Assistance of microbial glycolipid antigen processing by CD1e

Complexes between CD1 molecules and self or microbial glycolipids represent important immunogenic ligands for specific subsets of T cells. However, the function of one of the CD1 family members, CD1e, has yet to be determined. Here, we show that the mycobacterial antigens hexamannosylated phosphatidyl-myo-inositols (PIM6) stimulate CD1b-restricted T cells only after partial digestion of the oligomannose moiety by lysosomal alpha-mannosidase and that soluble CD1e is required for this processing. Furthermore, recombinant CD1e was able to bind glycolipids and assist in the digestion of PIM6. We propose that, through this form of glycolipid editing, CD1e helps expand the repertoire of glycolipidic T cell antigens to optimize antimicrobial immune responses.     

Role of a highly conserved bacterial protein in outer membrane protein assembly

After transport across the cytoplasmic membrane, bacterial outer membrane proteins are assembled into the outer membrane. Meningococcal Omp85 is a highly conserved protein in Gram-negative bacteria, and its homolog Toc75 is a component of the chloroplast protein-import machinery. Omp85 appeared to be essential for viability, and unassembled forms of various outer membrane proteins accumulated upon Omp85 depletion. Immunofluorescence microscopy revealed decreased surface exposure of outer membrane proteins, which was particularly apparent at the cell-division planes. Thus, Omp85 is likely to play a role in outer membrane protein assembly.     

Effect of Phosphorus and Arbuscular Mycorrhizal Fungi (AMF) Inoculation on Growth and Productivity of Maize (Zea mays L.) in a Tropical Ferralsol

Soil fertility in the Lubumbashi region often proves to be limiting factor for crop production due to their low nutrient reserves. The objective of this work was to evaluate the impact of arbuscular mycorrhizae on phosphorus uptake by maize on Ferralsol. The trial was conducted in pots with 30?kg or 60?kg of P₂O₅ ha^?1 and a control. These three levels of phosphorus were combined or not with arbuscular mycorrhizae. The combinations of 30?kg or 60?kg of phosphorus with the inoculum led to a male flowering of maize at 63 days after semi. Maize treated with 60?kg of phosphorus ha^?1 formed very few or almost no blisters in the roots. Cob weight, length, diameter, number of rows and kernel weight varied significantly with phosphorus on both inoculated and uninoculated pots. The inoculated plants had high averages for these yield parameters. Due to the lack of phosphate fertilizer, inoculum alone can be an alternative to phosphorus provided that nitrogen and potassium are added, resulting in small but seed-filled ears compared to the phosphorus-free control without mycorrhizae, which resulted in empty ears. Yield varied significantly with the addition of phosphorus (0.3 to 6.1 tons ha^?1) and less significantly with inoculum (3 to 3.7?t ha^?1). The combination of treatments showed a significant difference in favour of the 60?kg of phosphorus or 60?kg of phosphorus associated with the inoculum. The highest phosphorus content was obtained on the inoculum treatment alone, which provided 1.4?mg phosphorus?g^?1 maize compared to other treatments, which provided 0.69 to 0.71?mg phosphorus?g^?1 maize.

     

Framework for intake simulation of functional ingredients

OBJECTIVE: To create a general framework for the simulation of intakes from mandatory or voluntary fortification, which will make outcomes of simulation studies more comparable and give insight on uncertainties. DESIGN: A general framework was developed based on methods used in already published case studies of mandatory fortification. The framework was extended to be suitable for the simulation of voluntary fortification. Case studies of folic acid fortification were used to illustrate the general framework. RESULTS: The developed framework consists of six steps. First, the definition of the fortification strategy (step 1), followed by the identification of potential carrier products (step 2), and the definition of fortification levels or ranges (step 3). Thereafter, virtual food/supplement composition data are created (step 4) and food/supplement consumption data are required (step 5). Finally, the intake of the functional ingredient from functional foods, other foods and dietary supplements is calculated during the simulation resulting in total habitual intake distributions (step 6). CONCLUSIONS: Simulation of both mandatory and voluntary folic acid fortification in The Netherlands showed that the general framework is applicable. Also with incomplete data or data from different sources, the (habitual) intake distributions can be estimated using assumptions, statistical procedures or probabilistic modelling approaches. It is important that the simulation procedure is described well, so that an insight on uncertainties and knowledge gaps to be filled is given.     

Use of a commercial protease and yeasts to obtain CGRP-like molecules from saithe protein

Different bioactive molecules, such as CGRP-like peptides, can be found in fish protein hydrolysates. Calcitonin gene-related peptide (CGRP) is a neuropeptide known to act as a potent arterial and venous vasodilator in humans. This study focuses on the industrial obtaining of CGRP-like molecules from saithe (Pollachius virens) byproduct, derived from the filleting process. Protein from P. virens was primarily hydrolyzed with Alcalase and later treated with Saccharomyces cerevisiae live cells. Treatment with Saccharomyces doubled the quantity of bioactive molecules obtained. The CGRP-like molecules were partially purified by chromatography, and the immunoreactive material was further analyzed for its CGRP-like bioactivity, using a specific radioreceptor assay. The concentration of CGRP-like molecules increased over 100-fold after purification. The bioactive molecules were able to induce cyclic AMP stimulation in rat liver membranes. Finally, partial sequencing of the bioactive peptide was performed, showing some homology with alpha-actin and myosin of several fish species.     

Chimpanzee reservoirs of pandemic and nonpandemic HIV-1

Human immunodeficiency virus type 1 (HIV-1), the cause of human acquired immunodeficiency syndrome (AIDS), is a zoonotic infection of staggering proportions and social impact. Yet uncertainty persists regarding its natural reservoir. The virus most closely related to HIV-1 is a simian immunodeficiency virus (SIV) thus far identified only in captive members of the chimpanzee subspecies Pan troglodytes troglodytes. Here we report the detection of SIVcpz antibodies and nucleic acids in fecal samples from wild-living P. t. troglodytes apes in southern Cameroon, where prevalence rates in some communities reached 29 to 35%. By sequence analysis of endemic SIVcpz strains, we could trace the origins of pandemic (group M) and nonpandemic (group N) HIV-1 to distinct, geographically isolated chimpanzee communities. These findings establish P. t. troglodytes as a natural reservoir of HIV-1.     

Effect of Small and Large Wheat Starch Granules on Thermomechanical Behavior of Starch

The physicochemical properties of small‐ and large‐granule wheat starches were investigated to reveal whether gelatinization properties and rheological behavior differ between size classes of wheat starch. All samples contained 60% water (w/w, wb). The starch granule size and shape were examined by scanning electron microscopy in the separated A‐ and B‐type granule populations and in the whole wheat starch granule population. Differential scanning calorimetry (DSC) and electron spin resonance (ESR) analyses were performed in parallel with rheological measurements using dynamic mechanical thermal analysis (DMTA) to relate the viscoelastic changes to modifications in dynamic properties of aqueous solutions and structural disorganization of starch. The small (B‐type) granules had slightly higher gelatinization temperature and lower gelatinization enthalpy than did the large (A‐type) granules. Also, B‐type granules had higher enthalpy for the amylose‐lipid complex transition. Moreover, our results suggested that small granules have higher affinity for water at room temperature. It seems that there is a less ordered arrangement of the polysaccharide chains in the smaller granules when compared with the larger ones. These differences in functional properties of small and large granules suggested that the granule size distribution is an important parameter in the baking process.