Immunohistochemical expression of p53 in breast carcinoma is associated with the intron 1 BglII polymorphism of the p53 gene

Breast carcinoma is a public health problem worldwide. It is known that both genetic and environmental factors are important for breast carcinogenesis and that structural and/or functional alterations at p53 gene are commonly observed in breast tumors. In addition, polymorphisms of several genes in either their coding or non-coding sequences have been found related to cancer risk and/or clinicopathological characteristics of tumors. In this study we have evaluated the intron 1 BglII polymorphism of the p53 gene with a PCR-based approach in 117 cases of breast cancer and 102 healthy women and its association with the immunohistochemical expression of p53 in the tumors. The results showed that the presence of the polymorphism (allele 2) is highly associated with the tumor expression of p53 (p<0.0001) and that there is a trend for increased frequency of allele 2 in cases than in controls (p=0.2376). These data suggest that the germ-line variation in the intron 1 of the p53 gene could produce functional or structural changes of the protein that is reflected by its abnormal expression.     

Recognition of Neisseria meningitidis by the Long Pentraxin PTX3 and Its Role as an Endogenous Adjuvant

Long pentraxin 3 (PTX3) is a non-redundant component of the humoral arm of innate immunity. The present study was designed to investigate the interaction of PTX3 with Neisseria meningitidis. PTX3 bound acapsular meningococcus, Neisseria-derived outer membrane vesicles (OMV) and 3 selected meningococcal antigens (GNA0667, GNA1030 and GNA2091). PTX3-recognized microbial moieties are conserved structures which fulfil essential microbial functions. Ptx3-deficient mice had a lower antibody response in vaccination protocols with OMV and co-administration of PTX3 increased the antibody response, particularly in Ptx3-deficient mice. Administration of PTX3 reduced the bacterial load in infant rats challenged with Neisseria meningitidis. These results suggest that PTX3 recognizes a set of conserved structures from Neisseria meningitidis and acts as an amplifier/endogenous adjuvant of responses to this bacterium.     

High spatial resolution mass spectrometry imaging reveals the genetically programmed,developmental modification of the distribution of thylakoid membrane lipids among individual cells of maize leaf

Metabolism in plants is compartmentalized among different tissues, cells and subcellular organelles. Mass spectrometry imaging (MSI) with matrix‐assisted laser desorption ionization (MALDI) has recently advanced to allow for the visualization of metabolites at single‐cell resolution. Here we applied 5‐ and 10 μm high spatial resolution MALDI‐MSI to the asymmetric Kranz anatomy of Zea mays (maize) leaves to study the differential localization of two major anionic lipids in thylakoid membranes, sulfoquinovosyldiacylglycerols (SQDG) and phosphatidylglycerols (PG). The quantification and localization of SQDG and PG molecular species, among mesophyll (M) and bundle sheath (BS) cells, are compared across the leaf developmental gradient from four maize genotypes (the inbreds B73 and Mo17, and the reciprocal hybrids B73 × Mo17 and Mo17 × B73). SQDG species are uniformly distributed in both photosynthetic cell types, regardless of leaf development or genotype; however, PG shows photosynthetic cell‐specific differential localization depending on the genotype and the fatty acyl chain constituent. Overall, 16:1‐containing PGs primarily contribute to the thylakoid membranes of M cells, whereas BS chloroplasts are mostly composed of 16:0‐containing PGs. Furthermore, PG 32:0 shows genotype‐specific differences in cellular distribution, with preferential localization in BS cells for B73, but more uniform distribution between BS and M cells in Mo17. Maternal inheritance is exhibited within the hybrids, such that the localization of PG 32:0 in B73 × Mo17 is similar to the distribution in the B73 parental inbred, whereas that of Mo17 × B73 resembles the Mo17 parent. This study demonstrates the power of MALDI‐MSI to reveal unprecedented insights on metabolic outcomes in multicellular organisms at single‐cell resolution.     

Age and biostratigraphic significance of the Punung Rainforest Fauna, East Java, Indonesia, and implications for Pongo and Homo

The Punung Fauna is a key component in the biostratigraphic sequence of Java. It represents the most significant faunal turnover on the island in the last 1.5 million years, when Stegodon and other archaic mammal species characteristic of earlier Faunal stages were replaced by a fully modern fauna that included rainforest-dependent species such as Pongo pygmaeus (orangutan). Here, we report the first numerical ages for the Punung Fauna obtained by luminescence and uranium-series dating of the fossil-bearing deposits and associated flowstones. The Punung Fauna contained in the dated breccia is of early Last Interglacial age (between 128+/-15 and 118+/-3 ka). This result has implications for the age of the preceding Ngandong Fauna, including Homo erectus remains found in the Ngandong Terrace, and for the timing of Homo sapiens arrival in Southeast Asia, in view of claims for a modern human tooth associated with the Punung breccia.     

Multimeric HCV E2 protein obtained from <Emphasis Type="Italic">pichia pastoris</Emphasis> cells induces a strong immune response in mice

Production of immunogenic hepatitis C virus (HCV) envelope proteins will assist in the future development of preventive or therapeutics applications. Only properly folded monomeric E2 protein is able to bind a putative cellular co-receptor CD81, but this interaction may modulate cell immune function. Recombinant E2 proteins, similar to the native form, but lacking undesirable immunoregulatory features, might be promising components of vaccine candidates against HCV. To obtain E2 suitable for structural as well as functional studies, a recombinant E2 variant (E2₆₈₀) was produced in Pichia pastoris cells. E2₆₈₀, comprising amino acids 384 to 680 of the HCV polyprotein, was secreted into the culture supernatant in the N-glycosilated form and was mainly composed of disulide-linked multimers. Both monomeric and oligomeric forms of E2₆₈₀ were recognized by conformational-sensitive MAb H53. In addition, antibodies in sera from 70% of HCV-positive patients were reactive against E2₆₈₀. By immunizing E2₆₈₀ in BALB/c mice, both a specific cellular immune response and anti-E2₆₈₀ IgG antibody titers of 1:200,000 were induced. Our data suggest that recombinant E2₆₈₀ could be useful to successfully induce strong anti-HCV immunity.     

HCV core protein localizes in the nuclei of nonparenchymal liver cells from chronically HCV-infected patients

Understanding the mechanism of hepatitis C virus (HCV) pathogenesis is an important part of HCV research. Recent experimental evidence suggests that the HCV core protein (HCcAg) has numerous functional activities. These properties suggest that HCcAg, in concert with cellular factors, may contribute to pathogenesis during persistent HCV infection. HCV is capable of infecting cells other than hepatocytes. Although the extrahepatic cellular tropism of HCV may play a role in the pathophysiology of this infection, the precise biological significance of the presence of HCV components in different liver cell types presently remains to be established. In this study, HCcAg was detected in nonparenchymal liver cells of six patients out of eight positive for serum HCV RNA. Immunostaining with anti-HCcAg mAbs revealed the presence of this protein in different liver cell types such as lymphocytes, Kupffer, polymorphonuclear, pit, endothelial, stellate, and fibroblast-like cells. Interestingly, HCcAg was immunolabeled not only in the cytoplasm but also in the nucleus of these cells. Remarkably, HCcAg co-localized with large lipid droplets present in stellate cells and with collagen fibers in the extracellular matrix. Moreover, HCcAg was immunolabeled in bile canaliculus suggesting the involvement of the biliary system in the pathobiology of HCV. Data suggest that nonparenchymal liver cells may constitute a reservoir for HCV replication. Besides, HCcAg may contribute to modulate immune function and fibrosis in the liver as well as steatosis.     

HCV core protein-expressing DNA vaccine induces a strong class I-binding peptide DTH response in mice

In previous studies, we developed mouse genetic models and discovered genetic components of quantitative trait loci on mouse chromosomes that contribute to phenotypes such as bone size, bone density, and fracture healing. However, these regions contain dozens of genes in several overlapping bacterial artificial chromosomes (BACs) and are difficult to clone by physical cloning strategies. A feasible and efficient approach of identifying candidate genes is to transfer the genomic loci in BAC clones into mammalian cells for functional studies. In this study, we retrofitted a BAC construct into herpes simplex virus-1 amplicon and packaged it into an infectious BAC (iBAC) to test gene function in a cell-based system, using a 128-kb clone containing the complete bone morphogenetic protein-2 (BMP-2) gene. We transduced MC3T3-E1 cells with the iBAC bearing BMP-2 gene and examined transgene expression and function. Our results have demonstrated that an iBAC can efficiently deliver a BMP-2 genomic locus into preosteoblast cells and express functional BMP-2 protein, inducing a phenotype of cell differentiation, as indicated by an increase in alkaline phosphatase activity. Therefore, this experimental system provides a rapid, efficient cell-based model of high-throughput phenotypic screening to identify the BAC clones from physically mapped regions that are important for osteoblast differentiation. It also illustrates the potential of iBAC technology in functional testing of single nucleotide polymorphisms located in the distal promoter or/and intron regions responsible for low bone density.     

A new species of Hyphoderma (Meruliaceae, Polyporales) and its discrimination from closely related taxa

Thirty-five corticioid collections from the Canary Islands and Azores Archipelago were examined morphologically and subjected to molecular phylogenetic analysis. These specimens, almost all collected on endemic and/or xerophilic vegetation, were similar in morphological and ecological characteristics to Hypochnicium prosopidis from the Sonoran Desert (Arizona, USA) and Hyphoderma amoenum. Thirty-seven new ITS nrDNA sequences from these specimens, including the nomenclatural type of the above-mentioned species, were obtained and aligned with homologous sequences from GenBank. These collections were distributed in two strongly supported monophyletic clades. However, similar patterns of morphological variability shared by specimens included in both clades and their differences with related species suggest that they should be described as a single new species. Therefore Hyphoderma macaronesicum is proposed. Studies will be required to test, in a more robust multilocus genealogical framework, whether these populations constitute two cryptic species or whether they are the same taxon. The position of Hypochnicium prosopidis in the resolved tree and its morphological characters suggest that it should be included in Hyphoderma and the new combination Hyphoderma prosopidis is proposed.