Effect of interferon type I on the in vivo persistence of Salmonella typhimurium

The influence of type I interferon on the persistence of S. typhimurium in the body of mice has been studied. The injection of the preparation of interferon has been shown to be conductive to the survival of the animals and to reduce the time of Salmonella persistence in the body. The injection of interferon enhances the phagocytic activity of macrophages in the peritoneal exudate of mice.     

Delayed hypersensitivity and nonspecific cellular immunity. The role of mono- and polynuclear phagocytes

Differences in the influence produced by sensitization with BCG vaccine and Staphylococcus aureus and by the reaction of delayed hypersensitivity (DH) induced, respectively, by the injection of old tuberculin and staphylococcal phagolysate on the phagocytic activity of peritoneal macrophages and blood leukocytes in different animals were experimentally demonstrated. A considerable activation of the bactericidal and ingesting functions of macrophages was observed in animals showing a pronounced DH reaction (rabbits, guinea pigs and mice), while in Wistar rats no such activation was noted. The latter showed no DH reaction after sensitization with BCG vaccine and the injection of the specific antigen. Among different strains of mice, the activation of macrophages occurred in the animals with the most pronounced DH reaction. Sensitization with BCG vaccine led to an insignificant sensitization of macrophages, and sensitization with S. aureus even suppressed the phagocytic activity of macrophages. The treatment of mice with antimacrophagal preparations (carrageenan, silica and trypan blue, but T-lymphocyte antiserum) before and after the injection of the specific antigen into the sensitized animals abolished the stimulation of anti-infection immunity.     

The protective action of interferon type I in experimental Salmonella infection

The effect of interferon, type 1, on the course of Salmonella infection in mice has been studied. The study has shown that the injection of homologous interferon of type 1 leads to the rapid elimination of the infective agent from the blood and organs of infected mice. Morphological study has shown that the injection of the preparations of interferon of type 1 may diminish pathological changes in the organs of the infected animals and the coagulation system of their blood.     

Enzymatic coordination indices of leukocytes in the prognosis of mouse resistance to staphylococcal toxin

The activity of succinate, lactate and alpha-glycerophosphate dehydrogenases, as well as acid phosphatase, in the lymphocytes and neutrophils of the blood was studied in noninbred white mice prior to the intraperitoneal injection of 1 LD50 of staphylococcal toxin. As the result of intoxication, a half of the animals died and the other half survived. The two groups of the animals differed in the levels of the activity of succinate dehydrogenase and hyaloplasmatic alpha-glycerophosphate dehydrogenase in the neutrophils and lymphocytes, and also differed in the stability of correlations between the activity of succinate and lactate dehydrogenases in the lymphocytes and neutrophils and, besides, between the activity of lactate dehydrogenase in these types of cells.     

Interferon and cytotoxic factor (cytotoxin) released in the blood of mice infected with Mycobacterium bovis BCG. I. Enhanced production of interferon and appearance of cytotoxin stimulated by capsular polysaccharide of Klebsiella pneumoniae or bacterial lipopolysaccharide.

Interferon production stimulated by the active substance (neutral fraction) of the capsular polysaccharide of Klebsiella pneumoniae (neutral CPS-K) in BCG-infected mice was compared with that by bacterial lipopolysaccharide (LPS). Prior infection with BCG increased the responsiveness of mice to the lethal effect of neutral CPS-K as well as to that of LPS. Associated with this, BCG-infected mice showed a markedly enhanced ability to produce interferon after stimulation not only by LPS but also by neutral CPS-K. In addition, a cytotoxic factor (cytotoxin) was found to be released in the serum of BCG-infected mice after injection of these inducers. The kinetics of production of interferon and cytotoxin stimulated by neutral CPS-K were very similar to those stimulated by LPS. The time pattern of cytotoxin production was not in parallel with that of interferon production. Interferon reached a peak 2 hr and cytotoxin 3 hr after injection with these inducers. Interferon and cytotoxin produced by neutral CPS-K showed essentially the same stabilities to heating at 56 C and to treatment at pH 2 respectively as those produced by LPS. Interferon was inactivated by heating at 56 C more rapidly than cytotoxin. Cytotoxin was inactivated by treatment at pH 2 for 24 hr, whereas interferon activity was well preserved after this treatment. These results suggest that both activities are the result of different substances.     

Biological activity of a new Soviet natural inducer, double-stranded RNA

Antiviral activity of a two-spiral RNA (ts RNA), a new natural interferon inductor was studied. It was shown that ts RNA extracted from a phage infected E. coli culture was an active inductor of interferon and resistance to infection with the forestspring encephalitis virus experimental animals. In experiments on 10-12 g mice ts RNA administered in a dose of 50 micrograms/mouse 6 hours after the infection induced up to 1280 units/ml of the serum interferon. When the inductor was administered repeatedly, the experimental animals developed hyporeactivity resulting in a marked decrease in interferon production after the 3rd subsequent injection. The most pronounced effect with respect to the forest-spring encephalitis virus was observed when the inductor was administered intraperitoneally in a dose of 20 micrograms/mouse 4 hours before the infection. The protective effect was less pronounced when the inductor was administered 24 and 48 hours before the infection. A two-fold administration of the inductor did not increase the antiviral effect. When the inductor was administered in a dose of 100 micrograms 14 days before the infection, the animals showed an increase in the nonspecific resistance to the infection resulting in a marked antiviral effect.     

Effect of trypsin on the immune response in localized staphylococcal infection

The influence of trypsin on the formation of immune response induced by a thymus-dependent antigen at different periods of localized staphylococcal infection has been studied. A single intramuscular injection of bovine trypsin has been found to enhance immune response to sheep red blood cells (SRBC) in healthy mice and, to a still greater degree, in mice with localized staphylococcal infection. the development of localized staphylococcal infection has been shown to have no influence on the manifestation of the immuno-suppressive effect of splenocytes in SRBC-immunized mice or to enhance this effect. The injection of trypsin decreases the immunosuppressive effect of splenocytes in healthy or staphylococcus-infected hyperimmune mice.     

Effect of Diet and Strain Difference on the Virulence of Staphylococcus aureus for Mice

Years of intensive investigations in our laboratories on staphylococcal infections in mice have indicated a gradual decrease in the virulence of Staphylococcus aureus for this animal, particularly the strain we were using, the random-bred BT mouse. The present investigations, based on changes in diet and strain differences in mice, were undertaken in an attempt to improve susceptibility of our stock strain, on the one hand, and to determine whether susceptibility was influenced by genetic strain differences, on the other. In the first series of experiments, littermate mice of the BT strain were placed on different diets: one group received a commercial diet; the other, a basic diet previously established in our laboratories as adequate for growth requirements of the animals. An increase in the susceptibility of the animals to staphylococcal infection was noted in the mice receiving the basic diet. In the second series of investigations, three other strains of mice (the Swiss albino, the C3H/HeJ, and the C57B1) previously not used by our laboratories in staphylococcal experiments were studied for staphylococcal susceptibility. These experiments revealed that all of these strains of mice were highly susceptible to the infection, even though they were maintained on a commercial diet.     

Studies on the functional site on staphylococcal enterotoxin A responsible for production of murine gamma interferon

To identify the functional region(s) associated with induction of gamma interferon on the staphylococcal enterotoxin A molecule, native staphylococcal enterotoxin A molecules and 12 various synthetic peptides corresponding to different regions of entire staphylococcal enterotoxin A were compared to induce gamma interferon production in murine spleen cells. The native staphylococcal enterotoxin A molecule induced gamma interferon production, whereas all of the 12 synthetic peptides did not. Pre-treatment of the murine spleen cells with synthetic peptide A-9 (corresponding to amino acid residues 161-180) significantly inhibited the staphylococcal enterotoxin A-induced gamma interferon production, whereas those with other synthetic peptides did not. When native staphylococcal enterotoxin A was pre-treated with either anti-staphylococcal enterotoxin A serum or anti-peptide sera, anti-staphylococcal enterotoxin A serum and antisera to peptides A-1 (1-20), A-7 (121-140), A-8 (141-160), A-9 (161-180) and A-10 (181-200) inhibited the staphylococcal enterotoxin A-induced gamma interferon production. From these findings, the amino acid residues 161-180 on the staphylococcal enterotoxin A molecule may be an essential region for murine gamma interferon production. Furthermore, the neutralizing epitopes may be also located on regions of amino acid residues 1-20, 121-140, 141-160 and 181-200 on the staphylococcal enterotoxin A molecule.     

Rational design of a potent, long-lasting form of interferon: a 40 kDa branched polyethylene glycol-conjugated interferon alpha-2a for the treatment of hepatitis C

A potent, long-lasting form of interferon alpha-2a mono-pegylated with a 40 kilodalton branched poly(ethylene glycol) was designed, synthesized, and characterized. Mono-pegylated interferon alpha-2a was comprised of four major positional isomers involving Lys31, Lys121, Lys131, and Lys134 of interferon. The in vitro anti-viral activity of pegylated interferon alpha-2a was found to be only 7% of the original activity. In contrast, the in vivo antitumor activity was severalfold enhanced compared to interferon alpha-2a. Pegylated interferon alpha-2a showed no immunogenicity in mice. After subcutaneous injection of pegylated interferon alpha-2a, a 70-fold increase in serum half-life and a 50-fold increase in mean plasma residence time concomitant with sustained serum concentrations were observed relative to interferon alpha-2a. These preclinical results suggest a significantly enhanced human pharmacological profile for pegylated interferon alpha-2a. Results of Phase II/III hepatitis C clinical trials in humans confirmed the superior efficacy of pegylated interferon alpha-2a compared to unmodified interferon alpha-2a.     

Relative sensitivity of hepatitis B virus and other hepatotropic viruses to the antiviral effects of cytokines

We have previously shown that hepatitis B virus (HBV) replication is inhibited noncytopathically in the livers of transgenic mice following injection of HBV-specific cytotoxic T lymphocytes (CTLs) or infection with unrelated hepatotropic viruses, including lymphocytic choriomeningitis virus (LCMV) and adenovirus. These effects are mediated by gamma interferon (IFNgamma), tumor necrosis factor alpha (TNFalpha), and IFNalpha/beta. In the present study, we crossed HBV transgenic mice with mice genetically deficient for IFNgamma (IFNgammaKO), the TNFalpha receptor (TNFalphaRKO), or the IFNalpha/beta receptor (IFNalpha/betaRKO) in order to determine the relative contribution of each cytokine to the antiviral effects observed in each of these systems. Interestingly, we showed that HBV replicates in unmanipulated IFNgammaKO and IFNalpha/betaRKO mice at levels higher than those observed in control mice, implying that baseline levels of these cytokines control HBV replication in the absence of inflammation. We also showed that IFNgamma mediates most of the antiviral effect of the CTLs while IFNalpha/beta is primarily responsible for the early inhibitory effect of LCMV and adenovirus on HBV replication. In addition, we showed that the hepatic induction of IFNalpha/beta observed after injection of poly(I. C) is sufficient to inhibit HBV replication and that a similar antiviral effect is achieved by systemic administration of very high doses of IFNalpha. We also compared the relative sensitivity of LCMV and adenovirus to control by IFNgamma, TNFalpha, or IFNalpha/beta in these animals. Importantly, IFNalpha/betaRKO mice, and to a lesser extent IFNgammaKO mice, showed higher hepatic levels of LCMV RNA and adenovirus DNA and RNA than control mice, underscoring the importance of both interferons in controlling these other viral infections as well.     

Inhibitory effect of combined administration of neuraminidase and interferon in mice with Rauscher leukemia

A study was made of the effect of cholera vibrio neuraminidase and mouse interferon on the development of Rauscher's leukemia in BALB/c mice. It was shown that administration of 1500 units interferon to mice 4 hours before and 5 days after inoculation of Rauscher's leukemia virus prolonged the animals' lifespan. Preliminary treatment of the virus-containing material with neuraminidase prevented the death of one third of the experimental animals. Meanwhile the remainder of the animals inoculated with the same virus showed a longer lifespan. Combined use of both the preparations proved the most effective, enabling the prevention from death of 90% of the experimental animals. The mechanism of antiviral action of neuraminidase and interferon is discussed.     

Effect of human lymphoblastoid interferon on human yolk sac tumors in nude mice

The effect of human lymphoblastoid interferon on the growth of human tumors heterotransplanted into nude mice was examined. The human tumor lines examined, named YST-1, YST-2 and YST-3, were derived from yolk sac tumors of the ovary. Daily intraperioneal injection of 3 X 10(4) U interferon per mouse for 14 days did not inhibit the growth of any of these three human tumor lines. A close correlation was observed between the tumor volume and the level of alpha-fetoprotein in sera of mice bearing the YST-1 tumor (r = 0.55) or YST-2 tumor (r = 0.70). No histological differences were detected between tumor cells of interferon-treated and control mice. Tumor-bearing mice treated with interferon showed no marked weight loss.     

Cytokinin inducing and antiviral activity of cycloferon on experimental herpetic infection

Experimental data on the protective activity and the capacity for inducing the biosynthesis of some cytokins, the low molecular inductors of cycloferon, endogenic interferon of the acridanon group, in herpetic infection are presented. The herpes infection was modelled by intraperitoneal injection of herpes simplex virus, type 1 into BALB/c mice. In the animals with normal immune status cycloferon induced the formation of serum interferon (INF) in high titers (up to 1:20,000) with the peak achieved 4-8 hours after the injection of the preparation. In addition, cycloferon stimulated the synthesis of IL-2 and gamma INF, but decreased the concentration of IL-1b. Following immunosuppression caused by gamma-radiation or cyclophosphamide the titers of serum interferon decreased 4-8 times. In generalized herpes infection in non-inbred white mice with undamaged immune status cycloferon increased survival rate by 30-100% in comparison with the controls (untreated mice), while in case of immunosuppression the protective effect of this preparation was considerably lower. In infected mice the concentrations of gamma INF, IL-2, IL-1b were found to be elevated in comparison with their concentrations in healthy animals. In the course of the infectious process cycloferon suppressed the production of IL-2 and IL-1b, but did not influence the synthesis of gamma INF.     

Altered pharmacological properties of liposome-associated human interferon-alpha.

Human interferon-alpha was associated in different ways with positively (stearylamine) and negatively (phosphatidylserine) charged phosphatidylcholine multilamellar vesicles, depending on the presence or absence of a cholesterol component. Inclusion of cholesterol resulted in interferon that was significantly (P = 0.0001) more deeply internalized within the liposomes, such that detergent disruption was necessary before most of the interferon activity was expressed. Interferon was stably associated with stearylamine-containing liposomes, both with and without a cholesterol component. However, inclusion of cholesterol in the phosphatidylserine-containing liposomes was necessary for stable association of the interferon for more than 2 days at 4 degrees C or for more than 24 h at 37 degrees C. After intramuscular injection into mice, liposome-associated interferon in reverse-phase evaporation vesicles was retained at the local site of injection significantly longer than free interferon. Even 3 days after intramuscular injection, stearylamine-containing liposomes with or without cholesterol resulted in local interferon levels that were comparable to the peak levels obtained 2 to 4 h after free interferon was injected. In contrast, free interferon was not detectable in the local muscles 24 h after injection of 10(4.6) U. Liposomes containing phosphatidylserine and cholesterol resulted in intermediate levels of local interferon retention; without a cholesterol component, phosphatidylserine-containing liposomes resulted in no increased local interferon retention compared with the results when free interferon was injected.     

Circulating Interferon Production in the Mouse : Origin and nature of cells involved and influence of animal genotype

A radiobiological study of circulating interferon production in the mouse was undertaken in the hope of elucidating the site(s) of circulating interferon production. After total body X-irradiation of the animals, different radiosensitivities of circulating interferon production were observed with different viral inducers. Myxovirus-induced circulating interferon production was especially radiosensitive. Moreover, a study of interferon production in syngeneic and xenogeneic radiochimeras demonstrated that cells producing NDV (Newcastle disease virus)-induced circulating interferon were derived from hematopoietic stem cells. In addition, treatment of mice with antilymphocyte serum significantly reduced NDV- and Sendai virus-induced circulating interferon, as opposed to other inducers. Taken together, these results strongly suggest that the lymphocyte is the major source of myxovirus-induced circulating interferon. A survey of interferon production in 12 inbred mouse strains, using NDV as inducer, revealed the existence of low and high producers. A Mendelian analysis carried out with low producing Balb/c and high producing C57BL indicated that the difference between low and high interferon producers was caused by a single, autosomal, codominant factor.     

Chemotherapeutic effect of 3-(5-nitrofuryl)-7-(5-nitrofurfurylidene)-3,3a,4,5,6,7-hexahydro-2H-indazole in experimental staphylococcal infection]

Chemotherapeutic activity of 3-(5-nitrofuryl)-7-(5-nitrofurfuryliden)-3, 3a, 4, 5, 6, 7-hexahydro-2H-indazol (compound 26) was studied on albino mice with experimental staphylococcal infection. The animals were contaminated intraperitoneally. The results of culture of the specimens of the organs of the mice killed within various terms and the values of the spleen bacterial index served as the criteria of the effectiveness. Compound 26 was administered in doses of 20, 10 and 5 mg/kg once a day for 3 days. The treatment was started simultaneously with or 24 hours after the contamination. The results showed that compound 26 in a dose 20 mg/kg (0.4 mg/mouse) possessed high chemotherapeutic activity in experimental staphylococcal infection of albino mice and could be recommended for a thorough study as a potential agent for chemotherapy of staphylococcal infection.     

Delayed hypersensitivity and nonspecific cellular immunity. The cytotoxic activity of macrophages, natural and antibody-dependent killer cells

The experiment on (BALB/cXC57BL)F1 mice, showing a high level of delayed hypersensitivity (DH) when sensitized with BCG vaccine and Staphylococcus aureus strain B-243, has demonstrated the influence of such sensitization and DH reaction induced by the injection of a specific antigen (old tuberculin or staphylococcal phagolysate) into the sensitized animals on the cytotoxicity of macrophages, natural killers (NK) and antibody-dependent killers (ADK). Sensitization with BCG vaccine alone results in an insignificant rise in the activity of these effector cells, and sensitization with S. aureus produces no changes at all. The pronounced activation of the cytotoxicity of macrophages, NK and, to a lesser extent, ADK has been observed in DH reaction induced by the injection of a specific antigen into the sensitized mice. In the course of DH reaction a rise in the activity of NK and ADK not only against tumor target cells, but also against microbial ones (Candida albicans and S. aureus) has been found to occur.     

Endotoxin-induced susceptibility to staphylococcal infection and its reversal by adrenergic blocking agents

Sultzer, Barnet M. (Princeton Laboratories, Inc., Princeton, N.J.), and Henry H. Freedman. Endotoxin-induced susceptibility to staphylococcal infection and its reversal by adrenergic blocking agents. J. Bacteriol. 90:1001-1006. 1965.-The transient phase of increased susceptibility to bacterial infection in mice provoked by prior administration of small doses of endotoxin was investigated for possible mediation by vasoactive substances. Animals were given endotoxin intravenously shortly before intraperitoneal injection of Staphylococcus aureus Smith, thereby lowering the lethal inoculum 10-fold. To determine whether this susceptibility state could be obviated, mice were pretreated with phenoxybenzamine or dibenzylchlorethylamine. Mortality decreased from an average of 81% in the endotoxin control groups to about 23% in the treated mice, closely approximating the mortality in control mice injected with saline and staphylococci. Neither antiadrenergic agent independently altered the resistance of mice to a higher lethal staphylococcal challenge, nor did these materials induce extravascular leukocyte mobilization into the peritoneal cavity. The results suggest a possible role of vasoactive staphylococcal alpha-toxin, as well as epinephrine or epinephrine-like factors, in this altered state of resistance to staphylococcal infection.     

The axis of interleukin 12 and gamma interferon regulates acute vascular xenogeneic rejection

Recent advances using transgenic animals or exogenous complement inhibitors have demonstrated prevention of hyperacute rejection of vascularized organs, but not graft loss due to acute vascular rejection. Using various wild-type and cytokine-deficient mice strains, we have examined the mechanisms of acute vascular rejection. C57BL/6 mice deficient in interleukin12 or gamma interferon showed faster acute vascular rejection than did wild-type mice. Furthermore, mice defective in B-cell development showed no acute vascular rejection. These results demonstrate that the axis of interleukin 12 and gamma interferon provides a survival advantage in vascularized xenografts by delaying or preventing acute vascular rejection caused by a B cell-dependent mechanism.