Two formulations of pneumococcal vaccines are currently available to prevent invasive disease in adults and children. However, these vaccines will not protect against the majority of Streptococcus pneumoniae serotypes. The use of highly conserved cell-wall-associated proteins in vaccines may circumvent this problem. A proteomics approach was used to identify 270 S. pneumoniae cell-wall-associated proteins, which were then screened in a process that included in-silico, in-vitro and in-vivo validation criteria. Five potential candidates for inclusion in a vaccine were selected, expressed in Escherichia coli, and purified for use in immunisation experiments. These proteins were detected in at least 40 different serotypes of S. pneumoniae, and were expressed in S. pneumoniae isolates causing infection. Two of the five candidate proteins, the putative lipoate protein ligase (Lpl) and the ClpP protease, resulted in a reduced CFU titre and a trend towards reduced mortality in an animal sepsis model for investigating new S. pneumoniae protein vaccines.

The neural cell adhesion molecule (NCAM) plays a key role in morphogenesis of the nervous system and in remodeling of neuronal connections accompanying regenerative and cognitive processes. Recently, a new synthetic ligand of NCAM, the C3-peptide, which binds to the NCAM IgI module, has been identified by means of combinatorial chemistry (Rønn, L. C. B, Olsen, M., Ostergaard, S., Kiselyov, V., Berezin, V., Mortensen, M. T., Lerche, M. H., Jensen, P. H., Soroka, V., Saffell, J. L., Doherty, P., Poulsen, F. M., Bock, E., Holm, A., and Saffells, J. L. (1999) Nat. Biotechnol. 17, 1000 -1005). In vitro, the dendrimeric form of C3, termed C3d, disrupts NCAM-mediated cell adhesion, induces neurite outgrowth, and triggers intracellular signaling cascades similar to those activated by homophilic NCAM binding. The peptide may therefore be expected to regulate regeneration and synaptic plasticity. Here we demonstrate that in primary cultures of hippocampal neurons: 1) C3d induces a sustained neuritogenic response, the neuritogenic activity of the compound being dependent on the dose, starting time, and duration of peptide application; 2) the peptide triggers the neuritogenic response by forming an adhesive substratum necessary for NCAM-mediated neurite formation and elongation; 3) C3d promotes synapse formation; and 4) C3d modulates the presynaptic function, causing a transient increase of the function at low (2 and 5 M) doses and a reduction when applied at a higher concentration (10 M). The effect of the peptide is dependent on the activation of the fibroblast growth factor receptor. We suggest that C3d may constitute a useful lead for the development of compounds for treatment of various neurodegenerative disorders. The neural cell adhesion molecule (NCAM)1 plays a key role in morphogenesis of the nervous system (2) and in remodeling of neuronal connections associated with regenerative and cognitive processes (for review, see Ref.3). The extracellular part of NCAM binds to a variety of ligands, the most important being the NCAM molecule itself. Homophilic NCAM binding is thought to involve the first five immunoglobulin (IgI-IgV) modules of NCAM with a double reciprocal interaction between the IgI and IgII modules of two interacting NCAM molecules (4, 5). Upon homophilic NCAM binding, intracellular signaling cascades, including the Ras-mitogen-activated protein kinase (Ras-MAPK) and phospholipase C␥-associated pathways, are activated (6), resulting in neurite outgrowth. Antibody interventive studies have shown NCAM necessary for the induction and maintenance of long term potentiation and for stable memory retention in vivo (7,8), suggesting that NCAM is involved in synaptic plasticity.The modulation of processes of neuronal differentiation and plasticity through NCAM has been impeded by the absence of small synthetic agonists mimicking homophilic or heterophilic interactions of NCAM. However, recently, a new synthetic ligand of NCAM, the C3-peptide, has been identified by means of combinatorial chemistry. The dendrimeric...

No abstract

The synthesis of novel Boc/acyl protected monomers for the synthesis of peptide nucleic acid (PNA) is described. The oligomerization protocol using these new monomers has been optimized with regard to coupling reagents. The use of base-labile acyl protecting groups at the exocyclic amines of the heterocyclic bases (isobutyryl for guanine and benzoyl for adenine and cytosine) and a PAM-linked solid support offers an attractive alternative to the present procedures used in PNA synthesis. This strategy has been applied for the synthesis of a test 17mer PNA on both control pore glass (CPG) and a polystyrene MBHA support and was used in the preparation of PNA-DNA chimeras.

The synthesis of novel Boc/acyl protected monomers for the synthesis of peptide nucleic acid (PNA) is described. The oligomerization protocol using these new monomers has been optimized with regard to coupling reagents. The use of base-labile acyl protecting groups at the exocyclic amines of the heterocyclic bases (isobutyryl for guanine and benzoyl for adenine and cytosine) and a PAM-linked solid support offers an attractive alternative to the present procedures used in PNA synthesis. This strategy has been applied for the synthesis of a test 17mer PNA on both control pore glass (CPG) and a polystyrene MBHA support and was used in the preparation of PNA-DNA chimeras.