Interferon production in microcarrier culture of human fibroblast cells.

The microcarrier cell culture technique offers a convenient way of manipulating relatively large amounts of anchorage-dependent cultured mammalian cells in a relatively small volume. Other advantages of this system are ease of direct observation, and of monitoring and control of other culture parameters. The production of human fibroblasts interferon on microcarrier culture on a scale of up to 44 litres (very roughly equivalent to 1100 roller bottles) using a conventional inducation with poly(I) poly(C), followed by superinduction by treatment with metalolic inhibitors, is described.

Skin reactions to interferon inoculations are reduced but not abolished by purification.

The skin reactions to partially-purified fibroblast-derived (HulFN-beta) and leucocyte-derived (HulFN-alpha) interferons and to HulFN-alpha of increasing purity were studied in normal volunteers. Reactions consisted of an immediate flare followed by a dense well-circumscribed erythema maximal at 4-8 hours. HulFN-beta caused significantly larger reactions than HulFN-alpha of approximately the same purity.

Mechanism of binding of mouse interferon to controlled pore glass.

Many proteins bind to controlled pore glass; they are either acid elutable or alkali elutable. Mouse interferon is an acid-elutable protein. Since poly(L-lysine) and, to some extent, poly(L-arginine) are also eluted from controlled pore glass under acidic conditions, one may postulate that mouse interferon binds to controlled pore glass via some of the protein's epsilon-amino groups (of lysine) and/or guanidinium groups (of arginine) and the beads' silanol (hydroxyl groups).

Human fibroblast interferon for clinical trials: pharmacokinetics and tolerability in experimental animals and humans.

Human fibroblast interferon (F-interferon) purified by adsorption on controlled-pore glass was given intramuscularly to patients at daily dosages of up to 20 x 10(6) units. Serum levels of antiviral activity were low or undetectable. In contrast, reasonably high serum titers were found in patients receiving interferon prepared from leukocytes (L-interferon).

Human fibroblast interferon for clinical trials: production, partial purification, and characterization.

The production and partial purification of human fibroblast interferon for performing clinical trials is described. The interferon was produced by superinduction (exposure to riboinosinic-ribocytidylic acid, cycloheximide, and actinomycin D) of large numbers of human diploid fibroblast cultures. The yield averaged 750 units per cm(2) of culture area.

Double-blind study of interferon administration in renal transplant recipients.

In a double-blind trial renal allograft recipients were treated with fibroblast interferon preparations for 3 months in an attempt to prevent viral infections. Interferon therapy did not reduce the overall incidence of viral infections. No adverse effects were noted on liver function, platelet counts, or leucocyte counts, or acute rejection episodes.

Purification of human fibroblast interferon by zinc chelate affinity chromatography.

Zinc chelated by iminodiacetic acid linked to an insoluble matrix binds human fibroblast interferon quite selectively at neutral pH in 0.15 M NaCL. On reduction of the pH and increase of the ionic strength, the interferon is eluted.

Human interferon: mass production in a newly established cell line, MG-63.

MG-63 cells, a line derived from an osteosarcoma, produced high yields of interferon after superinduction with polyinosinic acid.polycytidylic acid, cycloheximide, and actinomycin D. Advantages of MG-63 cells over diploid fibroblasts as a substrate are: no requirement for aging between confluency and induction, no requirement for priming, and 3.

Stable and unstable forms of human fibroblast interferon.

There is a minor fraction of human fibroblast interferon that resembles human leukocyte interferon in being renaturable after treatment with guanidine hydrochloride. However, antigenically and in its low activity on heterologous cells, it resembles the bulk of human fibroblast interferon. Since the production of this stable interferon fraction is not greatly inhibited by glucosamine at concentrations that significantly reduce total interferon production, it is suggested that it differs from the bulk of human fibroblast interferon in the extent or nature of glycosylation.

Purification of interferon by adsorption chromatography on controlled pore glass.

Human fibroblast and mouse L929 cell interferons can be purified by adsoprtion to and subsequent elution from Controlled Pore Glass. Purification of 40 to 90-fold to specific activities of 1 to 5 times 10(6) units/mg of protein can be achieved in a single step, with good recovery of activity. Human leukocyte interferon does not bind to the glass and cannot be purified in this way.

Administration of human fibroblast interferon in chronic hepatitis-B infection.

One patient with hepatitis-B surface antigen (HBsAg)-positive chronic aggressive hepatitis, and two chimpanzee carriers of HBsAg, were each given seven doses of 10(7) I.U. of human fibroblast interferon over two weeks.

Comparison of rates of clearance of human fibroblast and leukocyte interferon from the circulatory system of rabbits.

In view of the lower physical stability of human fibroblast interferon than of human leukocyte interferon, the rates of clearance of the two types of interferon were compared in vivo. Both types were injected intravenously and intramuscularly into rabbits, and serum titers were determined at various times after injection. The rates of clearance of the two types of interferon were very similar after both intravenous and intramuscular injection, a finding which indicated that, at least in the circulatory system of rabbits, human fibroblast interferon is not less stable than human leukocyte interferon.

Human fibroblast and leukocyte interferons show different dose-response curves in assay of cell protection.

Preparations of human fibroblast and leukocyte interferons of similar potency show markedly different dose-response curves in an assay which measures the degree of protection of tissue cultures against virus c.p.e.