Showing papers on "Interferon published in 1981"

Natural killer cells: their roles in defenses against disease

Abstract: Natural killer cells are a recently discovered subpopulation of lymphoid cells that are present in most normal individuals of a range of mammalian and avian species. Natural killer cells have spontaneous cytolytic activity against a variety of tumor cells and some normal cells, and their reactivity can be rapidly augmented by interferon. They have characteristics distinct from other types of lymphoid cells and are closely associated with large granular lymphocytes, which comprise about 5 percent of blood or splenic leukocytes. There is increasing evidence that natural killer cells, with the ability to mediate natural resistance against tumors in vivo, certain virus and other microbial diseases, and bone marrow transplants, may play an important role in immune surveillance.

Evidence that types I and II interferons have different receptors.

Abstract: Interferons (IFNs) are a class of proteins, secreted by animal cells in response to various inducers1, which confer resistance to viral infections and are designated according to their cellular origin or to the inducing agent. Viruses induce type I Interferon, subdivided into α-interferon, produced by leukocytes (Le) or lymphoblastoid (Ly) cells, and β-interferon, produced by fibroblasts1. Mitogens and antigenic stimuli induce in lymphocytes type II immune IFN-γ. Interferons seem to bind to specific receptors2 to elicit a variety of cellular responses3; several early studies provided indirect evidence for such binding4–6. Direct evidence for specific interferon receptors was presented by Aguet7, who showed that biologically active 125I-labelled mouse (Mu)IFN binds to sensitive L1210-S cells, but not to interferon-resistant L1210-R cells8. The main obstacle in carrying out such studies is the availability of pure interferon. Recently, Maeda et al.9 constructed plasmids containing human interferon sequences. The plasmid p104 was used as a probe to isolate the coding region of a human interferon (IFLrA), which was expressed in Escherichia coli10 and purified with monoclonal antibodies11. This interferon, designated HuIFN-αA, was labelled with 125I for binding assays on human cells. We have determined the specificity of different HuIFNs for the cellular sites which bind HuIFN-αA and show here that HuIFN-γ does not compete for binding, whereas all type I HuIFNs do.

Regulation of the production of immune interferon and cytotoxic T lymphocytes by interleukin 2.

Abstract: The activation of alloantigen-specific cytotoxic T lymphocyte precursors is dependent upon the presence of both macrophages and helper T cells or regulatory molecules derived from these facilitative cells. Three biochemically distinct helper factors have been identified: interleukin 1 (macrophage-derived), Interleukin 2 (T cell derived), and immune interferon. All 3 factors are found in supernatants of mixed lymphocyte cultures (MLC), however, the removal of macrophages from these cultures completely ablates the production of these factors as well as the induction of cytotoxic T lymphocytes (CTL). The addition of IL 2 to these macrophage-depleted MLC restores the ability of responder T cells to: 1) bypass the requirement for macrophage soluble function, 2) produce immune interferon, and 3) generate CTL. The kinetics and dose response of immune interferon production in response to IL 2 correlates with the generation of CTL. The production of immune interferon as well as the generation of CTL requires T cells, alloantigen, and IL2. Furthermore, the induction of CTL by IL2 was neutralized by the addition of anti-immune interferon. These data suggest that: 1) the regulation of immune interferon production is based on a T to T cell interaction mediated by IL 2, and 2) immune interferon production may be required for IL 2 induction of CTL. These findings are consistent with the hypothesis that the induction of CTL involves a linear cell-factor interaction in which IL 1 (macrophage-derived) stimulates T cells to produce IL 2, which in turn stimulates other T cells to produce immune interferon and become cytotoxic.

Interferon action--sequence specificity of the ppp(A2'p)nA-dependent ribonuclease.

Abstract: The oligonucleotides pppA2'p5'A2'p5'A and related oligomers (2-5A) are synthesized by an enzyme that is widely distributed in a variety of cells, the activity of which varies with interferon treatment, growth and hormone status. Because significant amounts of 2-5A have recently been detected in interferon-treated cells, it has been suggested that the oligonucleotides may be involved in interferon action and in the control of cell metabolism. In both intact cells and cell-free systems 2-5A has been shown to activate a ribonuclease. We report here investigations of the sequence specificities of the 2-5A-dependent ribonucleases in extracts of rabbit reticulocytes, mouse ascites tumour cells and human lymphoblastoid cells in conditions of partial digestion using terminally labelled RNA substrates. The enzymes cleaved on the 3'-side of UN sequences to yield UpNp terminated products. Cleavage was observed predominantly at UA and UU sequences.

Induction of pulmonary indoleamine 2,3-dioxygenase by interferon

Abstract: Pulmonary indoleamine 2,3-dioxygenase [indoleamine: oxygen 2,3-oxidoreductase(decyclizing)] has been found to be induced (30- to 100-fold) in the mouse after a single intraperitoneal administration of bacterial endotoxin [Yoshida, R. & Hayaishi, O. (1978) Proc. Natl. Acad. Sci. USA 75, 3998-4000] or during in vivo virus infection [Yoshida, R., Urade, Y., Tokuda M. & Hayaishi, O. (1979) Proc. Natl. Acad. Sci. USA 76, 4084-4086]. In the present study, an in vitro system with mouse lung slices was developed in which bacterial endotoxin (5 micrograms/ml)produced an induction (approximately 10-fold) of indoleamine 2,3-dioxygenase. The endotoxin was substituted by interferon from mouse L cells or mouse brain. The pulmonary enzyme activity increased almost linearly for 48 hr after addition of mouse interferon (10(4) units/ml) to lung slices. Interferon from mouse L cells or mouse brain produced a 10- to 15-fold increase in the enzyme activity, whereas that from human leukocytes was all but ineffective. The effect also was observed using highly purified L-cell interferon, prepared by poly(U) affinity column chromatography. When interferon was treated either by heat, alpha-chymotrypsin, or anti-interferon serum, such increase in the enzyme activity was diminished essentially to the same extent as seen in the antiviral activity. The increase in the enzyme activity was blocked when actinomycin D or cycloheximide was added to the slices before interferon treatment. These results suggest that the enzyme induction was produced by interferon and not by possible contaminants in the interferon preparations.

A convenient and rapid cytopathic effect inhibition assay for interferon.

Abstract: Publisher Summary To meet the need for a rapid bioassay, a convenient microtiter assay based on reduction of cytopathic effect (CPE) is presents. The assay is quantitative, requires only 16 hr, and can be adapted to many cell and virus combinations in common use. For simplicity, the number of technical manipulations is reduced to a minimum. Various parameters affecting both speed and sensitivity are evaluated. The assay is developed primarily as a tool to aid in the purification of human leukocyte and fibroblast interferons; therefore, conditions have been optimized for the assay of these interferons. As an example, the standard procedure for assay of human leukocyte interferon with bovine MDBK cells and vesicular stomatitis virus (VSV) as the challenge virus is presented. It should be noted, however, that this general procedure is applicable for the assay of human fibroblast interferon and that other cell lines (WISH, FS-7, L cells), challenge viruses (Sindbis), and even human immune interferon can be used. A procedure for testing other cells and challenge viruses for applicability in the assay is outlined.

Antiviral treatment of chronic hepatitis B virus infection. I. Changes in viral markers with interferon combined with adenine arabinoside.

Abstract: Twenty patients with chronic active hepatitis and 12 patients with chronic persistent hepatitis associated with hepatitis B virus (HBV) infection were treated with human leukocyte interferon or adenine arabinoside alone or in combination. With interferon alone, four of 16 patients showed a permanent disappearance of HBV-associated DNA polymerase (DNAP) activity from serum. Of six patients treated with adenine arabinoside alone, only one patient became permanently DNAP-negative. With a regimen of multiple cycles of combined interferon and adenine arabinoside, seven of 16 male patients became permanently DNAP-negative. Of 69 patients who met the criteria for admission to the program, spontaneous decreases in DNAP activity without treatment were observed in only 9% during a mean observation period of 10 months. In general, patients with chronic active hepatitis, those who are female, and those with a history of recent steroid therapy responded to the antiviral agents significantly better than did the other patients. Since 1975 we have been evaluating the effect of interferon [1] and adenine arabinoside [2] in patients with chronic hepatitis B virus (HBV) infection. Our first publications on this research suggested that either antiviral agent could produce

Comparison of the antiviral activities of various cloned human interferon-alpha subtypes in mammalian cell cultures.

Abstract: Five human interferon-alpha (leukocyte) subtypes derived from genes cloned in Escherichia coli have been compared for their ability to induce antiviral activity against vesicular stomatitis virus infection of various mammalian cell cultures. These interferons, designated LeIF-A (IFN-alpha 2), -B, -C, -D (IFN-alpha 1) and LeIF-F, show different relative activities when assayed on human, bovine, hamster, mouse, rabbit and monkey cell lines. As with a natural human buffy-coat interferon-alpha preparation, three subtypes (LeIF-B, -C and -D) showed considerable activity on RK-13 rabbit cells, but two (LeIF-D and -F) also showed some activity on mouse L-929 cells. Of the five interferon subtypes examined, LeIF-F demonstrated the highest degree of species specificity.

Production of interferon in human leukocytes from normal donors with the use of Sendai virus.

Abstract: Publisher Summary This chapter describes the method used for the production of human leukocyte interferon The production of interferon is highly sensitive to changes in the incubation conditions Better yields are obtained in round flasks, for example, than in ordinary flat-bottom bottles The aeration seems to play an important role Attempts to improve production by bubbling air or CO 2 into the medium during the incubation have not been successful The cells must be kept in constant agitation If the stirrers are intentionally stopped at different times after induction, the production of interferon declines rapidly, although the settling of the cells to the bottom takes several hours The removal of most globulins by (NH 4 ) 2 SO 4 -precipitation does not affect the activity of serum, and the reduction of antibodies to Sendai virus appears not only to lower the amount of the inducer virus needed but also to make the yields of interferon more consistent Factors such as priming, induction, temperature, pH, and incubation medium, affect the yield of interferon, but not the kinetics of the production in human leukocyte suspensions The pH range for optimum interferon production is between 72 and 76

Toxicity of interferon.

Abstract: The effects of partially purified human leucocyte interferon (PIF) and of a preparation purified by passage twice through a monoclonal antibody affinity chromatography column (NK21F) were compared with those of a control solution in healhty volunteers. After intramuscular injections both interferon preparations caused rises in pulse rate and body temperature, changes in circulating white cell counts, and various unpleasant symptoms, the most common of which were headache, malaise, and fever. Slightly lower doses of NK21F were given, and this was reflected in lower peak serum concentrations. Mean symptom scores, however, were not lower after NK21F than after PIF. Local inflammatory reactions eight hours after intradermal inoculations of these interferons were similar. Purification of interferon using a monoclonal antibody does not reduce the facets of its activity considered in this study. They are therefore inherent in the leucocyte interferon type selected by the antibody.

Regulation of human natural killing. I. The role of monocytes, interferon, and prostaglandins.

Abstract: We have found that human endogenous natural killer activity as measured in a rapid 51Cr release assay is unaffected by the presence of monocytes. Moreover, stimulation of natural killer cells by poly I:C is independent of monocytes. In contrast, the presence of monocytes in a mixed population of mononuclear cells that have been stimulated by poly I:C suppresses NK activity. The suppression is shown to be partially reversible if indomethacin (10(-6) M) is added to the cultures during stimulation. Culture supernatants of monocytes stimulated with poly I:C are shown to contain PGE1 in a radioimmunoassay, and have NK inhibitory activity comparable to that obtained with exogenous PGE1 added to NK assays at a concentration range of 10(-7) to 10(-9) M. Culture supernatants from poly I:C-stimulated monocytes do not have detectable levels of antiviral activity. In contrast, plastic nonadherent cells stimulated with poly I:C produce significant levels of interferon (100 to 200 U/ml/2 x 10(6) cells) but almost undetectable amounts of PGE. Supernatants of nonadherent cells incubated with indomethacin (10(-6) M) alone augment NK activity. Taken together, the results suggest that stimulation of mononuclear cells with poly I:C is dependent on and regulated by the relative levels of interferon produced by lymphocytes and PGE produced by monocytes.

Hybrid human leukocyte interferons

Abstract: Disclosed herein are methods and means of microbially preparing novel human hybrid leukocyte interferons, useful in the treatment of viral and neoplastic diseases, by DNA recombination of parental interferon genes, taking advantage of common restriction endonuclease cleavage sites therein and in carrier expression plasmids.

Human lupus inclusions and interferon

Abstract: Raji cells, a human B lymphoblastoid cell line of Burkitt lymphoma origin, formed lupus inclusions when grown in a medium conditioned by the growth of Raji cells whose DNA thymidine residues had been unifilarly (single-strandedly) substituted with bromodeoxyuridine. Ultracentrifugation of this medium in excess of that required to remove Epstein-Barr virus and all other known mammalian viruses did not prevent the formation of the inclusions, and treatment of the conditioned medium with pronase destroyed the activity. These results demonstrate the presence of a protein that is secreted from bromodeoxyuridine-substituted Raji cells and is capable of inducing nonbromodeoxyuridine-substituted cells to form lupus inclusions. Interferon (100 units per milliliter) was found in the conditioned medium. Inclusions also formed in Raji cells grown in fresh medium supplemented with human leukocyte or fibroblast interferon (100 units per milliliter).

Interferon-neutralizing antibodies in a patient treated with human fibroblast interferon

Abstract: During recent years clinical trials have shown that human leukocyte interferon (HuIFN-alpha) may be useful in the treatment of cancer, but very little has been done concerning the possible use of human fibroblast interferon (HuIFN-beta). Treuner et al. recently reported the successful treatment of a nasopharyngeal carcinoma with HuIFN-beta: in the course of IFN-therapy a HuIFN-beta neutralizing activity appeared in the serum of this patient. We report here that such activity is due to IgG antibodies--this study is the first to present evidence for antigenicity of IFN in a homologous system.

Human fetal thymus and bone marrow contain target cells for natural killer cells.

Abstract: Previous studies in the mouse natural killer (NK) system have indicated that NK cells may be involved in lysing normal, primary hematopoietic tissues. In the present report, this was analyzed in the human NK system using fetal bone marrow (BM) cells and thymocytes as well as adult BM cells from healthy donors as target cells in a conventional 6 to 12-h 51Cr-release assay. Adult BM cells showed low but significant levels of sensitivity, which could be increased by using interferon (IFN)-activated peripheral blood leukocytes (PBL) as effector cells. BM cells from 16 to 19-week-old fetuses consistently showed higher sensitivity for lysis than adult BM, and also fetal thymocytes proved very sensitive for lysis, in contrast to what has previously been reported for adult thymocytes. When used as effector cells against K562 targets, adult BM showed a clear lytic activity which could be further activated with IFN. In contrast, fetal BM was totally NK-inactive also after IFN activation. Among healthy adult donors, autologous BM was lysed as efficiently as allogeneic BM, and when different NK cell donors were used, the same classification of these as NK high or low reactive cells was seen regardless of the source of BM targets. IFN could augment lysis in autologous as well as in allogeneic effector BM target combinations. IFN could also protect adult BM cells from NK lysis, but no protection was seen with fetal BM cells. The highest NK activity against BM targets was seen among nylon-nonadherent, E rosette-negative PBL and, therefore, the effector cell seemed to be of the same nature as that active against continuous cell lines. These results show that in the human NK system, NK cells can lyse normal BM cells and thymocytes. The higher sensitivity expressed by fetal BM cells and thymocytes as compared to adult cells may suggest an increased frequency of a particular primitive NK-sensitive cell type in these tissues, a finding which is in line with results seen in the mouse NK system.

Analysis of interferon mRNA in human fibroblast cells induced to produce interferon.

Abstract: The levels of interferon mRNA as a function of interferon induction by poly(rI) . poly(rC) in human fibroblast cells were determined by RNA hybridization using a cloned beta interferon cDNA and by translation in Xenopus oocytes. Whereas previous studies analyzed mixtures of interferons, the availability of the cloned beta interferon cDNA and the antiserum to purified beta interferon enabled us to focus on the expression of only one class (beta) of interferon genes. The induction of interferon synthesis depends primarily on the accumulation of interferon beta mRNA in the cells, and the interferon beta mRNA rapidly disappears several hours after its appearance in the cytoplasm. No detectable interferon beta mRNA sequences are present in uninduced cells. The degradation of interferon beta mRNA in the induced cells requires ongoing protein synthesis; accumulation of interferon beta mRNA was observed in the continuous presence of cycloheximide. The interferon beta mRNA detected at the early stages of induction is 1100 nucleotides long and its size progressively decreases with time. By both the hybridization and the translational assay in Xenopus oocytes, only one size of interferon beta mRNA and one species of beta interferon could be identified.

Influence of anti-mouse interferon serum on the growth and metastasis of tumor cells persistently infected with virus and of human prostatic tumors in athymic nude mice.

Abstract: Baby hamster kidney or HeLa cells form tumors in 100% of athymic nude mice. When such cells are persistently infected (PI) with RNA viruses, such as mumps or measles virus, the tumor cells either fail to grow or form circumscribed benign nodules. Neither the parental nor the virus PI tumor cells form invasive or metastatic lesions in nude mice. Previous studies have indicated a correlation between the susceptibility of virus-PI tumor cells in vitro and the cytolytic activity of natural killer (NK) cells and their failure to grow in vivo. Because interferon (IF) is the principal regulatory molecule governing the differentiation of NK cells, it was possible to test the relevance of the IF-NK cell system in vivo to restriction of tumor growth by treatment of nude mice with anti-IF globulin. This treatment was shown to reduce both IF production and NK activity in spleen cells. Both parental and virus-PI tumor cells grew and formed larger tumors in nude mice treated with anti-IF globulin than in control nude mice. The viral-PI tumor cells and the uninfected parental cells formed tumors in treated mice that were highly invasive and often metastatic. Some human tumor types have been notoriously difficult to establish as tumor lines in nude mice (e.g., primary human prostatic carcinomas). When transplanted into nude mice treated either with anti-IF globulin or anti-lymphocyte serum, two prostatic carcinomas grew and produced neoplasms with local invasiveness and some metastases. The results are consistent with the view that interferon may be important in restricting the growth, invasiveness, and metastases of tumor cells by acting indirectly through components of the immune system, such as NK cells.

Bacterial synthesis of a novel human leukocyte interferon.

Abstract: A novel human leukocyte interferon cDNA clone (LeIF B) was identified in a cDNA library prepared using polyadenylated mRNA of a myeloblastoid cell line. The nucleotide sequence of LeIF B differs significantly from other published leukocyte interferon cDNA sequences. An expression plasmid was constructed which directs the synthesis in E. coli of 8 x 10(7) interferon units per liter of culture. LeIF B exhibits markedly different specificities from another bacterially synthesized human leukocyte interferon, LeIF A.

Interferon acts directly on human B lymphocytes to modulate immunoglobulin synthesis.

Abstract: At different times of exposure, interferon (IFN) enhanced and suppressed pokeweed mitogen- (PWM) induced IgG synthesis by human peripheral blood lymphocytes (PBL). Pretreatment of PBL and IFN frequently increased antibody production by more than 100% when compared with that by untreated PBL. Results of experiments in which PBL were separated into T and B subpopulations indicated that IFN preparations acted directly on B cells. Thus, mixtures of IFN-treated B cells and untreated T cells from 5 of 7 persons tested produced 81% to 500% more IgG than untreated, matched control cells. However, IFN-treated monocytes mixed with untreated B and T cells or IFN-treated T cells mixed with untreated B cells failed to enhance IgG production significantly in similar assays. In contrast to the pretreatment protocol, when IFN was present in the incubation mixture throughout the PWM assay, IgG production decreased. Sephadex chromatography of the IFN and tests of the resulting fractions indicated that the IgG production-enhancing activity was located in the fraction carrying the antiviral activity.

Inhibition of cell division by interferons: Changes in the transport and intracellular metabolism of thymidine in human lymphoblastoid (Daudi) cells.

Abstract: The Daudi line of human lymphoblastoid cells shows a high sensitivity towards growth inhibition by human interferons. In cells pretreated with 70 reference units/ml of an interferon preparation for 48 h, the incorporation of exogenous [3H]thymidine into DNA is inhibited by as much as 85%. We are investigating the extent to which this effect reflects a true inhibition of the rate of DNA synthesis or whether it may be caused by changes in the metabolic utilization of exogenous thymidine by the cells. Interferon treatment results in a 30% inhibition of the rate of membrane transport and a 60% decrease in the rate of phosphorylation of [3H]thymidine in vivo. The latter effect is due to a decrease in V of thymidine kinase without any change in the value of Km for this enzyme. In addition to these changes, incorporation of [3H]uridine into DNA, which occurs as a result of the intracellular conversion of this precursor into thymidine nucleotides, is also inhibited by 75%, whereas RNA labelling by [3H]uridine is decreased by only 15% in interferon-treated cells. Thus several different metabolic events associated with thymidine nucleotide metabolism and DNA synthesis in Daudi cells are disrupted by interferon treatment.

Methods of decreasing the hydrophobicity of fibroblast and other interferons

Abstract: A method for improving the stability and usefulness of interferon, including human fibroblast interferon, is disclosed. In this method, interferon is bonded to a non-hydrophobic substance to create a molecular complex that is less hydrophobic than untreated interferon.

DNA sequence of two closely linked human leukocyte interferon genes.

Abstract: A single recombinant lambda bacteriophage isolated from a human genome library contains two closely related human interferon genes of the leukocyte or alpha type. The two genes are separated by 12 kilobase pairs and are oriented in the same direction with respect to transcription. Comparisons of the DNA sequences of these two genes and interferon complementary DNA clones indicate that the two interferon genes lack intervening sequences.

Natural cell-mediated immunity during viral infections.

Abstract: Viral infections elicit both specific and nonspecific responses in infected hosts. The specific responses include the production of antiviral antibody and the generation of virus-specific cytotoxic T cells. The non-specific responses include the elevation of body temperature, the synthesis of interferon, and the activation of macrophages and natural killer (NK) cells. While most of these parameters have been studied for a number of years, only recently has the concept been proposed that NK cells may contribute to the resistance or pathology in viral infections (reviewed in Welsh 1978a). This concept is particularly intriguing because NK cells may have the capacity to mediate both nonspecific and specific arms of the host response. Many investigators agree that NK cells and K lymphocytes, mediators of antibody-dependent, cell mediated cytotoxicity (ADCC), may represent identical, overlapping, or similar populations of effector cells (Ojo and Wigzell 1978; Herberman et al. 1979; Pape et al. 1979; Timonen 1979).

The transformation of adult but not newborn human lymphocytes by Epstein Barr virus and phytohemagglutinin is inhibited by interferon: the early suppression by T cells of Epstein Barr infection is mediated by interferon.

Abstract: In a previous study, it was demonstrated that T cells from adult individuals were able to suppress the transformation of B cells after infection by EBV. In this paper, it is shown that this suppression is mediated by interferon. Thus, the suppression is abrogated by anti-interferon serum and mimicked by human leukocyte interferon. Furthermore, the interferon is released in response to the virus-infected B cell, not the virus alone. The relevance of these results to previous clinical evidence, indicating a role for interferon in recovery from EBV infection, is discussed. Interferon will also suppress the transformation of adult B lymphocytes by the mitogen phytohemagglutinin (PHA). However, interferon at concentrations 2 to 3 orders of magnitude higher was unable to suppress the transformation of neonatal B lymphocytes by either EBV or PHA. These experiments suggest that EBV and PHA induced transformation share a common interferon sensitive step. Lastly, the resistance of newborn lymphocytes to the protective effect of interferon may be an important consideration in the application of interferon as an antiviral or anti-tumor agent.