Anna D. Inglot

Persistent Infection of Mouse Cells with Sindbis Virus: role of Virulence of Strains, Auto-interfering Particles and Interferon

Summary A carrier state of Sindbis virus with cycling pattern was induced in the mouse L cells and in the established mouse embryo cell line MEC/c. Chick-adapted virus readily induced the persistent infection whereas the mouse-adapted virus killed cultures during the first passage. In the MEC/c line small (sp) and large (lp) plaque mutants of Sindbis virus produced more stable carrier state than the giant (gp) plaque mutant. The persistently infected cultures periodically produced small amounts of interferon. Highly specific rabbit anti-interferon globulin, which can neutralize mouse interferon, incorporated into the growth medium of carrier L line caused a 100- to 1000-fold stimulation of the synthesis of Sindbis virus after incubation for 5 days at 37 °C. The activated virus destroyed the carrier culture.

Comparison of the Antiviral Activity in vitro of some Non-steroidal Anti-inflammatory Drugs

Summary In cultures of mouse or chick embryo cells several non-steroidal anti-inflammatory drugs (salicylates, Ibufenac, phenylbutazone, Indomethacin, flufenamic and mefenamic acids, CI-583, and chloroquine) inhibit the multiplication of various viruses (encephalomyocarditis, Sindbis, influenza A2, Newcastle disease, herpes simplex and vaccinia). Two factors were critical for the virus inhibitory action of these drugs: the concentration of serum and the pH of the medium. The antiviral effect of these drugs seems to be due mainly to limitation of intracellular synthesis. However, salicylates and anthranilates also inhibit the adsorption and/or penetration of encephalomyocarditis virus into mouse cells. The antiviral potency shows some correlation with other biochemical, cellular and clinical activities of these drugs.

Interferon responses in schizophrenia and major depressive disorders

The spontaneous and induced interferon (IFN) production in whole blood cultures was examined in 45 psychiatric inpatients and in 65 normal controls. Among inpatients there were 32 who were chronic schizophrenics (14 women, 18 men) and 13 who were severely depressed (11 women, 2 men). The analysis of the pooled results of assays in the heterogeneous population showed that leukocytes of the psychiatric patients produced significantly lower levels of IFN after stimulation with virus (NDV), lipopolysaccharide (LPS), and IFN spontaneously released without the inducers that control cells. In contrast, there was no difference between the psychiatric patients and controls in IFN response to phytohemagglutinin and phorbol myristate acetate (PHA + PMA). The results apparently confirmed observations made by Moises et al (1985) and Katila et al (1989). We have also tested our hypothesis that the statistics may mask the individual pattern of IFN response related to the specific psychiatric diagnosis, however. In fact, in the group of chronic schizophrenics we have found either high or low responders to all IFN inducers (NDV, PHA + PMA and LPS). Furthermore, the patients with high IFN response had dominant positive symptoms of schizophrenia (delusions, hallucinations, bizarre behavior and thought disorder). Whereas, in the patients with low IFN response the negative symptoms prevailed (asociality or withdrawal, flat affect, attention impairment, abolition or apathy). In plasma samples of schizophrenics, factors were detected that transferred a hypersensitivity to the IFN inducers to normal donor leukocytes. For instance, in leukocytes cultured in the presence of plasma from schizophrenics, there were 71% of high IFN responders after stimulation with NDV, versus 26% of high IFN responders in the presence of plasma from normal controls. We suggest that the factors may belong to the class of opioid peptides, which interact with the production of cytokines including IFNs.

Organoselenides as potential immunostimulants and inducers of interferon gamma and other cytokines in human peripheral blood leukocytes

A number of organoselenium compounds have been described as anti-inflammatory, antioxidant, glutathione peroxidase-like agents and inhibitors of prostaglandin synthesis. Here we report that bis [2-(N-phenyl-carboxamido)]phenyl diselenide, 2-phenyl-1,2-benzisoselenazol-3(2H)-one (Ebselen) and related compounds are inducers of interferon gamma (IFN-γ) and tumor necrosis factor (TNF) in human peripheral blood leukocytes. The IFN and TNF response was rapid, occurring within 20 h, and high-up to 1000 and 2000 units ml−1-and was clearly related to the dosage and the structure of the compounds. The action of the compounds and phytohemagglutinin was synergistic. The IFN gamma and TNF production was reduced after removing adherent cells. Although the mode of action of the compounds is not known, they appear to interact directly or indirectly with both adherent and non-adherent leukocytes, and stimulate the synthesis of a set of different cytokines including factors controlling the cell proliferation. Therefore, organoselenides may be regarded as the biological response modifiers.

Antagonism in action between mouse or human interferon and platelet growth factor

SummaryHuman leukocyte and mouse fibroblast interferons abolished the mitogenic effect of human or bovine platelet growth factor (PGF) on human or mouse cells. Conversely, the antiviral and anticellular activity of both forms of interferon was inhibited by PGF in the homologous and in certain heterologous cell systems.

Mitogenic activity of selenoorganic compounds in human peripheral blood leukocytes

A variety of organoselenium compounds were originally described as antiinflammatory, antioxidant or glutathione-peroxidase-like agents, and as inhibitors of prostaglandin and leukotriene synthesis. Recently, the compounds have also been found to be inducers of interferon gamma and tumor necrosis factor in human peripheral blood leukocytes (PBL). We evaluated the effects of bis [2-(N-phenylcarboxamido)phenyl] diselenide and Ebselen®; 2-phenyl-1,2-benzisoselenazol-3(2H)one, on the incorporation of tritiated thymidine into the DNA of PBL cultured in vitro. Both compounds were mitogenic and this effect was correlated with the expression of interleukin 2 receptor in T-lymphocytes. Therefore, we suggest that the selenoorganic compounds may induce mitogenic cytokines.

Tumor-associated antigens are cytokine inducers and hyporeactivity factors to the immune system

We investigated possible mechanisms leading to the inhibition of theimmune system in people with chronic disorders. Tumor cell produce proteinreleased into the circulation, such as tumor associated antigens, may playan important role in processes preceding paralysis of the immune system. Totest this hypothesis the following tumor associated antigens were used: AFP,OFP, CA-125, CA-50 and CA-19-9. Their role was assessed by modulatingcytokine production in cord blood lymphocytes and peripheral white bloodcells obtained from grown population of patients treated with colostrinin,an cytokine inducer. PHA, LPS and colostrinin were used as positive controlin those essays. Each antigen tested individually induced IFN, TNFαand IL-6 in dose dependent fashion. None of the tested cytokines werespontaneously released by the cells. Data generated from these experimentsindicated that tumor associated antigens are inducing type 1 cytokines insimilar fashion as LPS or colostrinin. However, lymphocytes taken frompatients undergoing therapy with colostrinin revealed progressive losscapability to produce type 1 cytokines as they did in case of colostrinin.The loss of the capability to respond to antigen may represent phenomenonleading to immune tolerance.

Non-steroidal anti-inflammatory drugs: effects on the utilization of glucose and production of lactic acid in tissue culture.

In der Kultur embryonalen Hühnchengewebes kommt es unter Einfluss nichtsteroider Antiphlogistica (Aspirin, Indomethacin, Mefenamicsäure) zu einer Steigerung des Glukoseverbrauchs bei gleichzeitiger Vermehrung der Milchsäureerzeugung. Der Milchsäureverbrauch verläuft in zwei Phasen, wobei der erste Gipfel bei geringsten Konzentrationen des Arzneimittels.auftritt.

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

SummaryMouse C-243 cell interferon (IF) binds to Blue Dextran 2000 (BD). The BD-IF complex could be precipitated by polyethylene glycol. When 0.05 to 0.2 per cent solutions of BD were used for binding IF, the recovery of IF activity in the sediment was complete. The BD-IF complex was shown to have high antiviral activity, it was stable for months at 4° C but it was inactivated by heating at 37°, 56° and 65° C as native IF.The rate of clearance of IF bound to BD from the mouse peritoneal cavity was found to be significantly slower than that of native IF. The BD-IF complex was highly immunogenic for rabbits and sheep. Furthermore, the BD-IF complex was neutralized to a greater extent by specific antibodies than native IF.

Hyporesponsiveness of Human Alveolar Leukocytes to Interferon-Alpha and Interferon-Gamma Inducers

Leukocytes were obtained from bronchoalveolar lavages (BAL) of 36 patients including 10 with lung cancer, 15 with inflammatory lung diseases and 11 healthy control patients undergoing diagnostic investigation. The entire alveolar cell population responded weakly to the classic interferon (IFN) inducers: Newcastle disease virus (NDV), phytohemagglutinin (PHA) and lipopolysaccharide (LPS). This refers mainly to normal healthy volunteers. Alveolar leukocytes from patients with inflammatory lung diseases and nonsteroid treated lung cancer responded better to the interferon inducers than did cells from other patients. The IFN-alpha or IFN-gamma response of whole blood leukocytes to the same inducers was 10 to 100-fold higher than that of the alveolar cells. Alveolar macrophages from 6 healthy individuals and 3 patients with inflammatory lung disease were cultured in vitro for 6 days. The IFN response to inducers appears to depend on the origin of the cultured cells. It increased in the initially hyporeactive macrophages from healthy subjects and decreased in the relatively reactive cells from the patients with inflammatory lung diseases. We suggest that the hyporeactivity to IFN induction is a physiological state of the alveolar leukocytes which are a specialized cell population having constant exposure to inhaled agents such as dust, smoke, microorganisms and their by-products. The hyporesponsiveness to IFN induction of the alveolar cells may have an important physiological role in protecting lungs against hyperproduction of cytokines involved in the inflammatory and allergic reactions.