A proteomic approach on the effects of TX527, a 1α,25-dihydroxyvitamin D3 analog, in human T lymphocytes

1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3), and its analogs (i.e. 14,20-bis-epi-19-nor-23-yne-1α,25(OH)2D3 - TX527) have been shown to prevent autoimmunity and prolong islet graft survival in the non-obese diabetic (NOD) mouse. Their effects are mediated by their action on various immune cell types, such as dendritic cells (DC) and T cells. We have previously reported important direct effects of TX527 on human T cells, on their cytokine/chemokine profiles, T regulatory cell markers, homing characteristics and chemotaxis. In order to fully understand the molecular mechanisms underlying the beneficial properties of TX527 on human T cells, we applied here 2-dimensional difference gel electrophoresis (2-D DIGE) to analyze the global protein alterations induced by TX527 on human synchronized T cells. We detected differential expression of 64 protein spots upon TX527 treatment, of which 65.6% could be successfully identified using tandem mass spectrometry (MALDI-TOF/TOF). The identified proteins function in various processes, such as metabolism and energy pathways, cytoskeleton and protein metabolism. When comparing the proteomics data to our previously performed microarray data on the same set of cells, we found an overlap of 17 different mRNAs/proteins. For some of these (e.g. PSME2, HSPA8), the direction of regulation was not similar, hereby reinforcing the important role of post-transcriptional/translational processes in the functionality of proteins. In addition, although 2-D DIGE offers the possibility of picking up post-translational processes, it lacks the ability to detect molecules with extreme molecular weight (MW) and isoelectrical point (pI) values, or very low abundant/hydrophobic proteins. This study highlights therefore the importance of combining different experimental approaches to obtain a complete picture of the underlying mechanisms and general processes being affected in T cells upon TX527 treatment. These processes lead altogether to the generation of T cells with interesting immunomodulatory features for clinical applications in the treatment of autoimmune diseases or in the prevention of graft rejection. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.

Surface enhanced Raman scattering, electronic spectrum and Mulliken charge distribution in the normal modes of bis(diethyldithiocarbamate)zinc(II) complex

Surface-enhanced Raman scattering (SERS) was used to study the interactions of the normal modes of the bis(diethyldithiocarbamate)zinc(II) complex, [Zn(DDTC)2], on nano-structured silver surfaces. The electronic spectrum of this complex was measured and the charge transfer bands were assigned through the TD-PBE1PBE procedure. To see the electronic dispersion, the Mulliken electronic charges were calculated for each normal mode and correlated with the SERS effect. Full assignment of the SERS spectra was also supported by carefully analysis of the distorted geometries generated by the normal modes.

Genome analysis of a severe and a mild isolate of Papaya ringspot virus-type W found in Brazil

Papaya ringspot virus-type W (PRSV-W) is one of the most economically threatening viruses of cucurbits in Brazil. Premunization is one of the most effective PRSV control measures currently applied in squash and zucchini crops. PRSV-W-1, a mild and premunizing strain of PRSV has been successfully used to protect cucurbits against both the severe PRSV-W-C strain and other Brazilian PRSVs. To aid in understanding the mechanism by which PRSV-W-1 premunization operates, the complete genome sequences of PRSV-W-1 and PRSV-W-C were determined. PRSV-W-1 had a genome size of 10,332 nucleotides, whereas indels within the coat protein encoding gene meant that the genome size of PRSV-W-C was six nucleotides shorter than that of the mild strain. The genomes of the two strains shared 94.63% nucleotide sequence identity, with the 5' UTR and P1 being the most variable regions, and the coat protein and 3' UTR being the most conserved. Rigorous recombination analysis revealed that neither PRSV-W-1 nor PRSV-W-C was obviously recombinant, there was significant evidence that many other fully sequenced PRSV genomes were recombinant.

First Report of Tomato severe rugose virus in Chili Pepper in Brazil

Three definitive and three tentative begomovirus species have been reported in tomato fields in Brazil according to a recent review (1). Extensive surveys have been conducted since the 1990s in solanaceous weeds and other crops planted close to tomato fields, but no tomato-infecting geminiviruses have been reported on those crops. During November 2003, leaves of one chili pepper plant "dedo-de-moça" (Capsicum baccatum var. pendulum) showing symptoms of yellow mosaic and leaf distortion were collected in Petrolina de Goiás (Goiás State). Serological analyses were carried out with polyclonal antisera produced in our laboratory against the following viruses: Potato virus Y (PVY), Pepper yellow mosaic virus (PepYMV), Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV), and Chrysanthemum stem necrosis virus (CSNV). Serological data showed that the plant was not infected with any of these viruses. A begomovirus-specific DNA-A fragment of 1.3 kb was amplified by polymerase chain reaction (PCR) from the analyzed plant. The fragment shared 98% identity to the partial coat protein coding region (CP), 94% to the intergenic region (IR), and 95% to the partial AC1 coding region of Tomato severe rugose virus (ToSRV) (GenBank Accession No. AY029750). Total DNA from the original infected plant was used to biolistically inoculate healthy plants of C. annuum and C. baccatum var. pendulum. Four resulting symptomatic plants, two from C. annuum and two from C. baccatum, were tested using PCR for begomovirus, and the nucleotide sequence of the amplified fragment confirmed they were infected with ToSRV. Whitefly inoculation of C. annuum, C. baccatum, and tomato was also performed, and all plants expressing symptoms were confirmed to be infected with ToSRV by sequencing a begomovirus-specific amplified fragment. Cloning of the complete DNA-A was achieved by using TempliPhi (Amersham Biosciences, Piscataway, NJ) amplification and digestion with a single cutting restriction endonuclease (2). Sequencing of several clones showed that the complete DNA-A (GenBank Accession No. DQ207749) was 97% identical to ToSRV, confirming the results of the previous PCR analysis. The deduced amino acid sequences showed identities of 97% to the CP, 95% to AC1, 96% to AC2, 96% to AC3, and 88% to AC4 of ToSRV. Although begomoviruses have not yet been causing any significant losses in chili pepper in Brazil, they may be of potential importance. Moreover, chili pepper, a plant commonly found in gardens throughout the country, may serve as an alternate host in tomato-producing areas. To our knowledge, this is the first report of a begomovirus infecting chili pepper in Brazil. References: (1) C. M. Fauquet et al. Arch. Virol. 148:405, 2003. (2). A. K. Inoue-Nagata et al. J Virol Methods 116:209, 2004.

Variance components and breeding values for growth traits from different statistical models

Estimates of genetic parameters resulting from various analytical models for birth weight (BWT, n = 4,155), 205-d weight (WWT, n = 3,884), and 365-d weight (YWT, n = 3,476) were compared. Data consisted of records for Line 1 Hereford cattle selected for postweaning growth from 1934 to 1989 at ARS-USDA, Miles City, MT. Twelve models were compared. Model 1 included fixed effects of year, sex, age of dam; covariates for birth day and inbreeding coefficients of animal and of dam; and random animal genetic and residual effects. Model 2 was the same as Model 1 but ignored inbreeding coefficients. Model 3 was the same as Model 1 and included random maternal genetic effects with covariance between direct and maternal genetic effects, and maternal permanent environmental effects. Model 4 was the same as Model 3 but ignored inbreeding. Model 5 was the same as Model 1 but with a random sire effect instead of animal genetic effect. Model 6 was the same as Model 5 but ignored inbreeding. Model 7 was a sire model that considered relationships among males. Model 8 was a sire model, assuming sires to be unrelated, but with dam effects as uncorrelated random effects to account for maternal effects. Model 9 was a sire and dam model but with relationships to account for direct and maternal genetic effects; dams also were included as uncorrelated random effects to account for maternal permanent environmental effects. Model 10 was a sire model with maternal grandsire and dam effects all as uncorrelated random effects. Model 11 was a sire and maternal grandsire model, with dams as uncorrelated random effects but with sires and maternal grandsires assumed to be related using male relationships. Model 12 was the same as Model 11 but with all pedigree relationships from the full animal model for sires and maternal grandsires. Rankings on predictions of breeding values were the same regardless of whether inbreeding coefficients for animal and dam were included in the models. Heritability estimates were similar regardless of whether inbreeding effects were in the model. Models 3 and 9 best fit the data for estimation of variances and covariances for direct, maternal genetic, and permanent environmental effects. Other models resulted in changes in ranking for predicted breeding values and for estimates of direct and maternal heritability. Heritability estimates of direct effects were smallest with sire and sire-maternal grandsire models.