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Biomedical subjects

E Falcoff

Publications and source records attributed to E Falcoff.

At least 73 records · Page 4Linked to original sources
PubMed1980

Production of antibodies against mouse immune T (type II) interferon and their neutralizing properties.

An antiserum to immune T-type mouse interferon was prepared in rabbits by repeated injections of interferon, induced by phytohaemagglutinin (PHA) in mouse spleen cells and purified to 1 X 10(5) units/mg protein. The antiserum neutralized mouse interferons synthesized in vitro in response to several T mitogens and Brucella organisms, and also the type II interferon present in the serum of BCG-sensitized mice after an injection of the specific antigen, tuberculin. All these interferons are thus antigenically related; they are also all unstable at pH 2. In contrast, the antiserum did not neutralize interferons induced by West Nile virus (WNV) and Newcastle disease virus (NDV) in vitro, or by lipopolysaccharide and Brucella organisms in vivo; all these interferons are stable at pH 2. It also failed to neutralize a non-glycosylated virus interferon prepared in the presence of tunicamycin.

Animals↗
PubMed1979

Physico-chemical characterization and partial purification of mouse immune interferon.

Mouse immune (type T) interferon was produced from suspensions of spleen cells (1 X 10(7) cells/ml) treated with 3 micrograms/ml of phytohaemagglutinin. The crude interferon was chromatographed on four sorbents with varying affinities, namely concanavalin A-Sepharose, Affi-Gel 202, Blue Sepharose CL-6B and Phenyl-Sepharose CL-4B. With each of these the interferon activity was observed to have considerable heterogeneity. By means of affinity chromatography, mouse immune interferon was purified 100 to 200 times with concomitant complete recovery of activity.

Animals↗
PubMed1978

Induction of interferon synthesis in mice by fractions from Nocardia.

Three fractions of Nocardia, Nocardia water-soluble mitogen (NWSM), Nocardia water-soluble mitogen pellet (NWSMP), and the cell wall peptidoglycan, which are mitogenic for B lymphocytes, were able to induce circulating interferon in mice, NWSMP and NWSM being the most active. The peak of interferon appeared about 2 h after injection. The interferon induced by NSWMP and NWSM was acid stable and antigenically related to viral interferon, as shown by neutralization with antibodies directed against Newcastle disease virus-induced interferon.

Animals↗
PubMed1978

Immune interferon induced by phytohemagglutinin in nude mouse spleen cells.

Phytohemagglutinin is able to trigger interferon synthesis in spleen cell cultures from nude (nu/nu) mice as effectively as in splenic cell cultures from haired, control (nu/+), thymus-bearing mice. A minor theta-bearing cell population present in the spleen of nude mice appears essential to phytohemagglutinin interferon production, although cooperating cells are also required. The properties of nude mouse phytohemagglutinin interferon are indistinguishable from those displayed by the interferon induced in thymus-bearing mouse spleen cell cultures. Both interferons are unstable at pH 2 and cannot be neutralized by an antiviral interferon serum; hence, their characteristics correspond to those described for type T interferon. As in the case of viral interferon, pretreatment of L cells with nude phytohemagglutinin interferon induced specific enhanced phosphorylation of a 67,000-molecular-weight protein in vitro when cell extracts were incubated with double-stranded RNA and gamma-[32P]ATP.

Animals↗
PubMed1977

The use of a complementary DNA probe to detect accumulation of mengo RNA in infected cells pretreated with interferon.

Complementary DNA (cDNA) from Mengo virus RNA has been synthesized and used as a probe to measure the synthesis and accumulation of viral RNA in Mengo infected L cell cultures, treated or untreated with interferon. Under experimental conditions used (200 units interferon/ml and 50 virus plaque-forming units/cell) results show that there is some synthesis of Mengo virus RNA in cells treated with interferon. One hour after infection, treated cells contain three times less viral RNA than untreated cells; five hours after infection, this difference has increased to ten fold. As in the control, no fragmented Mengo virus RNA molecules were found in interferon treated cells. The smaller recovery of infectious particles from interferon treated cells as compared to RNA accumulation suggests that not only RNA accumulation is inhibited but also a step posterior in viral maturation.

Cytoplasm↗
PubMed1977

Some properties of interferons induced by stimulants of T and B lymphocytes.

Murine interferons induced by viruses and by non viral substances such as lectins, tilorone, lipopolysaccharide and Brucella have been analysed by affinity chromatography on a column of Sepharose coupled to anti-bodies directed against viral interferon. B cell stimulants induced interferons which are antigenically related to viral interferon and T cell dependent mitogens induced an interferon species which appears to be antigenically and physicochemically different. Despite their antigenic differences, both kinds of interferon seem to follow similar pathways for the induction of the antiviral state (sensitivity to antimetabolites, and in vitro phosphorylation of a 67 000 MW protein).

Animals↗