Inhibitory action of neuraminidase ofVibrio cholerae in Rauscher mouse leukemia

The inhibitory action of the neuraminidase ofVibrio cholerae in Rauscher mouse leukemia was studied. After treatment of the spleen cells of leukemic mice with neuraminidase in doses of 50 units/ml or more, the ability of these cells to induce leukemia when injected into BALB/c mice was inhibited significantly. Neraminidase in the above concentration, if given by repeated parenteral injection, had no therapeutic action in Rauscher leukemia.D. I. Ivanovskii Institute of Virology, Academy of Medical Sciences of the USSR. Scientific-Research Laboratory of Experimental Immunobiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1357–1359, November, 1976.     

Immunohistochemical location of major histocompatibility complex class 1 antigens in human placenta

Distribution of major histocompatibility complex class I antigens in the postpartum human placenta was studied by immunohistochemical method. Positive staining was observed in endotheliocyte cytoplasm in vessels of chorionic villi. The surface of trophoblast, cytotrophoblast, and connective tissue cells did not stain. These data indicate a peculiar «masking» of antigens essential for normal course of gestation.     

Preparation of paraffin sections for immunofluorescence analysis of antigens differing in their chemical nature

A technique is suggested for preparing paraffin sections from tissues fixed with acetone which can be used for the immunohistochemical detection of antigens which differ in their chemical nature, including -fetoprotein, antigens of mouse leukemia viruses, alcohol-soluble antigens of hepatocyte membranes, and certain phospholipids.Laboratory of Immunochemistry and Diagnosis of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR. Laboratory of Pathological Anatomy, N. N. Burdenko Institute of Neurosurgery, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR G. V. Vygodchikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 1018–1020, August, 1976.     

Heterophilic antibodies to connective tissue antigens in the blood sera of rheumatic patients do not cross-react with group AStreptococcus antigens

Heterophilic antibodies reacting with antigens of interstitial connective tissue of bovine myocardium were found in the sera of patients with rheumatic fever. These antibodies were referred to class IgG. Immunologic specificity of the reaction with these antigens was confirmed in experiments with F(ab′)₂ fragments from IgG isolated from the sera of rheumatic patients. Heterophilic antibodies were not adsorbed by various antigens of group AStreptococcus, nor were they isolated in a column with immunosorbent prepared on the basis of nontype-specific streptococcal antigens. The reaction of patients' sera was not inhibited by monoclonal antibodies to nontype-specific antigens cross-reacting with antigens of myocardial interstitial connective tisSue. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 642–644, June, 1994 Presented by S. V. Prozorovskii, Member of the Russian Academy of Medical Sciences     

Formation of colonies of clonogenic stromal precursors in bone marrow and splenic cell cultures in the presence of streptococcal antigens in the culture medium

The presence of streptococcal M protein and A polysaccharide in culture medium is shown to have an inhibitory effect on the growth of clonogenic stromal precursors in cultures of healthy murine bone marrow and of healthy guinea pig bone marrow and spleen. The efficacy of colony formation dropped 1.5- to 2-fold in the presence of antigens in a concentration of 25 μg/ml in the medium. The inhibitory effect was absent if antigens were added to adhesive cell cultures. The addition of antigens to cultures originating from animals immunized with streptococcus resulted in inhibition of the efficacy of colony formation in complete cultures and in cultures of adhesive cells. The presence of streptococcal antigens in guinea pig stromal fibroblast cultures of different strains did not affect their growth or colony formation. These data indicate that the effects of streptococcal antigens appear to be aimed at the stromal cells not directly, but rather via another cellular category in the bone marrow and splenic cell cultures, probably lymphocytes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 11, pp. 489–492, November, 1994     

Detection of antibodies to HLA1 antigens by enzyme immunoassay

A modification of the MAILA (monoclonal antibody specific immobilization of lymphocyte antigens) method has been developed for the detection of antibodies to class 1 histocompatibility antigens. Russian biotin-treated monoclonal antibodies IKO-53 (Medbiospektr, Moscow) were used. In a complex with monoclonal antibodies, lymphocyte HLA antigen was found to retain its antigenic properties when stored for a long time. High specificity and sensitivity of the method were demonstrated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 315–317, September, 1995 Presented by V. I. Shumakov, Member of the Russian Academy of Medical Sciences     

Effect of immune “sessile” receptors on the choline receptors of the lymphocyte membrane in mice immunized with certain antigens

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 115, N ^o 2, pp. 384–386, April, 1993     

Role of various murine B-lymphocyte subpopulations in the immune response to T-independent antigens

Polyclonal antibodies to Lyb 5⁺ antigen of murine B lymphocytes are obtained and a methodological approach to the detection of cells carrying this antigen is developed with the aim of investigating the role of various subpopulations of mouse B lymphocytes in polyclonal activation induced by T-independent type 2 antigen. Hybridomas producing anti-Lyb 5.1 antibodies are obtained. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, 402–405, April, 1995 Presented by B. F. Semenov, Member of the Russian Academy of Medical Sciences     

Effect of soluble H-2 antigens on the cytotoxic effect and adsorption of immune lymphocytes

Serologically active preparations of soluble H-2 antigens were obtained by extraction with 3 M KCl from ascites cells of leukemia L1210 (H-2^d) and sarcoma MCh-11 (H-2^b). These preparations had no specific effect on the cytotoxic action of immune lymphocytes on target cells in vitro and did not inhibit adsorption of lymphocytes on a monolayer of the corresponding target cells.Laboratory of Immunochemistry and Diagnosis of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. Central Research Laboratory, Saratov Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 333–336, September, 1977.     

Characterization of Vibrio cholerae El Tor cytolysin as an oligomerizing pore-forming toxin

V. cholerae El Tor cytolysin is a secreted, water-soluble protein of M _r 60,000 that may be relevant to the pathogenesis of acute diarrhea. In this communication, we demonstrate that the toxin binds to and oligomerizes in target membranes to form SDS-stable aggregates of M _r 200000–250000 that generate small transmembrane pores. Pores formed in erythrocytes were approximately 0.7 nm in size, as demonstrated by osmotic protection experiments. Binding was shown to occur in a temperature-independent manner preceding the temperature-dependent oligomerization step. Pores were also shown to be formed in L929 and HEp-2 cells, human fibroblasts and keratinocytes, albeit with highly varying efficacy. At neutral pH and in the presence of serum, human fibroblasts were able to repair a limited number of lesions. The collective data identify V. cholerae El Tor cytolysin as an oligomerizing toxin that damages cells by creating small transmembrane pores.     

Cytotoxicity of antisera against brain and spinal cord antigens for heterogenous lymphocytes

The cytotoxic activity of rabbit antisera against brain and spinal cord antigens for mouse and guinea pig lymphocytes was investigated. None of the sera tested had any cytotoxic action on bone marrow lymphocytes, whereas sera against mouse brain and spinal cord, guinea pig brain, and myelin isolated from it were most toxic for lymphocytes of other lymphoid organs; the maximal toxic effect was found against thymocytes, it was less marked against lymph gland lymphocytes, and still less against spleen cells. The cytotoxicity of antisera against bovine spinal cord, and the myelin or basic protein isolated from it, was least of all and was the same against all the cells mentioned above; antiserum against encephalitogenic polypeptide 2c had virtually no cytotoxic activity. In its encephalitogenic properties fraction 2c considerably surpassed myelin and basic protein prepared from bovine spinal cord. Experiments with absorption of brain antiserum suggested that a cross-reacting antigen is present in the cerebral cortex. Subcutaneous injection of a relatively large dose of thymocytes (224×10⁶) in Freund's complete adjuvant did not lead to the development of allergic encephalomyelitis in guinea pigs.Department of Microbiology and Immunology, Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR V. I. Ioffe.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 968–970, August, 1976.     

Localization of common (cross-reacting) antigens with tissues of the human bronchopulmonary apparatus in cells ofNeisseria perflava andKlebsiella pneumoniae

The localization of common antigens with tissues of the human bronchopulmonary apparatus was studied in cells ofNeisseria perflava andKlebsiella pneumoniae. Cross reactions of several structures ofN. perflava andK. pneumoniae cells (capsule, cell walls, fractions of cytoplasmic structures, hyaloplasm) were studied in the complement fixation test (CFT) with antilung sera. Antigens cross-reacting with antilung sera were found not only in surface structures (cell walls) of the bacterial cells but also in deep components (cytoplasmic fraction rich in RNP) of the microorganism.Allergologic Research Laboratory, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 349–350, March, 1976.     

Characterizing lipopolysaccharide and core lipid A mutant O1 and O139 Vibrio cholerae strains for adherence properties on mucus-producing cell line HT29-Rev MTX and virulence in mice

Components of lipopolysaccharide (LPS), i.e. capsule, O antigen, core oligosaccharide, as well as the toxin-coregulated pili are among the factors which significantly contribute to intestinal colonization by Vibrio cholerae O1 and O139. To further address the contribution of LPS to V. cholerae virulence, we performed in vivo colonization experiments and mucus layer attachment studies with defined LPS and capsule mutants of O1 and O139. We investigated the interaction of V. cholerae strains with the differentiated human intestinal cell line HT29-Rev MTX, and found 3-5-fold reduced efficiencies for attachment by defined LPS and capsule mutants of O1 and O139 in comparison with the wild-type strains. In addition, two O1/O139-specific core oligosaccharide biosynthetic gene products, WavJ and WavD, were characterized and tested for colonization. We demonstrate that single and double knockout mutants in wavJ and wavD have an effect on core oligosaccharide biosynthesis, and that these mutants show an attenuated growth in the presence of novobiocin. Curiously, in the mouse intestinal colonization model, only the O139 wavJ,D mutants demonstrated reduced colonization.     

Vibrio cholerae cytolysin is essential for high enterotoxicity and apoptosis induction produced by a cholera toxin gene-negative V. cholerae non-O1, non-O139 strain

Cholera toxin (CT) gene-negative Vibrio cholerae non-O1, non-O139 strains may cause severe diarrhea though their pathogenic mechanism remains unclear. V. cholerae cytolysin (VCC) is a pore-forming exotoxin encoded in the hlyA gene of V. cholerae whose contribution to the pathogenesis is not fully understood. In this work, the virulence properties of a CT gene-negative V. cholerae non-O1, non-O139 strain causing a cholera-like syndrome were analyzed. Inoculation of rabbit ileal loops with the wild type strain induced extensive fluid accumulation, accompanied by severe histopathological damage characterized by villus shortening, lymphangiectasia and focal areas of necrosis. These pathogenic effects were abrogated by mutation of the hlyA gene thus pointing out the main role of VCC in the virulence of the strain. Interestingly, this toxin was capable of triggering apoptosis in human intestinal cell lines due to its anion channel activity. Moreover, the wild type strain also induced increased apoptosis of the intestinal epithelium cells which was not observed upon inoculation of the VCC null mutant strain, indicating that VCC may trigger apoptotic cell death during infection in vivo. Altogether, these results support a main role of VCC in the pathogenesis of the CT gene-negative V. cholerae non-O1, non-O139 strain and identify apoptosis as a previously unrecognized cell death pathway triggered by VCC.     

IL-1beta expression in Int407 is induced by flagellin of Vibrio cholerae through TLR5 mediated pathway

Vibrio cholerae, a noninvasive enteric bacterium, causing inflammatory diarrheal disease cholera, is associated with the secretion of proinflamammatory cytokines including IL-1β in cultured epithelial cells. Incubation of Int407 with live V. cholerae resulted in increased IL-1β mRNA expression as early as 2 h of infection, reached a peak at 3.5 h and decreased thereafter. The identity of the effector molecule(s) is largely unknown. The bacterial culture supernatant showed IL-1β stimulating activity. An engineered aflagellate V. cholerae flaA mutant (O395FLAN) resulted in highly reduced level of IL-1β expression in Int407. The crude flagellar protein of V. cholerae as well as recombinant FlaA induced IL-1β expression in Int407. Infection of Toll-like receptor 5 (TLR5) transfected HeLa cells with O395FLAN showed reduced expression of IL-1β compared to wild-type. Unlike wild-type V. cholerae, O395FLAN did not activate the NF-κB while the recombinant flagellin could activate NF-κB. Finally, the mitogen activated protein kinases (ERK1 and 2, p38) were phosphorylated in wild-type and recombinant flagellin treated Int407 cells and inhibition of the p38 and ERK pathways significantly decreased the IL-1β response induced by wild-type V. cholerae as well as recombinant flagellin. Our data clearly indicate that flagellin of V. cholerae could induce IL-1β expression by recognizing TLR5 that activate NF-κB and MAP kinase in Int407.