KSHV Genome Replication and Maintenance

Kaposi’s sarcoma associated herpesvirus (KSHV) or human herpesvirus 8 (HHV8) is a major etiological agent for multiple severe malignancies in immunocompromised patients. KSHV establishes lifetime persistence in the infected individuals and displays two distinct life cycles, generally a prolonged passive latent, and a short productive or lytic cycle. During latent phase, the viral episome is tethered to the host chromosome and replicates once during every cell division. Latency-associated nuclear antigen (LANA) is a predominant multifunctional nuclear protein expressed during latency, which plays a central role in episome tethering, replication and perpetual segregation of the episomes during cell division. LANA binds cooperatively to LANA binding sites (LBS) within the terminal repeat (TR) region of the viral episome as well as to the cellular nucleosomal proteins to tether viral episome to the host chromosome. LANA has been shown to modulate multiple cellular signaling pathways and recruits various cellular proteins such as chromatin modifying enzymes, replication factors, transcription factors and cellular mitotic framework to maintain a successful latent infection. Although many other regions within the KSHV genome can initiate replication, KSHV TR is important for latent DNA replication and possible segregation of the replicated episomes. Binding of LANA to LBS favors the recruitment of various replication factors to initiate LANA dependent DNA replication. In this review, we discuss the molecular mechanisms relevant to KSHV genome replication, segregation, and maintenance of latency

Egr-1 regulates RTA transcription through a cooperative involvement of transcriptional regulators

Kaposi's sarcoma associated herpesvirus (KSHV) regulates the host cellular environment to establish life-long persistent infection by manipulating cellular signaling pathways, with approximately 1-5% of cells undergoing lytic reactivation during the course of infection. Egr-1 (Early Growth Response Factor-1) is one such cellular transcription factor, which gets phosphorylated during the lytic phase of viral life cycle to perpetrate its function. This study demonstrates the mechanism of how Egr-1 mediates transcription of the immediate early gene, RTA (Replication and transcription activator), which is the lytic switch gene of KSHV. Egr-1 depleted KSHV infected cells exhibited reduced expression of RTA. Also, an increase in Egr1 phosphorylation led to a higher virion production, which was suppressed in the presence of p38 and Raf inhibitors. Reporter assays showed that coexpression of Egr1 and CBP (CREB-binding protein) enhances RTA promoter activity as compared to the expression of either Egr-1 or CBP alone. Binding of Egr-1 and CBP at RTA promoter was analyzed by chromatin immunoprecipitation assay (ChIP), which showed an enhanced accumulation during viral reactivation. Mutation in Egr-1 binding site of the RTA promoter eliminated Egr-1 response on promoter activation. Furthermore, de novo infection of THP-1 (monocytic) and HUVECs (endothelial) cells showed an upregulation of Egr-1 phosphorylation, whereas depletion of Egr-1 reduced the mRNA levels of RTA during primary infection. Together, these results demonstrate a cooperative role of Egr-1 and CBP in mediating RTA transcription, which significantly improves our understanding of the involvement of cellular factors controlling RTA transcription in KSHV pathogenesis

Emergence of a unique recombinant form of HIV-1 from Manipur (India)

Background: The AIDS epidemic in Manipur, India, manifests unique features, having co-circulation of B and C HIV-1 subtypes along with recombinant forms. Manipur has the highest incidence of HIV-1 infection compared to the other states of India, but limited information is available regarding the full-length sequence of HIV-1 recombinants. Objectives: To characterize the near full-length genome of a novel recombinant HIV-1 strain from an injecting drug user of Manipur. Study design: Viral RNA, extracted from the plasma of a male injecting drug user aged 35, was diagnosed with HIV-1 infection. Near full-length genome was amplified by polymerase chain reaction using primer walking approach. Phylogenetic relationships were determined with neighbor-joining trees. The recombination break points were detected using boot scan and Simplot analyses. Results: This recombinant predominantly had subtype C genome and exhibited mosaic structures with subtype B insertions at three different positions of HIV-1 genome. Simplot analysis of near full-length genome sequence from the recombinant HIV-1 strain, MAN86 exhibited similarity with the sequence of C.IN.93.93IN905 in its subtype C backbone, while the subtype B insertions showed resemblance with the sequence of B.TH.99.99TH_C1416. Conclusions: This study confirms the presence of a unique recombinant HIV-1 strain, emerging as a result of recombination between HIV-1 strains from India and Thailand

Cancer patient perspectives on survivorship goals from the Smart Patients online community

BackgroundCancer impacts individuals' life goals. Recent cancer care guidelines recommend discussing life goals as part of patient-provider communication. The goal of this study was to understand patients' attitudes toward goal sharing with their cancer care providers.Patients and methodsSemi-structured questionnaires were conducted via email with cancer patients and survivors (n = 39) on an online social network called Smart Patients. Participants answered open-ended questions about their life goals. They then completed a survey regarding their attitudes toward goal sharing with healthcare providers. The study team used an integrated inductive-deductive qualitative analysis to identify conceptual themes.ResultsParticipants listed goals related to improving physical activity, control, enjoyment/leisure, and inner strength while reducing pain, anxiety, fear of recurrence, and uncertainty. Most of these goals were life goals rather than goals specifically related to medical care. Across all goals, there was a focus on returning to normality. Our findings show that 87% of participants expect their cancer specialist to discuss their treatment preferences and goals regularly with them. However, participants were reluctant to share their goals with their providers. Respondents felt that their providers did not have an interest in their life goals or time to address them in addition to their medical treatment.ConclusionEven though cancer patient-provider communication guidelines advocate for discussions around life goals, participants in this study expressed reluctance to share life goals with providers. Further efforts to align expectations of patients and providers may facilitate adherence to cancer communication guidelines about life goals.Implications for cancer survivorsCancer survivors should be aware that discussing life goals is part of recommended communication with their cancer care teams

Relative measurement of the rate of apoptosis in immDCs upon subjecting them to treatment with Nef and gp120.

<p>(<b>A</b>) ELISA analysis of the apoptosis rate in immDCs upon subjecting them to treatment with Nef and gp120 in individual sets of experiments. The dosage of Nef and gp120 were 100 ng/ml and 4 µg/ml respectively. X-axis denotes the combined dosage of Nef and gp120. Y-axis represents the percentage of annexin positive cells. Data represent the mean±SEM (n = 3). Statistical analysis was performed using Student's t-test, with the levels of significance defined as p*<0.05 and p**<0.01. (<b>B</b>) FACS analysis of apoptotic immDCs cells on treating with gp120, Nef and combination of gp120 and Nef in a time dependent manner. The percentage denoted on the right side of each histogram denotes the positively stained cells.</p