Subpopulation Heterogeneity of NK Cells during the Genetic Modification for Subsequent Use in Targeted Therapy.

Obtaining genetically engineered NK cells is a developing area of immunotherapy. In this work, we analyzed the subset heterogeneity of NK cells subjected to retroviral transduction, taking into account the content of adaptive NK cell progenitors. It was shown that subsets KIR2DL2/DL3+, as well as CD57-KIR2DL2/DL3+NKG2C+, can be modified with greater efficiency than the corresponding subsets that do not carry the KIR2DL2/DL3 and NKG2C markers. After genetic modification, the CD57-KIR2DL2/DL3+NKG2C+ cells began to express CD57 de novo, acquiring the adaptive NK cell phenotype.

Heat Shock Protein 70 kDa as a Target for Diagnostics and Therapy of Cardiovascular and Cerebrovascular Diseases.

Acute focal ischemia is a main factor of pathogenesis of a number of widespread cardiovascular and cerebrovascular diseases, in particular, myocardial infarction and ischemic stroke. It is known that under the conditions of ischemia expression of intracellular heat shock proteins (HSPs), especially HSP70, grows greatly irrespective of the cell type. This stress-induced cell response is connected with cytoprotective properties of HSP70. The protective functions of HSP70 contribute to the cell survival under adverse conditions and inhibit development of programmed cell death. It was shown, that the level of HSP70 increases in cardiomyocytes and brain cells in response to ischemia, that was connected with cardioprotective and neuroprotective effects. Besides, in recent years, clinical studies of HSP70 have demonstrated elevated level of HSP70 in peripheral blood lymphocytes in groups of patients with ischemic stroke and myocardial infarction. This review indicates that HSP70 can serve as a target for developing new approaches to diagnostics and therapy of cardiovascular and cerebrovascular diseases.

A Novel Approach to Anticancer Therapy: Molecular Modules Based on the Barnase:Barstar Pair for Targeted Delivery of HSP70 to Tumor Cells.

One important distinction between many tumor cell types and normal cells consists in the translocation of a number of intracellular proteins, in particular the 70 kDa heat shock protein (HSP70), to the surface of the plasma membrane. It has been demonstrated that such surface localization of HSP70 on tumor cells is recognized by cytotoxic effectors of the immune system, which increases their cytolytic activity. The mechanisms behind this interaction are not fully clear; however, the phenomenon of surface localization of HSP70 on cancer cells can be used to develop new approaches to antitumor immunotherapy. At the same time, it is known that the presence of HSP70 on a cell's surface is not a universal feature of cancer cells. Many types of tumor tissues do not express membrane-associated HSP70, which limits the clinical potential of these approaches. In this context, targeted delivery of exogenous HSP70 to the surface of cancer cells with the aim of attracting and activating the cytotoxic effectors of the immune system can be considered a promising means of antitumor immunotherapy. Molecular constructs containing recombinant mini-antibodies specific to tumor-associated antigens (in particular, antibodies specific to HER2/neu-antigen and other markers highly expressed on the surface of a wide range of cancer cells) can be used to target the delivery of HSP70 to tumor tissues. In order to assess the feasibility and effectiveness of this approach, recombinant constructs containing a mini-antibody specific to the HER2/ neu-antigen in the first module and HSP70 molecule or a fragment of this protein in the second module were developed in this study. Strong selective interaction between the modules was ensured by a cohesive unit formed by the barnase:barstar pair, a heterodimer characterized by an unusually high constant of association. During testing of the developed constructs in in vitro models the constructs exhibited targeted binding to tumor cells expressing the HER2/neu antigen and the agents had a significant stimulating effect on the cytotoxic activity of NK cells against the respective cancer cells.

Tumor-Infiltrating Lymphocytes in Breast Cancer. Association with Clinical and Pathological Parameters.

In patients with primary resectable breast cancer, a positive correlation between the age and the count of CD16+ lymphocytes and a negative correlation of this parameter with the number of regulatory CD4+CD25+CD127- cells and proliferative activity of Ki-67 tumor cells were revealed. Higher level of Ki-67 was associated with reduced number of effector lymphocytes (CD8+ and CD16+) and elevated content of regulatory CD8+CD11b-CD28- T cells. The absence of expression of estrogen receptors was associated with reduced cytotoxic potential of CD8+ T cell in comparison with ER+ breast cancer. The percentage of CD8+ lymphocytes (CD3+CD8+ and CD8+CD11b+CD28+) among lymphocytes infiltrating the tumor was higher in PR+ breast cancer than in PR- tumors. With increasing the tumor load, the number of lymphocytes expressing CD16 marker and their cytotoxic potential decreased.

Current Approaches to Engineering of NK Cells for Cancer Immunotherapy.

Natural Killer (NK) cells belong to a unique subtype of lymphocytes with a great potential for cancer immunotherapy due to their ability to rapidly recognize and efficiently kill tumor cells. Their anti-cancer potential can be further increased by genetic and non-genetic modifications. However, the attempts of genetic improvements of NK cells over the past 20 years have been hampered by the difficulties of gene delivery into this cell type, thus preventing researchers from producing clinically relevant numbers of viable and biologically active NK cells. Currently, several successful approaches to genetic modification of NK cells have been described, and clinically applicable cell therapy products have been characterized. Now that we understand much better the ways of NK cell optimization to enhance their tumor regression-inducing capabilities, novel approaches to engineering NK surface receptors are being developed. In this review, we focus on the advantages and perspectives of various approaches to modification of NK cells. Positive results of several preclinical studies are described, demonstrating that genetically modified NK cells can be comparable to therapeutic T cells in their efficiency of recognizing and destroying tumor targets. Moreover, using allogenic NK cells to treat a number of cancer types might have even wider and eager clinical adoption than cytotoxic T cells due to a much decreased risk of graft versus host reaction inherent in NK cell-based immunotherapeutic products.

Effect of lipopeptide structure on gene delivery system properties: Evaluation in 2D and 3D in vitro models.

Development of efficient biodegradable, environmentally responsive, biocompatible and non-toxic delivery system is needed for efficient gene delivery. As well known, properties of the vehicle are determined by the structure of carrier components. The aim of the current study was to estimate in vitro transfection efficacy of aliphatic di-, tri- and tetrapeptide-based cationic lipoplexes loaded with siRNA in function of a number of cationic groups using 2D (monolayer culture) and 3D (multicellular tumor spheroids) in vitro models. Physicochemical properties and cytotoxicity of the liposomes were found to be dependent upon a number of amino acid derivatives in an amphiphilic polar head. Uptake of liposomes loaded with nucleic acid (lipoplexes) and their localization in HEK293T cells was studied by confocal microscopy. The liposomes based on lipotripeptides had the highest transfection efficiency which was 20-fold higher than those fabricated from lipotetrapeptides.

[Modulating Effect of Extracellular HSP70 on Generation of Reactive Oxigen Species in Populations of Phagocytes].

Reactive oxygen species (ROS) produced by phagocytic cells of the innate immune system play an important role in the first line of defense protecting the host from pathogens. The NADPH oxidase multi-subunit complex is the main source of ROS in all types of the phagocytes. Formation of the membrane-associated enzyme complex and its activity are dependent on many different factors controlling both intensification and suppression of the ROS production rate. However, the evidences are emerging in recent years indicating existence of poorly studied mechanisms of restriction of ROS generation level in phagocytes directed at protection of host tissues in the sites of inflammation from destruction caused by the oxygen free radicals. Our previous data and results of other authors demonstrate that a mechanism of the limitation of ROS production by phagocytes may by connected with immunomodulating activity of extracellular pool. of HSP70. In the present work, we used inhibitors of NADPH oxidase and in vitro cultures of different phagocytes to study a possible relationship between down-regulating effect of exogenous HSP70 on ROS generation and the interaction of the protein with the enzyme subunits. Our results confirmed the literature data concerning the ability of extracellular HSP70 to modulate NADPH oxidase activity and demonstrated for the first time an inhibitory effect of the protein on intracellular ROS generation in phagocytes.

[Eribulin in the treatment for metastatic breast cancer].

Eribulin is a novel antimicrotubule drug, which is approved in the second line treatment of advanced breast cancer in patients who received anthracyclines and taxanes. The article presents the results of two huge phase III clinical trials (301, 305) and their pooled analysis. Eribulin monotherapy demonstates staistically significant improved overall survival compared to standart treatments (15.2 mnths vs 12.8 mnths, p = 0.03 in pooled analysis). Certain subgroups of patients--Her2-negative and triple-negative have the most survival benefit. According to own experience with Eribulin inside the clinical trials, presented in the article, the drug is effective and well tolerated even by older patients.

[Alterations in heat shock protein 70 kDa levels in human neutrophils under the heat shock conditions].

Intracellular content of heat shock proteins of 70 kDa family (HSP70) possessing chaperone and cytoprotective functions depends on specialization and functional activity of the cells. The aim of this study was to analyze the dynamics of constitutive and inducible HSP70 levels evoked by heat shock in human neutrophils, the short-lived fraction of white blood cells providing non-specific defense against bacterial pathogens. Biphasic dynamics of the intracellular HSP70 level with an increase and following decrease in 15-30 min after the heat shock was revealed by flow cytometry. This dynamics was similar for constitutive and inducible forms of HSP70. Pre-incubation of neutrophils with cycloheximide, the inhibitor of protein synthesis, did not change the intracellular HSP70 dynamics registered by flow cytometry indicating that the increased HSP70 level detected immediately after the heat shock was not mediated by de novo protein synthesis. It was confirmed by Western blotting analysis of HSP70 intracellular content. It was suggested that the elevated HSP70 level was related to conformational HSP70 molecule changes and to increased availability of HSP70 epitopes for antibody binding. Using a panel of antibodies specific to the N-terminal ATP-binding or C-terminal substrate-binding domains of HSP70 it has been demonstrated by cell immunofluorescence and flow cytometry methods that the heat shock-associated increase of the intracellular HSP70 level was mediated by HSP70 interaction with antibodies recognizing HSP70 substrate-binding domain. It was demonstrated that the decrease of intracellular HSP70 level after heat treatment could be connected with a release of both inducible and constitutive HSP70 into extracellular space. Our data suggest that stress-induced release of HSP70 from neutrophils is regulated by ABC-transporters.

Bacterial lipopolysaccharide activates CD57-negative human NK cells.

NK cells play an important regulatory role in sepsis by induction and augmentation of proinflammatory reactions in early stages of the septic process and by suppression of immune response in later stages of inflammation. The present work was aimed at the effect of bacterial lipopolysaccharide (LPS), the main pathogenic factor of sepsis development, on human NK cells ex vivo. We show that LPS activates immature CD57-negative NK cells, which typically constitute less than half of the normal NK cell population in human peripheral blood. Under conditions of NK cell stimulation with IL-2, addition of LPS provokes an increase in IFN-γ production. However, LPS both increased and inhibited NK cell cytotoxic activity. It is important to note that the activation of NK cells on LPS addition was observed in the absence of TLR4 on the NK cell surface. These results confirm our previous data arguing for a direct interaction of LPS with NK cells and evidence an atypical mechanism of LPS-induced NK cell activation without the involvement of surface TLR4.

[Apoptosis induced by granzyme B].

Results of biochemical studies of apoptosis reactions induced by granzyme B are considered and summarized. Special attention is paid to the reactions of procaspase activation and limited proteolysis of apoptotic targets. Found values of kinetic constants of granzyme B-mediated enzymatic reactions are listed.

[Effect of hydrogen peroxide on ability of neutrophils to generate the reactive oxygen and chlorine species and secrete myeloperoxidase in vitro].

The influence of H2O2 at concentrations of 10(-8)--10(-2) mol/l on neutrophil ability to generate the reactive oxygen and chlorine species (ROCS) and secrete myeloperoxidase (MPO) was studied, and H202 injurious effect on neutrophils was also investigated in this work. It was revealed that H2O2 at concentrations of 2 x 10(-3)--2 x 10(-2) mol/l induced disturbance of the neutrophil membrane barrier properties and lactate dehydrogenase release. The incubation of the neutrophils with the addition of 10(-4)--10(-7) mol/l H2O2 led to an increase in the cell ability to generate ROCS during phagocytosis and decreased neutrophil ability to secrete MPO and ROCS in extracellular medium during adhesion. The mechanisms of H2O2 effect are coupled with arachidonic acid metabolism. Inhibition of metabolic pathways of 5-lipoxygenase or cyclooxygenase increased the destructive effect of H2O2 on the cells. Five-lipoxygenase way prohibition led to cancellation of H2O2 influence on MPO and ROCS secretion and to enhancement of H2O2 effect on neutrophil ability to generate ROCS during phagocytosis. The data obtained testify to the high neutrophil resistance to destructive effect of H2O2 and confirm the regulatory role of H2O2 with respect to the neutrophil functions.

[The long-term results of the dynamic observation of patients with adrenal gland adenomas].

The authors demonstrate the results of many years of observing patients with hormone-inactive adrenal gland adenomas. The subjects were 80 patients observed during 8 months to 12 years. The study shows that slow growth is generally typical of these adenomas. In 15% of patients an average growth of 1 mm/year was noted; this growth did not exceed 10 mm throughout the whole period of observation. The researchers also observed changes in the clinical symptoms and hormonal parameters over time. The study demonstrates that long existence of adenomas do not aggravate the clinical course of arterial hypertension and diabetes mellitus, and do not express any hormonal activity. The study established more precise indications to dynamic observation and its algorithm.

[Disputable points and negative tendencies in diagnosis and surgical treatment of accidentally revealed adrenal tumors].

Two main problems are discussed in detail: differential diagnosis of adrenal tumors before surgery, and policy of treatment of these patients. Indications for fine needle biopsy are determined, based on personal and world experience reasoned indications to surgical treatment and follow-up are formulated. Some negative tendencies in adrenal surgery are also discussed.

[Modification of the target cell surface with lipophilic glycoconjugates and interaction of the modified cells with natural killer cells]. / Modifikatsiia poverkhnosti kletok s pomoshch'iu lipofil'nykh glikokon''iugatov i vzaimodeistvie modifitsirovannykh kletok s natural'nymi killerami.

An experimental model system involving the modification of carbohydrate composition of the target cell surface with neoglycolipids was developed for studying the role of surface carbohydrates of target cells in the NK-cell-mediated cytotoxicity. The polymeric glycoconjugates of the Glyc-PAA-PEA and Glyc-PAA(Flu)-PEA types (where Glyc was an oligosaccharide residue, PAA poly(acrylamide) polymer, and PEA the phosphatidylethanolamine residue, and Flu fluorescein residue) capable of incorporation into the cell membrane were synthesized. The optimum structures of neoglycoconjugates and conditions for their incorporation into K562 and Raji cell lines, which differ in their sensitivity to the NK-cell-mediated lysis were selected. The mechanism of association of glycoconjugates with the plasma cell membrane and the kinetics of their elimination from the cell surface were investigated using the fluorescent-labeled Glyc-PAA(Flu)-PEA derivatives. The spatial accessibility of the carbohydrate ligands for the interaction with human NK cells was demonstrated. The target cells modified with the Le(x) trisaccharide were shown to be more sensitive to the cytotoxic effect of human NK cells than the intact cells. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 3; see also http://www.maik.ru.

[False acute abdomen in clinical practice]. / Lozhnyi ostryi zhivot v klinicheskoi praktike.

Some situations in which endocrinological diseases and their complications (diabetic ketoacidosis, acute adrenal failure, pheochromocytoma, thyrotoxicosis, thyrotoxic crisis, hyperparathyroidism crisis) give the picture of false acute abdomen are analyzed.

[Prospects of computer tomography in diagnosing adrenal tumors]. / Vozmozhnosit komp'iuternoi tomografii v diagnostiki novoobrazovanii nadpochechnikov.

Computed tomography (CT) is one of main topical methods of adrenal tumors diagnosis. Medical histories of 68 patients treated from 1995 to 2000 for various adrenal tumors were analyzed. CT was used in all the patients. These data were compared with results of morphological study. It is demonstrated that CT has high sensitivity in diagnosis of adrenal tumors (96.55% cases). It permits to predict the type of tumor with high probability. The degree of tumor size mistake made at CT was estimated. Mean coefficients to assess true sizes of tumors before surgery were calculated. This is important for choice of treatment policy in hormonal-unactive adrenal tumors.