70 research outputs found

    KSHV PAN RNA Associates with Demethylases UTX and JMJD3 to Activate Lytic Replication through a Physical Interaction with the Virus Genome

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    Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of Kaposi's sarcoma and body cavity lymphomas. KSHV lytic infection produces PAN RNA, a highly abundant noncoding polyadenylated transcript that is retained in the nucleus. We recently demonstrated that PAN RNA interacts with several viral and cellular factors and can disregulate the expression of genes that modulate immune response. In an effort to define the role of PAN RNA in the context of the virus genome we generated a recombinant BACmid that deleted the PAN RNA locus. Because of the apparent duplication of the PAN RNA locus in BAC36, we generated BAC36CR, a recombinant BACmid that removes the duplicated region. BAC36CR was used as a template to delete most of the PAN RNA locus to generate BAC36CRΔPAN. BAC36CRΔPAN failed to produce supernatant virus and displayed a general decrease in mRNA accumulation of representative immediate early, early and late genes. Most strikingly, K-Rta expression was decreased in lytically induced BAC36CRΔPAN-containing cell lines at early and late time points post induction. Expression of PAN RNA in trans in BAC36CRΔPAN containing cells resulted in an increase in K-Rta expression, however K-Rta over expression failed to rescue BAC36CRΔPAN, suggesting that PAN RNA plays a wider role in virus replication. To investigate the role of PAN RNA in the activation of K-Rta expression, we demonstrate that PAN RNA physically interacts with the ORF50 promoter. RNA chromatin immunoprecipitation assays show that PAN RNA interacts with demethylases JMJD3 and UTX, and the histone methyltransferase MLL2. Consistent with the interaction with demethylases, expression of PAN RNA results in a decrease of the repressive H3K27me3 mark at the ORF50 promoter. These data support a model where PAN RNA is a multifunctional regulatory transcript that controls KSHV gene expression by mediating the modification of chromatin by targeting the KSHV repressed genome

    Oral abstracts of the 21st International AIDS Conference 18-22 July 2016, Durban, South Africa

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    The rate at which HIV-1 infected individuals progress to AIDS is highly variable and impacted by T cell immunity. CD8 T cell inhibitory molecules are up-regulated in HIV-1 infection and associate with immune dysfunction. We evaluated participants (n=122) recruited to the SPARTAC randomised clinical trial to determine whether CD8 T cell exhaustion markers PD-1, Lag-3 and Tim-3 were associated with immune activation and disease progression.Expression of PD-1, Tim-3, Lag-3 and CD38 on CD8 T cells from the closest pre-therapy time-point to seroconversion was measured by flow cytometry, and correlated with surrogate markers of HIV-1 disease (HIV-1 plasma viral load (pVL) and CD4 T cell count) and the trial endpoint (time to CD4 count <350 cells/μl or initiation of antiretroviral therapy). To explore the functional significance of these markers, co-expression of Eomes, T-bet and CD39 was assessed.Expression of PD-1 on CD8 and CD38 CD8 T cells correlated with pVL and CD4 count at baseline, and predicted time to the trial endpoint. Lag-3 expression was associated with pVL but not CD4 count. For all exhaustion markers, expression of CD38 on CD8 T cells increased the strength of associations. In Cox models, progression to the trial endpoint was most marked for PD-1/CD38 co-expressing cells, with evidence for a stronger effect within 12 weeks from confirmed diagnosis of PHI. The effect of PD-1 and Lag-3 expression on CD8 T cells retained statistical significance in Cox proportional hazards models including antiretroviral therapy and CD4 count, but not pVL as co-variants.Expression of ‘exhaustion’ or ‘immune checkpoint’ markers in early HIV-1 infection is associated with clinical progression and is impacted by immune activation and the duration of infection. New markers to identify exhausted T cells and novel interventions to reverse exhaustion may inform the development of novel immunotherapeutic approaches

    An evaluation of the early effects of a combination antiretroviral therapy programme on the management of AIDS-associated Kaposi's sarcoma in KwaZulu-Natal, South Africa

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    Summary Roll-out of combination antiretroviral therapy (cART) in South Africa should impact on AIDS-associated Kaposi's sarcoma (KS). Government provision began in 2003, with 23% coverage for World Health Organization (WHO) stage IVAIDS in 2006. To assess the effect of cART availability on KS management, we evaluated records from 701 KS patients seen at a tertiary oncology centre in KwaZulu-Natal, South Africa, from 1995 to 2006. Associations between cART use and measures of KS care were evaluated. cART availability was 0% prior to 2001, 9.6% (2001-2003) and 44% (2004-2006). Documentation of HIV status increased incrementally from 65% to 92%. cART was associated with chemotherapy administration: 56% on cART versus 17% not on cART (P &lt; 0.001); and less loss to follow-up, 13% on cART versus 38% not on cART (P &lt; 0.001). cART availability improves the care of AIDS-associated KS. Further increases in cART availability for this population are needed in South Africa. </jats:p

    18FDG-PET in the management of malignant peritoneal mesothelioma: A retrospective review of 145 scans in 37 patients

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    20519 Background: Malignant peritoneal mesothelioma is a rare tumor best managed by an interdisciplinary approach. The role of 18FDG-PET scans in monitoring patients with peritoneal mesothelioma has not been defined. Methods: Patients with peritoneal mesothelioma treated at Columbia University (October, 1997 - October, 2006) who had a PET scan were reviewed. Data were gathered on modes of therapy, imaging, and clinical outcome. The frequency with which PET scans led to a change in management, defined as scans that led to a biopsy or initiation of chemotherapy, was evaluated. Results: 37 patients, 21 women (57%) and 16 men (43%), were reviewed. The median age was 50 (range 14 - 79) years. All patients underwent surgery, 35 (95%) intraperitoneal chemotherapy, 15 (41%) external beam radiation, and 17 (46%) intravenous chemotherapy. At 43 (range 8.5 - 127) months median follow-up, 27 (73 %) are alive. Among 145 PET scans, 66 (46%) were PET/CT scans, 52 (26%) were PET scans with a CT scan performed within one month, and 27 (19%) were PET scans only. 8 (6%) of PET scans were for initial staging, and 137 (95%) for monitoring. A change in management based on findings in PET imaging occurred in 11 (30%) patients and 14 (10%) scans. Two patients were started on salvage chemotherapy without further evaluation. Two were diagnosed with peritoneal recurrence, 1 with lung metastasis, 1 with lymph node metastasis, 1 with a second malignancy, and 3 with colon polyps. One had a false positive scan, proven by negative surgical biopsy. PET provided early detection of disease progression in 6 (16%) of patients evaluated. One patient (3%) had biopsy proven progressive disease despite no 18FDG uptake on PET scan. Conclusions: 18FDG-PET findings changed management in 30% of patients with peritoneal mesothelioma undergoing multimodality therapy, and provided early detection of recurrence in 16% of patients. Further evaluation of test characteristics and prognostic value of 18FDG-PET in the setting of peritoneal mesothelioma is warranted. No significant financial relationships to disclose. </jats:p

    Increasing incidence of Kaposi's sarcoma in black South Africans in KwaZulu-Natal, South Africa (1983–2006)

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    The aim of the study was to describe the temporal trends in the incidence of Kaposi's sarcoma (KS) in black South Africans in KwaZulu-Natal (KZN). The study was designed as a retrospective record review. The incidence of Kaposi's sarcoma was estimated using administrative records for patients receiving care for KS through public sector oncology clinics in KZN, 1983–2006. Annual age-standardized incidence rates were calculated using provincial census data for the denominator. Age-specific rates were calculated for the pre-AIDS (1983–1989) and for the generalized AIDS epidemic eras (2006). Age-standardized incidence of KS increased in KZN from &lt;1:100,000 in 1990 to at least 15:100,000 in 2006; this increase was observed in both men and women. There was a shift in the peak age-specific incidence rates from the sixth decade of life in the pre-AIDS era to the fourth and fifth decades in the AIDS era. In conclusion, KS is a growing public health problem in KZN, South Africa. These data reinforce the need for comprehensive national access to and roll-out of antiretroviral drugs, given their success in prevention and treatment of KS in first-world settings. </jats:p
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