Human Immune Interferon Research Articles

Evaluation of Immune‐enhancing Effects of Ibuprofen in an Immunodeficiency Model

Abstract: Three children and one adult with chronic mucocutaneous candidosis with documented deficient cellular immunity to Candida antigen were evaluated as a model to study the specific cellular immune‐enhancing potential of the prostaglandin synthetase inhibitor ibuprofen. Oral ibuprofen failed to have any consistent effect during sequential 4‐week on and off cycles on the following parameters: delayed hypersensitivity skin testing; lymphocyte transformation to Candida antigen; T‐cell subsets as determined by monoclonal antibody techniques; production of human immune interferon in response to staphylococcal enterotoxin A (SEA). Two patients showed a trend toward enhanced lymphocyte transformation to PHA while taking ibuprofen. In two patients who were studied 8–10 weeks after discontinuation of oral ketoconazole therapy, clinical recurrence of CMC was not prevented by oral ibuproten therapy.

Purification of the interferons

Many procedures have been described for the partial purification of human and animal interferons (for review and additional citations, see Berg, 1982; Pestka, 1981a, b, 1983). Although partial purification and purification of the interferons as bands on SDSpolyacrylamide gels was reported by a number of groups, it was not until 1978 and thereafter that any interferon had been purified to homogeneity in solution in sufficient amounts for its chemical and physical characterization (Rubinstein et al., 1978, 1979a, 1981 a; Stein et al., 1980; Friesen et aL, 1981). The introduction of reverse phase and normal phase high performance liquid chromatography to the purification of proteins (Rubinstein et al., 1979a; Stein et al., 1980; Friesen et al., 1981) lead to the first successful purification of these proteins so that sufficient amounts were available in solution without detergent for their chemical, biological and immunological studies. Various affinity purification techniques particularly antibody affinity chromatography were utilized to purify human leukocyte and fibroblast interferons (Knight, 1976; Berthold et al., 1978; Cabrer et aL, 1979; Zoon et al., 1979; Allen and Fantes, 1980; Okamura et al., 1980; Zoon, 1981a; Berg and Heron, 1981; Kawade et al., 1981; Berg, 1982; Knight and Fahey, 1982; as well as additional references within these citations). This review will concentrate on the purification of the human leukocyte and fibroblast interferons in their natural form as well as the leukocyte interferon produced by recombinant DNA technology. A short review of the purification of human immune interferon is also included.

Eradication of Cultured Human Melanoma Cells by Immune Interferon and Leukocytes<xref ref-type="fn" rid="FN2">2</xref>

For the determination of the conditions for the most effective cytolysis of human melanoma cells, leukocyte interferon (IFN-alpha), fibroblast interferon (IFN-beta), and immune interferon (IFN-gamma) were compared for their abilities to kill cultured human melanoma cells in the presence and absence of peripheral blood mononuclear leukocytes (PBL). A microassay was employed in which the viability of melanoma target cells was determined after various times of incubation with interferons alone or with PBL. On 7 human melanoma cell lines (from 6 different patients), IFN-gamma had significantly greater direct anticellular effect than IFN-alpha or IFN-beta. When PBL were added, all target cells were killed after 48 hours with IFN-gamma, but they were not killed with IFN-alpha or IFN-beta. When IFN-gamma was added to either IFN-alpha or IFN-beta, a potentiation of the anticellular effect was observed both with and without PBL. The actions of this "natural" IFN-gamma could be reproduced with recombinant IFN-gamma and could be neutralized by an antibody to a synthetic peptide encoded by the 5'-end of IFN-gamma complementary DNA. It was concluded that IFN-gamma is significantly more active against these human melanoma cell lines than either IFN-alpha or IFN-beta and, most significantly, that eradication can occur in the presence of IFN-gamma and PBL. Furthermore, synergistic anticellular action can be observed when IFN-gamma is added to IFN-alpha or IFN-beta. These findings point to the need for preclinical trials to evaluate eradication in vivo.

Recombinant human immune interferon induces increased IgE receptor expression on the human monocyte cell line U-937.

Human recombinant gamma interferon (IFN-gamma), which is free from other lymphokines, significantly increased expression of receptors for IgE (Fc epsilon R) on the human monocyte cell line U-937. Fc epsilon R were measured by assaying specific (saturable) binding of 125I-labeled or fluorescein isothiocyanate (FITC)-labeled human IgE (Sha) to U-937 cells. Cell-bound IgE was analyzed by gamma counting and by flow cytometry. IFN-gamma-induced enhancement in IgE binding was a consequence of an increase in the number and density of Fc epsilon R, as cell size did not change significantly after treatment. Scatchard analysis of 125I-IgE binding curves revealed the presence of a homogeneous population of binding sites for IgE in control and in IFN-gamma-treated cells. IFN-gamma treatment did not change the value of the dissociation constant of Fc epsilon R for 125I-IgE. IFN-alpha and IFN-beta had only slight effects on the expression of Fc epsilon R. Dexamethasone (200 nM) diminished the IFN-gamma-induced enhancement in the number of Fc epsilon R by about 50%, the same extent as in control cells. IFN-gamma treatment did not cause a significant alteration in cell number, cell cycle kinetics, or macromolecular synthesis, and enhanced expression of Fc epsilon R was probably not mediated through the cyclic AMP system.

Isolation of proteins from crude mixtures with silica and silica-based adsorbents

Silica and silica-based adsorbents have been used to isolate specific proteins from crude mixtures. Acid-activated Nugel silica and Nugel SP-Silica were used to extract human immune interferon from the conditioned medium of mixed lymphocyte cultures. Human interleukin-2 was extracted from the conditioned medium of Jurkat cells with LiChroprep RP-8. In each case, batch adsorption was accomplished by gentle stirring in a microcarrier vessel. The adsorbate was collected by sedimentation, and either batch-eluted or packed into a column for gradient caution. A high degree of concentration and purification was achieved with a high recovery of biological activity.

Monoclonal antibodies to human immune interferon and their application for affinity chromatography

Two IgG1/kappa class monoclonal antibodies specific for human immune interferon (IFN-gamma), designated B1 and B3, were developed. Specific binding of both monoclonal antibodies to natural or Escherichia coli-derived recombinant human IFN-gamma was demonstrated in a solid-phase radioimmunoassay or by immunoprecipitation. Antibody B3 showed potent neutralizing activity against both natural and recombinant IFN-gamma. Antibody B1, which showed neutralizing activity only when very high concentrations were employed, was used for preparing immunosorbents for affinity chromatography of IFN-gamma. When a highly purified preparation of 125I-labeled natural IFN-gamma was loaded onto the affinity column, all of the biological activity was retained on the column. The bulk of 125I-labeled IFN-gamma bound to the affinity column could be eluted in biologically active form, suggesting that antibody B1 could be used for the purification of human IFN-gamma. Analysis of IFN-gamma eluted from the column by NaDodSO 4/polyacrylamide gel electrophoresis (SDS-PAGE) indicated that both of the known molecular weight subspecies of IFN-gamma (25,000 and 20,000 MW), as well as the presumed dimer of 45,000 MW, were retained by the B1 antibody affinity column.

Lymphokine-mediated activation of human monocytes: Neutralization by monoclonal antibody to interferon-γ

Purified natural and recombinant human immune interferon (IFN-γ) were found to activate human monocytes from peripheral blood to exert enhanced cytotoxicity against human colon adenocarcinoma HT-29 cells. A marked monocyte activation was observed at low concentrations (1 and 10 U/ml) of IFN-γ. Marked monocyte activation was also obtained with two lymphokine preparations, produced in peripheral blood mononuclear cell (PBM) cultures induced with phytohemagglutinin (PHA) or by combined stimulation with PHA and 12- O-tetradecanoylphorbol 13-acetate (TPA). The component responsible for macrophage activation in such lymphokine preparations in the past was considered to be “macrophage-activating factor” (MAP). When monoclonal antibody specifically neutralizing IFN-γ was added to these lymphokine preparations, all MAF activity disappeared, indicating that IFN-γ is the sole protein showing MAP activity in these preparations.

Natural and recombinant Escherichia coli-derived interferon-gamma differ in their reactivity with monoclonal antibody.

Monoclonal antibody GIF-1 was found to neutralize human natural immune interferon (IFN-gamma), but not Escherichia coli-derived recombinant IFN-gamma. In addition, GIF-1 antibody failed to immunoprecipitate 125I-labeled recombinant IFN-gamma, whereas it precipitated natural IFN-gamma in a concentration-dependent manner. The lack of recognition of recombinant IFN-gamma by antibody GIF-1 may not be due to the absence of the oligosaccharide moiety in the molecules of recombinant IFN-gamma alone, because removal of carbohydrate from natural IFN-gamma by treatment with a mixture of glycosidases did not alter the selective binding of antibody, i.e., deglycosylated and untreated natural IFN-gamma were equally neutralized and immunoprecipitated by GIF-1 antibody. In addition, a minor monomeric component of natural IFN-gamma with the m.w. of 15,500, which apparently lacks carbohydrate, was also recognized by antibody GIF-1. These results suggest that the discriminative recognition of natural and recombinant IFN-gamma by monoclonal antibody GIF-1 may be due to a conformational difference at or near the active regions of natural and recombinant human IFN-gamma molecules.

The influence of mRNA primary and secondary structure on human IFN-gamma gene expression in E. coli.

Parameters influencing the efficiency of expression of the human immune interferon (IFN-gamma) gene in E. coli were studied by comparing a series of eight in vitro-derived gene variants. These contained all possible combinations of silent mutations in the first three codons of the mature IFN-gamma polypeptide coding sequence. Expression levels varied up to 50-fold among the different constructions. Comparison of messenger RNA secondary structure models for each variant suggested that the presence of stem-loop structures blocking the translation initiation signals could drastically decrease the efficiency of IFN-gamma synthesis. With variants displaying no stable mRNA secondary structure in the region, a C----U transition at position +11 after the AUG resulted in a 5-fold increase in expression indicating that RNA primary structure also plays an important role in expression. In addition we demonstrate that, in this system, a spacing of 8 nucleotides between the Shine-Dalgarno region and AUG was optimal for gene expression and that the steady-state production level of IFN-gamma rose exponentially with increasing rate of synthesis.

Activation of human monocyte cytotoxicity by natural and recombinant immune interferon.

Human T cell hybridomas were established by fusion of SH9 cells, the 6-thioguanine-resistant mutant line of human T lymphoma Hut 102-B2, with concanavalin A-stimulated human peripheral blood lymphocytes. Hybridoma line L38 produced a macrophage activating factor (MAF) with the ability to activate human peripheral blood monocytes to show enhanced cytotoxicity against human colon adenocarcinoma HT-29 cells in a 72-hr 125iododeoxyuridine-release assay. The L38 line was then cloned by the limiting dilution technique and two sublines, L38B and L38D, were found to produce high levels of MAF constitutively. Interferon activity was also detected in L38B and L38D supernatants. When interferon activity was neutralized with specific antiserum to purified human immune interferon (IFN-gamma), MAF activity was abrogated. To confirm that the MAF activity is indeed due to IFN-gamma, IFN-gamma was purified from the culture supernatant of another human T cell hybridoma, L265K2, a cell line known to produce high levels of IFN-gamma. Two highly purified IFN-gamma fractions with m.w. of 20,000 and 25,000, respectively, were obtained by NaDodSO4/polyacrylamide gel electrophoresis (SDS-PAGE). Similar fractions were obtained from IFN-gamma derived from human peripheral blood lymphocyte (PBL) cultures induced with 12-0-tetradecanoylphorbol-13-acetate (TPA) and phytohemagglutinin (PHA). In comparison, Escherichia coli-derived recombinant human IFN-gamma separated by SDS-PAGE yielded two major active fractions with m.w. of 17,000 and 34,000. With all three types of preparations, a close correlation was found between the presence of IFN-gamma activity demonstrable in an antiviral assay and MAF activity in individual fractions. Substantial quantitative differences were observed in the ability of various human IFN to activate monocytes. Although no MAF activity was detected with IFN-alpha and IFN-beta at concentrations up to 200 U/ml, both natural and recombinant IFN-gamma showed marked MAF activity at concentrations as low as 0.3 to 1 U/ml.

Isolation and characterization of a human interleukin 2 gene

An interleukin 2 (IL-2) gene was isolated from a Charon 4A human gene library. Electron microscopic examination of 15 heteroduplexes formed between the genomic DNAs and the IL-2 cDNAs demonstrated that the size of the IL-2 gene is about 5.1 ± 0.5 kb and that there are at least two introns in this gene. Nucleotide sequence of the 5′ flanking region of the IL-2 gene showed a homology with that of the corresponding region of the human immune interferon gene.

Expression and characterization of the product of a human immune interferon cDNA gene in Chinese hamster ovary cells.

Cotransformation with two plasmids, one [pSV2-IFN-gamma] encoding human immune interferon (Hu IFN-gamma) and the other [pAdD26SV(A)-3] encoding mouse dihydrofolate reductase, has been used to establish Chinese hamster ovary (CHO) cell lines that secrete high levels of Hu IFN-gamma. Hu IFN-gamma production by the transformed CHO cell lines E-10B and E-10C reached approximately 50,000 units/ml of culture medium, which compares favorably with that of stimulated lymphocytes. Furthermore, as the Hu IFN-gamma cDNA gene used in these studies is under the transcriptional control of the simian virus 40 early promoter, Hu IFN-gamma production is constitutive and thus does not require induction. CHO-produced Hu IFN-gamma migrates as two bands corresponding to molecular weights of 25,000 and 21,000 on NaDodSO4/polyacrylamide gels. These two species are shown to be the products of a single gene. As the molecular weight of native Hu IFN-gamma is around 55,000, it is likely to be a dimer. We have shown that the subunits of such a dimer cannot be linked by a disulfide bridge(s). Hu IFN-gamma from CHO cells is likely to be glycosylated and this should now permit comparison of the biological activities of glycosylated and nonglycosylated (bacterially produced) Hu IFN-gamma in animal studies.

Ia expression by vascular endothelium is inducible by activated T cells and by human gamma interferon.

We have used monoclonal antibody binding, measured by radioimmunoassay, fluorescence flow cytometry, and ultrastructural immunocytochemistry, to measure expression of Ia antigens on cultured human umbilical vein endothelial (HUVE) cells. Under standard culture conditions, HUVE cells do not express Ia antigens. However, treatment of primary HUVE cultures with phytohemagglutinin induces the expression of Ia antigens. Every endothelial cell in the culture becomes Ia-positive and endothelial cells appear to synthesize Ia. HLA-A,B is concomitantly increased. The expression of Ia appears to be mediated by T cells because (a) pretreatment of primary HUVE cultures with OKT3 plus complement blocks the action of the lectins but not of medium conditioned by lectin-activated peripheral blood mononuclear cells; (b) co-culture of endothelial cells with allogeneic T cells, in the absence of lectin, also induces endothelial Ia; and (c) human immune (gamma) interferon, produced by Chinese hamster ovary cells transfected with the human gamma interferon gene, directly induces endothelial Ia. During co-culture with lymphocytes, about one-third of the endothelial cells are Ia-positive after 24 h and all of the endothelial cells are Ia-positive by 72 h. Proliferation of allogeneic T cells starts by 96 h and peaks at 144 h. Thus, endothelial Ia appears sufficiently early to be a determinant for the proliferation of allogeneic T cells. Inducible expression of Ia by endothelium may be important both for allograft rejection and for recruitment of circulating T cells into the site of an immune response.

Human immune interferon gene is located on chromosome 12.

A cDNA clone for human immune interferon (IFN-gamma) gene sequences, plasmid p69, was used to chromosomally map the IFN-gamma gene by detecting human IFN-gamma gene sequences in DNA isolated from human-rodent somatic cell hybrids. We were able to map the IFN-gamma gene by correlating the human chromosomes present in these hybrids with the human specific 8.8 and 2.0 kilobase pair fragments produced by EcoRI digestion of genomic DNA. Southern blot analysis of 37 hybrid cell lines indicated that the gene for IFN-gamma was on human chromosome 12. A hybrid containing a portion of chromosome 12 localized the IFN-gamma gene to the p1205 leads to qter region.

Chromosomal localization of human leukocyte, fibroblast, and immune interferon genes by means of in situ hybridization

Chromosomal localization of human leukocyte, fibroblast, and immune interferon genes by means of <i>in situ</i> hybridization

A unique set of polypeptides is induced by gamma interferon in addition to those induced in common with alpha and beta interferons.

Human immune interferon (IFN-gamma) differs from leukocyte interferon (IFN-alpha) and fibroblast interferon (IFN-beta) in cell origin, inducing agents, physical and biological properties and amino acid sequence. These differences have led to interest in possible differences in the biological properties of IFN-gamma compared with IFN-alpha and IFN-beta. IFN-gamma has the same broad range of biochemical and biological actions as do IFN-alpha and IFN-beta, although relative potencies vary depending on the cell type and function investigated. There has so far been no direct evidence that IFN-gamma alters normal cell functions differently from other interferons. We report here striking qualitative and quantitative differences in the intracellular response of human fibroblasts to IFN-gamma compared with IFN-alpha and IFN-beta. Two-dimensional gel electrophoresis demonstrates, in addition to the induction of a common group of polypeptides, the existence of a set of polypeptides whose synthesis is uniquely induced by IFN-gamma.

4382027 Purification of human immune interferon: Irwin Braude assigned to Meloy Laboratories Inc

4382027 Purification of human immune interferon: Irwin Braude assigned to Meloy Laboratories Inc

Production of human immune interferon (Hu IFN-gamma) studied at the single cell level. Origin, evidence for spontaneous secretion and effect of cyclosporin A.

A reverse hemolytic plaque assay has been developed which specifically detects secretion of human immune interferon (Hu IFN-gamma) at the single cell level. Unstimulated peripheral blood lymphocytes from healthy adult volunteers spontaneously secreted IFN-gamma. Stimulation of these cells with concanavalin A, phytohemagglutinin, or the UCHT1 monoclonal anti-human T cell antibody significantly increased the number of IFN-gamma-secreting cells. The cell producing IFN-gamma, both spontaneously and after UCHT1 antibody stimulation, is an OKT3+,4+,8-,HLA-DR-T lymphocyte as determined at the single cell level. Finally, cyclosporin A, a potent and selective immunosuppressive drug for T cells, strongly inhibited the secretion of IFN-gamma as assayed at the cell level. This IFN-gamma reverse hemolytic plaque assay has great potential for the further study of IFN-gamma both in physiological and pathological conditions.

Expression in Escherichia coli of chemically synthesized gene for the human immune interferon.

A 454 base pair fragment of double stranded DNA consisting of a gene for a human immune interferon (hIFN-gamma), initiation and termination signals plus appropriate restriction endonuclease sites, was totally synthesized. The synthesis involved preparation of 62 oligodeoxyribonucleotides by rapid, solid phase procedures, and enzymatic ligation of the oligonucleotides. This synthetic gene was expressed in E. coli under the control of the lac UV5 promoter. The product has antiviral activity which was acid labile and completely neutralized by antiserum to hIFN-gamma but not by antiserum to hIFN-alpha or hIFN-beta. Molecular weight of hIFN-gamma produced by E. coli was estimated to be about 32,000 and 17,000 by gel filtration and SDS-polyacrylamide gel electrophoresis respectively.

Immunoregulation by lymphokines: immune interferon and lymphotoxin induction of lymphokine activity in human peripheral blood leukocyte cultures.

Supernatants of mitogen-induced human PBL cultures contain several lymphokine activities. Analysis of kinetic studies has suggested a correlation in the appearance in culture supernatants of lymphotoxin (LT) and immune interferon (Im-IF). We investigated this interaction between LT and Im-IF in the serum-free human PBL culture system. Partially purified LT was derived from a normal cell line, RPMI 1788. This LT, which had no contaminating IF activity, induced production of significant levels of IF activity as early as 15 hours after initiation of culture. This induced IF activity was identified as Im-IF by criteria of pH 2, SDS and heat sensitivity, as well as neutralization by AB to Im-IF. LT activity, in excess of the units added to the culture, was also measured in the LT-induced cultures. In another group of experiments, partially purified human Im-IF, produced by expression of a cloned gene in monkey COS-7 cells, was added to human PBL cultures. This Im-IF, at concentrations of 160 and 320 units/ml, caused induction of LT activity. The induced LT activity was neutralized by AB raised to 1788-derived LT. Im-IF treated cultures also contained IF activity in excess of the titers added to the cultures. These results would suggest an interaction between LT and Im-IF at the level of production by lymphoid cells.