Background: ALS patients and transgenic mice expressing ALS-associated superoxide dismutase 1 (SOD1) mutations show alterations in the blood-spinal cord barrier (B-SC-B) as suggested from the reduction of levels of various tight junction proteins (TJPs) including zonula occludens-1 (ZO-1), occludin and claudin-5 between endothelial cells and early protection of the B-SC-B integrity was found to delay onset of motor-neuron impairment and degeneration. Objective: The aim of this research was to investigate if inhibition of the axis CXCL12/CXCR4 receptor widely expressed in neurons and glial cells and modulates neuronal apoptosis, may improve motor neurons survival by increasing the expression of tight junction proteins and rehabilitation of the barrier. Materials and methods: Transgenic mice model of ALS were treated with AMD3100, antagonist of CXCR4. Motor function, weight changes and survival were evaluated. In a separate experiment, mice were sacrificed after one month of treatment and levels of proteins essential for the formation of the barrier in comparison with proteins that do not participate in the barrier were measured. Results: We found that chronic administration of AMD3100 to ALS mouse model was effective in restoring the expression of tight junction proteins and considerably increase the survival, confirming the importance of early treatment for rehabilitation of the barriers to prevent infiltration of neurotoxic products and microhemorrhages. Conclusions: These data reveal that multi-faceted action of AMD3100 may provide a novel option for ALS therapy leading to rehabilitation of B-SC-B proteins and thus preventing additional damage to motor neurons.

Aim: Ff phages are non-lytic bacteria viruses characterized by a filament and flexible structure. Although they have no tropism to mammalian cells, Ff phages can skew tumor associated macrophage polarization towards the anti-tumorigenic M1 phenotype and promote tumor destruction associated with cytotoxic neutrophils infiltration. Interestingly, owing to their unique dimensions, Ff phages were reported to penetrate the central nervous system following intranasal administration. The primary objective of this study was to assess whether Ff phages accumulated in the central nervous system and lungs following intranasal administration can inhibit orthotopic glioblastoma and lung carcinoma progression. Methods: The effect of Ff phages on tumor growth and survival was evaluated in subcutaneous as well as orthotopic models of GL261 glioblastoma and Lewis lung carcinoma using immunocompetent mice. Results: We demonstrate that Ff phages that do not display any proteins or peptides could inhibit the growth of subcutaneous tumors in mice and that this activity is mediated in part by lipopolysaccharide molecules attached to their virion. Ff phages administered via the intranasal route rapidly accumulated in the brains and lungs of mice and could attenuate progression of orthotopic glioblastoma and lung carcinoma. The anti-tumorigenic activity mediated by the phages was associated with prolonged survival. Conclusions: This study demonstrates the feasibility of delivering Ff phages non-invasively via the intranasal route to treat brain and lung malignancies. We propose that the anti-tumorigenic activity of Ff phages depends on an effective amount of virion associated lipopolysaccharide which can promote pro-inflammatory activity resulting in tumor suppression. Disclosure: All authors have declared no conflicts of interest.

More and more evidence shows that Alzheimer’s disease belongs to the family of conformational diseases characterized by protein self-association and tissue deposition as amyloid fibrils. As recently shown, monoclonal antibodies interact at strategic sites where conformational changes of proteins are initiated, stabilizing the protein and preventing further aggregation. These data, and the recent performance of such antibodies in transgenic mice as a model for human diseases, convert the immunological concept into a therapeutic strategy for the development of vaccination against such diseases. Here we describe a new immunization procedure against β-amyloid plaques using as antigen the EFRH peptide displayed on the surface of the filamentous phage. Antibodies to the epitope EFRH, representing residues 3–6 within the β-amyloid peptide, were found to modulate its in vitro solubility and aggregation. The EFRH phage induced effective anti-aggregating antibodies in transgenic mice that recapitulate the amyloid plaques and vascular pathology of Alzheimer’s disease. The immunization led to a considerable reduction in the number of β-amyloid plaques found in the brains of the sacrificed transgenic mice. However, effective means are required for in vivo brain imaging to monitor changes in the plaque burden of patients’ brains. We propose anti-β-amyloid antibodies displayed on genetically engineered filamentous phages as a specific probe to monitor amyloid plaque formation in living patients. Intranasal administration of filamentous phage as a delivery vector of anti- β-amyloid antibody fragment into brains of Alzheimer’s APP transgenic mice enables in vivo targeting of β-amyloid plaques.

Antibodies towards the N-terminal region of the beta-amyloid peptide bind to beta-amyloid fibrils, leading to their disaggregation. We generated anti-aggregating beta-amyloid antibodies using filamentous phages displaying the only four amino acids EFRH found to be the main regulatory site for beta-amyloid formation. In order to overcome the low permeability of the blood brain barrier for targeting 'anti-aggregating' mAbs to the betaA plaques in the brain, we applied antibody engineering methods to minimize the size of the mAbs while maintaining their biological activity. We found that single-chain antibodies displayed on the surface of the phage are capable of entering the central nervous system (CNS). The feasibility of these novel strategies for the production and targeting of anti-aggregating antibodies against beta-amyloid plaques to disease affected regions in the CNS may have clinical potential for treatment of Alzheimer's disease.

Treatment of Alzheimer's disease by recruiting an immune response against beta-amyloid was suggested by the findings that monoclonal antibodies against beta-amyloid peptide can keep the peptides from aggregating into neurotoxic fibrils and dissolve already formed amyloid. Subsequent beta-amyloid vaccination studies in transgenic mice models of Alzheimer's disease have shown a significant reduction in the number of amyloid plaques and overall amyloid burden and even some improvement in cognitive performance. It is not yet clear if immunization with soluble or fibrillar forms of beta-amyloid peptide will end up being a treatment to prevent or treat Alzheimer's disease. However, various strategies for mobilizing the immune system may be effective toward treatment and prevention of Alzheimer's disease in humans. (C) 2002 Prous Science. All rights reserved.

A set of 34 molecular dynamic (MD) simulations totaling 305 ns of simulation time of the prion protein‐derived peptide PrP106–126 was performed with both explicit and implicit solvent models. The objective of these simulations is to investigate the relative stability of the α‐helical conformation of the peptide and the mechanism for conversion from the helix to a random‐coil structure. At neutral pH, the wild‐type peptide was found to lose its initial helical structure very fast, within a few nanoseconds (ns) from the beginning of the simulations. The helix breaks up in the middle and then unwinds to the termini. The spontaneous transition into the random coil structure is governed by the hydrophobic interaction between His111 and Val122. The A117V mutation, which is linked to GSS disease, was found to destabilize the helix conformation of the peptide significantly, leading to a complete loss of helicity approximately 1 ns faster than in the wild‐type. Furthermore, the A117V mutant exhibits a different mechanism for helix‐coil conversion, wherein the helix begins to break up at the C‐terminus and then gradually to unwind towards the N‐terminus. In most simulations, the mutation was found to speed up the conversion through an additional hydrophobic interaction between Met112 and the mutated residue Val117, an interaction that did not exist in the wild‐type peptide. Finally, the β‐sheet conformation of the wild‐type peptide was found to be less stable at acidic pH due to a destabilization of the His111–Val122, since at acidic pH this histidine is protonated and is unlikely to participate in hydrophobic interaction. Proteins 2001;45:382–396. © 2001 Wiley‐Liss, Inc.