Cellular Receptors Involved in KSHV Infection

The process of Kaposi’s Sarcoma Herpes Virus’ (KSHV) entry into target cells is complex and engages several viral glycoproteins which bind to a large range of host cell surface molecules. Receptors for KSHV include heparan sulphate proteoglycans (HSPGs), several integrins and Eph receptors, cystine/glutamate antiporter (xCT) and Dendritic Cell-Specific Intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN). This diverse range of potential binding and entry sites allows KSHV to have a broad cell tropism, and entry into specific cells is dependent on the available receptor repertoire. Several molecules involved in KSHV entry have been well characterized, particularly those postulated to be associated with KSHV-associated pathologies such as Kaposi’s Sarcoma (KS). In this review, KSHV infection of specific cell types pertinent to its pathogenesis will be comprehensively summarized with a focus on the specific cell surface binding and entry receptors KSHV exploits to gain access to a variety of cell types. Gaps in the current literature regarding understanding interactions between KSHV glycoproteins and cellular receptors in virus infection are identified which will lead to the development of virus infection intervention strategies.     

Sodium-glucose co-transporter-2 inhibition and ocular outcomes in patients with type 2 diabetes: A systematic review and meta-analysis

Sodium-glucose co-transporter-2 (SGLT2) inhibitors are effective for the treatment of macrovascular complications and nephropathy in type 2 diabetes, but effects on microvascular eye outcomes are unclear. We conducted a systematic review and meta-analysis of randomized placebo-controlled trials to evaluate the effect of SGLT2 inhibition on total ocular events and retinopathy in patients with type 2 diabetes. We searched MEDLINE and Embase for the period from database inception date to October 11, 2019. Two reviewers working independently extracted relevant data. Random-effects models with inverse variance weighting were selected to estimate summary risk ratios (RRs) and 95% confidence intervals (CIs). We included nine studies, involving 39 982 patients with a mean follow-up of 2.8 years. There were 1414 total ocular events, of which 624 were retinopathy events. SGLT2 inhibition was not associated with a change in the risk of total ocular events (RR 0.97, 95% CI 0.85, 1.11) or retinopathy (RR 0.98, 95% CI 0.84, 1.16), with consistent effects across studies (P for heterogeneity = 0.35 and 0.45, respectively). The effects of SGLT2 inhibition on eye disease in individuals with type 2 diabetes are probably null, although the available data cannot exclude small to moderate benefits or harms.     

The effects of canagliflozin on heart failure and cardiovascular death by baseline participant characteristics: Analysis of the CREDENCE trial

Heart failure is prevalent in those with type 2 diabetes and chronic kidney disease, and is associated with significant mortality and morbidity. In the CREDENCE trial, canagliflozin reduced the risk of hospitalization for heart failure (HHF) or cardiovascular (CV) death by 31%. In the current analysis we sought to determine whether the effect of canagliflozin on HHF/CV death differed in subgroups defined by key baseline participant characteristics. Cox regression models were used to estimate hazard ratios and 95% confidence intervals. Canagliflozin was associated with a reduction in the relative risk of HHF/CV death regardless of age, sex, history of heart failure or CV disease, and the use of loop diuretics or glucagon-like peptide-1 receptor agonists (all p_interaction > .114). The absolute benefit of canagliflozin was greater in those at highest baseline risk, such as those with CV disease (50 fewer events/1000 patients treated over 2.5 years vs. 20 fewer events in those without CV disease) or advanced kidney disease (estimated glomerular filtration rate [eGFR] 30–45 mL/min/1.73m²: 61 events prevented/1000 patients treated over 2.5 years vs. 23 events in eGFR 60–90 mL/min/1.73m²). Canagliflozin consistently reduces the proportional risk of HHF/CV death across a broad range of subgroups with greater absolute benefits in those at highest baseline risk.     

Potent block of Cx36 and Cx50 gap junction channels by mefloquine

Recently, great interest has been shown in understanding the functional roles of specific gap junction proteins (connexins) in brain, lens, retina, and elsewhere. Some progress has been made by studying knockout mice with targeted connexin deletions. For example, such studies have implicated the gap junction protein Cx36 in synchronizing rhythmic activity of neurons in several brain regions. Although knockout strategies are informative, they can be problematic, because compensatory changes sometimes occur during development. Therefore, it would be extremely useful to have pharmacological agents that block specific connexins, without major effects on other gap junctions or membrane channels. We show that mefloquine, an antimalarial drug, is one such agent. It blocked Cx36 channels, expressed in transfected N2A neuroblastoma cells, at low concentrations (IC(50) approximately 300 nM). Mefloquine also blocked channels formed by the lens gap junction protein, Cx50 (IC(50) approximately 1.1 microM). However, other gap junctions (e.g., Cx43, Cx32, and Cx26) were only affected at concentrations 10- to 100-fold higher. To further examine the utility and specificity of this compound, we characterized its effects in acute brain slices. Mefloquine, at 25 microM, blocked gap junctional coupling between interneurons in neocortical slices, with minimal nonspecific actions. At this concentration, the only major side effect was an increase in spontaneous synaptic activity. Mefloquine (25 microM) caused no significant change in evoked excitatory or inhibitory postsynaptic potentials, and intrinsic cellular properties were also mostly unaffected. Thus, mefloquine is expected to be a useful tool to study the functional roles of Cx36 and Cx50.     

Human Papillomavirus Prevalence in Oropharyngeal Cancer before Vaccine Introduction,United States

We conducted a study to determine prevalence of HPV types in oropharyngeal cancers in the United States and establish a prevaccine baseline for monitoring the impact of vaccination. HPV DNA was extracted from tumor tissue samples from patients in whom cancer was diagnosed during 1995–2005. The samples were obtained from cancer registries and Residual Tissue Repository Program sites in the United States. HPV was detected and typed by using PCR reverse line blot assays. Among 557 invasive oropharyngeal squamous cell carcinomas, 72% were positive for HPV and 62% for vaccine types HPV16 or 18. Prevalence of HPV-16/18 was lower in women (53%) than in men (66%), and lower in non-Hispanic Black patients (31%) than in other racial/ethnic groups (68%–80%). Results indicate that vaccines could prevent most oropharyngeal cancers in the United States, but their effect may vary by demographic variables.     

T-cell activation Rho GTPase–activating protein expression varies with inflammation location and severity in Crohn's disease

Background

The T-cell activation Rho GTPase–activating protein (TAGAP) gene has a regulatory role in T cell activation. We have previously suggested a correlation between the TAGAP-associated single nucleotide polymorphism rs212388 and protection from anal sepsis in Crohn's disease (CD) patients. The present study sought to evaluate TAGAP's expression in colonic tissue of CD patients with varying disease severity and location.

Materials and methods

Five transverse, 17 left, and five sigmoid colectomy specimens from 27 CD patients with varying disease severity (16 male, mean age at diagnosis 26.4 ± 2.2 y) were evaluated for TAGAP messenger RNA expression. Fisher exact, Mann–Whitney, and Welch two-sample t-tests were used for statistical evaluation. Immunohistochemistry confirmed results.

Results

Patients with tissue demonstrating lower TAGAP messenger RNA expression (less than the overall mean) were younger at diagnosis (mean age 21.1 ± 6.3 versus 32.5 ± 13 y, P = 0.009). Increased TAGAP expression was seen in moderate or severely diseased tissue versus tissue with no or mild disease (RQ = 1.3 ± 0.34 versus 0.53 ± 0.09, P = 0.050). This was the most dramatic in the sigmoid colon (P = 0.041). TAGAP expression was increased in more distal tissue with a significant difference seen when comparing transverse versus sigmoid colon with moderate or severe disease (0.51 ± 0.14 versus 1.9 ± 0.37, P = 0.049).

Conclusions

Colonic expression of TAGAP in CD patients varied according to disease severity and location, being the most elevated in patients with severe disease in the sigmoid colon. Whether changes in TAGAP expression are a result of disease response or inherent to the disease pathophysiology itself remains to be determined. This gene warrants further investigation for its role in CD.     

Optimizing infant HIV diagnosis with additional screening at immunization clinics in three sub‐Saharan African settings: a cost‐effectiveness analysis

IntroductionUptake of early infant HIV diagnosis (EID) varies widely across sub‐Saharan African settings. We evaluated the potential clinical impact and cost‐effectiveness of universal maternal HIV screening at infant immunization visits, with referral to EID and maternal antiretroviral therapy (ART) initiation.MethodsUsing the CEPAC‐Pediatric model, we compared two strategies for infants born in 2017 in Côte d’Ivoire (CI), South Africa (SA), and Zimbabwe: (1) existing EID programmes offering six‐week nucleic acid testing (NAT) for infants with known HIV exposure (EID), and (2) EID plus universal maternal HIV screening at six‐week infant immunization visits, leading to referral for infant NAT and maternal ART initiation (screen‐and‐test). Model inputs included published Ivoirian/South African/Zimbabwean data: maternal HIV prevalence (4.8/30.8/16.1%), current uptake of EID (40/95/65%) and six‐week immunization attendance (99/74/94%). Referral rates for infant NAT and maternal ART initiation after screen‐and‐test were 80%. Costs included NAT ($24/infant), maternal screening ($10/mother–infant pair), ART ($5 to 31/month) and HIV care ($15 to 190/month). Model outcomes included mother‐to‐child transmission of HIV (MTCT) among HIV‐exposed infants, and life expectancy (LE) and mean lifetime per‐person costs for children with HIV (CWH) and all children born in 2017. We calculated incremental cost‐effectiveness ratios (ICERs) using discounted (3%/year) lifetime costs and LE for all children. We considered two cost‐effectiveness thresholds in each country: (1) the per‐capita GDP ($1720/6380/2150) per year‐of‐life saved (YLS), and (2) the CEPAC‐generated ICER of offering 2 versus 1 lifetime ART regimens (e.g. offering second‐line ART; $520/500/580/YLS).ResultsWith EID, projected six‐week MTCT was 9.3% (CI), 4.2% (SA) and 5.2% (Zimbabwe). Screen‐and‐test decreased total MTCT by 0.2% to 0.5%, improved LE by 2.0 to 3.5 years for CWH and 0.03 to 0.07 years for all children, and increased discounted costs by $17 to 22/child (all children). The ICER of screen‐and‐test compared to EID was $1340/YLS (CI), $650/YLS (SA) and $670/YLS (Zimbabwe), below the per‐capita GDP but above the ICER of 2 versus 1 lifetime ART regimens in all countries.ConclusionsUniversal maternal HIV screening at immunization visits with referral to EID and maternal ART initiation may reduce MTCT, improve paediatric LE, and be of comparable value to current HIV‐related interventions in high maternal HIV prevalence settings like SA and Zimbabwe.