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Integrin-mediated cell-extracellular matrix (ECM) interactions play crucial roles in a broad range of physiological and pathological processes. Kindlins are important positive regulators of integrin activation. The FERM-domain-containing kindlin family comprises three members, kindlin-1, kindlin-2 and kindlin-3 (also known as FERMT1, FERMT2 and FERMT3), which share high sequence similarity (identity >50%), as well as domain organization, but exhibit diverse tissue-specific expression patterns and cellular functions. Given the significance of kindlins, analysis of their atomic structures has been an attractive field for decades. Recently, the structures of kindlin and its β-integrin-bound form have been obtained, which greatly advance our understanding of the molecular functions that involve kindlins. In particular, emerging evidence indicates that oligomerization of kindlins might affect their integrin binding and focal adhesion localization, positively or negatively. In this Review, we presented an update on the recent progress of obtaining kindlin structures, and discuss the implication for integrin activation based on kindlin oligomerization, as well as the possible regulation of this process. Ministry of Education (MOE) Ministry of Health (MOH) National Research Foundation (NRF) Published version Our work in this area was supported by the Tier II grants MOE2017-T2-1-106 (Y.-G.G.) and MOE2016-T2-1-021 (S.-M.T.) from the Ministry of Education - Singapore (MOE). This research was also supported by the National Research Foundation Singapore under its Open Fund - Individual Research Grant (MOH000218) (S.-M.T.) and administered by the Singapore Ministry of Health’s National Medical Research Council.

The aim of the study was to study the characteristics of The IgE profile of sensitization to weeds, and in particular to Salsola kali, depending on the age of patients with respiratory allergies who live in the city of Tashkent. The serum of 401 patients with confirmed respiratory Allergy symptoms was tested using the Alex research allergo test (Macro Array Diagnostics). statistical analysis of the data was performed using IBM SPSS 20 and Microsoft Excel. Analysis of sensitization profiles showed that among 401 patients, specific IgE to Salsola kali were detected in 154 people, which is 38%, which indicates that this allergenic source is predominant in sensitization to weeds presented in the research chip. Most often, sensitization to Salsola kali was determined in patients aged 4 to 18 years - only 98 cases (almost 64% among all those sensitive to Salsola kali), while the largest number of sensitized to this source of Allergy was in the group "children" aged 4-11 years – 53 cases-almost 34.5% of all detected cases of sensitivity to Salsola kali. In the groups of patients aged 19-29 and 30-45 years, there were fewer cases – 28 patients (on average, this is 18% for each age group). There were no statistically significant gender differences in sensitivity to Salsola kali. The data obtained confirm the need for mandatory inclusion in the chip diagnostics of the major allergen Sal k1 in this region and for preventive and preventive measures in relation to allergosensitization to Salsola kali, especially in patients under the age of 18 years

Kindlin-1, -2, and -3 directly bind integrin β cytoplasmic tails to regulate integrin activation and signaling. Despite their functional significance and links to several diseases, structural information on full-length kindlin proteins remains unknown. Here, we report the crystal structure of human full-length kindlin-3, which reveals a novel homotrimer state. Unlike kindlin-3 monomer, which is the major population in insect and mammalian cell expression systems, kindlin-3 trimer does not bind integrin β cytoplasmic tail as the integrin-binding pocket in the F3 subdomain of 1 protomer is occluded by the pleckstrin homology (PH) domain of another protomer, suggesting that kindlin-3 is auto-inhibited upon trimer formation. This is also supported by functional assays in which kindlin-3 knockout K562 erythroleukemia cells reconstituted with the mutant kindlin-3 containing trimer-disrupting mutations exhibited an increase in integrin-mediated adhesion and spreading on fibronectin compared with those reconstituted with wild-type kindlin-3. Taken together, our findings reveal a novel mechanism of kindlin auto-inhibition that involves its homotrimer formation., The crystal structure of a human full-length kindlin protein (kindlin-3) reveals a homotrimeric complex; together with in vitro and in vivo data, this suggests an auto-inhibition model for kindlins in integrin activation.

The effect of acute restrained stress on cognitive functions and anxiety-like behavior in white rats has been studied; furthermore, the influence of the fragment ACTH(4–10) analog Semax on the stress effects was evaluated. It was shown that stress exposure leads to impaired retention of previously acquired food-motivated maze task as well as reduced anxiety-like behavior in the elevated plus maze in rats. Preliminary intraperitonial administration of Semax (0.1 mg/kg) attenuates cognitive impairment caused by acute restrained stress, but it does not affect stress-induced changes in anxiety.

Exposure to stress during early postnatal development can cause neurological disorders in adulthood. The aim of this study was to evaluate changes in behavior, learning ability, and the content of the neurotrophic factor BDNF in rats that underwent neonatal stress. In addition, we studied the possibility of correction of the effects of neonatal stress by subsequent administration of an analog of the ACTH(4-10) fragment Semax. Neonatal isolation (NI) was used as a stress stimulus. Rat pups were separated from their mother and littermates for 5 h per day each day during the period from the 1st to the 14th day of life. The control animals were left in their nest in the first 2 weeks of life. From the 15th to 28th day of life, half of the rats subjected to NI were intranasally treated with Semax daily at a dose of 0.05 mg/kg. The remaining animals received intranasal injection of solvent at the same time. It has been shown that NI leads to an increase in the level of anxiety, a slight increase in depression, and impaired retention of the passive avoidance task in rats during the second month of life. At the age of 1 month, we observed an increase in the content of BDNF in the frontal cortex in the rats with NI; at the age of 2 months, a decrease occurred in the neurotrophin level in the hippocampus. Administration of Semax to rats subjected to NI decreased anxiety and depression, improved learning ability, and normalized the BDNF content in brain structures of animals. Therefore, chronic intranasal Semax administration after NI weakens the negative effects of neonatal stress.

A key goal in process development for antibodies is to increase productivity while maintaining or improving product quality. During process development of an antibody, titers were increased from 4 to 10 g/L while simultaneously decreasing aggregates. Process development involved optimization of media and feed formulations, feed strategy, and process parameters including pH and temperature. To better understand how CHO cells respond to process changes, the changes were implemented in a stepwise manner. The first change was an optimization of the feed formulation, the second was an optimization of the medium, and the third was an optimization of process parameters. Multiple process outputs were evaluated including cell growth, osmolality, lactate production, ammonium concentration, antibody production, and aggregate levels. Additionally, detailed assessment of oxygen uptake, nutrient and amino acid consumption, extracellular and intracellular redox environment, oxidative stress, activation of the unfolded protein response (UPR) pathway, protein disulfide isomerase (PDI) expression, and heavy and light chain mRNA expression provided an in-depth understanding of the cellular response to process changes. The results demonstrate that mRNA expression and UPR activation were unaffected by process changes, and that increased PDI expression and optimized nutrient supplementation are required for higher productivity processes. Furthermore, our findings demonstrate the role of extra- and intracellular redox environment on productivity and antibody aggregation. Processes using the optimized medium, with increased concentrations of redox modifying agents, had the highest overall specific productivity, reduced aggregate levels, and helped cells better withstand the high levels of oxidative stress associated with increased productivity. Specific productivities of different processes positively correlated to average intracellular values of total glutathione. Additionally, processes with the optimized media maintained an oxidizing intracellular environment, important for correct disulfide bond pairing, which likely contributed to reduced aggregate formation. These findings shed important understanding into how cells respond to process changes and can be useful to guide future development efforts to enhance productivity and improve product quality.

Chromatin regulators (CRs) can dynamically modulate chromatin architecture to epigenetically regulate gene expression in response to intrinsic and extrinsic signalling cues. Somatic alterations or misexpression of CRs might reprogram the epigenomic landscape of chromatin, which in turn lead to a wide range of common diseases, notably cancer. Here, we present CR2Cancer, a comprehensive annotation and visualization database for CRs in human cancer constructed by high throughput data analysis and literature mining. We collected and integrated genomic, transcriptomic, proteomic, clinical and functional information for over 400 CRs across multiple cancer types. We also built diverse types of CR-associated relations, including cancer type dependent (CR-target and miRNA-CR) and independent (protein-protein interaction and drug-target) ones. Furthermore, we manually curated around 6000 items of aberrant molecular alterations and interactions of CRs in cancer development from 5007 publications. CR2Cancer provides a user-friendly web interface to conveniently browse, search and download data of interest. We believe that this database would become a valuable resource for cancer epigenetics investigation and potential clinical application. CR2Cancer is freely available at http://cis.hku.hk/CR2Cancer.

A kinetic method of biotesting of aqueous solutions using isolated cells of unicellular organism Spirostomum ambigua has been described. A kinetic scheme of interaction of cellular biosensor with ligands based on the Michaelis-Menten mechanism was proposed. It was shown that the death rate of S. ambigua featured the Arrhenius-type dependence on temperature. The activation energy was determined for different toxicants and drugs. For many compounds the activation energy of slow stage of the process of cellular biosensor death linearly correlates with parameter DL50 for the same substances at their oral administration to laboratory animals.

Perinatal hypoxia is an important factor that has a negative influence on the development of the central nervous system. Children who experience perinatal hypoxia are characterized by disturbances of locomotor functions, decreased learning abilities, attention disorder, hyperactivity, increased anxiety, and other cognitive impairments. The consequences of perinatal hypoxia are actively studied in experiments with animals. It has been shown that hypoxia triggers a cascade of biochemical and molecular processes, such as energy insufficiency, depolarization of membranes, an increase in the release of mediators and suppression of their reuptake, an increase in the intracellular calcium level, and production of free radicals, which damage neurons and induce neurodegeneration and cell death. Simultaneously, compensatory-adaptive mechanisms that increase the resistance of the body to an oxygen deficit also begin to function in hypoxia. Further studies on the consequences of neonatal hypoxia in experiments with animals are necessary for the elucidation of the mechanisms of the acute and delayed effects of hypoxia, as well as for development of effective means for the correction of the negative consequences of perinatal hypoxia in clinics.

The aim of the present study was to investigate biological properties of the novel nitrobenzoxadiazole derivative 7-(1-methyl3-pyrrolyl-)-4,6-dinitrobenzofuroxan. Materials and Methods: We used a bioluminescent test based on a set of lux-biosensors, which are genetically modified E.coli strains able to react on different types of factors that can induce an SOS-response with light emission. The spontaneous and induced mutation frequencies of antibiotic resistance in E. coli were determined by methods of classical genetics of microorganisms. Results: 7-(1-methyl-3-pyrrolyl-)-4,6-dinitrobenzofuroxan demonstrated inhibition of SOS-response in a biosensor model system and significantly reduced the frequency of spontaneous mutations and mutations induced by ciprofloxacin of antibiotic resistance. Conclusion: Based on our data, we can recommend using compound 1 as a starting point for the development of drugs that block mutagenesis associated with the emergence of antibiotic-resistant bacteria. (Int J Biomed. 2016;6(3):228-232.).

New therapies are needed against malaria, a parasitic infection caused by Plasmodium falciparum, as drug resistance emerges against the current treatment, artemisinin. We previously characterized the Atg8-Atg3 protein-protein interaction (PPI), which is essential for autophagy and parasite survival. Herein we illustrate the use of virtual library screening to selectively block the PPI in the parasite without inhibiting the homologous interaction in humans by targeting the A-loop of PfAtg8. This A-loop is important for Atg3 binding in Plasmodium, but is absent from the human Atg8 homologues. In this proof-of-concept study, we demonstrate a shift in lipidation state of PfAtg8 and inhibition of P. falciparum growth in both blood- and liver-stage cultures upon drug treatment. Our results illustrate how in silico screening and structure-aided drug design against a PPI can be used to identify new hits for drug development. Additionally, as we targeted a region of Atg8 that is conserved within apicomplexans, we predict that our small molecule will have cross-reactivity against other disease-causing apicomplexans, such as Toxoplasma, Cryptosporidium, Theileria, Neospora, Eimeria, and Babesia.

The kinetics of biological reactions depends on the deuterium/protium (D/H) ratio in water. In this work, we describe the kinetic model of biocatalytic reactions in living organisms depending on the D/H ratio. We show that a change in the lifetime or other characteristics of the vital activity of some organisms in response to a decrease or increase in the content of deuterium in the environment can be a sign of a difference in taxons. For animals&mdash, this is a curve with saturation according to the Gauss&rsquo, s principle, for plants&mdash, it is the Poisson dependence, for bacteria a weakly saturated curve with a slight reaction to the deuterium/protium ratio toward increasing deuterium. The biological activity of the aquatic environment with reduced, elevated, and natural concentrations of deuterium is considered. The results of the study are presented in different vital indicators of some taxons: the bacteria kingdom&mdash, the colony forming units (CFU) index (Escherichia coli), animals&mdash, the activation energy of the death of ciliates (Spirostomum ambiguum), embryogenesis of fish (Brachydanio rerio), plants&mdash, germination and accumulation of trace elements Callisia fragrans L., sprouting of gametophores and peptidomics of moss Physcomitrella patens. It was found that many organisms change their metabolism and activity, responding to both high and low concentrations of deuterium in water.

Background Tissue precursors of uterine carcinosarcomas remain unknown, therefore targeted therapy has not been determined. Methods This research is based on the investigation of formalin‐fixed, paraffin‐embedded tissue blocks from 17 women undergoing primary surgical treatment between 1961–2010, that were retrieved from the pathoanatomical department of the Institute of Oncology named after N.N.Petrov. In the present study, molecular investigations were applied to determine the pathogenesis of uterine carcinosarcomas. We have analyzed microsatellite instability, mutations of TP53 (exons 5-9), PTEN (exons 5, 8), K-RAS (exon 1) and loss of heterozygosity of variable loci of the chromosome 17 in epithelial and mesenchymal components of uterine carcinosarcomas. DNAs were extracted by proteinase K digestion («Fisher» US) by Herrington, C.S. & McGee, J.O. Mutations of TP53, PTEN and K-RAS were defined by SSCP with the next sequence. Highly sensitive markers BAT 26 and BAT 40 were used for analysis of microsatellite instability. Results The loss of heterozygosity of variable markers of the short arm of the 17th chromosome was detected (in 9 of 17 tumours- 52,9%). All 17 tumours were microsatellite stable. K-ras mutations were detected in 2 of 17 tumours - 11,7%. One tumour contained identical mutations in both components, other one contained mutations only in the epithelial component. Mutations in the TP53 were identified in 13 of 17 tumours - 76,5%. Five (29,4%) tumours contained identical mutations in both components, 8 (47,1%) - only in the epithelial component and 4 showed wild-type TP53. PTEN mutations were detected in 11 of 17 tumours - 64,7%. Six tumours (35,3%) contained wild-type PTEN. Tumours with PTEN mutations showed worse prospects than ones with wild-type PTEN: 1-yr overall survival - 12,5% vs 60 %, р Conclusions Uterine carcinosarcomas are the microsatellite stable tumours. This type of tumours is associated with chromosomal instability of the genome. PTEN mutations are matched with poor prognosis and low overall survival. The present study of PTEN damages may be important for targeted therapy by the PARP inhibitors. Legal entity responsible for the study Russian Medical Academy for Continuous Professional Education. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

The objective of the present study was the development of the comprehensive program for the medico-psychological follow-up of the male and female junior athletes (rhythmic gymnastics) with the purpose of stabilizing their hormonal and emotional status, as well as improving sport performances based on the use of modern hardware-software technologies.The comprehensive examination of 72 female athletes at the mean age of 11.5±0.6 years attending R. Kuznetsov specialized school of rhythmic gymnastics of the Olympic reserve in the city of Seversk has been undertaken on the basis of Tomsk Research Institute of Balneology and Physiotherapy, the branch of Siberian Federal Research and Clinical Centre.The program of comprehensive medical psychological rehabilitation for the junior athletes of either sex engaged in sportive activities requiring precise technical actions has been elaborated. The method of the combined therapeutic treatment included physical exercises therapy, manual massage, dry carbonic bathtubs, psychological activities with the application of biological feedback trainings and cognitive trainings; it was intended for the correction of the hormonal status and the improvement of the psycho-emotional conditions of the athletes. The combined treatment based on the use of the modern hardware-software technologies was shown to promote the restoration and development of the psychophysical and psychological qualities of the male and female junior athletes indispensable for the maintenance of their high readiness for the efficient sports activities at the subsequent stages of the training cycle. In addition, such treatment enhances the adaptation resources of the athletes.Цель — разработать комплексную программу медико-психологического сопровождения спортсменов-юниоров (художественная гимнастика), направленную на стабилизацию их гормонального и эмоционального статусов, развитие спортивно значимых качеств с использованием современных программно-аппаратных технологий. Материал и методы. На базе филиала ТНИИКиФ ФГБУ СибФНКЦ ФМБА России проведено комплексное обследование 72 спортсменов в возрасте 11,5±0,6 года, занимающихся в Специализированной детско-юношеской спортивной школе олимпийского резерва гимнастики им. Р. Кузнецова (Северск). Результаты. Разработана комплексная программа медико-психологической реабилитации спортсменов-юниоров, занимающихся сложнокоординационными видами спорта. Лечебный комплекс, включающий ручной массаж, сухие углекислые ванны, психологические мероприятия с применением тренингов с биологической обратной связью и когнитивных тренировок, направлен на коррекцию гормонального статуса и улучшение психоэмоционального состояния спортсменов. Комплексное лечение с применением современных программно-аппаратных технологий способствует восстановлению и развитию спортивно значимых психофизических и психологических качеств спортсменов, что обеспечивает их высокую готовность к эффективной спортивной деятельности на последующих этапах тренировочного цикла и повышает их адаптационный ресурс.

The aim of this work was to study the delayed effects of chronic neonatal administration of the selective serotonin reuptake inhibitor fluvoxamine (FA) to white rat pups and to estimate the possibility to correct these effects by treatment with semax. Fluvoxamine was injected intraperitoneally at a dose of 10 mg/kg from postnatal days 1 to 14, and semax was injected intranasally at a dose of 0.05 mg/kg from postnatal days 15 to 28. It was shown that neonatal FA administration produced a significant delay in animal somatic growth. A loss in body weight was detected both during FA administration and 4-6 weeks after the last injection. Furthermore, FA administration increased the anxiety level and disturbed the learning ability of animals. The negative consequences of neonatal FA administration were largely compensated by Semax.

Atg8 is a ubiquitin-like autophagy protein in eukaryotes that is covalently attached (lipidated) to the elongating autophagosomal membrane. Autophagy is increasingly appreciated as a target in diverse diseases from cancer to eukaryotic parasitic infections. Some of the autophagy machinery is conserved in the malaria parasite, Plasmodium. Although Atg8's function in the parasite is not well understood, it is essential for Plasmodium growth and survival and partially localizes to the apicoplast, an indispensable organelle in apicomplexans. Here, we describe the identification of inhibitors from the Malaria Medicine Venture Malaria Box against the interaction of PfAtg8 with its E2-conjugating enzyme, PfAtg3, by surface plasmon resonance. Inhibition of this protein-protein interaction prevents PfAtg8 lipidation with phosphatidylethanolamine. These small molecule inhibitors share a common scaffold and have activity against both blood and liver stages of infection by Plasmodium falciparum. We have derivatized this scaffold into a functional platform for further optimization.

The pepsinogenemia level is examined as a risk factor of atrophy and inflammation activity in gastroduodenal region mucous region in 20 patients with erosive and ulcerous changes this localization as before as after operations with cardiopulmonary bypass. It is marked that the values of pepsinogen 1 ((209,58 ± 14,41) μg/l) and pepsinogen 1 ((30,01 ± 4,00) μg/l) in plasma are exceeded than normal magnitudes. It is revealed that using omeprazole intravenous and peroral after that can prevent of acute ulcers and gastric bleeding in these patients and associated with decrease of pepsinogen 1 (in 1,2 times) and pepsinogen 2 (in 2,1 times) plasma levels comparing values before operation. In spite of acute ulcers and gastroduodenal bleeding default, gastropaty with erosions in antrum of stomach persists in 35% of cardiosurgical patiewnts.

Consistent performance of anti-drug antibody (ADA) assays through all stages of clinical development is critical for the assessment of immunogenicity and interpretation of PK, PD, safety, and efficacy. The electrochemiluminescent assays commonly employed for ADA measurement use drug conjugated with ruthenium and biotin to bind ADA in samples. Here we report an association between high nonspecific ADA responses in certain drug-naïve individuals and the storage buffer of the conjugated reagents used in a monoclonal antibody ADA assay. Ruthenylated reagents stored in phosphate-buffered saline (PBS) buffer had increased levels of aggregate and produced variable and high baseline responses in some subjects. Reagents stored in a histidine-sucrose buffer (HSB) had lower aggregate levels and produced low sample responses. In contrast to PBS, conjugated reagents formulated in HSB remained low in aggregate content and in sample response variability after 5 freeze/thaw cycles. A reagent monitoring control (RMC) serum was prepared for the real-time evaluation of conjugated reagent quality. Using appropriate buffers for storage of conjugated reagents together with RMCs capable of monitoring of reagent aggregation status can help ensure consistent, long-term performance of ADA methods.

The syntaxin 11 (STX11) gene is mutated in a proportion of patients with familial haemophagocytic lymphohistiocytosis (FHL) and exocytosis of cytotoxic granules is impaired in STX11-deficient NK cells. However, the subcellular localization, regulation of expression and molecular function of STX11 in NK cells and other cytotoxic lymphocytes remain unknown. Here we demonstrate that STX11 expression is strictly controlled by several mechanisms in a cell-type-specific manner and that the enzymatic activity of the proteasome is required for STX11 expression in NK cells. In resting NKL cells, STX11 was localized in the cation-dependent mannose-6-phosphate receptor (CD-M6PR)-containing compartment, which was clearly distinct from cytotoxic granules or Rab27a-expressing vesicles. These subcellular structures appeared to fuse at the contact area with NK-sensitive target cells as demonstrated by partial colocalization of STX11 with perforin and Rab27a. Although STX11-deficent allo-specific cytotoxic T-lymphocytes efficiently lysed target cells and released cytotoxic granules, they exhibited a significantly lower extent of spontaneous association of perforin with Rab27a as compared with STX11-expressing T cells. Thus, our results suggest that STX11 promotes the fusion of Rab27a-expressing vesicles with cytotoxic granules and reveal an additional level of complexity in the spatial/temporal segregation of subcellular structures participating in the process of granule-mediated cytotoxicity.

BCR-triggering shown as the first known B-cell-specific signal enhancing cellular sensitivity to TRAIL. TRAIL is known to cause death in tumor cells, but physiological regulation of its activity remains poorly characterized. We demonstrate that BCR triggering sensitizes transformed centroblast-like BL cells and peripheral blood memory B cells to TRAIL-mediated apoptosis. The sensitization correlated with surface down-regulation and intracellular retention of TRAIL-R4, along with changes in the expression of several Bcl-2 protein family members. Although enhancing FAS-mediated cell death, CD40 activation protected B cells from TRAIL-induced apoptosis. Combination of Ig cross-linking with CD40 ligation did not prevent TRAIL-R4 down-regulation but induced changes in the mitochondria-regulated pathway of apoptosis that are known to be associated with resistance to TRAIL. Human CD5+ B cells, presumably stimulated by reactivity to self without immunological help, exhibited very high ex vivo sensitivity to TRAIL. Our results define the first B-lymphocyte-specific physiological signal that increases cellular sensitivity to TRAIL. This may be important for our understanding of TRAIL involvement in the control of B cell responses and aid in designing TRAIL-based therapies for B cell lymphomas.

Weak neurotoxins belong to the superfamily of three-finger toxins from snake venoms. In general, weak toxins have a low toxicity and, contrary to other three-finger toxins, their molecular targets are not well characterized: in vitro tests indicate that these may be nicotinic acetylcholine receptors. Here, we report the influence of intraperitoneal and intravenous injections of weak neurotoxin from Naja kaouthia venom on mouse behaviour. Dose-dependent suppression of orientation-exploration and locomotion activities as well as relatively weak neurotropic effects of weak neurotoxin were observed. The myorelaxation effect suggests a weak antagonistic activity against muscle-type nicotinic acetylcholine receptors. Neurotoxic effects of weak neurotoxin were related to its influence on peripheral nervous system. The symptomatology of the intoxication was shown to resemble that of muscarinic agonists. Our data suggest that, in addition to interaction with nicotinic acetylcholine receptors observed earlier in vitro, weak neurotoxin interacts in vivo with some other molecular targets. The results of behavioural experiments are in accord with the pharmacological profile of weak neurotoxin effects on haemodynamics in mice and rat indicating the involvement of both nicotinic and muscarinic acetylcholine receptors.

The current therapy of uveal melanoma (UM) metastases remains inefficient, which warrants the development of new treatment modalities. For the first time we investigated the effects of retinoic acid (RA) on a panel of UM cell lines and found that RA induces morphological changes compatible with differentiation, suppresses proliferation and causes apoptosis in these cells. RA treatment resulted in an increase of p21, p27 and p53 protein levels and G1 arrest in UM cells, which correlated with significant down-modulation of surface Her2/neu proto-oncogene expression. In addition, RA-treated UM cells exhibited increased sensitivity to both MHC class I-restricted killing by cytotoxic T lymphocytes and NK cell-mediated lysis that were accompanied by more efficient conjugate formation between UM cells and killer lymphocytes. Taken together, our results implicate UM as a new target for treatment with retinoids and suggest that retinoids and T- or NK-cell based immunotherapy can have mutually enhancing effects in UM patients.

The ability of heat shock proteins (HSPs) to increase the potency of protein- and DNA-based vaccines has been previously reported. We have constructed several plasmid-based vectors encoding chimeric proteins containing prostate-specific antigen (PSA) fused to Mycobacterium tuberculosis hsp70, M. bovis hsp65, Escherichia coli DnaK (hsp70), or human hsp70. Immunizing mice with these plasmids induced CD8+ cytotoxic T lymphocytes (CTLs) specific to human PSA and protected mice from a subsequent subcutaneous challenge with PSA-expressing tumors. We did not observe a significant difference either in the levels of PSA-specific CTLs or in protection against tumor challenge in mice immunized with plasmids expressing PSA-HSP chimeric proteins, as compared to mice receiving a conventional PSA-expressing DNA plasmid. Our data indicate that using HSPs as fusion partners for tumor-specific antigens does not always result in the enhancement of antigen-specific CTL responses when applied in the form of DNA vaccines. The ability of heat shock proteins (HSPs) to increase the potency of protein- and DNA-based vaccines has been previously reported. We have constructed several plasmid-based vectors encoding chimeric proteins containing prostate-specific antigen (PSA) fused to Mycobacterium tuberculosis hsp70, M. bovis hsp65, Escherichia coli DnaK (hsp70), or human hsp70. Immunizing mice with these plasmids induced CD8+ cytotoxic T lymphocytes (CTLs) specific to human PSA and protected mice from a subsequent subcutaneous challenge with PSA-expressing tumors. We did not observe a significant difference either in the levels of PSA-specific CTLs or in protection against tumor challenge in mice immunized with plasmids expressing PSA-HSP chimeric proteins, as compared to mice receiving a conventional PSA-expressing DNA plasmid. Our data indicate that using HSPs as fusion partners for tumor-specific antigens does not always result in the enhancement of antigen-specific CTL responses when applied in the form of DNA vaccines.

This report describes studies cf the effects of the ACTH(4-10) analog Semax (MEHFPGP) on the behavior of white rats with lesions to the brain dopaminergic system induced by the neurotoxin MPTP. Neurotoxin was given as single i.p. doses of 25 mg/kg. Neurotoxin injections were shown to decrease movement activity and increase anxiety in the animals. Daily intranasal administration of Semax at a dose of 0.2 mg/kg decreased the severity of MPTP-induced behavioral disturbances. The protective activity of Semax in MPTP-induced lesions of the brain dopaminergic system may be associated with both its modulating effect on the dopaminergic system and the neurotrophic action of the peptide.

A decrease in the expression of HLA antigens is considered a characteristic of tumor progression and is considered an important tumor-escape mechanism. In general, HLA Class I expression is even further decreased on metastases. Tumor cells that loose their HLA Class I antigens become less susceptible to lysis by specific T cells, but may become more sensitive to Natural Killer cells. Loss of HLA Class I can be observed at different levels, i.e. total loss of Class I, loss of expression of one locus or one haplotype, or even one specific allele. We studied HLA expression on human uveal melanoma and observed that loss of expression of a locus or one or more alleles is a common phenomenon. However, in contrast with the commonly accepted paradigm, loss of HLA Class I expression on the uveal melanoma was not associated with tumor cell escape and a worse survival, but with a better survival of the patients involved. We hypothesize that this is due to the route of metastases formation: in uveal melanoma, spreading of metastases is purely hematogeneous, and it is quite possible that NK-cell mediated surveillance of tumor cells in the blood is the underlying mechanism. This is supported by our finding that metastases of uveal melanoma have a high HLA Class I expression, leading to our conclusion that uveal melanoma is an exception to the general rule regarding HLA Class I expression in tumor immunology.

Malaria, the disease caused by Plasmodium parasites, remains a major global health burden. The liver stage of Plasmodium falciparum infection is a leading target for immunological and pharmacological interventions. Therefore, novel approaches providing specific detection and isolation of live P. falciparum exoerythrocytic forms (EEFs) are warranted. Utilizing a recently generated parasite strain expressing green fluorescent protein (GFP) we established a method which, allows for detection and isolation of developing live P. falciparum liver stages by flow cytometry. Using this technique we compared the susceptibility of five immortalized human hepatocyte cell lines and primary hepatocyte cultures from three donors to infection by P. falciparum sporozoites. Here, we show that EEFs can be detected and isolated from in vitro infected cultures of the HC-04 cell line and primary human hepatocytes. We confirmed the presence of developing parasites in sorted live human hepatocytes and characterized their morphology by fluorescence microscopy. Finally, we validated the practical applications of our approach by re-examining the importance of host ligand CD81 for hepatocyte infection by P. falciparum sporozoites in vitro and assessment of the inhibitory activity of anti-sporozoite antibodies. This methodology provides us with the tools to study both, the basic biology of the P. falciparum liver stage and the effects of host-derived factors on the development of P. falciparum EEFs.

It has been found that inDatura innoxia lectins 21% of the tryptophan residues are selectively oxidized by N-bromosuccinimide (NBS) under nondenaturing conditions, which shows that one or two residues are exposed on the surface of the molecule. At the same time the hemagglutinating activity (HA) decreases by 50%. When half of all the Trp is oxidized only 30% of the HA is retained. A sharp fall in the HA on the oxidation of ∼1/7 of all the Trp indicates the great importance of at least one residue for the interaction of the lectin with erythrocytes. In the hydrophobic region of the molecule 79% of the Trp is screened, and this is exposed in 8 M urea.

Defects of antigen processing/presentation have been suggested to play a role in the escape of Burkitt's lymphoma (BL) from cytotoxic T lymphocyte (CTL)-mediated rejection. Impaired presentation of an immunodominant HLA AII-restricted epitope from the resident or recombinant vaccinia virus-expressed Epstein-Barr virus nuclear antigen (EBNA)4 was demonstrated in the EBV-positive E95B-BL28 and its EBV-negative parental BL28 cell lines. We have investigated whether this was due to (i) impaired production of the antigenic peptide, (ii) poor peptide translocation into the ER lumen or (iii) inefficient maturation and transport of the MHC-peptide complexes at the cell surface. The defect was not overcome by cytosolic expression of a pre-formed epitope, suggesting that presentation of EBNA4 is not limited by inefficient production of the antigenic peptide. BL28 expressed 5- to 10-fold lower levels of the transporter associated with antigen presentation (TAP) 1 and TAP2 proteins and behaved poorly in a streptolysin-O-mediated peptide translocation assay, whereas E95B-BL28 showed higher TAP expression and virtually normal transporter function. Up-regulation of HLA AII and reconstitution of TAP activity by treatment with IFN-γ did not restore presentation of the resident EBNA4 in E95B-BL28 and did not enhance presentation of the vaccinia virus-expressed intact protein or preformed epitope. Efficient maturation of class I molecules to Endo H-resistant species was demonstrated in pulse-chase experiments. Taken together, our findings identify a previously uncharacterized defect of antigen presentation which appears to affect events occurring after proteasomal degradation but before TAP-dependent peptide transport and MHC class I assembly and maturation. © 1996 Wiley-Liss, Inc.

We have investigated the reactivity to two human histocompatibility leukocyte antigen (HLA) A11-restricted cytotoxic T lymphocyte (CTL) epitopes derived from amino acids 416-424 (IVTDFSVIK, designated IVT) and 399-408 (AVFDRKSVAK, designated AVF) of the Epstein-Barr virus (EBV) nuclear antigen (EBNA) 4. A strong predominance of CTL clones specific for the IVT epitope was demonstrated in polyclonal cultures generated by stimulation of lymphocytes from the EBV-seropositive donor BK with the autologous B95.8 virus-transformed lymphoblastoid cell line (LCL). This was not due to intrinsic differences of CTL efficiency since clones specific for the two epitopes lysed equally well A11-positive phytohemagglutinin blasts and LCLs pulsed with the relevant synthetic peptide. Irrespective of the endogenous levels of EBNA4 expression, untreated LCLs were lysed more efficiently by the IVT-specific effectors, suggesting that a higher density of A11-IVT complexes is presented at the cell surface. In accordance, 10-50-fold higher amounts of IVT peptides were found in high-performance liquid chromatography fractions of acid extracts corresponding to an abundance of about 350-12,800 IVT and 8-760 AVF molecules per cell. Peptide-mediated competition of CTL sensitization, transport assays in streptolysin-O permeabilized cells, and induction of A11 expression in the transporter associated with antigen presentation-deficient T2/A11 transfectant demonstrated that the IVT and AVF peptides bind with similar affinities to A11, are translocated with equal efficiency to the endoplasmic reticulum, and form complexes of comparable stability over a wide range of temperature and pH conditions. A rapid surface turnover of A11 molecules containing the AVF peptide was demonstrated in metabolically active T2/A11 cells corresponding to a half-life of approximately 3.5 as compared to approximately 2 h for molecules induced at 26 degrees C in the absence of exogenous peptides and >12 h for IVT-containing complexes. This difference in persistence is likely to determine the representation of individual class I-restricted CTL epitopes within the cell surface pool of molecules, and may be an important factor contributing to their immunogenicity.

The establishment of persistent infections is a common feature of tumor-associated viruses. The capacity to maintain a long-term relationship with the host presupposes viral mechanisms for circumventing antiviral defenses. Recent findings have highlighted multiple strategies of immune evasion that allow the persistence of Epstein-Barr virus infected cells and promote the spread of the virus in immunocompetent hosts. These strategies are likely to play an important role in the pathogenesis of EBV-associated malignancies.

Lectins I1 and I2 of Datura innoxia, which are glycoproteins glycosylated to a very high degree, have been deglycosylated completely by the use of trifluoromethanesulfonic acid. The deglycosylated lectins retained their hemagglutinating activity.

Lectin was isolated from seeds of IndianDatura innoxia. Certain of its physicochemical properties were determined. Its hemaglutinizing activity was demonstrated. The effect of the obtained protein on proliferation of the hybrid KML cell line from murine B-16 melanoma was studied. Its mitogenic properties were demonstrated.

IFN-γ, a pleiotropic immune regulator, is implicated in both tumor immune surveillance and selection of tumor variants resistant to immune control, i.e., immunoediting. In uveal melanoma patients, elevated serum levels of IFN-γ correlate with the spread of metastasis and represent a negative prognostic marker. Treatment with IFN-γ boosted the MHC class I presentation machinery in uveal melanoma cells but suppressed their MHC class I-restricted CTL lysis. Tumor cells exposed to IFN-γ efficiently activated specific CTL but were less susceptible to permeabilization by perforin and exhibited a decreased capacity to bind and incorporate granzyme B. These results define a novel mechanism of resistance to granule-mediated CTL lysis in human tumors. Furthermore, the data suggest that immunoediting is not limited to genetic or epigenetic changes resulting in stable cellular phenotypes but also involves an inducible modulation of tumor cells in response to a microenvironment associated with immune activation.

Sympathetic neuronal differentiation is associated with favorable prognosis of neuroblastoma (NB), the most common extra-cranial solid tumor of early childhood. Differentiation agents have proved useful in clinical protocols of NB treatment, but using them as a sole treatment is not sufficient to induce tumor elimination in patients. Therefore, complementary approaches, such as immunotherapy, are warranted. Here we demonstrate that differentiation of NB cell lines and ex vivo isolated tumor cells in response to physiological or pharmacological stimuli is associated with acquisition of increased antigenicity. This manifests as increased expression of surface major histocompatibility class I complexes and ICAM-1 molecules and translates into increased sensitivity of NB cells to lysis by cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. The latter is paralleled by enhanced ability of differentiated cells to form immune conjugates and bind increased amounts of granzyme B to the cell surface. We demonstrate, for the first time, that, regardless of the stimulus applied, the differentiation state in NBs is associated with increased tumor antigenicity that enables more efficient elimination of tumor cells by cytotoxic lymphocytes and paves the way for combined application of differentiation-inducing agents and immunotherapy as an auxiliary approach in NB patients.

Neuroblastoma (NB) is often described as an unfavorable target for both HLA-restricted and death receptor-mediated elimination by cytotoxic T lymphocytes (CTLs) due to low or absent HLA class I and caspase-8 expression. We investigated the effects of soluble factors released by CTLs activated by TCR triggering (named as activated supernatant; AS) on the levels and composition of cell surface molecules involved in HLA-restricted and HLA-independent NB cell recognition (surface immune phenotype). Using a panel of long-term propagated NB cell lines and freshly isolated primary human NB cells, we analyzed surface expression of the (1) cognate receptors for TNFalpha, Fas and TRAIL; (2) HLA class I and II heterodimers; (3) adhesion molecules; (4) the intracellular expression and activation of caspase-8, as well as (5) the susceptibility of NB cells to death receptor-mediated killing prior to and after exposure to AS. The exposure of NB cells to soluble factors released by activated CTLs skewed the surface immune phenotype of both long term cultured and primary NB cells, induced the expression and activation of caspase-8 and increased the susceptibility of tumor cells to lysis by TRAIL and Fas-agonistic antibody. Blocking experiments identified IFNgamma and TNFalpha as main factors responsible for modulating the surface antigens of NB cells by AS. Our data suggest that recruitment of CTLs activated on third party targets into the vicinity of the NB tumor mass, may override the "silent" immune phenotype of NB cells via the action of soluble factors.

The MHC class I- restricted processing and presentation pathway is frequently nonfunctional in tumor cells; therefore, the direct targeting of tumor cells by CTLs may be difficult, if at all possible, to achieve. We used neuroblastoma (NB), which represents a striking example of a tumor with an impaired MHC class I pathway, as a model to study bystander effects of activated T lymphocytes on tumor cells. We found that NB cell lines are susceptible to killing by differentiated CD8+ CTL clones in a MHC class I-nonrestricted manner that involves two programs of cell death distinguished on the basis of different kinetics, sensitivities to caspase inhibitors, and cytokine-blocking reagents. The “early” death exhibited characteristic features of apoptosis, whereas the “delayed” caspase-independent death exhibited features associated with necrosis and was partially inhibited by TNF-α-blocking and prevented by overexpression of Bcl-2 or Bcl-xL. Our data reveal a previously unappreciated complexity of death pathways induced in tumor cells by immune activation and suggest that redirecting nonspecific effector CTLs to even a small proportion of NB cells or activating CTLs in a tumor’s proximity may have therapeutic effects in patients with NB.

The mechanisms of major histocompatibility complex (MHC) class I downregulation during Epstein-Barr virus (EBV) replication are not well characterized. Here we show that in several cell lines infected with a recombinant EBV strain encoding green fluorescent protein (GFP), the virus lytic cycle coincides with GFP expression, which thus can be used as a marker of virus replication. EBV replication resulted in downregulation of MHC class II and all classical MHC class I alleles independently of viral DNA synthesis or late gene expression. Although assembled MHC class I complexes, the total pool of heavy chains, and β2-microglobulin (β2m) were significantly downregulated, free class I heavy chains were stabilized at the surface of cells replicating EBV. Calnexin expression was increased in GFP+cells, and calnexin and calreticulin accumulated at the cell surface that could contribute to the stabilization of class I heavy chains. Decreased expression levels of another chaperone, ERp57, and TAP2, a transporter associated with antigen processing and presentation, correlated with delayed kinetics of MHC class I maturation. Levels of both class I heavy chain and β2m mRNA were reduced, and metabolic labeling experiments demonstrated a very low rate of class I heavy chain synthesis in lytically infected cells. MHC class I and MHC class II downregulation was mimicked by pharmacological inhibition of protein synthesis in latently infected cells. Our data suggest that although several mechanisms may contribute to MHC class I downregulation in the course of EBV replication, inhibition of MHC class I synthesis plays the primary role in the process.

The heptapeptide Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is an analogue of the N-terminal fragment (4-10) of adrenocorticotropic hormone which, after intranasal application, has profound effects on learning and memory formation in rodents and humans, and also exerts marked neuroprotective effects. A clue to the molecular mechanism underlying this neurotropic action was recently given by the observation that Semax stimulates the synthesis of brain-derived neurotrophic factor (BDNF), a potent modulator of synaptic plasticity, in astrocytes cultured from rat basal forebrain. In the present study, we investigated whether Semax affects BDNF levels in rat basal forebrain upon intranasal application of the peptide. In addition, we examined whether cell membranes isolated from this brain region contained binding sites for Semax. The binding of tritium-labelled Semax was found to be time dependent, specific and reversible. Specific Semax binding required calcium ions and was characterized by a mean ± SEM dissociation constant (K D ) of 2.4 ± 1.0 nM and a B MAX value of 33.5 ± 7.9 fmol/mg protein. Sandwich immunoenzymatic analysis revealed that Semax applied intranasally at 50 and 250 μg/kg bodyweight resulted in a rapid increase in BDNF levels after 3 h in the basal forebrain, but not in the cerebellum. These results point to the presence of specific binding sites for Semax in the rat basal forebrain. In addition, these findings indicate that the cognitive effects exerted by Semax might be associated, at least in part, with increased BDNF protein levels in this brain region.

Lectins I1 and I2 of Datura innoxia — highly active hemagglutinins — possess a high resistance to the effects of heat, of the pH of the medium, and of pronase. On reduction, the lectins lose their activity.

Mechanisms responsible for resistance of tumors to death receptor-mediated damage by cytotoxic lymphocytes are not well understood. Uveal melanoma cells expressed Fas but were insensitive to Fas triggering induced by bystander cytotoxic T lymphocytes or a Fas-specific agonistic antibody; this could not be ascribed to tumor counterattack against T cells or general resistance of the tumors to apoptosis. Treatment with inhibitors of metalloproteases rendered uveal melanomas sensitive to Fas-mediated cytotoxicity. Metalloprotease inhibitors did not affect the expression of Fas but increased the surface expression of Fas ligand (FasL), which correlated with the disappearance of soluble FasL from culture supernatants of tumor cells. FasL eluted from the surface of uveal melanomas specifically inhibited cytotoxic T lymphocyte lysis of tumor cells pretreated with an inhibitor of metalloproteases. In addition to uveal melanomas, a number of other tumor cell lines of various cellular origins were sensitized to Fas-mediated cytotoxicity by metalloprotease inhibitors. Our results show that autocrine secretion of FasL shields tumor cells from Fas-mediated killing by cytotoxic lymphocytes. This defines a novel mechanism of tumor escape from immune surveillance.

The present concept of relative instability of regulatory peptides (RPs) in organisms must be amended. The recently characterized family of glyprolines and some other prolyl–glycyl–proline (PGP)-containing oligopeptides show the stability quite comparable with those of major pharmacological preparations. The ability of glyprolines to pass gastro-enteric tract barriers opens ways to per-oral administration of this new group of drugs such as semax, selank and their fragments. The most interesting approach is the creation of hybrid ("chimeric") peptide drugs combining the unmodified representatives of various natural RPs that distinctly manifest their inherent physiological activities and cooperate with each other in stabilization of whole peptide in vivo. As the result, the activity of such peptides as semax and selank may have value in a vide variety of pathological processes.

The HER-2/neu (HER-2) oncogene is expressed in normal epithelial surfaces at low levels and overexpressed in several types of tumors. The low immunogenicity against this self tumor Ag can be improved by developing epitopes with amino acid replacements in their sequences. In this study, three HER-2/neu.369 (HER-2.369) analogue peptides, produced by modifying both anchor positions by introducing L, V, or T at position 2 and V at the C terminus, were analyzed for their capacity to induce CTLs in vitro from human PBMC and in vivo in HLA-A2.1/Kb transgenic mice. One of the analogues (HER-2.369 V2V9) sensitized target cells for HER-2-specific recognition by human CTLs and induced specific CTLs in vitro at 100-fold lower concentrations than the HER-2.369 wild-type epitope. These CTLs were also able to recognize the wild-type epitope and HER-2-expressing tumors in an MHC-restricted manner. Furthermore, a 100-fold lower amount of the HER-2.369 V2V9 analogue compared with the wild-type epitope was required to induce CTLs in HLA-A2.1/Kb transgenic mice. However, the V2V9 analogue demonstrated only marginally better binding to the MHC class I A2 allele compared with wild type. To establish thermodynamic parameters, we developed radiolabeled F3*Y analogues from both the HER-2.369 epitope and the V2V9 analogue. Our results indicate that the high biological activity of the HER-2.369 V2V9 epitope is associated with a slower dissociation kinetic profile, resulting in an epitope with greater HLA-A2 stability.

Motor neuron disease (MND) results in the selective degeneration of motor neurons in the cerebral cortex, brain stem and spinal cord. The most common form of MND is amyotrophic lateral sclerosis (ALS). MND is complex and many genetic systems may be involved in the pathogenesis of this disease. Pathological and animal studies implicate neurofilament involvement in MND. The heavy subunit (NEFH) tail domain contains a repeated motif. In humans, there are two common variants: the 45 motif repeats long allele (L) and 44 motif repeats short allele (S). Previous studies have shown that the NEFH tail may be involved in the pathogenesis of MND. To investigate whether the L/S genotypes of the NEFH gene are associated with MND, we studied the frequency of L and S alleles in sporadic MND patients and a control population from Moscow. We observed a difference in SS genotype frequency between the control population and sporadic MND patients from Moscow. It was established that the SS genotype is sufficiently higher in sporadic MND patients. Moreover, we determined that patients with the SS genotype have the highest value of loss of the total clinical score. In summary, we conclude that the NEFH gene is involved in the pathogenesis of sporadic MND. The SS genotype represents a risk factor for the development and progression of sporadic MND in the Moscow population.

The interaction of the lectins ofDatura innoxia with ovalbumin has been investigated. The latter exhibits an inhibiting effect in relation to the lectins studied at a molar ratio of lectin to ovalbumin of 1:280 when the concentration of ovalbumin in the solution is not less than 50 mg/ml. Under these conditions a phase transition is observed in the solution, with the formation of a precipitate of the inhibitor. Characteristic features of the interaction of the lectin with ovalbumin have been studied.