Exposure to Leishmania major modulates the proportion of CD4+ T cells without affecting cellular immune responses

The immune responses of individuals exposed to Leishmania major were evaluated and compared with those of non-exposed volunteers. Forty-one patients with active lesion(s), 43 healed individuals, 15 vaccinees 1 month or 1 year post vaccination, and 15 non-exposed volunteers were studied. Leishmanin skin test (LST) response, proliferative response of lymphocyte (PRL) to L. major antigen, IFN-gamma and IL-4 production, and percentage of L. major-specific CD4+, CD8+ and CD16+/CD56+ cells in peripheral blood mononuclear cells were assessed. Data showed positive LST (>5 mm) in 92% of patients, 98% of healed, and 80% or 43% of vaccinees 1 month and 1 year post vaccination, respectively. Positive PRL (SI>2.5) was displayed in 90%, 84%, 46% and 7% of patients, healed, vaccinated (post 1 year) and non-exposed donors, respectively. The mean +/-S.E. of IFN-gamma was 924 +/- 149, 1,278 +/- 185, 470 +/- 282 or 258 +/- 82 pg/ml in patients, healed cases and vaccinees after 1 month or 1 year, respectively. Positive IFN-gamma responders (>300 pg/ml) were shown in 72% of patients, 81% of healed cases, 31% or 39% of vaccinees and 0% of non-exposed donors. A reduced percentage of CD4+ T-cells and an increased percentage of NK cells were found in exposed individuals compared to non-exposed donors. The data indicated that exposure to L. major modulates the proportion of CD4+ T cells and increases NK cells percentage. However, the cellular immune responses including induction of LST, and IFN-gamma production are increased in exposed individuals.     

Genotyping strategy matters when analyzing hypervariable major histocompatibility complex‐Experience from a passerine bird

Genotyping of classical major histocompatibility complex (MHC) genes is challenging when they are hypervariable and occur in multiple copies. In this study, we used several different approaches to genotype the moderately variable MHC class I exon 3 (MHCIe3) and the highly polymorphic MHC class II exon 2 (MHCIIβe2) in the bluethroat (Luscinia svecica). Two family groups (eight individuals) were sequenced in replicates at both markers using Ion Torrent technology with both a single‐ and a dual‐indexed primer structure. Additionally, MHCIIβe2 was sequenced on Illumina MiSeq. Allele calling was conducted by modifications of the pipeline developed by Sommer et al. (BMC Genomics, 14, 2013, 542) and the software AmpliSAS. While the different genotyping strategies gave largely consistent results for MHCIe3, with a maximum of eight alleles per individual, MHCIIβe2 was remarkably complex with a maximum of 56 MHCIIβe2 alleles called for one individual. Each genotyping strategy detected on average 50%–82% of all MHCIIβe2 alleles per individual, but dropouts were largely allele‐specific and consistent within families for each strategy. The discrepancies among approaches indicate PCR biases caused by the platform‐specific primer tails. Further, AmpliSAS called fewer alleles than the modified Sommer pipeline. Our results demonstrate that allelic dropout is a significant problem when genotyping the hypervariable MHCIIβe2. As these genotyping errors are largely nonrandom and method‐specific, we caution against comparing genotypes across different genotyping strategies. Nevertheless, we conclude that high‐throughput approaches provide a major advance in the challenging task of genotyping hypervariable MHC loci, even though they may not reveal the complete allelic repertoire.     

秦岭产珠子参叶的达玛烷型皂甙研究(1)

从陕西省秦岭产珠子参(Panax japonicus C.A.Meyer var.major(Burk.)Wu etFeng)的叶中分离到十个新的达玛烷型四环三萜皂甙,经光谱测定和化学降解,其中四个的化学结构分别为珠子参甙(majoroside)F_1(1)、F_2(2)、F_3(3)和F_4(4)。同时,还分离到已知的人参甙(ginsenoside)Rd(5)、Re(6)、Rg_1(7)、Rg_2(8)和F_2(9)。     

Identification of Tumor Antigens in the HLA Peptidome of Patient-derived Xenograft Tumors in Mouse

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Highlights

• •Sufficient tumor tissues are often unavailable large HLA peptidome discovery.
• •Using patient derived xenograft (PDX) tumors can overcome this limitation.
• •The large PDX HLA peptidomes expand significantly those of the original biopsies.
• •The HLA peptidomes of the PDX tumors included many tumor antigens.

     

Thermostability/infectivity defect caused by deletion of the core protein V gene in human adenovirus type 5 is rescued by thermo-selectable mutations in the core protein X precursor

Mastadenoviruses represent one of the four major genera of the Adenoviridae family comprising a variety of mammalian pathogens including human adenovirus (Ad), whose genomes encode a gene for minor core protein V (pV), not found in other genera of Adenoviridae. Deletion of other genus-specific genes (gene IX and E3 genes) from the Ad type 5 (Ad5) genome has been studied experimentally in vitro and the results on biological characterization of the mutants support the phylogenetic evidence of those genes being non-essential for Ad viability. On this basis it seemed logical to suggest that a deletion of gene V from the Ad5 genome could also be tolerated. To test this hypothesis we constructed and rescued the first pV-deletion mutant of human Ad5. As compared to Ad5, this mutant formed small plaques, had dramatically reduced thermostability and lower infectivity. A subsequent thermoselection screen of the pV-deleted Ad5 allowed isolation of a suppressor mutant Ad5-dV/TSB with restored biological characteristics. Since replication and viral assembly of Ad5-dV/TSB could still occur in the absence of pV, we conclude that pV is a non-essential component of the virion. The observed rescue of the biological defects appears to be associated with a cluster of point mutations in the gene encoding the precursor for the other core protein, X/Mu. This finding, thus, suggests possible roles of pV and protein X/Mu precursor in viral assembly. It also provides an interesting insight into genetic events that mediate molecular adaptation of viruses to possible changes in the genetic background in the course of their evolutionary divergence. The possible mechanism of the observed genetic suppression is discussed.     

Characterization of RNase-like major storage protein from the ginseng root by proteomic approach

The most abundant root proteins of ginseng (Panax ginseng) have been detected and identified by comparative proteome analysis with cultured hairy root of ginseng. Four abundant proteins (28, 26, 21 and 20 kDa) of P. ginseng had isoforms with different pl values on two-dimensional gel electrophoresis (2DE). The results of N-terminal and internal amino acid sequencing, however, showed that all of them originate from a 28 kDa protein, known as ginseng major protein (GMP). The GMP gene was searched for in the expressed sequence tag database of P. ginseng and found to encode a 27.3 kDa protein having 238 amino acid residues. Analysis of the amino acid sequences indicates that GMP exhibits high sequence homology with plant RNases and RNase-like proteins. However, purified GMP had no RNase activity even though it has conserved amino acid residues known to be essential for active sites of RNase. The GMPs present in ginseng main root were not expressed in cultured hairy roots of ginseng. 2DE analysis showed that the amounts of GMPs in main roots change according to seasonal fluctuation. These results suggest that the GMPs are root-specific RNase-like proteins, which function as vegetative storage proteins of ginseng for survival in the natural environment.     

DNA recognition by β-sheets

The modes of DNA recognition by β-sheets are analyzed by using the known crystal and solution three-dimensional structures of DNA-protein complexes. Close fitting of the protein surface and the DNA surface determines the binding geometry. Interaction takes place so that essentially the N-to-C direction of the β-strands either follows or crosses the DNA groove. Upon following the major groove a two-stranded antiparallel β-sheet dives into the groove and contacts DNA bases with its convex side facing the DNA, while upon following the minor groove, it binds around the sugar-phosphate backbones, with its opposite concave side shielding the DNA. In order for the β-strands crossing the minor groove to interact with the DNA, the dinucleotide steps need to almost totally helically untwist and roll around major groove. The β-sheet, on the other hand, needs to adopt a concave curvature on the binding surface in the direction that follows the DNA minor groove, and a convex surface in the direction that bridges the sugar-phosphate backbones across the groove. The result is to produce a hyperbolic paraboloidal DNA-binding surface. © 1998 John Wiley & Sons, Inc. Biopoly 44: 335–359, 1997     

Climate change and breeding parameters of great and blue tits throughout the western Palaearctic

Increasing evidence suggests that climate change has consequences on avian breeding phenology. Here, variations in laying date and clutch size of great tit Parus major and blue tit Parus caeruleus within and between breeding populations through the western Palaearctic are examined in relation to climatic fluctuations, measured by the winter North Atlantic Oscillation (NAO) index. Within and across breeding sites, laying date was related to winter‐NAO index such that great and blue tit females lay earlier after warmer, moister winters (positive values of winter NAO‐index). The present study shows that for most populations there is an advancement of laying date, but the rate of change with respect to NAO significantly differed geographically across the western Palaearctic and did not differ between species. However, clutch size of great and blue tits was not affected by climatic fluctuations, presumably because the whole season is being shifted, but not in relation to food supplies. These combined analyses for the two species controlled for potentially confounding variables such as latitude, longitude, elevation and habitat of each study site.     

产漆酶菌株筛选及一株产酶菌株的优化与鉴定

【目的】从26株真菌菌株中筛选高产漆酶菌株。【方法】采用愈创木酚法进行产漆酶菌株的筛选,通过正交实验对筛选出的高产菌株进行优化,并通过形态学和分子系统学对菌株进行鉴定。【结果】26株真菌菌株中有4株可产生漆酶,其中菌株H52.1为产漆酶最好菌株;菌株H52.1产漆酶优化培养基碳源为可溶性淀粉,氮源为硝酸铵,pH为8,金属离子为Ca2+;经鉴定,该菌株为大孢戴氏霉。【结论】大孢戴氏霉在产漆酶方面值得进一步研究开发。