A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

EPR study of the oxidation reaction of nickel(0) phosphine complexes with Lewis and Brønsted acids

The oxidation of Ni(PPh₃)₄ with BF₃ · OEt₂, H₃CCOOH, and F₃CCOOH, and that of (PPh₃)₂Ni(C₂H₄) with BF₃ · OEt₂ is studied by EPR spectroscopy. The reaction of the Ni(0) complexes with BF₃ · OEt₂ gives Ni(II) complexes with which they react to form Ni(I) compounds with covalent Ni-F and Ni-B bonds that transform with excess BF₃ · OEt₂ into cationic paramagnetic Ni(I) complexes. Acetic acid also adds oxidatively to Ni(PPh₃)₄ to form a Ni(II) complex that reacts further to give Ni(I) hydride and carboxylate complexes. The Ni(I) hydride is transformed by the acid into the Ni(I) carboxylate with release of hydrogen, the amount of which depends on the rate of acid addition. The following Ni(I) complexes are identified in the reaction medium: [Ni(PPh₃)₃]BF₄, [(PPh₃)₂Ni(OEt₂)]BF₄, [(PPh₃)Ni(OEt₂)_n]BF₄, (PPh₃)₂NiBF₂, (PPh₃)₃NiOOCCH₃, and [(PPh₃)₂Ni(OEt₂)P(OEt)₃]BF₄. Oxidation schemes of Ni(0) complexes by Lewis and Brønsted acids are given.     

Molecular genetic characterization of H5N1 influenza virus strains isolated from poultry in the Kurgan region in 2005

In the second half of 2005, a large-scale outbreak of influenza in poultry and wild birds was caused by a highly pathogenic H5N1 influenza virus in Russia. The level of pathogenicity is a polygenic trait, and most individual genes contribute to the influenza A virus pathogenicity in birds, animals, and humans. The full-length nucleotide sequences were determined for H5N1 strains isolated in the Kurgan region (Western Siberia). The structure of viral proteins was analyzed using the deduced amino acid sequences. The receptor-binding site of hemagglutinin (HA) in strains A/chicken/Kurgan/05/2005 and A/duck/Kurgan/08/2005 was typical for avian influenza viruses and contained Glu and Gly at positions 226 and 228, respectively. The structure of the basic amino acid cluster located within the HA cleavage site was identical in all isolates: QGERRRKKR. According to the neuraminidase structure, all H5N1 isolates from the Kurgan region were assigned to the Z genotype. Amino acid residues typical for the avian influenza virus were revealed in 30 out of 32 positions of M1, M2, NP, PA, and PB2, determining the host range specificity. One of the strains contained Lys at position 627 of PB2. Isolates from the Kurgan region were shown to have a remantadine-sensitive genotype. Both strains contained Glu at position 92 of NS1, indicating that the virus is interferon-resistant. Phylogenetic analysis related the Kurgan isolates to subclade 2 of clade 2 of highly pathogenic H5N1 influenza viruses.     

Association of gene polymorphisms of matrix metalloproteinases with reproductive losses in the first trimester of pregnancy

In the present study, the frequencies of genotypes and alleles of candidate genes with respect to polymorphisms associated with increased pregnancy loss in the first trimester of pregnancy, including MMP1–1607insG, MMP9 A–8202G, and TIMP1 С536T, were reported. The frequency of homozygotes for allele MMP9 A–8202 was increased by a factor of two among women with miscarriage in the first trimester compared to the control. Significant models of interaction of genes MMPs and TIMP1 were revealed. The genotypes of genes MMP1 (rs1799750), MMP9 (rs11697325), and TIMP1 (rs11551797) increasing the risk of pregnancy loss in the first trimester were determined.     

Identification of signature and primers specific to genus <Emphasis Type="Italic">Pseudomonas</Emphasis> using mismatched patterns of 16S rDNA sequences

Background

Pseudomonas, a soil bacterium, has been observed as a dominant genus that survives in different habitats with wide hostile conditions. We had a basic assumption that the species level variation in 16S rDNA sequences of a bacterial genus is mainly due to substitutions rather than insertion or deletion of bases. Keeping this in view, the aim was to identify a region of 16S rDNA sequence and within that focus on substitution prone stretches indicating species level variation and to derive patterns from these stretches that are specific to the genus.

Results

Repeating elements that are highly conserved across different species of Pseudomonas were considered as guiding markers to locate a region within the 16S gene. Four repeating patterns showing more than 80% consistency across fifty different species of Pseudomonas were identified. The sub-sequences between the repeating patterns yielded a continuous region of 495 bases. The sub-sequences after alignment and using Shanon's entropy measure yielded a consensus pattern. A stretch of 24 base positions in this region, showing maximum variations across the sampled sequences was focused for possible genus specific patterns. Nine patterns in this stretch showed nearly 70% specificity to the target genus. These patterns were further used to obtain a signature that is highly specific to Pseudomonas. The signature region was used to design PCR primers, which yielded a PCR product of 150 bp whose specificity was validated through a sample experiment.

Conclusions

The developed approach was successfully applied to genus Pseudomonas. It could be tried in other bacterial genera to obtain respective signature patterns and thereby PCR primers, for their rapid tracking in the environmental samples.

     

Structural organization of the human genome: distribution of nucleotides, Alu-repeats and exons in chromosomes 21 and 22]

Analysis of DNA sequences of the human chromosomes 21 and 22 performed using a specially designed MegaGene software allowed us to obtain the following results. Purine and pyrimidine nucleotide residues are unevenly distributed along both chromosomes, displaying maxima and minima (Y waves phi) with a period of about 3 Mbp. Distribution of G + C along both chromosomes has no distinct maxima and minima, however, chromosome 21 contains considerably less G + C than chromosome 22. Both exons and Alu repeats are unevenly distributed along chromosome 21: they are scarce in its left part and abundant in the right part, while MIR elements are quite monotonously spread along this chromosome. The Alu repeats show a wave-like distribution pattern similar for both repeat orientations. The number of the Alu repeats of opposite orientations was equal for both studied chromosomes, and this may be considered a new property of the human genome. The positive correlation between the exon and Alu distribution patterns along the chromosome, the concurrent distribution of Alu repeats in both orientations along the chromosome, and the equal copy numbers for Alu in direct and inverted orientations within an individual chromosome point to their important role in the human genome, and do not fit the notion that Alu repeats belong to parasitic (junk) DNA.     

Structural Organization of the Human Genome: Distribution of Nucleotides,AluRepeats, and Exons in Chromosomes 21 and 22

Analysis of DNA sequences of the human chromosomes 21 and 22 performed using a specially designed MegaGene software allowed us to obtain the following results. Purine and pyrimidine nucleotide residues are unevenly distributed along both chromosomes, displaying maxima and minima (waves) with a period of about 3 Mbp. Distribution of G+C along both chromosomes has no distinct maxima and minima, however, chromosome 21 contains considerably less G+C than chromosome 22. Both exons and Alurepeats are unevenly distributed along chromosome 21: they are scarce in its left part and abundant in the right part, while MIR elements are quite monotonously spread along this chromosome. The Alurepeats show a wave-like distribution pattern similar for both repeat orientations. The number of the Alurepeats of opposite orientations was equal for both studied chromosomes, and this may be considered a new property of the human genome. The positive correlation between the exon and Aludistribution patterns along the chromosome, the concurrent distribution of Alurepeats in both orientations along the chromosome, and the equal copy numbers for Aluin direct and inverted orientations within an individual chromosome point to their important role in the human genome, and do not fit the notion that Alurepeats belong to parasitic (junk) DNA.     

Meiotic analysis of four cross-pollinated generations in a synthetic autotetraploid population of husk tomato (<i>Physalis ixocarpa</i>)

The cultivated husk tomato (Physalis ixocarpa) (2n = 2x = 24) is native from Mexico and Central America and shows a wide genetic variation. Presently, it is the fourth horticultural crop in cultivation surface in Mexico. The working team of this research previously developed an autotetraploid population by using colchicine. The objectives of the present work were to analyze the ploidy level and meiotic behavior of the subsequent generations (C3, C4, C5, C6) from the original (C2) composed only by plants with the duplicated genome from the Rendidora cultivar, and to determine pollen viability. As a diploid control the cultivar Rendidora of P. ixocarpa was used. Ploidy level was determined by flow citometry and meiotic analysis. For the meiotic study, the microsporocytes were prepared by the squash method, stained with carmin and analyzed in diakinesis. Pollen viability was evaluated through 0.01% Buffalo Black staining. The tetraploid condition prevailed through four cross-pollinating generations, maintaining a constant chromosome number 2n = 4x = 48. In diakinesis, the chromosomes of the diploid cultivar were associated into bivalents, whereas in tetraploid plants the chromosomes associated into univalents, bivalents and trivalents. Highly significant differences in bivalent pairing were detected between autotetraploid plants and between generations. Pollen viability did not show significant differences between generations and allowed reproduction. These results indicate that it is possible to develop an autotetraploid cultivar, because the polyploid state is naturally maintained and the plants are fertile. Furthermore, given the differences in bivalent pairing between plants and generations, a response to selection toward meiotic stability is expected.     

Synthesis and anti-viral activity of azolo-adamantanes against influenza A virus

Chemotherapy and chemoprophylaxis of influenza is one of the most important directions of health protection activity. Due to the high rate of drug-resistant strains of influenza virus, there is a need for the search and further development of new potent antivirals against influenza with a broad spectrum of activity. In the present study, a set of di-, tri- and tetrazole derivatives of adamantane was efficiently prepared and their anti-influenza activities evaluated against rimantadine-resistant strain A/Puerto Rico/8/34. In general, derivatives of tetrazole possessed the highest virus-inhibiting activity. We demonstrated that several compounds of this set exhibited much higher activity than the currently used antiviral rimantadine, a compound of related structure. Moreover, we showed that these azolo-adamantanes were significantly less toxic. This study demonstrates that influenza viruses can be inhibited by adamantyl-azoles and thus have potential for developing antiviral agents with an alternate mechanism of action.