On the use of adenovirus dodecahedron as a carrier for glycoconjugate vaccines

Glycoconjugate Journal - Virus-Like Particles (VLPs) have been used as immunogenic molecules in numerous recombinant vaccines. VLPs can also serve as vaccine platform to exogenous antigens, usually...     

Isolation and Characterization of Microsatellite Loci for the Isopod Crustacean Armadillidium vulgare and Transferability in Terrestrial Isopods

Armadillidium vulgare is a terrestrial isopod (Crustacea, Oniscidea) which harbors Wolbachia bacterial endosymbionts. A. vulgare is the major model for the study of Wolbachia-mediated feminization of genetic males in crustaceans. As a consequence of their impact on host sex determination mechanisms, Wolbachia endosymbionts are thought to significantly influence A. vulgare evolution on various grounds, including population genetic structure, diversity and reproduction strategies. To provide molecular tools for examining these questions, we isolated microsatellite loci through 454 pyrosequencing of a repeat-enriched A. vulgare genomic library. We selected 14 markers and developed three polymorphic microsatellite multiplex kits. We tested the kits on two A. vulgare natural populations and found high genetic variation, thereby making it possible to investigate the impact of Wolbachia endosymbionts on A. vulgare nuclear variation at unprecedented resolution. In addition, we tested the transferability of these kits by cross-species amplification in five other terrestrial isopod species harboring Wolbachia endosymbionts. The microsatellite loci showed good transferability in particular in Armadillidium nasatum and Chaetophiloscia elongata, for which these markers represent promising tools for future genetic studies.     

Hybrid cardiac procedure: the ultimate cooperation

In medical terms, a hybrid therapy or procedure is a mixture of therapies from different subspecialities. By these definitions, a hybrid cardiac procedure is a combination of surgical and catheter-based intervention to the heart. Hybrid coronary artery revascularisation is a combination of surgical and catheter-based intervention to the diseased coronary arteries.     

Acute rejection in the absence of cognate recognition of allograft by T cells

We studied the effects of the indirect pathway of allograft recognition using T cells from TCR transgenic Marilyn mice, which recognize the male Ag H-Y in an I-A(b)-restricted fashion. The T cells are not alloreactive to the H-2(k) haplotype, because they are not activated when adoptively transferred into recombinase-activating gene-2(-/-) common gamma-chain(-/-) double-mutant H-2(k) male or female mice. However, skin from H-2(k) males, but not from H-2(k) females, is acutely rejected by recombinase-activating gene-2(-/-) transgenic female recipients. In vitro, Marylin spleen cells primed by H-2(k) skin grafting proliferated and secreted both IL-4 and IFN-gamma in response to H-2(k) male stimulators. However, the removal of H-2(b) APC from the responding population abolished the response. Taken together, these results show that the indirect recognition that triggers rejection in this model is due to the recognition of H-Y Ag shed from H-2(k) male allograft and presented by the recipient's own I-A(b) APC to transgenic T cells. This study demonstrates unequivocally the capacity of naive CD4(+) T cells to promote the rejection of allografts through mechanisms that involve indirect destruction of grafted tissues.     

In vivo analysis of cell division, cell growth, and differentiation at the shoot apical meristem in Arabidopsis

The aerial parts of the plant are generated by groups of rapidly dividing cells called shoot apical meristems. To analyze cell behavior in these structures, we developed a technique to visualize living shoot apical meristems using the confocal microscope. This method, combined with green fluorescent protein marker lines and vital stains, allows us to follow the dynamics of cell proliferation, cell expansion, and cell differentiation at the shoot apex. Using this approach, the effects of several mitotic drugs on meristem development were studied. Oryzalin (depolymerizing microtubules) very rapidly caused cell division arrest. Nevertheless, both cell expansion and cell differentiation proceeded in the treated meristems. Interestingly, DNA synthesis was not blocked, and the meristematic cells went through several rounds of endoreduplication in the presence of the drug. We next treated the meristems with two inhibitors of DNA synthesis, aphidicolin and hydroxyurea. In this case, cell growth and, later, cell differentiation were inhibited, suggesting an important role for DNA synthesis in growth and patterning.     

Discrete mutations in the presequence of potato formate dehydrogenase inhibit the in vivo targeting of GFP fusions into mitochondria

Most mitochondrial proteins are encoded by the nucleus, translated in the cytosol, and imported. Mitochondrial precursors generally contain their targeting information in a cleavable N-terminal presequence, which is rich in hydroxylated and positively charged residues and can form amphiphilic alpha-helices. We report the in vivo targeting of green fluorescent protein (GFP) by the FDH presequence, as well as several truncated or mutated variants. Some of these mutations modify the amphiphilicity of the predicted alpha-helix. The removal of the first two residues abolishes import and some single amino acid mutations strongly inhibit import. Such strong effects on import had not been observed in similar studies on other plant mitochondrial presequences, suggesting that the FDH presequence is a particularly good model for functional studies.     

Cell numbers and leaf development in Arabidopsis: a functional analysis of the STRUWWELPETER gene

The struwwelpeter (swp) mutant in Arabidopsis shows reduced cell numbers in all aerial organs. In certain cases, this defect is partially compensated by an increase in final cell size. Although the mutation does not affect cell cycle duration in the young primordia, it does influence the window of cell proliferation, as cell number is reduced during the very early stages of primordium initiation and a precocious arrest of cell proliferation occurs. In addition, the mutation also perturbs the shoot apical meristem (SAM), which becomes gradually disorganized. SWP encodes a protein with similarities to subunits of the Mediator complex, required for RNA polymerase II recruitment at target promoters in response to specific activators. To gain further insight into its function, we overexpressed the gene under the control of a constitutive promoter. This interfered again with the moment of cell cycle arrest in the young leaf. Our results suggest that the levels of SWP, besides their role in pattern formation at the meristem, play an important role in defining the duration of cell proliferation.     

The Arabidopsis TONNEAU2 gene encodes a putative novel protein phosphatase 2A regulatory subunit essential for the control of the cortical cytoskeleton

In Arabidopsis ton2 mutants, abnormalities of the cortical microtubular cytoskeleton, such as disorganization of the interphase microtubule array and lack of the preprophase band before mitosis, markedly affect cell shape and arrangement as well as overall plant morphology. We present the molecular isolation of the TON2 gene, which is highly conserved in higher plants and has a vertebrate homolog of unknown function. It encodes a protein similar in its C-terminal part to B" regulatory subunits of type 2A protein phosphatases (PP2As). We show that the TON2 protein interacts with an Arabidopsis type A subunit of PP2A in the yeast two-hybrid system and thus likely defines a novel subclass of PP2A subunits that are possibly involved in the control of cytoskeletal structures in plants.