Transforming growth factor-beta inhibits the antiviral action of interferons in human embryonic fibroblasts.

Transforming growth factor-beta (TGF-beta) at concentration of 10 ng/ml inhibited the development of the interferon-alpha- (IFN-alpha) or IFN-gamma-induced antiviral state in quiescent human embryonic fibroblasts. The action of the cytokines was dose-related; TGF-beta had no direct effect on the replication of either vesicular stomatitis virus (VSV) or encephalomyocarditis virus (EMCV) used as the challenge viruses in the IFN assays. We suggest that despite the fact that TGF-beta acts mainly as a "negative" growth factor, its interactions with IFNs in the antiviral assays resemble known effects of the typical "positive" peptide growth factors.

Bovine transforming growth factor beta. Purification and characterization.

Polypeptide growth factor isolated from bovine platelets was classified on the basis of its physico-chemical and biological properties to be transforming growth factor type beta (TGF beta). This growth factor was completely purified from platelet lysate by acid ethanol extraction, Bio-Gel P-60 filtration, ion-exchange chromatography on CM-Sephadex followed by two successive gel filtrations on Bio-Gel P-10 and Sephadex G-100. After the last gel filtration over 35,000-fold purified TGF beta was obtained.

Choline and halogen derivatives of CMA (9-oxo-10-acridine acetic acids) as tools for monitoring the interaction of the interferon inducers via a specific receptor.

New choline and halogen derivatives of CMA (9-oxo-10-acridine acetic acid) were investigated as interferon (IFN) inducers in mice and in the mouse bone marrow-derived macrophage cultures. Two of the choline derivatives, DMCMA and CSCMA, were active IFN inducers presumably because they were hydrolyzed so as to release CMA. The halogen analogues of CMA were inactive or weak IFN inducers in vivo and in vitro.

Tolerance or hyperreactivity to interferon induction by sodium salt of 9-oxo-10-acridineacetic acid and analogs in mice and in the mouse macrophage cultures.

Choline and halogen analogs of 9-oxo-10-acridineacetic acid (CMA) were studied as IFN inducers in mice and in the mouse bone marrow-derived macrophage cultures. Two of the choline analogs--DMCMA and CSCMA were inducers of IFN in the macrophages. The response was found to be dose related.

Induction of interferon in mice by sodium salt of 9-oxo-10-acridineacetic acid: specific enhancement by analogs.

9-oxo-10-acridineacetic acid bearing the common name of 10-carboxymethyl-9-acridanone or CMA (6) was found to be a very potent interferon (IFN) inducer in adult Balb/c mice. Seven structural analogs of CMA were synthetized and assayed for the interferon inducing ability. Three of the compounds had new chemical structures.

Hormonal-like modulation of growth of moloney virus-induced tumors by interferon and platelet-derived growth factor.

Continued intramuscular (i.m.) administration of highly purified preparations of mouse interferon (MuIFN) and/or bovine platelet-derived growth factor (PDGF) to the Moloney sarcoma virus (MSV) infected Balb/c mice resulted in a hormonal-like modulation of growth of tumors.

Platelet-derived growth factor (PDGF) enhances the growth of Moloney sarcoma virus-induced tumors in mice.

The intramuscular (i.m.) administration of bovine or human platelet derived growth factor (PDGF) had a marked potentiating effect on the growth of Moloney sarcoma virus (MSV)-induced tumors in Balb/c mice.

Dextran T fractions substituted with cibacron blue F3G-A as carriers for mouse interferon.

Commercial dextran T fractions covering the molecular weight (Mt) range 10,000-2,000,000 were substituted with a covalently linked chromophore: Cibacron blue F3G-A. Mouse interferon (IF) was found to bind firmly to the blue dextran (BD) fractions. Fractions of high Mt (BD 2000 and BD 500) associated with IF are precipitated from the solution by polyethylene glycol (PEG).

Effect of anti-mouse type-1 interferon globulin on the evolution of Moloney sarcoma virus induced disease in mice.

The prolonged administration of potent sheep anti-mouse type-1 interferon globulin (anti-IF IgG) had a marked potentiating effect on Moloney sarcoma virus (MSV) infection in mice. The extent of resistance to the MSV-induced disease was age-related. In 4-week-old BALB/c mice, anti-IF IgG consistently induced 70-80% mortality due to the progression of early or late tumours and erythroleukaemia, whereas mortality of control mice was significantly lower.

Effects of anti-interferon serum on growth and regression of Moloney sarcoma virus induced tumours in mice.

Administration of sheep anti-mouse interferon serum or globulin to weanling BALB/c mice infected with Moloney sarcoma virus (MSV) accelerated the growth of tumours at the site of virus inoculation, increased the number and size of tumours, and inhibited their regression. The outcome of the MSV-induced disease after injection of anti-interferon globulin depended on the age of mice. The antigenic stimulation by normal sheep serum or globulin also enhanced the growth and mortality due to MSV but to a significantly lesser extent than anti-interferon globulin.

Biological properties of mouse interferon bound to a high molecular weight carrier: Blue Dextran 2000.

Mouse C-243 cell interferon (IF) binds to Blue Dextran 2000 (BD). The BD-IF complex could be precipitated by polyethylene glycol. When 0.

Antigenic similarity of morphologic type CIII1 bacteriophages.

The aim of the study was to demonstrate antigenic differentiation among bacteriophages belonging to the same morphologic type--CIII1 according to Krzywy and Slopek or A2 according to Ackermann. Twenty-six bacteriophages which multiplied on various strains of bacteria of the genera Escherichia, Shigella and Klebsiella, were studied. Serologic tests were done by the quantitative complement fixation test.

Actinomycetes of the genus Streptomyces in soil from Syria.

Species identification and antagonistic properties of 55 actinomycete strains isolated from Syrian soil were studied. The actinomycete strains belonged to 22 species, of which most abundantly represented were Streptomyces antimycoticus, S. rubiginosohelvolus, S.