Theranostic applications of phage display to control leishmaniasis: Selection of biomarkers for serodiagnostics, vaccination, and immunotherapy

© 2015, Sociedade Brasileira de Medicina Tropical. All rights reserved. Phage display is a high-throughput subtractive proteomic technology used for the generation and screening of large peptide and antibody libraries. It is based on the selection of phage-fused surface-exposed peptides that recognize specific ligands and demonstrate desired functionality for diagnostic and therapeutic purposes. Phage display has provided unmatched tools for controlling viral, bacterial, fungal, and parasitic infections, and allowed identification of new therapeutic targets to treat cancer, metabolic diseases, and other chronic conditions. This review presents recent advancements in serodiagnostics and prevention of leishmaniasis -an important tropical parasitic disease- achieved using phage display for the identification of novel antigens with improved sensitivity and specificity. Our focus is on theranostics of visceral leishmaniasis with the aim to develop biomarker candidates exhibiting both diagnostic and therapeutic potential to fight this important, yet neglected, tropical disease.Peer Reviewe

Electrochemical Investigation of Oligonucleotide-DNA Hybridization on Poly(4-Methoxyphenethylamine)

This work describes the immobilization of purine and pyrimidine bases and immobilization/hybridization of synthetic oligonucleotides on graphite electrodes modified with poly(4-methoxyphenethylamine) produced in acid medium. The immobilization of adenine, guanine, cytosine and thymine on these modified electrodes was efficient, producing characteristic peaks. Another relevant observation is that, according to the literature, pyrimidine bases, cytosine and thymine are more difficult to detect. However, when immobilized onto the poly(4-methoxyphenethylamine), a significant increase in the magnitude of the current was obtained. The observation of the hybridization between the poly(GA) probe and its complementary, poly(CT) target, was possible by monitoring the guanosine and adenosine peaks or through methylene blue indicator, using differential pulse voltammetry. Hybridization results in a decrease of the peak current of guanosine and adenosine or the signal of methylene blue accumulated on the modified electrode surface. The hybridization with the complementary target was also investigated by electrochemical impedance spectroscopy. The results showed a significant modification in the Nyquist plot, after addition of the complementary target, with increase of the charge transference resistance

Identification and analysis of seven effector protein families with different adaptive and evolutionary histories in plant-associated members of the Xanthomonadaceae.

The Xanthomonadaceae family consists of species of non-pathogenic and pathogenic γ-proteobacteria that infect different hosts, including humans and plants. In this study, we performed a comparative analysis using 69 fully sequenced genomes belonging to this family, with a focus on identifying proteins enriched in phytopathogens that could explain the lifestyle and the ability to infect plants. Using a computational approach, we identified seven phytopathogen-enriched protein families putatively secreted by type II secretory system: PheA (CM-sec), LipA/LesA, VirK, and four families involved in N-glycan degradation, NixE, NixF, NixL, and FucA1. In silico and phylogenetic analyses of these protein families revealed they all have orthologs in other phytopathogenic or symbiotic bacteria, and are involved in the modulation and evasion of the immune system. As a proof of concept, we performed a biochemical characterization of LipA from Xac306 and verified that the mutant strain lost most of its lipase and esterase activities and displayed reduced virulence in citrus. Since this study includes closely related organisms with distinct lifestyles and highlights proteins directly related to adaptation inside plant tissues, novel approaches might use these proteins as biotechnological targets for disease control, and contribute to our understanding of the coevolution of plant-associated bacteria

A sportomics soccer investigation unveils an exercise-induced shift in tyrosine metabolism leading to hawkinsinuria

Tyrosine metabolism has an intense role in the synthesis of neurotransmitters. Our study used an untargeted, sportomics-based analysis of urine samples to investigate changes in metabolism during a soccer match in 30 male junior professional soccer players. Samples were collected before and after the match and analyzed using liquid chromatography and mass spectrometry. Results showed significant changes in tyrosine metabolism. Exercise caused a downregulation of the homogentisate metabolites 4-maleylacetoacetate and succinylacetone to 20% (p = 4.69E−5) and 16% (p = 4.25E−14), respectively. 4-Hydroxyphenylpyruvate, a homogentisate precursor, was found to be upregulated by 26% (p = 7.20E−3). The concentration of hawkinsin and its metabolite 4-hydroxycyclohexyl acetate increased ~six-fold (p = 1.49E−6 and p = 9.81E−6, respectively). Different DOPA metabolism pathways were also affected by exercise. DOPA and dopaquinone increased four-to six-fold (p = 5.62E−14 and p = 4.98E−13, respectively). 3-Methoxytyrosine, indole-5,6-quinone, and melanin were downregulated from 1 to 25%, as were dopamine and tyramine (decreasing to up to 5% or 80%; p= 5.62E−14 and p = 2.47E−2, respectively). Blood TCO2 decreased as well as urinary glutathione and glutamate (40% and 10% respectively) associated with a two-fold increase in pyroglutamate. Our study found unexpected similarities between exercise-induced changes in metabolism and the inherited disorder Hawkinsinuria, suggesting a possible transient condition called exercise-induced hawkinsinuria (EIh). Additionally, our research suggests changes in DOPA pathways may be involved. Our findings suggest that soccer exercise could be used as a model to search for potential countermeasures in Hawkinsinuria and other tyrosine metabolism disorders

Active regulatory T-cells contribute to broadened T-cell repertoire diversity in ivIg-treated SLE patients

Octapharma

Previous exposure to musical auditory stimulation immediately influences the cardiac autonomic responses to the postural change maneuver in women

Background\ud Chronic exposure to musical auditory stimulation has been reported to improve cardiac autonomic regulation. However, it is not clear if music acutely influences it in response to autonomic tests. We evaluated the acute effects of music on heart rate variability (HRV) responses to the postural change maneuver (PCM) in women.\ud \ud Method\ud We evaluated 12 healthy women between 18 and 28 years old and HRV was analyzed in the time (SDNN, RMSSD, NN50 and pNN50) and frequency (LF, HF and LF/HF ratio) domains. In the control protocol, the women remained at seated rest for 10 minutes and quickly stood up within three seconds and remained standing still for 15 minutes. In the music protocol, the women remained at seated rest for 10 minutes, were exposed to music for 10 minutes and quickly stood up within three seconds and remained standing still for 15 minutes. HRV was recorded at the following time: rest, music (music protocol) 0–5, 5–10 and 10–15 min during standing.\ud \ud Results\ud In the control protocol the SDNN, RMSSD and pNN50 indexes were reduced at 10–15 minutes after the volunteers stood up, while the LF (nu) index was increased at the same moment compared to seated rest. In the protocol with music, the indexes were not different from control but the RMSSD, pNN50 and LF (nu) were different from the music period.\ud \ud Conclusion\ud Musical auditory stimulation attenuates the cardiac autonomic responses to the PCM.This study received financial support from Fundação para o Desenvolvimento da UNESP (FUNDUNESP – Process number 9139213)

The -786T>C promoter polymorphism of the NOS3 gene is associated with prostate cancer progression

<p>Abstract</p> <p>Background</p> <p>There is no biological or epidemiological data on the association between <it>NOS3 </it>promoter polymorphisms and prostate cancer. The polymorphisms in the promoter region of <it>NOS3 </it>gene may be responsible for variations in the plasma NO, which may promote cancer progression by providing a selective growth advantage to tumor cells by angiogenic stimulus and by direct DNA damage.</p> <p>Methods</p> <p>This study aimed evaluating the <it>NOS3 </it>promoter polymorphisms by PCR-SSCP and sequencing, associating genotypes and haplotypes with <it>NOS3 </it>expression levels through semi-quantitative RT-PCR, and with <it>PCA</it>3 mRNA detection, a specific tumor biomarker, in the peripheral blood of pre-surgical samples from 177 patients; 83 PCa and 94 BPH.</p> <p>Results</p> <p>Three novel SNPs were identified -764A>G, -714G>T and -649G>A in the <it>NOS3 </it>gene promoter region, which together with the -786T>C generated four haplotypes (N, T, C, A). <it>NOS3 </it>gene expression levels were affected by the -786T>C polymorphism, and there was a 2-fold increase in <it>NOS3 </it>levels favored by the incorporation of each C allele. <it>NOS3 </it>levels higher than 80% of the constitutive gene expression level (<it>B2M</it>) presented a 4-fold increase in PCa occurrence.</p> <p>Conclusion</p> <p>The -786T>C polymorphism was the most important promoter alteration of the <it>NOS3 </it>gene that may affect the PCa progression, but not its occurrence, and the incorporation of the C allele is associated with increased levels of <it>NOS3 </it>transcripts. The <it>NOS3 </it>transcript levels presented a bimodal behavior in tumor development and may be used as a biomarker together with the <it>PCA3 </it>marker for molecular staging of the prostate cancer.</p

Septic shock in older people: a prospective cohort study

Abstract\ud \ud Background\ud Septic shock is the first cause of death in Intensive Care Units. Despite experimental data showing increased inflammatory response of aged animals following infection, the current accepted hypothesis claims that aged patients are immunocompromised, when compared to young individuals.\ud \ud \ud Results\ud Here, we describe a prospective cohort study designed to analyze the immune profile of this population.\ud \ud \ud Conclusion\ud Older people are as immunocompetent as the young individual, regarding the cytokines, chemokines and growth factors response to devastating infection

Broadened T-cell Repertoire Diversity in ivIg-treated SLE Patients is Also Related to the Individual Status of Regulatory T-cells

Intravenous IgG (ivIg) is a therapeutic alternative for lupus erythematosus, the mechanism of which remains to be fully understood. Here we investigated whether ivIg affects two established sub-phenotypes of SLE, namely relative oligoclonality of circulating T-cells and reduced activity of CD4 + Foxp3+ regulatory T-cells (Tregs) reflected by lower CD25 surface density.Octapharma research funding; Fundação para a Ciência e a Tecnologia postdoctoral fellowships: (SFRH/BPD/20806/2004, SFRH/BPD/34648/2007); FCT Programa Pessoa travel grant