CHARACTERIZATION OF THE COLONIZATION FACTOR ANTIGEN II PLASMID (CFA/II) FROM ENTEROTOXIGENIC ESCHERICHIA COLI

The etiological role of enterotoxigenic E. coli (ETEC) in diarrheal diseases of man and domestic animals is firmly established. Besides the production of enterotoxins (ST and LT), ETEC produces other important virulence factors; the colonization factor antigens (CFAs). CFAs mediate the attachment of ETEC to the epithelial cells of the small intestine, and this favors colonization by the bacteria and facilitates delivery of the enterotoxins to the intestinal cells.^ The production of enterotoxin and CFA is determined by plasmids and has been found to be restricted to a select number of E. coli serotypes.^ In this work, plasmid DNA analysis was performed in twenty-three CFA/II-producing enterotoxigenic Escherichia coli strains and their spontaneous CFA/II-negative derivatives. In some cases, strains lost the high molecular weight plasmid and also the ability to produce CFA/II, ST and LT. In other cases there was a deletion of the plasmid, which produced strains that were CFA/II('-), ST('-), LT('-) or CFA/II('-), ST('+), LT('+).^ The CFA/II plasmid from strain PB-176 (06:H16:CFA/II('+), ST('+), LT('+)) was transferred by transformation into E. coli K12 with concomitant transfer of the three characteristics: CFA/II, ST and LT.^ A physical map of the prototype CFA/II:ST:LT (pMEP60) plasmid was constructed by restriction endonuclease analysis and compared to plasmids from three other CFA/II-producing strains. A CFA/II-negative (but ST and LT positive) deletion derivative of pMEP60 (pMEP30) was also included in the map. The four CFA/II plasmids analyzed had a common region of approximately 30 kilobase pairs. The toxin genes were approximately 5 kbp apart and about 20 kbp from the common region. The information given by this physical map could be of great value when constructing a clone that will express the CFA/II genes but not the toxin genes. ^

STUDIES ON THE CLASS I GLYCOPROTEINS OF THE MURINE MAJOR HISTOCOMPATIBILITY COMPLEX (TRANSPLANTATION ANTIGEN, LYMPHOCYTE, CELL SURFACE MOLECULE)

A series of studies were undertaken to analyze and compare various aspects of murine class I glycoproteins. An initial area of investigation characterized the Qa-1 alloantigens using two-dimensional gel electrophoresis. Analysis of the products of the Qa-1('b), Qa-1('c) and Qa-1('d) alleles indicated that these were distinct molecules as determined by their lack of comigration upon comparative two-dimensional gel analysis. The importance of asparagine-linked glycosylation in the cell surface expression of class I molecules was also examined. These studies employed tunicamycin, an inhibitor of N-linked glycosylation. Tunicamycin treatment of activated T lymphocytes diminished the surface expression of Qa-1 to undetectable levels; the levels of other class I molecules exhibited little or no decrease. These results indicated that N-linked glycosylation has a differential importance in the cell surface expression of various class I molecules. The molecular weight diversity of class I molecules was also investigated. Molecular weight determination of both the fully glycosylated and unglycosylated forms of H-2 and Qa/Tla region encoded molecules established that there is a significant variation in the sizes of these forms of various class I molecules. The most significant difference ((TURN)9,000 daltons) exists between the unglycosylated forms of H-2K('b) and Qa-2, suggesting that the structural organization of these two molecules may be very different. A comparative two-dimensional gel analysis of various class I glycoproteins isolated from resting and activated T and B lymphocytes indicated that class I molecules expressed on activated T cells exhibited an isoelectrophoretic pattern that was distinct from the isoelectrophoretic pattern of class I molecules expessed on the other cell populations. This difference was attributed to a lower sialic acid content of the molecules expressed on activated T cells. Analysis of cell homogenates determined that activated T cells contained a higher level of endogenous neuraminidase activity than was detected in the other populations, suggesting that this may be the basis of the lower sialic acid content. The relationship of the Qa-4 and Qa-2 alloantigens was also examined. It was established that upon mitogen activation, the expression of Qa-4 was greatly decreased, whereas Qa-2 expression was not decreased. However, an anti-Qa-2 monoclonal antibody blocked the binding of an anti-Qa-4 monoclonal antibody to resting cells. These studies established that Qa-4 is a determinant restricted to resting cells, which is closely associated on the surface with the Qa-2 molecule. ^

Anmerkungen : va-ethanan ekev re'eh shoftim ki-tetse ki-tavo

Nathan Birnbaum

Na 1 Nachlass Max Horkheimer, 67 - Korrespondenzen u.a. mit der Columbia University New York (p. II 5, 1-219)

17 Briefe und Beilage zwischen Joseph Christ und Max Horkheimer, 1942-1943; 13 Briefe zwischen Elliot E. Cohen und Max Horkheimer, 1946-1947; 7 Briefe zwischen Stewart G. Cole und Max Horkheimer, 1944-1945 sowie 1 Sonderdruck; 1 Memorandum von Theodor W. Adorno an F. Pollock, 1948; 5 Briefe zwischen dem Collegium [Studentischer Club an der Universität Frankfurt am Main] und Max Horkheimer, 1949; 17 Briefe und Beilage zwischen dem College of Jewish Studies, 1948-1949, 1951 sowie Drucksachen und 9 Papers zum Antisemitismus; 18 Briefe und Beilagen zwischen der Columbia University New York und Max Horkheimer, 1942-1947;

Ms. Praed. 67 - Compendium theologicae veritatis

Vorbesitzer: Radulfus de Zelandia alias de Bruxella; Dominikanerkloster Frankfurt am Main

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 67 - Übersendung einer Publikation

u.a.: beabsichtigtes Treffen am 2. oder 3. Juli 1857 in Frankfurt am Main;

Ms.Ff.F.Stoltze 3. 67 - Brief von Friedrich August Finger an Friedrich Stoltze

Wilhelm Sauerwein: "Der Gräff, wie er leibt und lebt", Georg Friedrich Gräff, Samuel Friedrich Hassel

Ms. Barth. 181 (Ausst. 67) - Evangelistarium

Vorbesitzer: Hartmann Becker; Margarethe von Appenheim; Bartholomaeusstift Frankfurt am Main

Sinfonie no. V oeuv. 67

de Louis v. Beethoven. Arr. en quintetto pour deux violons, deux violes et violoncelle par C. F. Ebers

Katharina Kiß von Itebe, Brustbild

Signatur des Originals: S 36/F01787

Goethe im 67. Jahre, Zur Erinnerung an Goethe's 150 jähr. Geburtstag 28. Aug. 1899 : Goethe's Wohnhaus am Frauenplan zu Weimar, Blick vom Garten auf das Arbeits- u. Sterbezimmer

Signatur des Originals: S 36/F04206