Cell recruitment and cytokines in skin mice sensitized with the vaccine adjuvants: saponin, incomplete Freund's adjuvant, and monophosphoryl lipid A

Vaccine adjuvants are substances associated with antigens that are fundamental to the formation of an intense, durable, and fast immune response. In this context, the use of vaccine adjuvants to generate an effective cellular immune response is crucial for the design and development of vaccines against visceral leishmaniasis. The objective of this study was to evaluate innate inflammatory response induced by the vaccine adjuvants saponin (SAP), incomplete Freund's adjuvant (IFA), and monophosphoryl lipid A (MPL). After a single dose of adjuvant was injected into the skin of mice, we analyzed inflammatory reaction, selective cell migration, and cytokine production at the injection site, and inflammatory cell influx in the peripheral blood. We found that all vaccine adjuvants were able to promote cell recruitment to the site without tissue damage. In addition, they induced selective migration of neutrophils, macrophages, and lymphocytes. The influx of neutrophils was notable at 12 h in all groups, but at other time points it was most evident after inoculation with SAP. With regard to cytokines, the SAP led to production of interleukin (IL)-2, IL-6, and IL-4. IFA promoted production of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-6, IL-17, IL-4, and IL-10. We also observed that MPL induced high production of IL-2, TNF-α, and IFN-γ, in addition to IL-6, IL-17, and IL-10. In peripheral blood, values of certain cell populations in the local response changed after stimulation. Our data demonstrate that the three vaccine adjuvants stimulate the early events of innate immune response at the injection site, suggesting their ability to increase the immunogenicity of co-administered antigens. Moreover, this work provides relevant information about elements of innate and acquired immune response induced by vaccine adjuvants administered alone.     

Diversity of the KIR gene cluster in an urban Brazilian population

The activity of natural killer cells depends on the balance between activating and inhibitory signals coming from their receptors. Among these are the killer cell immunoglobulin-like receptors (KIR) that recognize specific HLA class I allotypes. Here we characterized KIR genetic diversity and their HLA ligands in the population of Curitiba, Paraná State (n = 164), and compared it with other worldwide populations. The distribution of 2DL4 alleles was also analyzed. The Curitiba population did not differ significantly from European and Euro-descendant populations, but as an admixed population showed higher genetic diversity. We found 27 KIR profiles, many of them uncommon in European populations, in agreement with the elevated historically recent gene flow in the study population. The frequencies of KIR genes and their respective HLA ligands were distributed independently and none of the analyzed individuals lacked functional KIR–HLA ligand combinations. KIR gene frequencies of 33 worldwide populations were consistent with geographic and ethnic distribution, in agreement with demography being the major factor shaping the observed gene content diversity of the KIR locus.     

Cell wall polysaccharides from fern leaves: evidence for a mannan-rich Type III cell wall in Adiantum raddianum

Primary cell walls from plants are composites of cellulose tethered by cross-linking glycans and embedded in a matrix of pectins. Cell wall composition varies between plant species, reflecting in some instances the evolutionary distance between them. In this work the monosaccharide compositions of isolated primary cell walls of nine fern species and one lycophyte were characterized and compared with those from Equisetum and an angiosperm dicot. The relatively high abundance of mannose in these plants suggests that mannans may constitute the major cross-linking glycan in the primary walls of pteridophytes and lycophytes. Pectin-related polysaccharides contained mostly rhamnose and uronic acids, indicating the presence of rhamnogalacturonan I highly substituted with galactose and arabinose. Structural and fine-structural analyses of the hemicellulose fraction of leaves of Adiantum raddianum confirmed this hypothesis. Linkage analysis showed that the mannan contains mostly 4-Man with very little 4,6-Man, indicating a low percentage of branching with galactose. Treatment of the mannan-rich fractions with endo-β-mannanase produced characteristic mannan oligosaccharides. Minor amounts of xyloglucan and xylans were also detected. These data and those of others suggest that all vascular plants contain xyloglucans, arabinoxylans, and (gluco)mannans, but in different proportions that define cell wall types. Whereas xyloglucan and pectin-rich walls define Type I walls of dicots and many monocots, arabinoxylans and lower proportion of pectin define the Type II walls of commelinoid monocots. The mannan-rich primary walls with low pectins of many ferns and a lycopod indicate a fundamentally different wall type among land plants, the Type III wall.     

Application of 2D BN/SDS-PAGE coupled with mass spectrometry for identification of VDAC-associated protein complexes related to mitochondrial binding sites for type I brain hexokinase

Two types of binding sites for hexokinase, designated as Type A or Type B sites, have been shown to coexist on brain mitochondria. The ratio of these sites varies between species.HK1 attaches by reversibly binding to the voltage dependent anion channel (VDAC). Regarding the nature of hexokinase binding sites, we investigated if it was linked to distinct VDAC interactomes. We approached this question by 2D BN/SDS-PAGE of mitochondria, followed by mass spectrometry.Our results are consistent with the possibility that the ratio of Type A/Type B sites is due to differential VDAC interactions in bovine and rat neuronal cells.     

Anti-Influenza Neuraminidase Inhibitor Oseltamivir Phosphate Induces Canine Mammary Cancer Cell Aggressiveness

Oseltamivir phosphate is a widely used anti-influenza sialidase inhibitor. Sialylation, governed by sialyltransferases and sialidases, is strongly implicated in the oncogenesis and progression of breast cancer. In this study we evaluated the biological behavior of canine mammary tumor cells upon oseltamivir phosphate treatment (a sialidase inhibitor) in vitro and in vivo. Our in vitro results showed that oseltamivir phosphate impairs sialidase activity leading to increased sialylation in CMA07 and CMT-U27 canine mammary cancer cells. Surprisingly, oseltamivir phosphate stimulated, CMT-U27 cell migration and invasion capacity in vitro, in a dose-dependent manner. CMT-U27 tumors xenograft of oseltamivir phosphate-treated nude mice showed increased sialylation, namely α2,6 terminal structures and SLe(x) expression. Remarkably, a trend towards increased lung metastases was observed in oseltamivir phosphate-treated nude mice. Taken together, our findings revealed that oseltamivir impairs canine mammary cancer cell sialidase activity, altering the sialylation pattern of canine mammary tumors, and leading, surprisingly, to in vitro and in vivo increased mammary tumor aggressiveness.     

Previous Exercise Training Has a Beneficial Effect on Renal and Cardiovascular Function in a Model of Diabetes

Exercise training (ET) is an important intervention for chronic diseases such as diabetes mellitus (DM). However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ)-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA) and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS) were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (p<0.05). Additionally, RSNA was normalized in the trained diabetic and previously trained diabetic animals (p<0.05). The ejection fraction was increased in the previously trained diabetic animals compared with the diabetic and trained diabetic groups (p<0.05), and the myocardial performance index was improved in the previously trained diabetic group compared with the diabetic and trained diabetic groups (p<0.05). In addition, the previously trained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p<0.05). This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ.     

Tyrosine 9 is the key amino acid in microcin J25 superoxide overproduction

Escherichia coli microcin J25 (MccJ25) is a lasso-peptide antibiotic comprising 21 l -amino acid residues (G¹-G-A-G-H⁵-V-P-E-Y-F¹⁰-V-G-I-G-T¹⁵-P-I-S-F-Y²⁰-G). MccJ25 has two independent substrates: RNA-polymerase (RNAP) and the membrane respiratory chain. The latter is mediated by oxygen consumption inhibition together with an increase of superoxide production. In the present paper, the antibiotic MccJ25 was engineered by substituting Tyr⁹ or Tyr²⁰ with phenylalanine. Both mutants were well transported into the cells and remained active on RNAP. Only the Y9F mutant lost the ability to overproduce superoxide and inhibit oxygen consumption. The last results confirm that the Tyr⁹, and not Tyr²⁰, is involved in the MccJ25 action on the respiratory chain target.     

Trypanosoma cruzi IV Causing Outbreaks of Acute Chagas Disease and Infections by Different Haplotypes in the Western Brazilian Amazonia

Background

Chagas disease is an emergent tropical disease in the Brazilian Amazon Region, with an increasing number of cases in recent decades. In this region, the sylvatic cycle of Trypanosoma cruzi transmission, which constitutes a reservoir of parasites that might be associated with specific molecular, epidemiological and clinical traits, has been little explored. The objective of this work is to genetically characterize stocks of T. cruzi from human cases, triatomines and reservoir mammals in the State of Amazonas, in the Western Brazilian Amazon.

Methodology/Principal Findings

We analyzed 96 T. cruzi samples from four municipalities in distant locations of the State of Amazonas. Molecular characterization of isolated parasites from cultures in LIT medium or directly from vectors or whole human blood was performed by PCR of the non-transcribed spacer of the mini-exon and of the 24 S alfa ribosomal RNA gene, RFLP and sequencing of the mitochondrial cytochrome c oxidase subunit II (COII) gene, and by sequencing of the glucose-phosphate isomerase gene. The T. cruzi parasites from two outbreaks of acute disease were all typed as TcIV. One of the outbreaks was triggered by several haplotypes of the same DTU. TcIV also occurred in isolated cases and in Rhodnius robustus. Incongruence between mitochondrial and nuclear phylogenies is likely to be indicative of historical genetic exchange events resulting in mitochondrial introgression between TcIII and TcIV DTUs from Western Brazilian Amazon. TcI predominated among triatomines and was the unique DTU infecting marsupials.

Conclusion/Significance

DTU TcIV, rarely associated with human Chagas disease in other areas of the Amazon basin, is the major strain responsible for the human infections in the Western Brazilian Amazon, occurring in outbreaks as single or mixed infections by different haplotypes.     

Flow through a Collapsible Tube: Experimental Analysis and Mathematical Model

Flow through thin-wall axisymmetric tubes has long been of interest to physiologists. Analysis is complicated by the fact that such tubes will collapse when the transmural pressure (internal minus external pressure) is near zero. Because of the absence of any body of related knowledge in other sciences or engineering, previous workers have directed their efforts towards experimental studies of flow in collapsible tubes. More recently, some attention has been given towards analytical studies. Results of an extensive series of experiments show that the significant system parameter is transmural pressure. The cross-sectional area of the tube depends upon the transmural pressure, and changes in cross-section in turn affect the flow geometry. Based on experimental studies, a lumped parameter system model is proposed for the collapsible tube. The mathematical model is simulated on a hybrid computer. Experimental data were used to define the functional relationship between cross-sectional area and transmural pressure as well as the relation between the energy loss coefficient and cross-sectional area. Computer results confirm the validity of the model for both steady and transient flow conditions.