Inhibition of Chlamydia trachomatis multiplication by interferon inducer larifan in mice with experimental infection]

Interferon (IF)-inducing capacity of C. trachomatis was shown in experiments on mice CBA. The levels of IF production in the parenchymatous organs correlated with accumulation of the pathogen in them. The use of larifan, a natural double-stranded IF inductor, according to the treatment scheme provided high levels of endogenic IF in infected mice. It inhibited multiplication of Chlamydiae in the lungs and lymph nodes detected cytoscopically by light and fluorescence microscopy and with infection titration. The effect of the inductor combined with tetracycline was of additive nature. Double intraperitoneal administration of larifan with an account of the hyporeactivity phase and daily administration of tetracycline proved to be the most efficient. It is possible to successfully use IF inductors in accordance with the treatment schemes in infection caused by C. trachomatis which makes promising their clinical application in therapy of chlamydiosis.     

The induction of interferon by levamisole in mice.

Viral inhibitor(s) with the properties of interferon (IF) was found in the sera of DDI mice injected intraperitoneally with 5 to 10 mg/kg of levamisole. A significant level of IF activity appeared by 20 hr and reached a peak by 24 hr after the injection. The induction was abrogated when the mice were pretreated with either whole-body X irradiation of more than 500 R or 2.5 mg of hydrocortisone acetate but was not affected by macrophage-specific depressors such as carrageenan and trypan blue. Also, no induction was detected in thymus-defective nude mice. These results suggest that thymus-derived lymphocytes in the mouse may be required for IF induction by levamisole.     

The two-step leukocyte migration inhibition factor (LIF) assay. Its use in evaluation of cellular immune function in patients with immunodeficiency diseases.

Administration of interferon (IF) inducers to mice enhances the uptake of antibody-coated erythrocytes (EA) by peritoneal macrophages. To evaluate the role of induced IF in macrophage activation, serum IF titers and phagocytosis of EA by macrophages were determined in recombinant inbred (RI) mice inoculated with Newcastle disease virus (NDV). RI strains carry either a “high” or a “low” response allele for a gene that controls their IF titers induced by NDV. C × BH and C × BK strains, both high responders for IF induction, were also found to be high responders for enhancement of phagocytosis by NDV. Conversely, strains C × BD, C × BI and C × BJ, low responders for IF induction, were also shown to be low responders for phagocytosis of EA by macrophages. In contrast, phagocytosis of EA by macrophages from high responder C × BH mice and low responder C × BD mice was similarly enhanced by the administration of a lipopolysaccharide. When data from all NDV-inoculated mice were analysed, a significant correlation was obtained between serum IF titers and the percentage of macrophages that ingested four or more EA. The results are compatible with two main possibilities: (i) IF induced by NDV enhances phagocytosis of EA by macrophages; or (ii) a macrophage-activating factor different from IF is released together with IF in response to NDV and the activity of this factor correlates with serum IF titers.     

Effect of Exposure to High Isoflavone-Containing Diets on Prenatal and Postnatal Offspring Mice

Isoflavone (IF), a type of phytoestrogen, has multiple beneficial effects, but too much phytoestrogen can have adverse effects on offspring. To examine whether chronic exposure to high IF has adverse effects on reproductive development, mice offspring were exposed to IF through dietary administration to dams during pregnancy and lactation and to the offspring directly after weaning until sacrifice. In male offspring, there was no difference between the IF group and controls; however, in female offspring in the IF group, remarkably earlier puberty and induction of multioocyte follicles on postnatal day (PND) 21 were observed. Gene expression levels of estrogen receptor β decreased in the ovary and vagina on PND 21. These results suggest that chronic exposure to higher than normal levels of IF induces alterations in the reproductive development of female mice through an estrogenic effect.     

Effect of exposure to high isoflavone-containing diets on prenatal and postnatal offspring mice

Isoflavone (IF), a type of phytoestrogen, has multiple beneficial effects, but too much phytoestrogen can have adverse effects on offspring. To examine whether chronic exposure to high IF has adverse effects on reproductive development, mice offspring were exposed to IF through dietary administration to dams during pregnancy and lactation and to the offspring directly after weaning until sacrifice. In male offspring, there was no difference between the IF group and controls; however, in female offspring in the IF group, remarkably earlier puberty and induction of multioocyte follicles on postnatal day (PND) 21 were observed. Gene expression levels of estrogen receptor beta decreased in the ovary and vagina on PND 21. These results suggest that chronic exposure to higher than normal levels of IF induces alterations in the reproductive development of female mice through an estrogenic effect.     

The role of circulating interferon in the modifications of immune responsiveness by mouse hepatitis virus (MHV-3).

MHV-3 modifies the humoral immune response to SRBC. During acute infections timing was critical: infecting mice before antigen administration led to immunodepression. Simultaneous injection with virus and SRBC resulted in immunostimulation. Persistent MHV-3 infections were associated with a chronic immunodepression. The presence of circulating interferon (IF) was well correlated with these modifications. IF peaking before antigen was associated with immunodepression whereas IF secretion after antigen was associated with immunostimulation. Low, permanent levels of IF were associated with chronic immunodepression. Since IF is, up to now, the only product of activated lymphocytes that has been shown to modulate immune responses, our results suggest that induction of IF by MHV-3 may be the main mechanism by which this virus modifies immune responsiveness. Moreover, we have shown that MHV-3 infection in susceptible mice diminishes the secretion of lymphocyte IF in response to Sendai virus. In these animals, the thymus cortex was profoundly depleted although the thymus medulla remained unchanged. The MHV-3 infection may, therefore, interfere with a subpopulation of IF-secreting lymphocytes. The possible physiologic role of such lymphocyte subpopulation in terms of host-virus relationships is discussed.     

Induction of immune interferon in mice treated with a bacterial immunopotentiator,OK-432

Summary When a bacterial immunopotentiator, OK-432, was injected to intact DDI mice, a viral inhibitor with the properties of immune interferon (IF) was induced in the circulation. The maximum titer of antiviral activity (10,240 units/ml) was observed 24 h after intraperitoneal (IP) injection of 50 KE OK-432/kg body weight. The possibility that the induction of immune IF may depend upon the action of thymus-derived (T) lymphocytes and macrophages was inferred from experiments with thymus-defective nude mice and DDI mice treated with either X-rays or immunosuppressive agents.     

Production and properties of immune interferon from spleen cell cultures of Toxoplasma-infected mice

In response to antigenic stimulation, spleen cells from Toxoplasma-infected mice produce a factor showing inhibitory activity against vesicular stomatitis virus infection in L cell cultures. When BALB/C and ICR mice were inoculated intraperitoneally with the low-virulent S-273 strain of T. gondii, such activity was first detected in 4 and 7 days and reached maximum levels at 10 and 14 days respectively, and retained these levels for at least three weeks. However, BALB/C mice, which are considerably more sensitive to Toxoplasma infection than ICR mice, produced significantly smaller amounts of interferon (IF) after challenge with the high virulent strain. The IF produced in this system possessed certain known properties of immune (type II) IF and was not neutralized by rabbit antiserum against mouse type I IF. The immune IF preparation also inhibited multiplication of Toxoplasma within nonphagocytic L cells in an IF-like fashion, whereas Newcastle disease virus-induced (type I) IF had no effect on this parasite. The antiviral and anti-Toxoplasma activity in immune IF preparations could not be distinguished solely on the bases of their molecular weight and isoelectric point. The experiments with anti-theta serum plus complement and with nylon wool column effluent cells strongly suggest that immune IF was produced by T lymphocytes and required the assistance of macrophages.     

Ontogeny of Nk-1+ natural killer cells. I. Promotion of Nk-1+ cells in fetal, baby, and old mice

Using anti-Nk-1.1 serum, the alloantiserum specific for murine natural killer (NK) cells, we followed the ontogenetic development of Nk-1+ cells in fetal thymus, liver, and spleen. A transient population of Nk-1+ cells in fetal thymus was observed on day 14 but not on day 16 of gestation. On day 16 of gestation, Nk-1+ cells were detected only in liver and spleen. The proportion of Nk-1+ cells in spleen remained high (20 to 30%) at birth and persisted until 2 to 3 wk old. The Nk-1+ cells in "baby" (1 to 2 wk old) spleen bound to YAC cells but failed to lyse them in 51Cr-release assay. Upon induction with interferon (IF), the proportion of Nk-1+ cells increased, but the lytic activity remained low, suggesting that the "baby" NK-1+ cells are immature in lytic function. In old mice (12 to 14 mo), Nk-1+ cells were also detectable, even though NK activities were lower compared with those of the young adult (6 to 8 wk old) mice. The Nk-1+ cells of old mice were readily induced by IF to exhibit activities, and the induced NK cells were Nk-1+. We have thus established Nk-1.1 antigen as an early hemopoietic differentiation antigen. Splenic Nk-1- cells could be induce by IF to become NK-1+ cells, which could be inactive or active in NK assays, dependent on the age of the mice.     

Role of macrophage migration inhibitory factor (MIF) in allergic and endotoxin-induced airway inflammation in mice

Macrophage migration inhibitory factor (MIF) has recently been forwarded as a critical regulator of inflammatory conditions, and it has been hypothesized that MIF may have a role in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Hence, we examined effects of MIF immunoneutralization on the development of allergen-induced eosinophilic inflammation as well as on lipopolysaccharide (LPS)-induced neutrophilic inflammation in lungs of mice. Anti-MIF serum validated with respect to MIF neutralizing capacity or normal rabbit serum (NRS) was administered i.p. repeatedly during allergen aerosol exposure of ovalbumin (OVA)-immunized mice in an established model of allergic asthma, or once before instillation of a minimal dose of LPS into the airways of mice, a tentative model of COPD. Anti-MIF treatment did not affect the induced lung tissue eosinophilia or the cellular composition of bronchoalveolar lavage fluid (BALF) in the asthma model. Likewise, anti-MIF treatment did not affect the LPS-induced neutrophilia in lung tissue, BALF, or blood, nor did it reduce BALF levels of tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-1alpha (MIP-1alpha). The present data suggest that MIF is not critically important for allergen-induced eosinophilic, and LPS-induced neutrophilic responses in lungs of mice. These findings do not support a role of MIF inhibition in the treatment of inflammatory respiratory diseases.     

Ectopic expression of desmin in the epidermis of transgenic mice permits development of a normal epidermis

Cell architecture is largely based on the interaction of cytoskeletal proteins, which include intermediate filaments (IF), microfilaments, microtubules, as well as their type-specific membrane-attachment structures and associated proteins. In order to further our understanding of IF proteins and to address the fundamental issue whether different IF perform unique functions in different tissues, we expressed a desmin transgene in the basal epidermis of mice. Ectopic expression of desmin led to the formation of an additional, keratin-independent IF cytoskeleton and did not interfere with the keratin-desmosome interaction. We show that ectopic expression of a type III IF protein in basal keratinocytes did not interfere with the normal epidermal architecture and the program of terminal differentiation. This demonstrated that keratinocytes suffered no obvious detrimental effects from extra desmin filaments in their cytoplasm. In addition, we asked whether stable expression of desmin could rescue K5 null mice, which served as a model for severe EBS. Transgenic mice ectopically expressing desmin in the basal layer were mated with K5 heterozygous deficient animals to generate desmin rescue mice and analysed. In summary, our study support the notion that the different IF like desmin or keratins composing a IF network in vivo are central to cytoskeletal architecture and design in cells.     

Subset-specific reductions in lung lymphocyte accumulation following intratracheal antigen challenge in endothelial selectin-deficient mice

We previously demonstrated induction and expression of CD62E and CD62P in the lungs of mice primed and then challenged with intratracheal (i.t.) SRBC. The current study examined accumulation of endogenous lymphocytes in the lungs of endothelial E- and P-selectin-deficient (E(-)P(-)) mice after i.t. SRBC challenge. Compared with syngeneic wild-type (wt) mice, E(-)P(-) mice showed an 85-95% decrease in CD8(+) T cells and B cells in the lungs at both early and late time points. In contrast, CD4(+) T cell accumulation was reduced by approximately 60% early, but equivalent to wt levels later. Surprisingly, many gammadelta T cells were found in lungs and blood of E(-)P(-) mice but were undetectable in the lungs and blood of wt mice. Absolute numbers of peripheral blood CD4, CD8, and B lymphocytes in E(-)P(-) mice equaled or exceeded the levels in wt mice, particularly after challenge. Trafficking studies using alphabeta T lymphoblasts confirmed that the recruitment of circulating cells after challenge was markedly reduced in E(-)P(-) mice. Furthermore, Ag priming occurred normally in both the selectin-deficient and wt mice, because primed lymphocytes from both groups transferred Ag sensitivity into naive wt mice. Lung production of mRNA for six CC and two CXC chemokines after challenge was equivalent by RT-PCR analysis in wt and E(-)P(-) mice. Therefore, reduced lung accumulation of alphabeta T cells and B cells in E(-)P(-) mice did not result from reduced delivery of circulating lymphocytes to the lungs, unsuccessful Ag priming, or defective pulmonary chemokine production. Selectin-dependent lymphocyte recruitment into the lungs following i.t.-SRBC challenge is subset specific and time dependent.     

Relationship between Immunity and Interferon Production in Macrophages

In vitro interferon (IF) production in peritoneal macrophages of normal and Newcastle disease virus (NDV)-immunized mice was studied. Of ascites cells used, 80% were macrophages, 14% lymphocytes, and 6% polymorphonuclear leukocytes. It was indicated that IF was produced mainly in the macrophages after NDV inoculation. IF production in the macrophages derived from immunized mice was more enhanced than that in those from normal mice. It is not clear at present, however, whether this enhancement is based on immunological specificity. The IF production in the culture of macrophages reached its maximum value in 6 to 9 hr after inoculation of the inducer. After 12 hr, the IF titer in the culture fluid decreased gradually. A possible explanation of this fact is that there may be partial inactivation of IF by some cellular components.     

Kinetics of Organ-Associated Natural Killer Cells and Intermediate CD3 Cells during Pulmonary and Hepatic Granulomatous Inflammation Induced by Mycobacterial Cord Factor

We investigated here the kinetics of natural killer (NK) cells and extrathymic T cells, which include intermediate CD3 cells and γδ T cells, in the cord factor-induced granulomatous inflammation of the lungs and liver. In Balb/c mice, pulmonary inflammation elevated the proportion of NK cells and that of extrathymic T cells to mononuclear cells in the lungs. C3H/He mice exhibited shorter-term inflammation of the lungs than Balb/c mice and accordingly showed a smaller increase in the proportions of pulmonary NK cells and intermediate CD3 cells. In the liver of Balb/c mice, hepatic NK cells increased as well with the granulomatous changes, while intermediate CD3 cells exhibited a transient decrease before they increased. The present study has demonstrated that granulomatous inflammation is accompanied by the increase of lung-associated NK cells and extrathymic T cells and that there exists a difference between these two mouse strains in the induction of these lymphocyte subsets by cord factor.     

The role of immunocytes in the production of interferon in response to its induction by aromatic hydrocarbons]

Interferon (IF) was synthesized in animals by diverse populations of immunocytes in response to induction by various low molecular weight aromatic hydrocarbons. The level of the involvement of either population of the immunocytes in IF production is determined by the chosen inductor. IF induction by acridanone L-1 was mainly observed in macrophages and B-lymphocytes. T-Cells actively participated in IF synthesis induced by amyxin, a representative of the fluorenone group. IF synthesized by lymphocytes of human peripheral blood in response to L-1 was completely neutralized by antiserum to alpha-IF while IF induced by amyxin in the same culture was a mixture of alpha- and beta-IFs at a ratio of 3:1.     

Teratological studies of prenatal exposure of mice to a 20 kHz sawtooth magnetic field

In order to evaluate the importance of gestational age in possible effects due to exposure to a 20 kHz sawtooth magnetic field, pregnant ICR mice at gestational 2.5-15.5 days post-coitus, which is the most sensitive stage for the induction of major congenital malformations, were exposed in a carrousel irradiator. The mice were exposed to a 20 kHz intermediate frequency (IF) sawtooth magnetic field had a 6.5 microT peak intensity for 8 h/day. The animals were sacrificed on the 18th day of gestation; and the fetuses were examined for mortality, growth retardation, changes in head size, and other morphological abnormalities. From the above conditions, it is concluded that the exposure to a 20 kHz sawtooth magnetic field with 6.5 microT peak intensity does not inflict any adverse effect on fetuses of pregnant mice.     

Prostaglandin E2 Production and T Cell Function in Mouse Adenovirus Type 1 Infection following Allogeneic Bone Marrow Transplantation

Adenovirus infections are important complications of bone marrow transplantation (BMT). We demonstrate delayed clearance of mouse adenovirus type 1 (MAV-1) from lungs of mice following allogeneic BMT. Virus-induced prostaglandin E₂ (PGE₂) production was greater in BMT mice than in untransplanted controls, but BMT using PGE₂-deficient donors or recipients failed to improve viral clearance, and treatment of untransplanted mice with the PGE₂ analog misoprostol did not affect virus clearance. Lymphocyte recruitment to the lungs was not significantly affected by BMT. Intracellular cytokine staining of lung lymphocytes demonstrated impaired production of INF-γ and granzyme B by cells from BMT mice, and production of IFN-γ, IL-2, IL-4, and IL-17 following ex vivo stimulation was impaired in lymphocytes obtained from lungs of BMT mice. Viral clearance was not delayed in untransplanted INF-γ-deficient mice, suggesting that delayed viral clearance in BMT mice was not a direct consequence of impaired IFN-γ production. However, lung viral loads were higher in untransplanted CD8-deficient mice than in controls, suggesting that delayed MAV-1 clearance in BMT mice is due to defective CD8 T cell function. We did not detect significant induction of IFN-β expression in lungs of BMT mice or untransplanted controls, and viral clearance was not delayed in untransplanted type I IFN-unresponsive mice. We conclude that PGE₂ overproduction in BMT mice is not directly responsible for delayed viral clearance. PGE₂-independent effects on CD8 T cell function likely contribute to the inability of BMT mice to clear MAV-1 from the lungs.     

Augmentation of mouse natural killer cell activity by interferon and interferon inducers.

Interferon (IF), in addition to its anti-viral capacity, is increasingly being found to be a regulator of cell division, cell surface antigens, and cell function. To determine whether IF also plays a role in the regulation of natural killer (NK) cell activity in mice, the in vivo and in vitro effects of IF and IF inducers on NK activity were studied. We observed that pyran, lipopolysaccharide, and polyinosinicopolycytidylic acid (poly I:C) as well as crude and purified IF preparations significantly elevated splenic NK levels in normal mice within 3 to 24 hr of i.p. administration. Normal spleen cells treated with poly I:C or IF in vitro also had augmented NK activity. Poly I:C and IF were themselves not cytotoxic and their presence was not required during the lytic process, indicating that IF acts on lymphocytes to activate NK function. The addition of anti-IF in the incubation medium completely blocked the boosting of NK activity by poly I:C or IF. The characteristics of the effector cells activated by IF were consistent with those of NK cells rather than macrophages, since the boosted effector cells were not retained by a rayon column or removed by carbonyl iron. Moreover, they were resistant to treatment with anti-Thy 1.2 serum plus complement, which eliminated mature T cells.     

The effects of interferon on murine erythropoiesis

The effects of interferon (IF) on erythropoietin (Ep) action and production were studied in mice. In comparison to control animals, Ep action in exhypoxic, polycythemic mice was significantly decreased (p less than 0.05) following two low dose injections of IF (2.9-3.5 X 10(4) units). In addition, renal Ep production in normal intact mice was also significantly decreased (p less than 0.01) following a single injection of IF (5.4-6.3 X 10(4) units) and hypoxic exposure.