pathogenesis by down-regulation of THBS1, a major regulator of cell adhesion, migration, and angiogenesis. Keywords: comparison, experiemental versus control
Project description:Kaposi sarcoma is the most common cancer in AIDS patients and is typified by red skin lesions. The disease is caused by the KSHV virus (HHV8) and is recognizable by its distinctive red skin lesions. The lesions are KSHV infected spindle cells, most commonly the lymphatic endothelial and blood vessel endothelial cells (LEC and BEC), plus surrounding stroma. The effects of KSHV infection of LECs were assayed using Affymetrix hgu133plus2 chips at 6 and 72 hours post infection.