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Biomedical subjects

H M Johnson

Publications and source records attributed to H M Johnson.

At least 181 records · Page 10Linked to original sources
PubMed1979

Large-scale production and partial purification of mouse immune interferon.

Large-scale production of high-titered (10(2.2) to 10(4) U/ml) immune interferon (type II) was carried out in roller cultures of mouse spleen cells by using the T-cell mitogen staphylococcal enterotoxin A. Precipitation of 90% of this interferon by 55 to 80% saturated ammonium sulfate resulted in a 20-fold concentration and a two- to sixfold purification. After application of this interferon to either bovine serum albumin (BSA)-Affi-Gel 10 or hydroxylapatite columns, 100% of the interferon activity was recovered. By BSA-Affi-Gel 10 chromatography, 7% of the recovered activity was not bound, 45% was eluted with pH gradient 5 to 7, and 48% was eluted with 1 M NaCl. The pH- and salt-eluted interferons from the BSA-Affi-Gel 10 column were purified 62- and 390-fold, respectively, when compared with the starting materials. Rechromatography of the pH- and salt-eluted interferon peaks from the BSA-Affi-Gel 10 column did not alter their elution patterns. Stepwise elution of interferon from the BSA-Affi-Gel 10 columns with buffers of various pH and salt contents also resulted in greater than 300-fold purification. Specific activities of up to 2 x 10(5) U of interferon per mg of protein were attained with either elution procedure from BSA-Affi-Gel 10 columns. By hydroxylapatite chromatography, 5% of the recovered activity was not bound, 20% was eluted with a salt gradient, and 75% was eluted with 30% glycerin. Purification was 107- and 16-fold, respectively, for the two fractions. Ultrogel AcA 34 chromatography of the interferon resulted in two peaks of activity, a major one with a molecular weight of approximately 40,000 and a minor peak of molecular weight 70,000 to 90,000. Thus, by different types of chromatography, immune interferon was found to be heterogeneous.

Animals↗
PubMed1979

Potentiation of interferon activity by mixed preparations of fibroblast and immune interferon.

Mixed preparations of fibroblast and immune interferons interacted with cells synergistically to cause the development of a much greater level of protection than expected on the basis of their separate activities. This increased level of protection was 5- to 20-fold greater than expected on the basis of a simple additive effect of the interferons. The potentiating factor copurified with both fibroblast interferon and immune interferon as they were partially purified. The potentiation was not an artifact of a more rapid development of immune interferon-induced antiviral resistance in the presence of fibroblast interferon. The results were consistent with the hypothesis that fibroblast and immune interferons mutually potentiate each other, thus supporting the supposition that they have different modes of action.

Animals↗
PubMed1979

Large-scale production and physicochemical characterization of human immune interferon.

Large-scale production of crude high-titered (10(2.3) to 10(4) U/ml) human immune interferon (type II) was carried out in roller bottle cultures of human peripheral lymphocytes by using the T-cell mitogen staphylococcal enterotoxin A. Over 99% of human immune interferon was destroyed by pH 2 or heat at 56 degrees C for 1 h. The interferon was not neutralized by antibody to human leukocyte interferon. The kinetics of development of the antiviral state were slow for immune interferon relative to those for leukocyte interferon. Ultrogel AcA 54 chromatography of crude or the concentrated interferon resulted in two peaks of activity, a major one (87% of recovered activity) with a molecular weight of 40,000 to 46,000 and a minor peak of molecular weight 65,000 to 70,000. The column elution buffer consisting of 18% ethylene glycol and 1 M NaCl in phosphate-buffered saline resulted in at least 100% recovery of added interferon. The data suggest, then, that the interferon produced under large-scale conditions was immune (type II). The efficiency of the production was comparable to that described for large-scale production of human leukocyte interferon. Our large-scale production system for human immune interferon offers a feasible approach to preparation of large quantities of purified immune interferon for structure studies, antibody production, and clinical application.

Cell Line↗
PubMed1979

Induction of an inhibitor of interferon action in a mouse lymphokine preparation.

An inhibitor of interferon action was identified in mouse lymphokine preparations. The inhibito was first detected in the supernatant fluid of mouse spleen cells at 72 h after stimulation by staphylococcal enterotoxin A. Inhibitor was not detected in supernatant fluids from unstimulated cultures. This inhibitor blocks the antiviral activity of both immune and fibroblast interferons. The inhibitor was purified 1,000-fold by two-step column chromatography. The partially purified inhibitor blocked the antiviral activity of up to 400 U of interferon. The immunosuppressive effect of interferon was also blocked by the inhibitor, suggesting that the inhibitor may modulate the immunoregulatory function of interferon.

Animals↗
PubMed1979

Immune-type interferon-induced transfer of viral resistance.

Mouse immune-type interferon (type II), a lymphokine, caused the transfer of viral resistance from mouse L cells to human WISH cells. The interferon was incapable of protecting WISH cells in the absence of L cells. The transfer of viral resistance occurred with interferon preparations of various specific activities, and was in proportion to the interferon concentration in the preparations. The transferred resistance had the characteristics of an interferon-induced antiviral state in that it was blocked by actinomycin D, effective against different types of viruses, and resulted from an action on the cell rather than on the virus. Mouse immune-type interferon was more efficient than virus-type (type I) at eliciting the transfer of protection. The transfer phenomenon may represent a mechanism for amplification of the interferon system as a host defense against viral infection. Further, it serves as a model for studying the mechanism of lymphokine-induced transfer of information between cells.

Animals↗
PubMed1978

Biological effects of staphylococcal enterotoxin A on human peripheral lymphocytes.

The mitogenicity, ability to induce immune interferon, and relationship between interferon synthesis and cell proliferative response were studied using human peripheral lymphocytes stimulated by staphylococcal enterotoxin A (SEA), phytohemagglutinin-P (PHA-P), and concanavalin A (ConA). Maximum cell proliferative responses ([(3)H]thymidine incorporation) and protein synthesis ((14)C-amino acid incorporation) occurred on days 3 and 4, respectively, after stimulation by each of the three mitogens. Maximal immune interferon levels were found 3 or 4 days after mitogen stimulation. SEA-treated cultures produced approximately three times more interferon than did cultures stimulated with PHA-P or ConA. Furthermore, SEA stimulated maximal cell proliferation over a much broader concentration range than did PHA-P and ConA (SEA, 10(-5) to 10(2) mug/ml; PHA-P, 10(1) to 10(2) mug/ml; ConA, 10(1) to 10(1.5) mug/ml). Interferon was also produced at maximal or near maximal levels over a broad concentration range of SEA (10(-2) to 10(2) mug/ml). Also, we found that inhibition of mitogen-induced DNA and protein synthesis to control levels by mitomycin C or cytosine arabinoside partially reduced interferon production. The DNA inhibitor studies indicate that immune interferon synthesis occurs maximally in association with at least some proliferative response and that submaximal levels of interferon production occur in mitogen-treated cultures in the absence of detectable proliferation. The ability of SEA to stimulate maximal DNA and immune interferon synthesis at concentrations of 3.5 x 10(-13) M and 3.5 x 10(-10) M, respectively, puts it in a potency range similar to that of hormones. Thus, SEA may play an important role in gut immunity and Staphylococcus aureus infections at concentrations well below those required for emetic effects.

Bacterial Proteins↗
PubMed1978

The role of interferon in virus infections and antibody formation.

Virus-type interferon is capable of suppressing the antibody response both in vivo and in vitro. Interferon induced by antigen or mitogen (immune interferon), primarily in T-lymphocytes, also appears capable of suppressing the antibody response. Cyclic AMP has a regulatory effect on the induction of both virus-type and immune interferon. The immunosuppressive effects of virus-type and immune interferon may differ at the cellular or subcellular level.

Animals↗
PubMed1977

Effect of interferon on antibody formation.

Virus-type interferon is capable of suppressing the antibody response both in vivo and in vitro. Interferon induced by antigen or mitogen (immune interferon) primarily in T lymphocytes also appears capable of suppressing the antibody response. Cyclic AMP has a regulatory effect on the induction of both virus-type and immune interferon. The immunosuppressive effects of virus-type and immune interferon may differ at the cellular or subcellular level.

Animals↗