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The host kinase casein kinase 2 (CSNK2) has been proposed to be an antiviral target against β-coronaviral infection. To pharmacologically validate CSNK2 as a drug target in vivo, potent and selective CSNK2 inhibitors with good pharmacokinetic properties are required. Inhibitors based on the pyrazolo[1,5-a]pyrimidine scaffold possess outstanding potency and selectivity for CSNK2, but bioavailability and metabolic stability are often challenging. By strategically installing a fluorine atom on an electron-rich phenyl ring of a previously characterized inhibitor 1, we discovered compound 2 as a promising lead compound with improved in vivo metabolic stability. Compound 2 maintained excellent cellular potency against CSNK2, submicromolar antiviral potency, and favorable solubility, and was remarkably selective for CSNK2 when screened against 192 kinases across the human kinome. We additionally present a co-crystal structure to support its on-target binding mode. In vivo, compound 2 was orally bioavailable, and demonstrated modest and transient inhibition of CSNK2, although antiviral activity was not observed, possibly attributed to its lack of prolonged CSNK2 inhibition. [ABSTRACT FROM AUTHOR]

ObjectiveHerpesvirus shedding in the oral cavity was analyzed to determine if presence in the oral compartment correlates with systemic changes in HIV-associated immune deficiency as measured by CD4 cell counts, plasma HIV viral load and presence of AIDS-defining events.DesignA5254 is a multicenter, cross-sectional, single-visit study to evaluate oral complications of HIV/AIDS and determine the association between clinical appearance, herpesvirus shedding, and immune status as ascertained by CD4 cell count and HIV viral load. In total, 307 HIV-infected individuals were evaluated and throat wash collected.MethodsFisher's exact test and Kruskal-Wallis test were used to assess the association between presence of herpesviruses and the state of immunodeficiency as stratified by a combination of CD4 cell count and HIV viral load. Relationship between pathogens and HIV viral load in plasma was modeled by logistic regression.ResultsThe presence of cytomegalovirus (CMV) and herpes simplex virus-1 in throat wash was associated with decreased CD4 cell counts. By contrast, Kaposi sarcoma-associated herpesvirus and Epstein-Barr virus were similarly detectable across all levels of CD4 cell counts. One unit increase in log10 (HIV viral load) was associated with 1.31 times higher odds of detecting CMV in throat wash when controlling for oral candidiasis, CD4 cell count, and sites (95% confidence interval 1.04-1.65, P = 0.02).ConclusionOral CMV shedding was significantly higher in highly immunocompromised HIV participants. Our finding supports the recommendations to start antiretroviral therapy independent of CD4 cell count as this may have the added benefit to lower the risk of herpesvirus transmission among persons infected with HIV and their partners.

Introduction: Clinical reports of multicentric Castleman disease (MCD) from sub‐Saharan Africa (SSA) are scarce despite high prevalence of HIV and Kaposi sarcoma‐associated herpesvirus (KSHV). Our objective is to describe characteristics and survival for HIV‐associated MCD patients in Malawi. To our knowledge, this is the first HIV‐associated MCD case series from the region. Methods: We describe HIV‐positive patients with MCD in Lilongwe, and compare them to HIV‐associated lymph node Kaposi sarcoma (KS) and non‐Hodgkin lymphoma (NHL) patients treated at our centre. All patients were enrolled into a prospective longitudinal cohort study at a national teaching hospital and cancer referral centre serving half of Malawi's 16 million people. We included adult patients≥18 years of age with HIV‐associated MCD (n=6), lymph node KS (n=5) or NHL (n=31) enrolled between 1 June 2013 and 31 January 2015. Results and discussion: MCD patients had a median age of 42.4 years (range 37.2–51.8). All had diffuse lymphadenopathy and five had hepatosplenomegaly. Concurrent KS was present for one MCD patient, and four had performance status ≥3. MCD patients had lower median haemoglobin (6.4 g/dL, range 3.6–9.3) than KS (11.0 g/dL, range 9.1–12.0, p=0.011) or NHL (11.2 g/dL, range 4.5–15.1, p=0.0007). Median serum albumin was also lower for MCD (2.1 g/dL, range 1.7–3.2) than KS (3.7 g/dL, range 3.2–3.9, p=0.013) or NHL (3.4 g/dL, range 1.8–4.8, p=0.003). All six MCD patients were on antiretroviral therapy (ART) with median CD4 count 208 cells/µL (range 108–1146), and all with HIV RNA Conclusions: HIV‐associated MCD occurs in Malawi, is diagnosed late and is associated with high mortality. Improvements in awareness, diagnostic facilities, treatment and supportive care are needed to address this likely under‐recognized public health problem in SSA., Introduction HIV‐associated multicentric Castleman disease (MCD) is a lymphoproliferative disorder caused by Kaposi sarcoma‐associated herpesvirus (KSHV) [1–5]. Unlike Kaposi sarcoma (KS), MCD incidence may be increasing in the antiretroviral therapy [...]

Plasma Epstein‐Barr virus (EBV) DNA measurement has established prognostic utility in EBV‐driven lymphomas, where it serves as a circulating tumor DNA marker. The value of plasma EBV measurement may be amplified in sub‐Saharan Africa (SSA), where advanced imaging and molecular technologies for risk stratification are not typically available. However, its utility in diffuse large B‐cell lymphoma (DLBCL) is less certain, given that only a subset of DLBCLs are EBV‐positive. To explore this possibility, we measured plasma EBV DNA at diagnosis in a cohort of patients with DLBCL in Malawi. High plasma EBV DNA at diagnosis (≥3.0 log10 copies/mL) was associated with decreased overall survival (OS) (P =.048). When stratified by HIV status, the prognostic utility of baseline plasma EBV DNA level was restricted to HIV‐positive patients. Unexpectedly, most HIV‐positive patients with high plasma EBV DNA at diagnosis had EBV‐negative lymphomas, as confirmed by multiple methods. Even in these HIV‐positive patients with EBV‐negative DLBCL, high plasma EBV DNA remained associated with shorter OS (P =.014). These results suggest that EBV reactivation in nontumor cells is a poor prognostic finding even in HIV‐positive patients with convincingly EBV‐negative DLBCL, extending the potential utility of EBV measurement as a valuable and implementable prognostic marker in SSA. [ABSTRACT FROM AUTHOR]

Kaposi sarcoma (KS) is among the most common childhood malignancies in central, eastern, and southern Africa. Although its unique clinical features have been established, biological mechanisms related to the causative agent, KS‐associated herpes‐virus (KSHV), have yet to be explored in children. We performed a prospective observational pilot study to explore associations between KSHV viral load (VL), human interleukin‐6 (IL‐6) and IL‐10 levels, and clinical characteristics of 25 children with KS in Lilongwe, Malawi from June 2013–August 2015. The median age was 6.4 years. Lymphadenopathy was the most common site of KS involvement (64%), followed by skin and oral mucosa (44% each), woody edema (12%), and pulmonary (8%). Baseline samples for plasma KSHV VL, IL‐6 and IL‐10 analyses were available for 18/25 patients (72%) at time of KS diagnosis. KSHV VL was detectable at baseline in 12/18 (67%) patients, the median baseline IL‐6 level was 8.53 pg/mL (range 4.31–28.33), and the median baseline IL‐10 level was 19.53 pg/mL (range 6.91–419.69). Seven (39%) patients presented with an IL‐6 level > 10 pg/mL (exceeding twice the upper limit of normal). Detectable KSHV VL was significantly associated with lymphadenopathic KS (p = 0.004), while having undetectable KSHV VL was associated with a higher likelihood of presenting with hyperpigmented skin lesions (p = 0.01). Detectable KSHV VL and elevated IL‐6 levels are present in a subset of children with KS. Lytic activation of KSHV and associated elevation in KSHV VL may contribute to the unique clinical manifestations of pediatric KS in KSHV‐endemic regions of Africa. What's new? Kaposi sarcoma is among the most common childhood malignancies in regions endemic for Kaposi sarcoma‐associated herpesvirus (KSHV), but virological characteristics of the disease remain undefined. Here the authors studied 25 children with Kaposi sarcoma in southeastern Africa and established links between distinct clinical patterns and elevated KSHV viral load and interleukin‐6 levels. The results points to a role of KSHV lytic activation and a potential KSHV inflammatory cytokine syndrome in the lymphadenopathic form of childhood Kaposi sarcoma. [ABSTRACT FROM AUTHOR]

The K1 gene product of Kaposi's sarcoma-associated herpesvirus (KSHV) is encoded by the first open reading frame (ORF) of the viral genome. To investigate the role of the K1 gene during the KSHV life cycle, we constructed a set of recombinant viruses that contained either wild-type (WT) K1, a deleted K1 ORF (KSHVΔK1), stop codons within the K1 ORF (KSHV-K15STOP), or a revertant K1 virus (KSHV-K1REV). We report that the recombinant viruses KSHVΔK1 and KSHV-K15STOP displayed significantly reduced lytic replication compared to WT KSHV and KSHV-K1REV upon reactivation from latency. Additionally, cells infected with the recombinant viruses KSHVΔK1 and KSHV-K15STOP also yielded smaller amounts of infectious progeny upon reactivation than did WT KSHV- and KSHV-K1REV-infected cells. Upon reactivation from latency, WT KSHV- and KSHVK1REV- infected cells displayed activated Akt kinase, as evidenced by its phosphorylation, while cells infected with viruses deleted for K1 showed reduced phosphorylation and activation of Akt kinase. Overall, our results suggest that K1 plays an important role during the KSHV life cycle. [ABSTRACT FROM AUTHOR]

The pyrazolo[1,5- a ]pyrimidine scaffold is a promising scaffold to develop potent and selective CSNK2 inhibitors with antiviral activity against β-coronaviruses. Herein, we describe the discovery of a 1,2,4-triazole group to substitute a key amide group for CSNK2 binding present in many potent pyrazolo[1,5- a ]pyrimidine inhibitors. Crystallographic evidence demonstrates that the 1,2,4-triazole replaces the amide in forming key hydrogen bonds with Lys68 and a water molecule buried in the ATP-binding pocket. This isosteric replacement improves potency and metabolic stability at a cost of solubility. Optimization for potency, solubility, and metabolic stability led to the discovery of the potent and selective CSNK2 inhibitor 53 . Despite excellent in vitro metabolic stability, rapid decline in plasma concentration of 53 in vivo was observed and may be attributed to lung accumulation, although in vivo pharmacological effect was not observed. Further optimization of this novel chemotype may validate CSNK2 as an antiviral target in vivo.