[Syndrome of secondary immunodeficiency: pathogenesis and approaches to treatment].
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Adjuvants, Immunologic↗
Biomedical subjects
S V Suchkov
Publications and source records attributed to S V Suchkov.
[Autoimmune myocarditis: current aspects of immune pathogenesis].
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Autoantibodies↗
Comparative study of catalytic (DNA-hydrolyzing) and cytotoxic properties of anti-dna autoantibodies.
DNA-hydrolyzing and cytotoxic properties of anti-DNA autoantibodies isolated from patients with systemic autoimmune diseases and from autoimmune MRL-lpr/lpr, SJL/J, and (NZBx NZW)F1 mice were studied. Cytotoxic and catalytic properties of these antibodies correlated. A relationship between the stage of systemic lupus erythematosus and catalytic and cytotoxic properties of DNA abzymes was revealed. Of all studied cells, L929 cells were most sensitive were most sensitive to in vitro effect of antibodies. Treatment of target cells with anti-DNA autoantibodies with cytotoxic properties induced internucleosomal DNA fragmentation, which is characteristic of apoptosis.
Animals↗
Mechanisms underlying cytotoxicity of anti-DNA antibodies.
We studied mechanisms underlying cytotoxicity of catalytic anti-DNA autoantibodies or DNA abzymes isolated from the blood of patients with systemic lupus erythematosus and autoimmune mice. Experiments were performed on L929, HL-60, Raji, and K562 cells. Treatment with DNA abzymes caused internucleosomal DNA fragmentation in target cells typical of apoptosis. Direct immunofluorescence assay demonstrated that DNA abzymes can penetrate into the nucleus of target cells. The dependence of antibody-mediated cytotoxicity on the duration of incubation indicated that cell death is realized via at least 2 mechanisms: penetration of DNA abzymes into the cell nucleus followed by degradation of nuclear DNA or induction of apoptosis.
Animals↗
[Immunological aspects of laboratory diagnosis of chronic urticaria].
High prevalence of allergic diseases necessitates search for new methods of laboratory diagnosis thereof. We studied the diagnostic significance of the count of cells expressing low-affinity receptors to IgE (CD23+ cells) and compared this test with skin tests with non-infectious allergens and measurement of total serum IgE. 104 patients with various forms of chronic relapsing urticaria were examined. The count of CD23+ cells was markedly increased in atopic urticaria. The increase in the count of these cells and correlation with the results of skin test were less expressed in infectious allergic urticaria. In other forms of chronic urticaria characterized by negative results of skin tests the count of CD23+ cells was normal. The level of total serum IgE was low virtually in all patients. Hence, the count of cells carrying low-affinity receptors to IgE is highly informative, detecting IgE-mediated reactions in the patients, though this parameter does not allow identification of the allergen. This test can be used in complex with other methods of allergodiagnosis, particularly in cases when skin tests are for this or that reason impossible.
Adolescent↗
[DNA-abzymes and their clinical significance in systemic lupus erythematosis].
AIM: To evaluate occurrence of DNA-abzymes with catalytic (DNA-hydrolysing) and cytotoxic properties in patients with systemic lupus erythematosus (SLE) for examination of clinical value of DNA-abzymes in diagnosis of autoimmune syndrome and apoptosis level in different variants of immunopathology. MATERIAL AND METHODS: The study group consisted of patients with verified SLE diagnosis (n = 120). They were compared to 72 patients with rheumatoid arthritis (RA), 82 patients with scleroderma systematica (SS), 60 patients with discoid lupus erythematosus (DLE), 88 patients with focal scleroderma (FS) and 198 autoimmune uveitis (AU) patients. 128 donors served control. Catalytic and cytotoxic activity of DNA-abzymes were determined by methods of molecular biology and enzymology. All the patients were examined for blood levels of IgG, IgM and IgA, anti-DNA, anti-Sm and other IgG-autoantibodies, CIC titers, phagocyting activity, content of main D-cell subpopulations. Key immunoregulatory indices were also estimated. RESULTS: DNA-abzymes were detected more often in SLE and RA patients. In SLE, catalytic and cytotoxic activities of DNA-abzymes reached their maximum. There was a correlation with leading clinicoimmunological signs of SLE. The disease was most severe with apparent immunopathology in patients with maximal catalytic and cytotoxic activity of DNA-abzymes. With lowering cytotoxic activity of DNA-abzymes more patients demonstrate low SLE activity without severe organic lesions and alleviated symptoms of immunopathology. CONCLUSION: An important role of DNA-abzymes in pathogenesis of SLE is shown. They are also valuable tools in diagnosis of various clinicoimmunological variants of the disease.
Apoptosis↗
Novel functional activities of anti-DNA autoantibodies from sera of patients with lymphoproliferative and autoimmune diseases.
DNA-hydrolyzing activity of IgG autoantibodies from sera of patients with various types of lymphoproliferative diseases was investigated. The association of DNA-hydrolyzing activity with the antibody (Ab) fraction has been proved by newly developed affinity-capture assay. Study of abzyme incidence in blood tumors and systemic lupus erythematosis (SLE) revealed linkage of anti-DNA Ab catalysts to mature B-cell tumors, and increased probability of DNA-abzymes formation on the background of autoimmune manifestations. These data suggest possible similarity between mechanisms of abzyme formation in SLE and B-cell lymphomas. A new mechanism of formation of DNA-specific catalytic Abs has been proposed based on the increased crossreactivity of polyclonal DNA-abzymes to DNA-depleted nuclear matrix proteins. The possibility of the abzyme production as Ab to the energetically destabilized ground state of the antigen has been discussed. Preliminary results were obtained that indicate the complement-independent cytotoxicity of anti-DNA autoantibodies isolated from blood of patients with SLE and chronic lymphocytic leukemia.
Antibodies, Antinuclear↗
[A clinico-immunological assessment of the efficacy of combined methods of treating patients with different immunopathological forms of focal scleroderma].
To help the physicians choose a rational scheme of combined therapy of patients with various immunopathologic forms of focal scleroderma, the authors present a clinical and immunologic assessment of the efficacies of 2 combined therapeutic courses, enzyme immunotherapy and penicillin immunotherapy, as well as of the individual course of tactivin immunotherapy. Inclusion of tactivin in any complex therapeutic scheme appears to be necessary. In patients suffering from the condition for a long time, with multiple foci of involvement, tactivin should be combined with enzymic drugs, like hyaluronidase (lydase). Enzyme immunotherapy promoted a more active resolution of the skin process. Penicillin immunotherapy alone is disputable, and further studies of such treatment are necessary. Enzyme immunotherapy should be considered as the optimal scheme of rational combined treatment for focal scleroderma.
Adjuvants, Immunologic↗
[The cyclic nucleotide system of patients with focal scleroderma].
Studies of the function of cyclic nucleotide system in the lymphocytes of patients with focal scleroderma have revealed that this condition is characterized by growth of the intracellular cAMP/cGMP ratio, correlating with the process duration, severity, and dissemination. A correlation between lymphocyte regulatory function defect and the presence of immunodeficiency syndrome was demonstrated. Sensitivity of lymphocytic cyclic nucleotides in focal scleroderma patients to thymoptin, a thymic agent, was examined. Manifest clinical effect of this drug is based on stabilization of the function of lymphocytic cyclic nucleotides system and, consequently, on normalization of the immunologic parameters. Potentialities and prospects of thymic factors immunotherapy of focal scleroderma patients are discussed.
Adjuvants, Immunologic↗
[Clinico-immunological parallels in patients with focal scleroderma].
Combined immunological examination of patients with focal scleroderma included studies of the humoral and cellular immunity parameters. The findings evidence that mainly immunological disorders underlie the pathogenesis of this disease, whose various combinations form this of that immunopathological pattern. An immunological classification of focal scleroderma is suggested. Clinical and immunological parallels in patients with different immunological variants of focal scleroderma are analyzed. The results permit a conclusion on the two basic mechanisms in the pathogenesis of focal scleroderma: (1) immunodeficiency involving the effector B component and (2) an isolated hyperfunction of natural killer cells.
Adolescent↗
Factors of activation and stabilization of DNA-methylases from Shigella sonnei 47 and Mycobacterium smegmatis butyricum cells.
A comparative study of factors of activation and stabilization of individual DNA-methylases from two bacterial strains--Shigella sonnei 47 and Mycobacterium smegmatis butyricum--isolated by isoelectrofocusing in a pH gradient has been carried out. Storage of enzymes at +4 degrees C (pH 7.5) is accompanied by periodic changes in the methylating activity. No such changes are observed when the enzymes are stored at pI of the protein. In this case the methylases with alkaline or close to neutral values of pI remain stable over a period of at least two weeks, whereas acidic proteins are irreversibly inactivated by the end of a two-week period. A stabilizing effect of BSA on DNA-methylases of Sso 47 and Mbu strains has been demonstrated. A direct correlation between the stabilizing effect of BSA and the degree of enzyme purity has been established. Ca2+ appear to be a universal activator of methylases of the above strains; these cations produce a potent, although a short-term effect and can be used in the production of enzyme preparations with a high specific activity in DNA recombinant technology. Protease inhibitors do not exert any appreciable effect on the methylase activity upon storage. Storage at -20 degrees C and at neutral pH leads to complete inactivation of all DNA-methylases within 24 hours. In this case glycerol is fairly ineffective as a stabilizing agent.
Alkalies↗
[Immunocorrecting therapy in focal scleroderma].
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Adjuvants, Immunologic↗
[Study of the conditions of activation and stabilization of DNA-methylases from Shigella sonnei 47 during fractionation, purification and storage].
A comparative study of activation factors and stabilization conditions of partially purified and individual fractions of DNA-methylases of Shigella sonnei 47 was carried out. The stability of DNA-methylases in the course of storage was examined. The influence of activating factors and stabilization conditions differed significantly depending on the degree of purification and composition of methylase preparations. It was shown that glycerol is ineffective as a stabilizing agent. The activating effect of Ca2+ on Shigella sonnei 47 DNA-methylases was found to be universal, while albumin was shown to exert a more potent stabilizing action. The inactivating effect of proteases on DNA methylation enzymes during storage was demonstrated. A phenomenon of spontaneous fluctuations in the methylating activity of enzymatic preparations of Shigella sonnei 47 upon storage was observed.
DNA (Cytosine-5-)-Methyltransferases↗
[Determination of the adenine-specific methylase recognition site of Shigella sonnei 47, using hydrazinolysis with subsequent separation of purine oligonucleotides by thin layer chromatography on DEAE- cellulose].
A procedure for separation of oligopurine blocks of different length and composition by two-dimensional thin layer chromatography on DEAE-cellulose plates has been developed. This method allows a comparative analysis of the purine isostich content in the DNAs of various origin. In case of methylated DNA, the method permits to compare the substrate specificity of different enzymes responsible for the adenine residue methylation in the DNA. In combination with enzymatic treatment of labeled methylated isostichs, the method described can be used for the deciphering of the methylated sequences as well as for constructing, in a number of cases, the recognition site of adenine-specific methylases. Thus, it was demonstrated that methylase SsoI recognizes the 5...G-A-A-T-T-C ... 3' sequence and methylates its adenine residue nearest to the 5'-end.
Adenine↗
Sequence specificity of isolated DNA-adenine methylases from Mycobacterium smegmatis (butyricum) and Shigella sonnei 47 cells.
A set of four individual DNA-adenine methylases differing in pI (isoelectric point) values (MMbu4.2, MMbu6.4, MMbu7.3, and MMbu8.7), and a sole methylating enzyme with the same base specificity (MSso9.5) are present in M. smegmatis (butyricum) and Sh. sonnei 47 cells, respectively. The sequence specificity of each of those was studied 'in vitro' by a combined approach that comprised isostich (purine tract) analysis and identification of the immediate neighbourhood of the methylated base within the sequence methylated. The MSso9.5 recognition site has been established as the hexanucleotide 'palindromic' 5'-G-A-A-T-T-C-3' sequence which is structurally similar to the analogous MEco RI recognition site. However, in contrast to MEco RI, MSso9.5 methylates the 5'-end adenine residue in the sequence and thus it appears to be an isometimer of MEco RI. By means of the same approach, the partial nucleotide sequences methylated by each of the four individual M. butyricum enzymes were determined. MMbu7.3 and MMbu8.7 exhibit the identical sequence specificity upon methylation of the degenerative trinucleotide 5'-Py-A-Py-3' sequence and thus these enzymes are assumed to represent the different molecular forms of the methylase. MMbu4.2 methylates the 5'-G-G-A-3' sequence and thus it is of a great value as the tool for negating effects of the RBam HI and RAva II-type restriction. MMbu6.4 is of a particular interest on account of its unique DNA methylation pattern which is distinguished in the pronounced clustering of purine bases in the 5'-Pu-Pu-Pu-Pu-Pu-3' sequence methylated.
Base Sequence↗
[Fractionation and purification of DNA-methylases from Shigella sonnei 47].
Possible applications of various column chromatography techniques and isoelectrofocusing for the study of DNA-methylases of Shigella sonnei 47 cells were analyzed. A simple, rapid and convenient procedure based on the use of cation-exchange chromatography was developed for obtaining a highly active total preparation of methylases. Affinity chromatography on heparin-Sepharose was shown to be a promising approach for separating methylases according to their specificity towards nitrous bases. Isoelectrofocusing was used to identify in Shigella sonnei 47 cells six individual methylating enzymes differing in their pI values. Under the stipulation that Shigella sonnei 47 DNA-methylases show a tendency to aggregate in the course of fractionation, column chromatography is of little or no use in isolating and purifying individual methylating enzymes of the given strain. The advantages of the isoelectrofocusing technique and its utility in the study of different molecular forms of site-specific enzymes are discussed.
Chromatography, Affinity↗
[Site-specificity of DNA methylases from Shigella sonnei 47 cells].
A complex approach involving isoplith analysis, enzymatic treatment of methylated isopliths and a computer analysis of experimental data has been used for determining site specificity of six methylases from Shigella sonnei 47 cells termed according to their specificity for a nitrous base and pI as MC4.2, MC5.3, MC6.2, MC7.4, MC8.4 and MA9.5. It has been found that the recognition site of MA9.5 is a palyndrome six-member structure of the 5'...GAATTC...3' type and that this enzyme is an isometimer with respect to MEcoRI. It has been demonstrated for the first time for methylases that the recognition site of MC4.2 is represented by a non-symmetrical four-member sequence, 5'...NCCCCN...3' characterized by unique blocking of cytosines. MC8.4 possesses a broad specificity of substrate recognition and methylates the cytosine residue within the composition of the non-symmetrical unique sequence 5'...N (C/Pu) CCN...3', whose 5'-terminal base is depleted in three nucleotides. MC5.3 methylates the 3'-terminal cytosine residue within the composition of the pentanucleotide palindrome recognition site, 5'...CCNGG...3'. MC6.2 and MC7.4 possess identical pentanucleotide recognition sites of 5'...(Py)CNG(Pu)...3', but are distinguished in pI. The latter finding has been shown for the first time for different methylases within one strain.
Base Sequence↗
Sequence specificity of isolated DNA-cytosine methylases from Shigella sonnei 47 cells.
Five individual DNA-cytosine methylases differing in pI (isoelectric point) values are present in Shigella sonnei 47-cells. The sequence specificity of each of those was determined 'in vitro' by a highly efficient combined approach that included pyrimidine tract (isostic) analysis, identification of the immediate neighbourhood of the methylated base within the recognition sequence and the calculation method. The enzyme with pI 5.3 (MSso5.3) is the counterpart of the RSso 47 II in the Sso 47 II restriction-modification system and methylates the internal cytosine residue of the 'palindromic' 5'-C-C-N-G-G-3' sequence. The enzymes with pI 6.2 (MSso6.2) and 7.4 (MSso7.4) exhibit identical specificity upon methylation of the 'palindromic' 5'-Py-C-N-G-Pu-3' sequence, but differ in the pI values of the proteins. The enzyme with pI 4.2 (MSso4.2) recognizes the unique tetranucleotide 5'-C-C-C-C-3' sequence and methylates the second cytosine residue at the 5'-end of the sequence. The enzyme with pI 8.4 (MSso8.4) methylates the central cytosine residue within the degenerative trinucleotide 5'-(PuC)-C-C-3' sequence. MSso5.3, MSso6.2, and MSso7.4 are presumed to belong to the 'family' of sequence-specific (Eco RII-like) enzymes. These DNA-cytosine methylases are likely to be evolutionary related to Eco RII and to have undergone a sufficient genetic drift so as to recognize similar (but more degenerative) nucleotide sequences.
Base Sequence↗