Interferon and cytotoxic factor (cytotoxin) released in the blood of mice infected with Mycobacterium bovis BCG. III. Interferon and cytotoxin induced by the specific antigen as compared with those induced by bacterial lipopolysaccharide

The time course of development and decline of the ability of BCG-infected mice to produce interferon in the serum in response to the intravenous infection of purified protein derivative of tuberculin (PPD) was very similar to that of their systemic hypersensitivity to PPD. A cytotoxic factor (cytotoxin) was produced in parallel with interferon in the serum of BCG-infected mice after stimulation with PPD. The duration of the period in which cytotoxin-production responsiveness to PPD was definitely detectable was much shorter than that for interferon-production responsiveness although the periods for the maximum production of interferon and cytotoxin coincided. The kinetics of release of interferon in the serum of BCG-infected mice after stimulation with PPD did not parallel that of release of cytotoxin. The four kinds of activities, interferons and cytotoxins induced by PPD and lipopolysaccharide (LPS) in the serum of BCG-infected mice, were compared for their stability to heating at 56 C and to treatment at pH 2. The kinetics of inactivation of these four activities differed significantly, when the serum was either heated at 56 C or treated at pH 2. Interferon produced in response to LPS could be neutralized by anti-L cell(NDV) interferon rabbit serum as easily as L cell (NDV) interferon, 16 times as much antiserum was required to neutralize the same amount of interferon in response to PPD, but cytotoxins induced by PPD and LPS were not neutralized at all by the antiserum. From these findings it is thought likely that interferons and cytotoxins induced by PPD and LPS in the serum of BCG-infected mice are different substances, although the antigenic relationship between cytotoxins induced by PPD and LPS remains unknown.     

Action of PGI2 analogs on the pulmonary and systemic circulations in the conscious newborn lamb

Previous work (Lock , J. Pharm. Exp. Ther. :156, 1980) has shown that conventional screening procedures for vasoactive PGI₂ analogs have little value in predicting pulmonary vasodilator activity in the newborn lamb. To gain a better insight into the structural requirements for pulmonary vasoactivity and possibly identify useful compounds for the management of neonatal pulmonary hypertensive disorders, we have tested the following PGI₂ analogs in normoxic and hypoxic newborn lambs: 15(S)-9-deoxy-15-methyl1–9α, 6-nitrilo-PGF₁ (analog I); 9-deoxy-9α, 5-nitrilo-PGF₁ (analog II); (6S, 15S)-15-methyl-PG1₁ (analog III); and (6R, 15S)-15-methyl-PGI₁ (analog IV). A prostaglandin analog mimicking PGI₂ (compound BW245C; (±)-5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropyl)hydantoin) was tested as well. Compounds were injected into a branch pulmonary artery and any local pulmonary effect could be assessed from the change in the ratio of blood flow to the injected lung over total flow. None of the analogs tested proved to be a selective pulmonary dilator. BW245C was a potent peripheral vasodilator (threshold around 0.5 μg/kg) and indirectly lowered pulmonary vascular resistance through its systemic effects. Analog I also dilated the systemic circulation, but only at the highest dose tested (100 μg/kg). The latter finding is surprising because it was previously shown that the parent, non-methylated compound is a fairly potent and selective pulmonary vasodilator. Analog II and IV were inactive at a dose up to, respectively, 30 and 20 μg/kg. Analog III, on the other hand, weakly constricted the systemic circulation at a dose of 10 μg/kg. These findings suggest that the neonatal pulmonary vasculature is endowed with specific receptor sites which can discriminative between closely related PGI₂ analogs.     

Changes in Electrophoretic Patterns of Oocyte Proteins during Oocyte Maturation in Oryzias latipes

Changes in the two-dimensional SDS-electrophoretic patterns of extracts of maturing denuded oocytes of the medaka ( Oryzias latipes ) were surveyed. In oocytes without follicular constituents several proteins became detectable in the area between the acidic and slightly basic proteins on the two-dimensional electrophoretograms, while a few of the protein spots disappeared during the process of oocyte maturation. The former proteins were detected also in oocytes that were induced to mature in vivo without breakdown of the germinal vesicle. Several proteins newly observed in extracts of post-vitellogenic oocytes during maturation after breakdown of the germinal vesicle were also identified by two-dimensional electrophoresis. Of several proteins that exhibited noticeable changes in maturing oocytes, only one spot incorporated ¹⁴C-labeled amino acid during maturation, suggesting that post-translational modification of many proteins occurred during oocyte maturation.     

Reversible susceptibility to natural cell-mediated cytotoxicity observed in altered BHK cells resistant to HVJ (Sendai virus) infection

Altered baby hamster kidney (BHK-R) cells which were subcultured in the continuous presence of HVJ (hemagglutinating virus of Japan--the Sendai strain of parainfluenza 1 virus) showed a high susceptibility to natural cell-mediated cytotoxicity, although BHK-R cells are not transiently or persistently infected with HVJ but contain the restricted amount of sialic acid. By repeated subcultivation of BHK-R cells in growth medium free of HVJ, the sensitivity to natural killer cytotoxicity decreased to the level of normal BHK cells with a counter increase of cellular sialic acid, and the subsequent treatment of the cells with neuraminidase caused a loss of proper sialic acid residues, once again resulting in a significant enhancement of lysis by natural killer cells. In the BHK-R cell system which exhibits a reversible resistance to the interferon action, the enhancing effect induced by interferon on target cell susceptibility to natural killer activity became more pronounced in accord with the recovery of sensitivity to the antiviral action of interferon.     

Bag3-Induced Autophagy Is Associated with Degradation of JCV Oncoprotein, T-Ag

JC virus, JCV, is a human neurotropic polyomavirus whose replication in glial cells causes the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). In addition, JCV possesses oncogenic activity and expression of its transforming protein, large T-antigen (T-Ag), in several experimental animals induces tumors of neural origin. Further, the presence of JCV DNA and T-Ag have been repeatedly observed in several human malignant tissues including primitive neuroectodermal tumors and glioblastomas. Earlier studies have demonstrated that Bag3, a member of the Bcl-2-associated athanogene (Bag) family of proteins, which is implicated in autophagy and apoptosis, is downregulated upon JCV infection of glial cells and that JCV T-Ag is responsible for suppressing the activity of the BAG3 promoter. Here, we investigated the possible impact of Bag3 on T-Ag expression in JCV-infected human primary glial cells as well as in cells derived from T-Ag-induced medulloblastoma in transgenic animals. Results from these studies revealed that overexpression of Bag3 drastically decreases the level of T-Ag expression by inducing the autophagic degradation of the viral protein. Interestingly, this event leads to the inhibition of JCV infection of glial cells, suggesting that the reduced levels of T-antigen seen upon the overexpression of Bag3 has a biological impact on the viral lytic cycle. Results from protein-protein interaction studies showed that T-Ag and Bag3 physically interact with each other through the zinc-finger of T-Ag and the proline rich domains of Bag3, and this interaction is important for the autophagic degradation of T-Ag. Our observations open a new avenue of research for better understanding of virus-host interaction by investigating the interplay between T-Ag and Bag3, and their impact on the development of JCV-associated diseases.     

Serious adverse events following treatment with ivermectin for onchocerciasis control: a review of reported cases

This paper presents a summary of reported cases of Serious Adverse Events (SAEs) following treatment with Mectizan^® (ivermectin, Merck, Sharpe &; Dohme) in onchocerciasis mass treatment programs from January 1, 1989 to December 31, 2001 through a passive surveillance system. A total of 207 SAE cases were reported out of approximately 165 million reported treatments delivered during the period under review, giving rise to a cumulative incidence of 1 reported SAE per 800,000 reported treatments. The mean age was 40 years and 70% of the cases were males. The mean time between ivermectin intake and onset of illness was 1 day. For 57% of the cases (n = 118), that was their first exposure to ivermectin. The majority of cases were reported from Cameroon (n = 176; 85%) with peaks in the incidence of SAE reporting in 1989–1991 and 1994–1995 when the program expanded to ivermectin-naïve populations. Fifty-five percent of the cases from Cameroon (i.e. 97 out of 176 cases) were encephalopathic and were reported from the central-southern region of the country; two-thirds of these cases were 'probable' or 'possible' cases of Loa loa encephalopathy temporally related to ivermectin treatment. Reporting bias may explain some but not all of the differences in SAE reporting between the 34 onchocerciasis-endemic countries that have, or have had, mass treatment programs. Further research is needed to understand the apparent clustering of encephalopathy cases in central-southern Cameroon since L. loa infection alone probably does not explain the increased incidence of this type of SAE from this region.     

Myo-Inositol Treatment and GABA-A Receptor Subunit Changes After Kainate-Induced Status Epilepticus

Identification of compounds preventing the biochemical changes that underlie the epileptogenesis process is of great importance. We have previously shown that myo-Inositol (MI) daily treatment prevents certain biochemical changes that are triggered by kainic acid (KA)-induced status epilepticus (SE). The aim of the current work was to study the further influence of MI treatment on the biochemical changes of epileptogenesis and focus on changes in the hippocampus and neocortex of rats for the following GABA-A receptor subunits: α1, α4, γ2, and δ. After SE, one group of rats was treated with saline, while the second group was treated with MI. Control groups that were not treated by the convulsant received either saline or MI administration. 28–30 h after the experiment, a decrease in the amount of the α1 subunit was revealed in the hippocampus and MI had no significant influence on it. On the 28th day of the experiment, the amount of α1 was increased in both the KA? and KA + MI-treated groups. The α4 and γ2 subunits were strongly reduced in the hippocampus of KA-treated animals, but MI significantly halted this reduction. The effects of MI on α4 and γ2 subunit changes were significantly different between hippocampus and neocortex. On the twenty-eighth day after SE, a decrease in the amount of α1 was found in the neocortex, but MI treatment had no effect on it. The obtained results indicate that MI treatment interferes with some of the biochemical processes of epileptogenesis.     

Immunomodulatory strategies prevent the development of autoimmune emphysema

Background

The presence of anti-endothelial cell antibodies and pathogenic T cells may reflect an autoimmune component in the pathogenesis of emphysema. Whether immune modulatory strategies can protect against the development of emphysema is not known.

Methods

Sprague Dawley rats were immunized with human umbilical vein endothelial cells (HUVEC) to induce autoimmune emphysema and treated with intrathymic HUVEC-injection and pristane. Measurements of alveolar airspace enlargement, cytokine levels, immuno histochemical, western blot analysis, and T cell repertoire of the lung tissue were performed.

Results

The immunomodulatory strategies protected lungs against cell death as demonstrated by reduced numbers of TUNEL and active caspase-3 positive cells and reduced levels of active caspase-3, when compared with lungs from HUVEC-immunized rats. Immunomodulatory strategies also suppressed anti-endothelial antibody production and preserved CNTF, IL-1alpha and VEGF levels. The immune deviation effects of the intrathymic HUVEC-injection were associated with an expansion of CD4+CD25+Foxp3+ regulatory T cells. Pristane treatment decreased the proportion of T cells expressing receptor beta-chain, Vβ16.1 in the lung tissue.

Conclusions

Our data demonstrate that interventions classically employed to induce central T cell tolerance (thymic inoculation of antigen) or to activate innate immune responses (pristane treatment) can prevent the development of autoimmune emphysema.