HIV-1 with Multiple CCR5/CXCR4 Chimeric Receptor Use Is Predictive of Immunological Failure in Infected Children

BACKGROUND: HIV-1 R5 viruses are characterized by a large phenotypic variation, that is reflected by the mode of coreceptor use. The ability of R5 HIV-1 to infect target cells expressing chimeric receptors between CCR5 and CXCR4 (R5(broad) viruses), was shown to correlate with disease stage in HIV-1 infected adults. Here, we ask the question whether phenotypic variation of R5 viruses could play a role also in mother-to-child transmission (MTCT) of HIV-1 and pediatric disease progression. METHODOLOGY/PRINCIPAL FINDINGS: Viral isolates obtained from a total of 59 HIV-1 seropositive women (24 transmitting and 35 non transmitting) and 28 infected newborn children, were used to infect U87.CD4 cells expressing wild type or six different CCR5/CXCR4 chimeric receptors. HIV-1 isolates obtained from newborn infants had predominantly R5(narrow) phenotype (n = 20), but R5(broad) and R5X4 viruses were also found in seven and one case, respectively. The presence of R5(broad) and R5X4 phenotypes correlated significantly with a severe decline of the CD4+ T cells (CDC stage 3) or death within 2 years of age. Forty-three percent of the maternal R5 isolates displayed an R5(broad) phenotype, however, the presence of the R5(broad) virus was not predictive for MTCT of HIV-1. Of interest, while only 1 of 5 mothers with an R5X4 virus transmitted the dualtropic virus, 5 of 6 mothers carrying R5(broad) viruses transmitted viruses with a similar broad chimeric coreceptor usage. Thus, the maternal R5(broad) phenotype was largely preserved during transmission and could be predictive of the phenotype of the newborn's viral variant. CONCLUSIONS/SIGNIFICANCE: Our results show that R5(broad) viruses are not hampered in transmission. When transmitted, immunological failure occurs earlier than in children infected with HIV-1 of R5(narrow) phenotype. We believe that this finding is of utmost relevance for therapeutic interventions in pediatric HIV-1 infectio

The druggable genome and support for target identification and validation in drug development

Target identification (determining the correct drug targets for a disease) and target validation (demonstrating an effect of target perturbation on disease biomarkers and disease end points) are important steps in drug development. Clinically relevant associations of variants in genes encoding drug targets model the effect of modifying the same targets pharmacologically. To delineate drug development (including repurposing) opportunities arising from this paradigm, we connected complex disease- and biomarker-associated loci from genome-wide association studies to an updated set of genes encoding druggable human proteins, to agents with bioactivity against these targets, and, where there were licensed drugs, to clinical indications. We used this set of genes to inform the design of a new genotyping array, which will enable association studies of druggable genes for drug target selection and validation in human disease

Regulation of atypical MAP kinases ERK3 and ERK4 by the phosphatase DUSP2

The atypical MAP kinases ERK3 and ERK4 are activated by phosphorylation of a serine residue lying within the activation loop signature sequence S-E-G. However, the regulation of ERK3 and ERK4 phosphorylation and activity is poorly understood. Here we report that the inducible nuclear dual-specificity MAP kinase phosphatase (MKP) DUSP2, a known regulator of the ERK and p38 MAPKs, is unique amongst the MKP family in being able to bind to both ERK3 and ERK4. This interaction is mediated by a conserved common docking (CD) domain within the carboxyl-terminal domains of ERK3 and ERK4 and the conserved kinase interaction motif (KIM) located within the non-catalytic amino terminus of DUSP2. This interaction is direct and results in the dephosphorylation of ERK3 and ERK4 and the stabilization of DUSP2. In the case of ERK4 its ability to stabilize DUSP2 requires its kinase activity. Finally, we demonstrate that expression of DUSP2 inhibits ERK3 and ERK4-mediated activation of its downstream substrate MK5. We conclude that the activity of DUSP2 is not restricted to the classical MAPK pathways and that DUSP2 can also regulate the atypical ERK3/4-MK5 signalling pathway in mammalian cells

Increased Sensitivity to Broadly Neutralizing Antibodies of End-Stage Disease R5 HIV-1 Correlates with Evolution in Env Glycosylation and Charge

BACKGROUND: Induction of broadly neutralizing antibodies, such as the monoclonal antibodies IgGb12, 2F5 and 2G12, is the objective of most antibody-based HIV-1 vaccine undertakings. However, despite the relative conserved nature of epitopes targeted by these antibodies, mechanisms underlying the sensitivity of circulating HIV-1 variants to broadly neutralizing antibodies are not fully understood. Here we have studied sensitivity to broadly neutralizing antibodies of HIV-1 variants that emerge during disease progression in relation to molecular alterations in the viral envelope glycoproteins (Env), using a panel of primary R5 HIV-1 isolates sequentially obtained before and after AIDS onset. PRINCIPAL FINDINGS: HIV-1 R5 isolates obtained at end-stage disease, after AIDS onset, were found to be more sensitive to neutralization by TriMab, an equimolar mix of the IgGb12, 2F5 and 2G12 antibodies, than R5 isolates from the chronic phase. The increased sensitivity correlated with low CD4(+) T cell count at time of virus isolation and augmented viral infectivity. Subsequent sequence analysis of multiple env clones derived from the R5 HIV-1 isolates revealed that, concomitant with increased TriMab neutralization sensitivity, end-stage R5 variants displayed envelope glycoproteins (Envs) with reduced numbers of potential N-linked glycosylation sites (PNGS), in addition to increased positive surface charge. These molecular changes in Env also correlated to sensitivity to neutralization by the individual 2G12 monoclonal antibody (mAb). Furthermore, results from molecular modeling suggested that the PNGS lost at end-stage disease locate in the proximity to the 2G12 epitope. CONCLUSIONS: Our study suggests that R5 HIV-1 variants with increased sensitivity to broadly neutralizing antibodies, including the 2G12 mAb, may emerge in an opportunistic manner during severe immunodeficiency as a consequence of adaptive molecular Env changes, including loss of glycosylation and gain of positive charge

Current practice in the removal of benign endometrial polyps: a Dutch survey

The purpose of this study is to evaluate the current practice of Dutch gynecologists in the removal of benign endometrial polyps and compare these results with the results of a previous study from 2003. In 2009 Dutch gynecologists were surveyed by a mailed questionnaire about polypectomy. Gynecologists answered questions about their individual performance of polypectomy: setting, form of anesthesia, method, and instrument use. The results were compared with the results from the previous survey. The response rate was 70% (585 of 837 gynecologists). Among the respondents, 455 (78%) stated to remove endometrial polyps themselves. Polyps were mostly removed in an inpatient setting (337; 74%) under general or regional anesthesia (247; 54%) and under direct hysteroscopic vision (411; 91%). Gynecologists working in a teaching hospital removed polyps more often in an outpatient setting compared with gynecologists working in a nonteaching hospital [118 (43%) vs. 35 (19%) p < 0.001]. These results are in accordance with the results from 2003. Compared to 2003 there was an increase in the number of gynecologists performing polypectomies with local or no anesthesia [211 (46%) vs. 98 (22%), p < 0.001]. An increase was also noted in the number of gynecologists using direct hysteroscopic vision [411 (91%) vs. 290 (64%), p < 0.001] and 5 Fr electrosurgical instruments [181 (44%) vs. 56 (19%), p < 0.001]. Compared to the situation in 2003, there is an increase in removal under direct hysteroscopic vision, with 5 Fr electrosurgical instruments, using local or no anesthesia. This implies there is progress in outpatient hysteroscopic polypectomy in the Netherlands

Turing patterns on networks

Turing patterns formed by activator-inhibitor systems on networks are considered. The linear stability analysis shows that the Turing instability generally occurs when the inhibitor diffuses sufficiently faster than the activator. Numerical simulations, using a prey-predator model on a scale-free random network, demonstrate that the final, asymptotically reached Turing patterns can be largely different from the critical modes at the onset of instability, and multistability and hysteresis are typically observed. An approximate mean-field theory of nonlinear Turing patterns on the networks is constructed.Comment: 4 pages, 4 figure

Mutations in MITF and PAX3 Cause “Splashed White” and Other White Spotting Phenotypes in Horses

During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The “splashed white” pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white horses are deaf. We analyzed a Quarter Horse family segregating for the splashed white coat color. Genome-wide linkage analysis in 31 horses gave a positive LOD score of 1.6 in a region on chromosome 6 containing the PAX3 gene. However, the linkage data were not in agreement with a monogenic inheritance of a single fully penetrant mutation. We sequenced the PAX3 gene and identified a missense mutation in some, but not all, splashed white Quarter Horses. Genome-wide association analysis indicated a potential second signal near MITF. We therefore sequenced the MITF gene and found a 10 bp insertion in the melanocyte-specific promoter. The MITF promoter variant was present in some splashed white Quarter Horses from the studied family, but also in splashed white horses from other horse breeds. Finally, we identified two additional non-synonymous mutations in the MITF gene in unrelated horses with white spotting phenotypes. Thus, several independent mutations in MITF and PAX3 together with known variants in the EDNRB and KIT genes explain a large proportion of horses with the more extreme white spotting phenotypes

Metals and kidney markers in adult offspring of endemic nephropathy patients and controls: a two-year follow-up study

Abstract Background The etiology of Balkan Endemic Nephropathy, (BEN), a tubulointerstitial kidney disease, is unknown. Although this disease is endemic in rural areas of Bosnia, Bulgaria, Croatia, Romania, and Serbia, similar manifestations are reported to occur in other regions, for instance Tunisia and Sri Lanka. A number of explanations have been stated including lignites, aristolochic acid, ochratoxin A, metals, and metalloids. Etiologic claims are often based on one or a few studies without sound scientific evidence. In this systematic study, we tested whether exposures to metals (cadmium and lead) and metalloids (arsenic and selenium) are related to Balkan Endemic Nephropathy. Methods In 2003/04 we recruited 102 adults whose parents had BEN and who resided in one of three communities (Vratza, Bistretz, or Beli Izvor, Bulgaria). A control group comprised of 99 adults having non-BEN hospitalized parents was enrolled in the study during the same time. We conducted face-to-face interviews, ultrasound kidney measurements, and determined kidney function in two consecutive investigations (2003/04 and 2004/05). Metals and metalloids were measured in urine and blood samples. To assess the agreement between these consecutive measurements, we calculated intraclass correlation coefficients. Repeated measurement data were analyzed using mixed models. Results We found that cadmium and arsenic were associated with neither kidney size nor function. Lead had a significant but negligible effect on creatinine clearance. Selenium showed a weak but significant negative association with two of the four kidney parameters, namely creatinine clearance and β2-microglobulin. It was positively related to kidney length. These associations were not restricted to the offspring of BEN patients. Adding credence to these findings are reports showing comparable kidney effects in animals exposed to selenium. Conclusion The findings of this 2-year follow-up study indicate that metals and metalloids do not play a role in the etiology of Balkan Endemic Nephropathy. Against the assumption in the literature, selenium was not protective but a risk factor. Since comparable associations were observed in animals, future studies are needed to explore whether selenium may have adverse renal effects in humans.</p