Oligoclonal expansions of CD8(+) T cells in chronic HIV infection are antigen specific

Acute HIV infection is associated with a vigorous immune response characterized by the proliferation of selected T cell receptor V beta (BV)-expressing CD8(+) T cells. These 'expansions', which are commonly detected in the peripheral blood, can persist during chronic HIV infection and may result in the dominance of particular clones. Such clonal populations are most consistent with antigen-driven expansions of CD8(+) T cells. However, due to the difficulties in studying antigen-specific T cells in vivo, it has been hard to prove that oligoclonal BV expansions are actually HIV specific. The use of tetrameric major histocompatibility complex-peptide complexes has recently enabled direct visualization of antigen-specific T cells ex vivo but has not provided information on their clonal composition. We have now made use of these tetrameric complexes in conjunction with anti-BV chain-specific monoclonal antibodies and analysis of cytotoxic T lymphocyte lines/clones to show that chronically clonally expanded CD8(+) T cells are HIV specific in vivo

Malaria control under the Taliban regime: insecticide-treated net purchasing, coverage, and usage among men and women in eastern Afghanistan

BACKGROUND: Scaling up insecticide-treated mosquito net (ITN) coverage is a key malaria control strategy even in conflict-affected countries 12. Socio-economic factors influence access to ITNs whether subsidized or provided free to users. This study examines reported ITN purchasing, coverage, and usage in eastern Afghanistan and explores women's access to health information during the Taliban regime (1996-2001). This strengthens the knowledge base on household-level health choices in complex-emergency settings. METHODS: Fifteen focus group discussions (FGDs) and thirty in-depth interviews were conducted with men and women from ITN-owning and non-owning households. FGDs included rank ordering, pile sorting and focused discussion of malaria knowledge and ITN purchasing. Interviews explored general health issues, prevention and treatment practices, and women's malaria knowledge and concerns. Seven key informant interviews with health-related workers and a concurrent survey of 200 ITN-owning and 214 non-owning households were used to clarify or quantify findings. RESULTS: Malaria knowledge was similar among men and women and ITN owners and non-owners. Women reported obtaining health information through a variety of sources including clinic staff, their husbands who had easier access to information, and particularly female peers. Most participants considered ITNs very desirable, though not usually household necessities. ITN owners reported more household assets than non-owners. Male ITN owners and non-owners ranked rugs and ITNs as most desired, while women ranked personal assets such as jewellery highest. While men were primarily responsible for household decision-making and purchasing, older women exerted considerable influence. Widow-led and landless households reported most difficulties purchasing ITNs. Most participants wanted to buy ITNs only if they could cover all household members. When not possible, preferential usage was given to women and children. CONCLUSIONS: Despite restricted access to health facilities and formal education, Afghan women were surprisingly knowledgeable about the causes of malaria and the value of ITNs in prevention. Inequities in ITN usage were noted between rather than within households, with some unable to afford even one ITN and others not wanting ITNs unless all household members could be protected. Malaria knowledge thus appears a lesser barrier to ITN purchasing and coverage in eastern Afghanistan than are pricing and distribution strategies

Role of the PAS sensor domains in the Bacillus subtilis sporulation kinase KinA

Histidine kinases are sophisticated molecular sensors that are used by bacteria to detect and respond to a multitude of environmental signals. KinA is the major histidine kinase required for initiation of sporulation upon nutrient deprivation in Bacillus subtilis. KinA has a large N-terminal region (residues 1 to 382) that is uniquely composed of three tandem Per-ARNT-Sim (PAS) domains that have been proposed to constitute a sensor module. To further enhance our understanding of this "sensor" region, we defined the boundaries that give rise to the minimal autonomously folded PAS domains and analyzed their homo- and heteroassociation properties using analytical ultracentrifugation, nuclear magnetic resonance (NMR) spectroscopy, and multiangle laser light scattering. We show that PAS(A) self-associates very weakly, while PAS(C) is primarily a monomer. In contrast, PAS(B) forms a stable dimer (K-d [dissociation constant] o

Bicistronic Lentiviruses Containing a Viral 2A Cleavage Sequence Reliably Co-Express Two Proteins and Restore Vision to an Animal Model of LCA1

The disease processes underlying inherited retinal disease are complex and are not completely understood. Many of the corrective gene therapies designed to treat diseases linked to mutations in genes specifically expressed in photoreceptor cells restore function to these cells but fail to stop progression of the disease. There is growing consensus that effective treatments for these diseases will require delivery of multiple therapeutic proteins that will be selected to treat specific aspects of the disease process. The purpose of this study was to design a lentiviral transgene that reliably expresses all of the proteins it encodes and does so in a consistent manner among infected cells. We show, using both in vitro and in vivo analyses, that bicistronic lentiviral transgenes encoding two fluorescent proteins fused to a viral 2A-like cleavage peptide meet these expression criteria. To determine if this transgene design is suitable for therapeutic applications, we replaced one of the fluorescent protein genes with the gene encoding guanylate cyclase -1 (GC1) and delivered lentivirus carrying this transgene to the retinas of the GUCY1*B avian model of Leber congenital amaurosis – 1 (LCA1). GUCY1*B chickens carry a null mutation in the GC1 gene that disrupts photoreceptor function and causes blindness at hatching, a phenotype that closely matches that observed in humans with LCA1. We found that treatment of these animals with the 2A lentivector encoding GC1 restored vision to these animals as evidenced by the presence of optokinetic reflexes. We conclude that 2A-like peptides, with proper optimization, can be successfully incorporated into therapeutic vectors designed to deliver multiple proteins to neural retinal. These results highlight the potential of this vector design to serve as a platform for the development of combination therapies designed to enhance or prolong the benefits of corrective gene therapies

Protocol for: Sheffield Obesity Trial (SHOT): A randomised controlled trial of exercise therapy and mental health outcomes in obese adolescents [ISRCNT83888112]

Background While obesity is known to have many physiological consequences, the psychopathology of this condition has not featured prominently in the literature. Cross-sectional studies have indicated that obese children have increased odds of experiencing poor quality of life and mental health. However, very limited trial evidence has examined the efficacy of exercise therapy for enhancing mental health outcomes in obese children, and the Sheffield Obesity Trial (SHOT) will provide evidence of the efficacy of supervised exercise therapy in obese young people aged 11–16 years versus usual care and an attention-control intervention. Method/design SHOT is a randomised controlled trial where obese young people are randomised to receive; (1) exercise therapy, (2) attention-control intervention (involving body-conditioning exercises and games that do not involve aerobic activity), or (3) usual care. The exercise therapy and attention-control sessions will take place three times per week for eight weeks and a six-week home programme will follow this. Ninety adolescents aged between 11–16 years referred from a children's hospital for evaluation of obesity or via community advertisements will need to complete the study. Participants will be recruited according to the following criteria: (1) clinically obese and aged 11–16 years (Body Mass Index Centile > 98th UK standard) (2) no medical condition that would restrict ability to be active three times per week for eight weeks and (3) not diagnosed with insulin dependent diabetes or receiving oral steroids. Assessments of outcomes will take place at baseline, as well as four (intervention midpoint) and eight weeks (end of intervention) from baseline. Participants will be reassessed on outcome measures five and seven months from baseline. The primary endpoint is physical self-perceptions. Secondary outcomes include physical activity, self-perceptions, depression, affect, aerobic fitness and BMI

CD26/dipeptidyl peptidase IV (CD26/DPPIV) is highly expressed in peripheral blood of HIV-1 exposed uninfected Female sex workers

<p>Abstract</p> <p>Background</p> <p>Design of effective vaccines against the human immunodeficiency virus (HIV-1) continues to present formidable challenges. However, individuals who are exposed HIV-1 but do not get infected may reveal correlates of protection that may inform on effective vaccine design. A preliminary gene expression analysis of HIV resistant female sex workers (HIV-R) suggested a high expression CD26/DPPIV gene. Previous studies have indicated an anti-HIV effect of high CD26/DPPIV expressing cells in vitro. Similarly, high CD26/DPPIV protein levels in vivo have been shown to be a risk factor for type 2 diabetes. We carried out a study to confirm if the high CD26/DPPIV gene expression among the HIV-R were concordant with high blood protein levels and its correlation with clinical type 2 diabetes and other perturbations in the insulin signaling pathway.</p> <p>Results</p> <p>A quantitative CD26/DPPIV plasma analysis from 100 HIV-R, 100 HIV infected (HIV +) and 100 HIV negative controls (HIV Neg) showed a significantly elevated CD26/DPPIV concentration among the HIV-R group (mean 1315 ng/ml) than the HIV Neg (910 ng/ml) and HIV + (870 ng/ml, p < 0.001). Similarly a FACs analysis of cell associated DPPIV (CD26) revealed a higher CD26/DPPIV expression on CD4+ T-cells derived from HIV-R than from the HIV+ (90.30% vs 80.90 p = 0.002) and HIV Neg controls (90.30% vs 82.30 p < 0.001) respectively. A further comparison of the mean fluorescent intensity (MFI) of CD26/DPPIV expression showed a higher DPP4 MFI on HIV-R CD4+ T cells (median 118 vs 91 for HIV-Neg, p = 0.0003). An evaluation for hyperglycemia, did not confirm Type 2 diabetes but an impaired fasting glucose condition (5.775 mmol/L). A follow-up quantitative PCR analysis of the insulin signaling pathway genes showed a down expression of NFκB, a central mediator of the immune response and activator of HIV-1 transcription.</p> <p>Conclusion</p> <p>HIV resistant sex workers have a high expression of CD26/DPPIV in tandem with lowered immune activation markers. This may suggest a novel role for CD26/DPPIV in protection against HIV infection in vivo.</p

Transport of glutamine into the xylem of sunflower (Helianthus annuus).

Sunflower (Helianthus annuus L.) plants were grown on nutrient solution with ammonium nitrogen. After 12 days of growth the ammonium in the nutrient solution was labeled with N (99%). Three hours later glutamine-N in the xylem exudate was labeled for 56% as shown by GC-MS; this percentage increased to 63% after 8, and to 69% after 24 hours of incubation. When the xylem exudate had been collected from the epicotyl instead of the hypocotyl, 15-N abundances were 52%, 56% and 63% respectively. Results are consistent with an import of glutamine into the transpiration stream during its ascension in the xylem. On basis of the differences in abundance of double-labeled, single-labeled and unlabeled glutamine between the two sampling sites it was estimated that at least 20% of the xylem glutamine was imported into xylem along this distance (~4cm)

Sex-differential impact of human cytomegalovirus infection on in vitro reactivity to toll-like receptor 2, 4 and 7/8 stimulation in Gambian infants

Human cytomegalovirus (HCMV) infection rates approach 100% by the first year of lifein low-income countries. It is not known if this drives changes to innate immunity in early life andthereby altered immune reactivity to infections and vaccines. Given the panoply of sex differences inimmunity, it is feasible that any immunological effects of HCMV would differ in males and females.We analysed ex vivo innate cytokine responses to a panel of toll-like receptor (TLR) ligands in 108nine-month-old Gambian males and females participating in a vaccine trial. We found evidencethat HCMV suppressed reactivity to TLR2 and TLR7/8 stimulation in females but not males. Thisis likely to contribute to sex differences in responses to infections and vaccines in early life and hasimplications for the development of TLR ligands as vaccine adjuvants. Development of an effectiveHCMV vaccine would be able to circumvent some of these potentially negative effects of HCMVinfection in childhood