Immunobiotic lactic acid bacteria beneficially regulate immune response triggered by poly(I:C) in porcine intestinal epithelial cells

ABSTRACT: This study analyzed the functional expression of TLR3 in various gastrointestinal tissues from adult swine and shows that TLR3 is expressed preferentially in intestinal epithelial cells (IEC), CD172a+CD11R1high and CD4+ cells from ileal Peyer's patches. We characterized the inflammatory immune response triggered by TLR3 activation in a clonal porcine intestinal epitheliocyte cell line (PIE cells) and in PIE-immune cell co-cultures, and demonstrated that these systems are valuable tools to study in vitro the immune response triggered by TLR3 on IEC and the interaction between IEC and immune cells. In addition, we selected an immunobiotic lactic acid bacteria strain, Lactobacillus casei MEP221106, able to beneficially regulate the anti-viral immune response triggered by poly(I:C) stimulation in PIE cells. Moreover, we deepened our understanding of the possible mechanisms of immunobiotic action by demonstrating that L. casei MEP221106 modulates the interaction between IEC and immune cells during the generation of a TLR3-mediated immune response.     

Immunobiotic Lactobacillus strains augment NLRP3 expression in newborn and adult porcine gut-associated lymphoid tissues

We isolated cDNA encoding porcine nucleotide-binding domain-like receptor family, pryin domain containing 3 (NLRP3) from Peyer's patches. The complete nucleotide open reading frame of porcine NLRP3 contains 3108-bp encoding a deduced polypeptide of 1036-amino acid residues. The porcine NLRP3 amino acid sequence is more similar to the longest isoform of human than the mouse counterpart. The predicted amino acid sequence of porcine NLRP3 presented nine C-terminal leucine-rich repeat domains. In newborn swine, the expression of NLRP3 was detected at higher levels in spleen and mesenteric lymph nodes, while lower levels were observed in intestinal tissues. In adult swine, NLRP3 was strongly expressed in Peyer's patches and the mesenteric lymph nodes, and the expression level in the lower intestinal tissues was comparable to that in spleen. Toll-like receptor and nucleotide-binding domain ligands, as well as Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus gasseri, enhanced NLRP3 expression in gut-associated lymphoid tissues (GALT) of newborn and adult swine. Our results should aid in understanding the intestinal immunoregulatory mechanisms underlying NLRP3 activation and the priming ability of immunobiotic lactic acid bacteria in porcine GALT.     

The effects of artificial selection on the maize genome

Domestication promotes rapid phenotypic evolution through artificial selection. We investigated the genetic history by which the wild grass teosinte (Zea mays ssp. parviglumis) was domesticated into modern maize (Z. mays ssp. mays). Analysis of single-nucleotide polymorphisms in 774 genes indicates that 2 to 4% of these genes experienced artificial selection. The remaining genes retain evidence of a population bottleneck associated with domestication. Candidate selected genes with putative function in plant growth are clustered near quantitative trait loci that contribute to phenotypic differences between maize and teosinte. If we assume that our sample of genes is representative, approximately 1200 genes throughout the maize genome have been affected by artificial selection.     

An asymmetric energetic type Ic supernova viewed off-axis, and a link to gamma ray bursts

Type Ic supernovae, the explosions after the core collapse of massive stars that have previously lost their hydrogen and helium envelopes, are particularly interesting because of their link with long-duration gamma ray bursts. Although indications exist that these explosions are aspherical, direct evidence has been missing. Late-time observations of supernova SN 2003jd, a luminous type Ic supernova, provide such evidence. Recent Subaru and Keck spectra reveal double-peaked profiles in the nebular lines of neutral oxygen and magnesium. These profiles are different from those of known type Ic supernovae, with or without a gamma ray burst, and they can be understood if SN 2003jd was an aspherical axisymmetric explosion viewed from near the equatorial plane. If SN 2003jd was associated with a gamma ray burst, we missed the burst because it was pointing away from us.     

Cryopreservation of shoot tips of Caryophyllaceae ornamentals

Summary Shoot tips of 5 genera 38 species and cultivars of the Caryophyllaceae ornamentals were cryopreserved. Excised shoot tips were cooled at a rate of 0.5°C/min down to -40°C in the presence of 10% dimethyl sulphoxide and 3% glucose prior to immersion into liquid nitrogen. The shoot tips of all species and cultivars were viable after thawing. Little variation among species was observed in shoot regeneration. High viability of the cryopreserved shoot tips was maintained for up to 4 years. The plants derived from the cryopreserved shoot tips grew and flowered normally.Abbreviations BA 6-benzylaminopurine - DMSO dimethyl sulphoxide - MS Murashige & Skoog - NAA 1-naphtalenacetic acid     

Identification of QTL controlling adventitious root formation during flooding conditions in teosinte (Zea mays ssp. huehuetenangensis) seedlings

Adventitious root formation (ARF) at the soil surface is one of the most important adaptations to soil flooding or waterlogging. Quantitative trait loci (QTL) controlling ARF under flooding condition were identified in a 94 F₂ individual population by crossing maize (Zea mays L., B64) × teosinte (Z. mays ssp. huehuetenangensis). A base-map was constructed using 66 SSR and 42 AFLP markers, covering 1,378 cM throughout all ten maize chromosomes. The ARF capacity for seedlings was determined by evaluating the degree of root formation at the soil surface following flooding for 2 weeks. ARF showed continuous variation in the F₂ population. Interval mapping and composite interval mapping analyses revealed that the QTL for ARF was located on chromosome 8 (bin 8.05). Utilising a selective genotyping strategy with an additional 186 F₂ population derived from the same cross combination and 32 AFLP primer combinations, regions on chromosomes 4 (bin 4.07) and 8 (bin 8.03) were found to be associated with ARF. Z. mays ssp. huehuetenangensis contributed all of the QTL detected in this study. Results of the study suggest a potential for transferring waterlogging tolerance to maize from Z. mays ssp. huehuetenangensis.     

Regulation of interferon regulatory factor-3 by the hepatitis C virus serine protease

Persistent infections with hepatitis C virus (HCV) are likely to depend on viral inhibition of host defenses. We show that the HCV NS3/4A serine protease blocks the phosphorylation and effector action of interferon regulatory factor-3 (IRF-3), a key cellular antiviral signaling molecule. Disruption of NS3/4A protease function by mutation or a ketoamide peptidomimetic inhibitor relieved this blockade and restored IRF-3 phosphorylation after cellular challenge with an unrelated virus. Furthermore, dominant-negative or constitutively active IRF-3 mutants, respectively, enhanced or suppressed HCV RNA replication in hepatoma cells. Thus, the NS3/4A protease represents a dual therapeutic target, the inhibition of which may both block viral replication and restore IRF-3 control of HCV infection.     

Strawberry cultivar identification based on hypervariable SSR markers

We genotyped strawberry cultivars by two newly selected and two previously reported SSR markers. All four markers produced interpretable electropherograms from 75 accessions consisting of 72 Fragaria × ananassa cultivars or lines and three octoploid Fragaria species accessions. These SSR markers were highly polymorphic; in particular, one of the newly developed markers, FxaHGA02P13, was capable of distinguishing all of the accessions except for a mutant strain that was derived from another accession in the set. When two markers were combined, all 48 full-sib individuals could be distinguished. Fingerprinting patterns were reproducible between multiple samples, including the leaves, sepals, and fruit flesh of the same accession. Principal-coordinate analysis of the 75 accessions detected several groups, which reflect taxon and breeding site. Together with other available markers, these SSR markers will contribute to the management of strawberry genetic resources and the protection of breeders’ rights.