[Therapeutic monitoring and prediction of the efficacy of neurotrophic treatment in patients with amnestic type of mild cognitive impairment]. / Terapevticheskii monitoring i prognoz éffektivnosti neirotroficheskoi terapii u patsientov s sindromom miagkogo kognitivnogo snizheniia amnesticheskogo tipa.

AIM: To perform therapeutic monitoring and prediction of the neurotrophic therapy efficacy in patients with amnestic type of mild cognitive impairment (aMCI) in a model of course cerebrolysin therapy. MATERIAL AND METHODS: The study involved a group of 19 elderly patients who met the diagnostic criteria of aMCI. All patients received a course of neurotrophic therapy consisting of 20 intravenous infusions of cerebrolysin (30 ml of cerebrolysin in 100 ml of isotonic sodium chloride solution). To assess the therapy efficacy, psychometric scales (CGI, MMSE, MoCA-test, МDRS, FAB, Clock Drawing Test, BNT, Word Recall test, delayed reproduction of 10 words, naming digits in a direct and reverse order) were used at 0, 4, 10 and 26 weeks of the study. Antibodies to p75 neurotrophin receptor (NTR) were measured by ELISA in blood serum of 19 patients before cerebrolysin therapy and after 10 and 26 weeks of treatment. RESULTS AND CONCLUSION: The study showed that аMCI patients had an increased level of antibodies against P75NTR that was significantly decreased after 5.5 month of cerebrolysin treatment. Therefore, it can be a potential biomarker of long-term therapeutic effect of cerebrolysin treatment in aMCI patients. The modified fragment 155-164 of P75 NTR determined in the serum of patients can be an effective indicator for monitoring and predicting the efficacy of long-term neurotrophic therapy.

[Protective Activity of Prion Protein Fragments after Immunization of Annimals with Experimentally Induced Alzheimer's Disease].

The prion protein is considered as one of the membrane targets of neurotoxic beta-amyloid during Alzheimer's disease development. We have chosen and synthesized 17-33, 23-33, 95-110 and 101-115 prion fragments involved in beta-amyloid binding. The effect of immunization with the peptides on the features of Alzheimer's disease was investigated in animals with an experimentally induced form of the disease. It was shown that immunization either with peptide 17-33 or with protein conjugates of peptides 23-33 and 101-115 increases the level of brain beta-amyloid and improves morfofunctional state of the brain.

[Fragment of Receptor for Advanced Glycation End Products Improves Memory State in a Model of Alzheimer's Disease].

A number of synthetic peptides corresponding to potentially important regions in the sequence of the four membrane proteins known as beta-amyloid cell receptors have been investigated on their ability to improve memory state in experimental model of Alzheimer's disease. Nine fragments repeating all the exposed nonstructural regions of the RAGE protein according to X-ray data, have been synthesized. The activity of these peptides and synthesized earlier immunoprotective fragments of other three proteins (acetylcholine receptor alpha7-type, prion protein and neurotrophin receptor p75) has been investigated under intranasal administration, without immune response to the peptide. Only one fragment RAGE (60-76) was shown to have a therapeutic activity improving the memory state of bulbectomized mice and leads to decreasing in the level of brain beta-amyloid.

Immunization with either prion protein fragment 95-123 or the fragment-specific antibodies rescue memory loss and neurodegenerative phenotype of neurons in olfactory bulbectomized mice.

Epidemiological studies demonstrated association between head injury (HI) and the subsequent development of Alzheimer's disease (AD). Certain hallmarks of AD, e.g. amyloid-ß (Aß) containing deposits, may be found in patients following traumatic BI (TBI). Recent studies uncover the cellular prion protein, PrP(C), as a receptor for soluble polymeric forms of Aß (sAß) which are an intermediate of such deposits. We aimed to test the hypothesis that targeting of PrP(C) can prevent Aß related spatial memory deficits in olfactory bulbectomized (OBX) mice utilized here to resemble some clinical features of AD, such as increased level of Aß, memory loss and deficit of the CNS cholin- and serotonin-ergic systems. We demonstrated that immunization with the a.a. 95-123 fragment of cellular prion (PrP-I) recovered cortical and hippocampus neurons from OBX induced degeneration, rescued spatial memory loss in Morris water maze test and significantly decrease the Aß level in brain tissue of these animals. Affinity purified anti-PrP-I antibodies rescued pre-synaptic biomarker synaptophysin eliciting similar effect on memory of OBX mice, and protected hippocampal neurones from Aß25-35-induced toxicity in vitro. Immunization OBX mice with a.a. 200-213 fragment of cellular prion (PrP-II) did not reach a significance in memory protection albeit having similar to PrP-I immunization impact on Aß level in brain tissue. The observed positive effect of targeting the PrP-I by either active or passive immunization on memory of OBX mice revealed the involvement of the PrP(C) in AD-like pathology induced by olfactory bulbectomy. This OBX model may be a useful tool for mechanistic and preclinical therapeutic investigations into the association between PrP(C) and AD.

A synthetic peptide based on the NS1 non-structural protein of tick-borne encephalitis virus induces a protective immune response against fatal encephalitis in an experimental animal model.

Linear immunogenic peptides corresponding to amino acid sequences from the NS1 non-structural protein from tick-borne encephalitis virus (strain Sophyin) were predicted using established algorithms and synthesized. Of the 12 peptides predicted, 11 were able to induce peptide-specific antibodies in BALB/c mice but only 1 of these 11 was able to induce antibodies, which reacted with the native protein in a radio-immune precipitation assay. This peptide corresponds to amino acids 37--55, and forms one of the predicted structurally conserved alpha helices of the virus NS1 protein. It was able to protect 60% of animals against lethal challenge with the homologous highly pathogenic tick-borne encephalitis virus strain, and adoptive transfer experiments indicated the involvement of the antibodies induced by this peptide in its protective activity in mice.

A monoclonal antibody that recognizes the predicted tick-borne encephalitis virus E protein fusion sequence blocks fusion.

The fusion motif of tick-borne encephalitis virus E protein has been predicted to be located within its conserved region (98-120). Results are presented to demonstrate that non-neutralizing monoclonal antibody which recognizes a synthetic peptide corresponding to residues 98-113 of the E protein sequence can block the fusion of the virus particles with artificial membranes.

A peptide construct containing B-cell and T-cell epitopes from the foot-and-mouth disease viral VP1 protein induces efficient antiviral protection.

A new peptide construct Palm135-158-GGA-170-188(Acm) has been synthesized and investigated in a number of in vitro and in vivo test systems. The construct contains a virus specific T-helper epitope within the 170-188 sequence of VP1, in addition to the main antigenic 135-158 region of the foot-and-mouth disease viral VP1 protein (strain A22). The construct has higher protective, antigenic, immunogenic and T-cell proliferative activity then the previously described shorter peptide Palm(2)135-159. The 170-188 part of the construct serves as a virus specific T-epitope, responsible for the enhanced immunogenic and protective activity of the construct.

Synthetic vaccine against foot-and-mouth disease based on a palmitoyl derivative of the VP1 protein 135-159 fragment of the A22 virus strain.

The peptide Palm2 135-159, a dipalmitoyl derivative of the 135-159 fragment of VP1 protein of the foot-and-mouth disease virus strain A22 was synthesized. In the experiments on mice, guinea pigs and sheep Palm2 135-159 possesses greater immunogenic and protective activity than the nonacylated 135-159 peptide. The synthetic vaccine against foot-and-mouth disease for use in sheep was developed on the basis of the lipopeptide. Synthetic polymethylsiloxane oil was found to be a suitable adjuvant for this vaccine. The dependencies of protective and immunogenic effects from the dose of peptide were studied. The vaccine was found to be stable to storage for 1 year at 18 degrees C. It was shown that the synthetic vaccine provides 1 year protection of sheep against foot-and-mouth disease after a single administration. The vaccine is allowed for veterinary use in Russia.

New virus-specific T-helper epitopes of foot-and-mouth disease viral VP1 protein.

Immunogenicity studies of synthetic peptides from different regions of VP1 protein of foot-and-mouth disease virus strain A22 revealed the following active fragments: 39-61, 50-69, 135-159, 175-189, 170-189 and 197-213. Testing of virus neutralizing antibody production in rabbits primed by peptides and then inoculated by the virus showed that only peptides 135-159 and 170-189 were able to induce the functional T-cell helper activity. Localization of virus-specific T-cell recognition sites in sequences 135-159 and 170-189 was confirmed in in vitro recognition experiments of the virus by peptide activated mice lymphocytes.