HLA-DR+ CD38+ CD4+ T lymphocytes have elevated CCR5 expression and produce the majority of R5-tropic HIV-1 RNA in vivo

Percentages of activated T cells correlate with HIV-1 disease progression, but the underlying mechanisms are not fully understood. We hypothesized that HLA-DR(+) CD38(+) (DR(+) 38(+)) CD4(+) T cells produce the majority of HIV-1 due to elevated expression of CCR5 and CXCR4. In phytohemagglutinin (PHA)-stimulated CD8-depleted peripheral blood mononuclear cells (PBMC) infected with HIV-1 green fluorescent protein (GFP) reporter viruses, DR(-) 38(+) T cells constituted the majority of CCR5 (R5)-tropic (median, 62%) and CXCR4 (X4)-tropic HIV-1-producing cells (median, 61%), although cell surface CCR5 and CXCR4 were not elevated in this subset of cells. In lymph nodes from untreated individuals infected with R5-tropic HIV-1, percentages of CCR5(+) cells were elevated in DR(+) 38(+) CD4(+) T cells (median, 36.4%) compared to other CD4(+) T-cell subsets (median values of 5.7% for DR(-) 38(-) cells, 19.4% for DR(+) 38(-) cells, and 7.6% for DR(-) 38(+) cells; n = 18; P < 0.001). In sorted CD8(-) lymph node T cells, median HIV-1 RNA copies/10(5) cells was higher for DR(+) 38(+) cells (1.8 × 10(6)) than for DR(-) 38(-) (0.007 × 10(6)), DR(-) 38(+) (0.064 × 10(6)), and DR(+) 38(-) (0.18 × 10(6)) subsets (n = 8; P < 0.001 for all). After adjusting for percentages of subsets, a median of 87% of viral RNA was harbored by DR(+) 38(+) cells. Percentages of CCR5(+) CD4(+) T cells and concentrations of CCR5 molecules among subsets predicted HIV-1 RNA levels among CD8(-) DR/38 subsets (P < 0.001 for both). Median HIV-1 DNA copies/10(5) cells was higher in DR(+) 38(+) cells (5,360) than in the DR(-) 38(-) (906), DR(-) 38(+) (814), and DR(+) 38(-) (1,984) subsets (n = 7; P ≤ 0.031). Thus, DR(+) 38(+) CD4(+) T cells in lymph nodes have elevated CCR5 expression, are highly susceptible to infection with R5-tropic virus, and produce the majority of R5-tropic HIV-1. PBMC assays failed to recapitulate in vivo findings, suggesting limited utility. Strategies to reduce numbers of DR(+) 38(+) CD4(+) T cells may substantially inhibit HIV-1 replication.     

The Mediterranean Sea under siege: spatial overlap between marine biodiversity,cumulative threats and marine reserves

Aim A large body of knowledge exists on individual anthropogenic threats that have an impact on marine biodiversity in the Mediterranean Sea, although we know little about how these threats accumulate and interact to affect marine species and ecosystems. In this context, we aimed to identify the main areas where the interaction between marine biodiversity and threats is more pronounced and to assess their spatial overlap with current marine protected areas in the Mediterranean. Location Mediterranean Sea. Methods We first identified areas of high biodiversity of marine mammals, marine turtles, seabirds, fishes and commercial or well‐documented invertebrates. We mapped potential areas of high threat where multiple threats are occurring simultaneously. Finally we quantified the areas of conservation concern for biodiversity by looking at the spatial overlap between high biodiversity and high cumulative threats, and we assessed the overlap with protected areas. Results Our results show that areas with high marine biodiversity in the Mediterranean Sea are mainly located along the central and north shores, with lower values in the south‐eastern regions. Areas of potential high cumulative threats are widespread in both the western and eastern basins, with fewer areas located in the south‐eastern region. The interaction between areas of high biodiversity and threats for invertebrates, fishes and large animals in general (including large fishes, marine mammals, marine turtles and seabirds) is concentrated in the coastal areas of Spain, Gulf of Lions, north‐eastern Ligurian Sea, Adriatic Sea, Aegean Sea, south‐eastern Turkey and regions surrounding the Nile Delta and north‐west African coasts. Areas of concern are larger for marine mammal and seabird species. Main conclusions These areas may represent good candidates for further research, management and protection activities, since there is only a maximum 2% overlap between existing marine protected areas (which cover 5% of the Mediterranean Sea) and our predicted areas of conservation concern for biodiversity.     

Rapid Isolation of Extracellular Vesicles from Cell Culture and Biological Fluids Using a Synthetic Peptide with Specific Affinity for Heat Shock Proteins

Recent studies indicate that extracellular vesicles are an important source material for many clinical applications, including minimally-invasive disease diagnosis. However, challenges for rapid and simple extracellular vesicle collection have hindered their application. We have developed and validated a novel class of peptides (which we named venceremin, or Vn) that exhibit nucleotide-independent specific affinity for canonical heat shock proteins. The Vn peptides were validated to specifically and efficiently capture HSP-containing extracellular vesicles from cell culture growth media, plasma, and urine by electron microscopy, atomic force microscopy, sequencing of nucleic acid cargo, proteomic profiling, immunoblotting, and nanoparticle tracking analysis. All of these analyses confirmed the material captured by the Vn peptides was comparable to those purified by the standard ultracentrifugation method. We show that the Vn peptides are a useful tool for the rapid isolation of extracellular vesicles using standard laboratory equipment. Moreover, the Vn peptides are adaptable to diverse platforms and therefore represent an excellent solution to the challenge of extracellular vesicle isolation for research and clinical applications.     

Identifying Elements of Patient-Centered Care in Underserved Populations: A Qualitative Study of Patient Perspectives

Patient-centered care is an important goal in the delivery of healthcare. However, many patients do not engage in preventive medical care. In this pilot study, we conducted twenty in depth, semi-structured qualitative interviews at the University of Illinois at Chicago Health Sciences campus in a four month time frame. Many patients were underserved and underinsured, and we wanted to understand their experiences in the healthcare system. Using content analysis, several themes emerged from the interview data. Participants discussed the need for empathy and rapport with their providers. They identified provider behaviors that fostered a positive clinical relationship, including step-by step explanations of procedures, attention to body language and clinic atmosphere, and appropriate time management. Participants identified cost as the most common barrier to engaging in preventive care and discussed children and social support as motivating factors. A long-term relationship with a provider was an important motivator for preventive care, suggesting that the therapeutic alliance was essential to many patients. Conversely, many participants discussed a sense of dehumanization in the healthcare system, reporting that their life circumstances were overlooked, or that they were judged based on insurance status or ethnicity. We discuss implications for provider training and healthcare delivery, including the importance of patient-centered medical homes.     

Circulating ceramides are inversely associated with cardiorespiratory fitness in participants aged 54–96 years from the Baltimore Longitudinal Study of Aging

Cardiorespiratory fitness (VO₂ peak) declines with age and is an independent risk factor for morbidity and mortality in older adults. Identifying biomarkers of low fitness may provide insight for why some individuals experience an accelerated decline of aerobic capacity and may serve as clinically valuable prognostic indicators of cardiovascular health. We investigated the relationship between circulating ceramides and VO₂ peak in 443 men and women (mean age of 69) enrolled in the Baltimore Longitudinal Study of Aging (BLSA). Individual species of ceramide were quantified by HPLC–tandem mass spectrometry. VO₂ peak was measured by a graded treadmill test. We applied multiple regression models to test the associations between ceramide species and VO₂ peak, while adjusting for age, sex, blood pressure, serum LDL, HDL, triglycerides, and other covariates. We found that higher levels of circulating C18:0, C20:0, C24:1 ceramides and C20:0 dihydroceramides were strongly associated with lower aerobic capacity (P < 0.001, P < 0.001, P = 0.018, and P < 0.001, respectively). The associations held true for both sexes (with men having a stronger association than women, P value for sex interaction <0.05) and were unchanged after adjusting for confounders and multiple comparison correction. Interestingly, no significant association was found for C16:0, C22:0, C24:0, C26:0, and C22:1 ceramide species, C24:0 dihydroceramide, or total ceramides. Our analysis reveals that specific long‐chain ceramides strongly associate with low cardiovascular fitness in older adults and may be implicated in the pathogenesis of low fitness with aging. Longitudinal studies are needed to further validate these associations and investigate the relationship between ceramides and health outcomes.     

Decline of FoxP3+ Regulatory CD4 T Cells in Peripheral Blood of Children Heavily Exposed to Malaria

FoxP3+ regulatory CD4 T cells (T_regs) help to maintain the delicate balance between pathogen-specific immunity and immune-mediated pathology. Prior studies suggest that T_regs are induced by P. falciparum both in vivo and in vitro; however, the factors influencing T_reg homeostasis during acute and chronic infections, and their role in malaria immunopathogenesis, remain unclear. We assessed the frequency and phenotype of T_regs in well-characterized cohorts of children residing in a region of high malaria endemicity in Uganda. We found that both the frequency and absolute numbers of FoxP3+ T_regs in peripheral blood declined markedly with increasing prior malaria incidence. Longitudinal measurements confirmed that this decline occurred only among highly malaria-exposed children. The decline of T_regs from peripheral blood was accompanied by reduced in vitro induction of T_regs by parasite antigen and decreased expression of TNFR2 on T_regs among children who had intense prior exposure to malaria. While T_reg frequencies were not associated with protection from malaria, there was a trend toward reduced risk of symptomatic malaria once infected with P. falciparum among children with lower T_reg frequencies. These data demonstrate that chronic malaria exposure results in altered T_reg homeostasis, which may impact the development of antimalarial immunity in naturally exposed populations.     

Integrated Proteomics Identified Up-Regulated Focal Adhesion-Mediated Proteins in Human Squamous Cell Carcinoma in an Orthotopic Murine Model

Understanding the molecular mechanisms of oral carcinogenesis will yield important advances in diagnostics, prognostics, effective treatment, and outcome of oral cancer. Hence, in this study we have investigated the proteomic and peptidomic profiles by combining an orthotopic murine model of oral squamous cell carcinoma (OSCC), mass spectrometry-based proteomics and biological network analysis. Our results indicated the up-regulation of proteins involved in actin cytoskeleton organization and cell-cell junction assembly events and their expression was validated in human OSCC tissues. In addition, the functional relevance of talin-1 in OSCC adhesion, migration and invasion was demonstrated. Taken together, this study identified specific processes deregulated in oral cancer and provided novel refined OSCC-targeting molecules.     

Does polyandry control population sex ratio via regulation of a selfish gene?

The extent of female multiple mating (polyandry) can strongly impact on the intensity of sexual selection, sexual conflict, and the evolution of cooperation and sociality. More subtly, polyandry may protect populations against intragenomic conflicts that result from the invasion of deleterious selfish genetic elements (SGEs). SGEs commonly impair sperm production, and so are likely to be unsuccessful in sperm competition, potentially reducing their transmission in polyandrous populations. Here, we test this prediction in nature. We demonstrate a heritable latitudinal cline in the degree of polyandry in the fruitfly Drosophila pseudoobscura across the USA, with northern population females remating more frequently in both the field and the laboratory. High remating was associated with low frequency of a sex-ratio-distorting meiotic driver in natural populations. In the laboratory, polyandry directly controls the frequency of the driver by undermining its transmission. Hence we suggest that the cline in polyandry represents an important contributor to the cline in sex ratio in nature. Furthermore, as the meiotic driver causes sex ratio bias, variation in polyandry may ultimately determine population sex ratio across the USA, a dramatic impact of female mating decisions. As SGEs are ubiquitous it is likely that the reduction of intragenomic conflict by polyandry is widespread.