[Generation of transgenic animals, expressing alpha- and beta-chains of autoreactive TCR].

Transgenic animal studies has become a key approach for gene function analysis as well as for modeling of different human diseases, including autoimmune diseases caused by activation of T-lymphocyte clones whose TCRs possesses high affinity for syngeneic MHC molecules. In this study we cloned genes, encoding alpha- and beta- chains of autoreactive TCR of hybridoma 7, specific for syngeneic MHC class II molecules A(b). Amplified DNA fragments, containing rearranged genomic DNA of alpha- and beta-chains of hybridoma 7 were cloned into special cassette vectors, containing natural promoter and enhancer elements for direct expression of genes encoding TCR alpha- and beta-chains in T-lymphocytes of transgenic animals.

[Coreceptor function of CD4 in response to MHC class I molecule].

Specificity of T cell receptor (TCR) and its interaction with coreceptor molecules play decisive role in successful passing of T lymphocytes via check-points during their development and finally determine the efficiency of adaptive immunity. Genes encoding alpha- and beta-chains of TCR hybridoma 1D1 have been cloned. The hybridoma 1D1 was established by the fusion of BWZ.

[Endovascular correction of a multi-level arterial lesion in an elderly patient with lower-limb critical ischaemia].

Presented herein is a clinical case report showing possibilities of endovascular surgery in comprehensive treatment of a multi-level stenosing lesion in an elderly male patient presenting with pyo-necrotic alterations of the crus and foot. A 67-year-old male patient suffering from diabetes mellitus, lower-limb vessels atherosclerosis, critical ischaemia, indolent wound of the left foot following amputation of the toes was subjected to collaterally approached balloon-mediated angioplasty of critical stenoses of the left common iliac artery and deep femoral artery. During the operation, we used elements of coronary interventions technique.

Suppression of primary allogenic response by CD8+ memory cells.

Immune response to allogenic tumor cells is associated with the appearance of long-living CD8+ memory cells capable of rapid restimulation and lysis of tumor cells in case of repeated injection of these cells. In order to acquire the effector function, allorestricted memory cells need antigen restimulation for 2 days, which is a specific feature of central memory cell population. These cells can suppress proliferation of naive splenocytes in vitro.

[Motifs in the primary structure of MHC Class I molecules and their use for the design of synthetic T-cell receptor ligands].

This paper attempts to describe a great variety of allelic forms of mammalian major histocompatibility gene complex (MHC) Class I molecules as a single "formula" that contains information on motifs in their primary structure. The positions of amino acid residues that are invariant even in highly evolutionarily different species have been found in the structure of MHC Class I molecular domains that are recognizable by T-cell receptors (TCR). The spatial arrangement of invariant residues in the tertiary structure of MHC molecules is indicative of their structure-forming function: they are generally located at the sites of contact of alpha-helices and beta-sheets.

Cross reactivity of T cell receptor on memory CD8+ cells isolated after immunization with allogeneic tumor cells.

Experiments on mice deficient in expression of class I major histocompatibility complex molecules showed that memory CD8+ cells recognizing the alloantigen by the direct allogeneic recognition mechanism selectively proliferated in response to heated allogeneic cells. Adoptive transfer of memory cells from mice expressing green fluorescent protein transgene to wild-type animals showed for the first time that long-living memory cells suppress the response of naive T cells and abolish their involvement in the pool of memory cells. The pool of long-living memory T cells was obtained in vitro with heated allogeneic stimulators.

[Peripheral pool of CD8+ T-cells contains lymphocytes with antigen-specific receptors that recognize syngeneic MHC class II molecules].

The capacity of T-lymphocytes to recognize "nonself" and tolerating "self" is formed as a result of positive and negative selection in the thymus. While obtaining and testing specificity of T-hybridomas, we demonstrated that the major part of peripheral pool of CD8+ T-lymphocytes carried receptors specific to "self" MHC class II molecules. Such an unexpected specificity of receptors has been found in some T-cell hybridomas produced by fusion of activated peripheral CD8+ T-lymphocytes with a tumor partner transfected by the coreceptor CD4 gene.

Colorimetric in vitro evaluation of T-cell cytotoxicity.

We propose a new colorimetric method for evaluation of specific T lymphocyte cytotoxicity based on the capacity of viable cells to incorporate alamar blue dye, an indicator of cell metabolic activity. This method is effective for highly specific strains of cytotoxic T lymphocytes and for primary T killers formed in vivo and constituting a small part of analyzed cell population. This test is a simple nonradioactive method for evaluating specific cellular cytotoxicity exhibiting sufficient sensitivity for evaluation of this parameter in the presence of effector cells.

[Multi-functionality of allospecific cytotoxic T-lymphocytes in vitro].

The data presented demonstrate the capacity of allospecific cytotoxic lymphocytes to fulfill noncytolytic regulatory functions. Cytotoxic lymphocytes suppress cell proliferation induced during development of a response in reactions of a mixed culture of lymphocytes and blast transformation irrespective of haplotypes of the cells involved in these reactions. At the same time, cytotoxic lymphocytes do not practically affect spontaneous proliferation of T-cells.

[Characteristics of the cells producing thymic chemotactic factor for bone marrow stem cells].

It was shown using complement-dependent cytolysis and monoclonal antibodies against CD4, CD8, and NK1.1 antigens that the cortisone-resistant CD3+4-8-NK1.1(-)-thymocytes spontaneously secreted a chemotactic transmitter inducing the release and directed migration of bone marrow cells.

[Use of heat shock of antigen-presenting cells for functional testing of allospecificity memory T-cells].

For many years, the search for the appropriate method of testing the functional activity of the memory T-cells was an urgent problem and determined progress in the study of immunological memory. We proposed simple methods of functional testing the memory of CD8+ T-cells specific to the H-2Kb alloantigen based on measuring their proliferation in response to heat-treated allogenic splenocytes and cells of allogenic tumors in vitro. Primary proliferative response to the alloantigen was shown not to develop when the allogenic antigen-presenting cells were subjected to an acute (45 degrees C, 1 h) or moderate (42 degrees C, 30 min) heat shock.

[The diagnosis and surgical treatment of nonepithelial stomach tumors].

The work analyzes clinical manifestations, diagnosis and surgical treatment of nonepithelial tumors in 117 patients. Difficulties of the pre- and intraoperative diagnosing, especially of differentiation of the benign character of the process are shown. The timeliness and the correct volume of surgical interventions are responsible for sufficient effectiveness of treatment, especially in patients with malignant tumors.

[Use of histocompatibility class I molecule peptides for in vivo induction of specific T-suppressors in allogenic systems and prolongation of mouse skin graft life].

Six synthetic peptides were selected for the individual molecule H-2Kb of the major histocompatibility complex class 1. Optimum conditions were elaborated for the induction of specific suppressor T cells in vivo by peptide 6 (alpha 2 domain) in an intravenous dose of 33 micrograms to the tail vein or 100 micrograms to the orbital sinus, followed by testing the suppressor activity in inhibiting in vitro proliferation in the three-cell MLC in response to irradiated cells of the stimulator Kb (BL/6) in the absence of suppressed response to the foreign stimulator Kk (B10.BR).

[Isolation, study of activity, and characteristics of an immunosuppressive liver factor causing apoptosis of EL-4 thymoma cells in vitro].

Immunosuppressive factor (ISFnp) which inhibits proliferation and viability of thymoma EL-4 cells was isolated from mouse liver. The testing procedure based on the biotransformation of MTT-tetrazolium by mitochondrial enzymes of viable cells allowed us to purify this factor as individual peak of protein, that allowed to obtain polyclonal rabbit antibodies to this factor. By the methods of double immunodiffusion, gel-filtration and SDS-PAGE with subsequent immunoblotting we shown that this factor specifically localized in liver and consists two subunits of 40 and 42 kDa which form dimers with apparent M(r) about 70-80 kDa.

[Use of peptides of major histocompatibility type I molecules for induction of specific T-suppressors in vivo in an allogeneic system and extending the life of a murine skin transplant].

Six synthetic peptides represented as variable sequences of the MHC class 1 molecule H-2Kb were synthesized. Appropriate conditions were elaborated for induction of specific suppressor T cells in vivo by peptide 6 (alpha 2 domain) that is introduced intravenously in a dose of 33 micrograms into the tail vein or 100 micrograms into the orbital venous sinus with subsequent testing for inhibition of proliferation in vitro in response to irradiated stimulator cells Kb (BL/6), whereas the stimulator Kk (B10.BR) did not induce any suppressor activity.

[The effect of hyperbaric oxygenation on the osmotic status of children with surgical pathology of the abdominal organs].

The effect of hyperbaric oxygenation (HBO) on blood osmolality has been studied in children with abdominal pathology. It has been shown that HBO has a considerable effect on blood osmolality evident both during and after the HBO session. To prevent possible HBO-induced disturbances of blood osmolality special pretreatment with ten infusion solutions has been suggested.