The O-polysaccharide of Escherichia coli F5, which is structurally related to that of E. coli O28ab, provides cells only weak protection against bacteriophage attack.

Several types of Escherichia coli O-antigens form highly effective shields protecting the bacterial cell surface and preventing bacteriophages from interacting directly with their secondary (terminal) receptors. However, it is not clear if O-antigens of various types (O-serotypes) differ in their anti-phage protection efficacy. Here, we describe a new E. coli strain, F5, which has an E. coli O28ab-related O-antigen. Although the amount of O-antigen produced by this strain is comparable to that produced by other E. coli strains we tested, it appears to give the cells significantly lower protection against phage attack than other O-antigen types, such as the O-polysaccharide of E. coli F17, which we studied earlier.

Erratum to: "Structural Relationships Between Genetically Closely Related O-Antigens of Escherichia coli and Shigella spp." [Biochemistry (Moscow), 81, 600 (2016)].

This corrects the article DOI: 10.1134/S0006297916060067.

Structural Relationships Between Genetically Closely Related O-Antigens of Escherichia coli and Shigella spp.

Gene clusters for biosynthesis of 24 of 34 basic O-antigen forms of Shigella spp. are identical or similar to those of the genetically closely related bacterium Escherichia coli. For 18 of these relatedness was confirmed chemically by elucidation of the O-antigen (O-polysaccharide) structures. In this work, structures of the six remaining O-antigens of E. coli O32, O53, O79, O105, O183 (all related to S. boydii serotypes), and O38 (related to S. dysenteriae type 8) were established using (1)H and (13)C NMR spectroscopy. They were found to be identical to the Shigella counterparts, except for the O32- and O38-polysaccharides, which differ in the presence of O-acetyl groups. The structure of the E. coli O105-related O-polysaccharide of S. boydii type 11 proposed earlier is revised. The contents of the O-antigen gene clusters of the related strains of E. coli and Shigella spp. and different mechanisms of O-antigen diversification in these bacteria are discussed in view of the O-polysaccharide structures established. These data illustrate the value of the O-antigen chemistry and genetics for elucidation of evolutionary relationships of bacteria.

[Submicroscopic features of cells in the microenvironment of hematopoietic development of virus-induced Rauscher leukemia]. / Submikroskopicheskie osobennosti kletok mikrookruzheniia krovetvornykh organov v protsesse razvitiia virusindutsirovannogo leikoza Raushera.

The study was made of submicroscopic changes in the cells of bone marrow and splenic microenvironment in mice developing virus-induced Rauscher leukemia. As shown by electron microscopy, ultrastructural cytochemistry and immunocytochemistry, ultrastructure of the complexes from the stromal and hemopoietic cells underwent noticeable alterations as early as the first days after the virus introduction. This suggests that bone marrow is the primary target of the virus in Rauscher leukemia. Affections of the macrophages, dendrite, interdigital and lymphoid cells of the spleen reflect their participation in the body defenses against the virus. Progressive shift of erythropoiesis from the bone marrow into the spleen is related to morphofunctional changes in the microenvironmental cells. The findings may be useful in consideration of cellular pathogenetic aspects of acute leukemia.

[The morphofunctional characteristics of lymphoma NK/LY cells treated with concanavalin A and Vibrio cholerae neuraminidase]. / Morfofunktsional'ne osobennosti kletok limfomy NK/LY, obrabotannykh konkanavalinom A i neiraminidazoi kholernykh vibrionov.

Mouse NK/LY lymphoma cells were modified by Con A or Vibrio cholerae neuraminidase (VCN). Severe damage of the modified cells was not revealed by either supravital staining or light microscopy. Ultrastructural signs of metabolic lowering in the Con-A-treated cells were determined. Some increase in electrophoretic mobility of Con-A-modified cells was found, along with its decrease in VCN-modified cells. The decrease in the pool of proliferating cells was determined in both the types of modification, being more evident in the Con-A-modified material. A marked tumorigenic decrease of Con-A-modified cells was fixed.

[Ultrastructural features of erythropoiesis disorder in Rauscher virus leukemia]. / Ul'trastrukturnye osobennosti narusheniia éritropoéza pri virusnom leikoze Raushera.

The population of leukemic cells (beginning from the precursor cells) has been identified by electron-microscopy methods. Ultrastructural changes typical of the erythropoiesis alteration are determined. Peculiarities in the formation of a leukemic cells population in different hemopoietic organs and changes in erythroid islands (the main morphofunctional unit of erythropoiesis) are revealed. Data obtained show the significant disturbances in differentiation of erythroid cells in the virus leukoses and are very important form the further study of the leukemogenesis mechanisms.

[Ultrastructural characteristics of the blood lymphocytes in some forms of sporadic T-cell lympholeukemia and leukemia associated with the HTLV virus]. / Ul'trastrukturnye osobennosti limfotsitov krovi pri nekotorykh formakh sporadicheskogo T-kletochnogo limfoleikoza i leikoza, assotsiirovannogo s virusom HTLV.

The electron microscopic study of the blood cells in some patients with sporadic T-cell acute lymphoblastic leukemias has shown some ultrastructural peculiarities similar to T-cell lympholeukemia associated with HTLV virus, that is important for the further elucidation of etiology and pathogenesis of the T-cell lymphoproliferative diseases.

[Ultrastructural characteristics of bone marrow subendosteal region cells in T-cell virus-induced leukemia]. / Ul'trastrukturnye osobennosti kletok subéndostal'noi oblasti kostnogo mozga pri T-kletochnom virusindutsirovannom leikoze.

The experiments were carried out to study hemopoietic and stromal cells of bone marrow subendosteal regions during T-cell lymphomagenesis in AKR mice, using transmission electron microscopy and electron microscopic immunocytochemistry methods. It is shown that the subendosteal region of mice with lympholeukosis is replaced by lymphocytes at different stages of differentiation with certain ultrastructural peculiarities. The association of alkaline-phosphatase positive reticulum cells with granulocytes is destroyed. The alkaline phosphatase activity in reticulum cells of the subendosteal region of mice with spontaneous lympholeukosis is very low or absent. The results obtained may be useful for understanding the AKR lymphomagenesis.