Cytokine and eosinophil responses in the lung, peripheral blood, and bone marrow compartments in a murine model of allergen-induced airways inflammation

Selective accumulation of eosinophils and activated CD4+ cells is now considered a central event in the pathogenesis of asthma, and this process is thought to be mediated by a number of cytokines including tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), and the Type 2 cytokines interleukin-4 (IL-4) and IL-5. To carry out a detailed time-course analysis of cellular changes in the bronchoalveolar lavage fluid (BAL), peripheral blood (PB), and bone marrow (BM), and of changes in the aforementioned cytokines in BAL and serum, Balb/c mice were sensitized by intraperitoneal injection with ovalbumin (OVA) adsorbed to aluminum hydroxide on two occasions 5 days apart, and were subjected to an OVA aerosol challenge 12 days after the second sensitization. This resulted in an airways inflammatory response characterized by early transient neutrophilia, marked eosinophilia, and, to a lesser extent, lymphocytosis in the BAL. Inflammatory events were first observed 3 h and 24 h after antigen challenge in the lung tissue and BAL, respectively, and lasted for 21 days. In the BM, we detected a 1.5- and 5-fold increase in the total number of cells and eosinophils, respectively, 4 days after the second sensitization. This was followed by a decrease, although BM eosinophilia remained clearly present at the time of antigen challenge. A second eosinopoietic event was observed in the BM shortly after challenge and reached a peak at day 3. BM cellularity returned to normal at day 21 after challenge. Serum OVA-specific IgE was first detected 3 days following the second sensitization (150 ng/ml). IgE levels then decreased but remained at the 75 ng/ml range at the time of the aerosol challenge. During the sensitization period, TNF-alpha (approximately 25 pg/ml), IL-4 (approximately 40 pg/ml), and IL-5 (approximately 250 pg/ml) were detected in serum, but not in the BAL fluid (BALF) and returned to background levels at the time of the antigen challenge. After antigen challenge, TNF-alpha, IL-4, IL-5, and GM-CSF were detected in serum. Peak levels were observed at 3 h (approximately 40 pg/ml), 3 h (approximately 120 pg/ml), 12 h (approximately 350 pg/ml), and 3 h (approximately 10 pg/ml), respectively, and returned to background levels 24 h after challenge. In the BALF, we detected peak levels of TNF-alpha, IL-4, IL-5, and GM-CSF at 6 h (approximately 250 pg/ml), 24 h (approximately 140 pg/ml), 24 h (350 pg/ml), and 3 h (approximately 10 pg/ml), respectively, with a return to background levels 5 days after challenge. No IL-10 could be detected at any time point during sensitization or after challenge in either serum or BAL. We also detected approximately 40 pg/ml of interferon-gamma (IFN-gamma) in the serum of normal untreated mice. Serum IFN-gamma levels fluctuated during sensitization and after challenge, but never exceeded those observed in untreated mice. Thus, the cytokine profile observed in this experimental model of allergic inflammation is characterized by IL-4 and IL-5 dominance, with an apparently minor TNF-alpha and GM-CSF contribution and relatively low or undetectable levels of IFN-gamma and IL-10.

Adenoviral vector-mediated interleukin-10 expression in vivo: intramuscular gene transfer inhibits cytokine responses in endotoxemia

Interleukin-10 (IL-10) is a potent anti-inflammatory/immune cytokine and has received growing attention for its therapeutic potential. To aid therapeutic studies of IL-10 in vivo, a replication-deficient adenoviral vector expressing mouse IL-10 was constructed and characterized. The transgene protein IL-10 was shown to markedly inhibit endotoxin-induced tumor necrosis factor alpha (TNF alpha) production by mouse and rat macrophages in vitro. Intramuscular injection of this vector in mice resulted in efficient expression of transgene mRNA in the muscle and active release of IL-10 protein into the bloodstream. To investigate the therapeutic potential of IL-10 using this vector, endotoxemia was induced by intraperitoneal injection of a sublethal dose of endotoxin. Expression of TNF alpha and IL-6 mRNA in the lung, spleen and heart and the circulating levels of these cytokines markedly increased in endotoxemia. This endotoxin-induced TNF alpha and IL-6 up-regulation was however suppressed in mice expressing IL-10 after intramuscular gene transfer. While cytokine gene expression was inhibited to varying degrees in different organs, a maximal reduction was seen in the lung, thus also indicating the efficacy of systemic IL-10 gene product at multiple tissue sites. Finally, we provided evidence that only when present in abnormally high concentrations in the circulation following intraperitoneal gene delivery, IL-10 by itself had some toxic effects of transient nature, primarily manifested by acute phase reaction and hemostatic disturbance. Thus, our studies demonstrate the usefulness of adenoviral vectors for therapeutic applications of IL-10 in vivo.

Overexpression of granulocyte-macrophage colony-stimulating factor induces pulmonary granulation tissue formation and fibrosis by induction of transforming growth factor-beta 1 and myofibroblast accumulation

We have previously reported that transfer to rat lung of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene leads to high expression of GM-CSF between days 1 and 4 and granulation tissue formation followed by an irreversible fibrotic response starting from day 12 onward. In the current study, we investigated the underlying mechanisms. We found that GM-CSF overexpression did not enhance production of tumor necrosis factor-alpha in a significant manner at any time after GM-CSF gene transfer. However, the content of transforming growth factor-beta 1 in bronchoalveolar lavage fluid was markedly induced at day 4 and appeared to be maximal around day 7 and remained high at day 12. Macrophages purified from bronchoalveolar lavage fluid 7 days after GM-CSF gene transfer spontaneously released significant quantities of transforming growth factor-beta 1 protein in vitro. After peak transforming growth factor-beta 1 production was the emergence of alpha-smooth muscle actin-rich myofibroblasts. Accumulation of these cells was most prominent at day 12 within the granulation tissues and they were still present in fibrotic areas between days 12 and 24 and diminished markedly afterward. Thus, we provide the first in vivo evidence that tumor necrosis factor-alpha may be dissociated from participation in a fibrotic process in the lung and GM-CSF may play a more direct role in pulmonary fibrogenesis at least in part through its capability to induce transforming growth factor-beta 1 in macrophages and the subsequent emergence of myofibroblast phenotypes. This GM-CSF transgene lung model is useful for a stepwise dissection of both cellular and molecular events involved in pulmonary fibrosis.

Overexpression of RANTES using a recombinant adenovirus vector induces the tissue-directed recruitment of monocytes to the lung

RANTES (regulated on activation, normal T cell expressed and secreted) is a member of the C-C superfamily of chemokines and is reported to function as a potent chemoattractant for monocytes, eosinophils, and a subpopulation of CD4+ T cells. Using a recombinant human type 5 adenovirus containing the murine RANTES cDNA (Ad5E3 mRANTES), which is capable of expressing biologically active cytokine upon infection, we initiated a study to characterize the biologic functions of RANTES cytokine in vivo. Intratracheal administration of Ad5E3 mRANTES targeted transient RANTES expression to the bronchial epithelium of the lung in Sprague-Dawley rats. Bronchoalveolar lavage fluids (BAL) collected at 24 h had increased chemotactic activity vs controls as measured in a murine CD4+ T cell Boyden chamber microchemotaxis assay. There was a dramatic increase in the number of cells (macrophage, monocytes, and neutrophils) recovered from BAL samples taken from Ad5E3 mRANTES-treated animals at 24 h, with a >50-fold increase in monocytes, indicating a proinflammatory effect for this cytokine in vivo. This effect on monocytes was transient, decreasing by 7 days, with evidence of increased eosinophils and lymphocytes at this time. Histologic examination of lung sections at 24 h revealed greatly increased numbers of mononuclear cells, primarily monocytes, within the lungs of Ad5E3 mRANTES-treated animals, with increased extravasation of monocytes around blood vessels, indicating an ongoing process of peripheral blood monocyte recruitment. This study provides further evidence for RANTES to be a monocyte chemoattractant in vivo.

Overexpression of RANTES using a recombinant adenovirus vector induces the tissue-directed recruitment of monocytes to the lung

RANTES (regulated on activation, normal T cell expressed and secreted) is a member of the C-C superfamily of chemokines and is reported to function as a potent chemoattractant for monocytes, eosinophils, and a subpopulation of CD4+ T cells. Using a recombinant human type 5 adenovirus containing the murine RANTES cDNA (Ad5E3 mRANTES), which is capable of expressing biologically active cytokine upon infection, we initiated a study to characterize the biologic functions of RANTES cytokine in vivo. Intratracheal administration of Ad5E3 mRANTES targeted transient RANTES expression to the bronchial epithelium of the lung in Sprague-Dawley rats. Bronchoalveolar lavage fluids (BAL) collected at 24 h had increased chemotactic activity vs controls as measured in a murine CD4+ T cell Boyden chamber microchemotaxis assay. There was a dramatic increase in the number of cells (macrophage, monocytes, and neutrophils) recovered from BAL samples taken from Ad5E3 mRANTES-treated animals at 24 h, with a >50-fold increase in monocytes, indicating a proinflammatory effect for this cytokine in vivo. This effect on monocytes was transient, decreasing by 7 days, with evidence of increased eosinophils and lymphocytes at this time. Histologic examination of lung sections at 24 h revealed greatly increased numbers of mononuclear cells, primarily monocytes, within the lungs of Ad5E3 mRANTES-treated animals, with increased extravasation of monocytes around blood vessels, indicating an ongoing process of peripheral blood monocyte recruitment. This study provides further evidence for RANTES to be a monocyte chemoattractant in vivo.

Adenovirus-vector-mediated cytokine gene transfer to lung tissue

In summary, we have been able to demonstrate that adenovirus vectors are valuable tools in examining the roles played by individual cytokines in lung responses and inflammation. These viral vectors have marked trophism for the epithelial cells of the lung and are highly efficient in transferring the genes into these lining cells. This results in significant expression of cytokines both within the lumen and the parenchyma of the lung. As a result of an individual cytokine being overexpressed, there are cytokine-specific changes seen-IL-6 resulting in lymphocytosis, MIP2 resulting in neutrophil accumulation, RANTES resulting in monocyte accumulation, TGF beta resulting in monocytosis but no fibrosis, and GM-CSF most surprisingly resulting in tissue eosinophilia, granuloma formation, and subsequently the onset of fibrosis. These vectors have helped pinpoint the role of a number of the cytokines in inducing chronic inflammatory changes to the lung and imply that a single cytokine may not be the only trigger resulting in chronic changes within the lung parenchyma.

Adenoviral gene transfer of macrophage inflammatory protein-2 in rat lung

Replication-defective adenoviral vectors are capable of localized transfer and expression of incorporated gene product in lung tissue. We have constructed an adenoviral vector that expresses rat macrophage inflammatory protein (MIP)-2, a C-X-C chemokine specifically chemotactic for neutrophils, Supernatants from 293 cells, infected with the adenoviral MIP-2 (ADMIP-2) construct, showed potent chemotactic activity and the ability of the ADMIP-2 vector to transcribe and make functional protein was confirmed. In vivo analysis of bronchoalveolar lavage fluid from rats after intratracheal instillation of ADMIP-2 (10(9) plaque-forming units) showed a 10-fold increase in the absolute number of neutrophils in bronchoalveolar lavage fluid as opposed to rats treated with an equal titer of an E1-disabled control virus expressing firefly luciferase (ADCA-18). Neutrophils constituted 65% of total BAL cells with alveolar macrophages being the other major cell type recovered. Rat MIP-2 protein was increased (nanograms per milliliter) in bronchoalveolar lavage fluid over a period of 7 days in ADMIP-2-treated animals. MIP-2 mRNA was demonstrated by Northern blot analysis in lung tissue, and histological analysis confirmed the presence of massive localized tissue neutrophilia. Evidence of chronic tissue injury and repair (ie, fibrosis) was not detected up to 2 weeks after the neutrophil infiltrate had resolved, subsequent to decreased chemokine presence. Adenoviral gene transfer proved an effective tool for the assessment of lung tissue expression of this chemokine in vivo and is useful in developing rodent models of tissue neutrophilia.

[A study on using rIL-4 and IFN-gamma to regulate IgE synthesis in bronchial asthma patients in vitro]

OBJECTIVE

In order to elucidate the cytokines responsible for altered IgE producing in patients with asthma.

METHODS

The in vitro effects of recombinant interleukin-4 (rIL-4) and interferon-gamma (IFN-gamma) on synthesis of IgE by peripheral blood mononuclear cell (PBMC) were studied.

RESULTS

Spontaneous IgE synthesis by PBMC was significantly increased in patients with asthma compared with the controls (t = 4. 4712, P < 0.001). Although the maximum amounts of IgE synthesis using PBMC after stimulation with rIL-4 were almost the same both in patients with asthma and in controls (t = 0.0620, P > 0.05), the enhancement rate of rIL-4-induced IgE synthesis was lower in asthma tic patients than in the controls (t = 4. 6719, P < 0.005). IFN-gamma suppressed not only spontaneous but also rIL-4-induced IgE synthesis by PBMC in asthmatic patients. The suppressive effect on IgE synthesis was more prominent in patients with asthma than in the controls (t = 7.1833, P < 0.001).

CONCLUSIONS

These results suggest that asthma attacks are related to IgE- dependent trigger mechanism; the imbalance of Il-4 and IFN-gamma in vivo is involved in the development of asthma.

Searching eye movement, smooth pursuit eye movement and schizophrenia

OBJECTIVE

To detect whether the smooth pursuit eye movement (SPEM) and searching eye movement (SEM) could be considered as a biological marker of schizophrenia, and used as a tool in helping diagnosis of schizophrenia.

METHODS

88 schizophrenics, 77 patients with mood disorders, 32 with "neurosis", and 74 normal healthy controls were examined for SPEM and SEM individually. The authors verified the results in all the first-visit 150 outpatients in March 1993 by comparing the examination results with the clinical diagnoses after a 6-month follow-up.

RESULTS

Significant differences were found in the number of eye fixation (NEF) and total eye scanning length (TESL) of SEM between schizophrenics and normal controls or patients with other disorders. Less NEF and shorter TESL could be helpful in differential diagnosis, and the agreement rate, Kappa coefficient was 0.62. No significant differences were found in SPEM in this investigation between non-medicated schizophrenics and normal controls.

CONCLUSION

Searching eye movement (SEM) might be considered as a biological marker of schizophrenia and might be used as a supplementary tool in its diagnosis.

CD40 expression by human peripheral blood eosinophils

In this study, we have investigated CD40 expression in human peripheral blood eosinophils and in human chronically inflamed nasal tissues, i.e., nasal polyps. We show by both reverse transcriptase-PCR and Northern blot analysis that eosinophils from allergic subjects express human CD40 mRNA. We also show that constitutive CD40 mRNA expression in eosinophils could be upregulated by exposure to IgA immune complexes and downregulated by IL-10 and the synthetic steroid budesonide. In addition, we demonstrate that eosinophils express CD40 protein by flow cytometry. Such expression is biologically functional as cross-linking CD40 with CD40 mAbs enhances eosinophil survival in a dose-dependent fashion; in addition, CD40 ligation stimulates eosinophils to release GM-CSF. CD40-mediated eosinophil survival was largely inhibited by an anti-GM-CSF neutralizing antibody suggesting GM-CSF involvement in the survival enhancing mechanism. CD40 mRNA was also detected in total RNA extracted from nasal polyp tissues but not in RNA isolated from normal nasal mucosa (inferior turbinate); by immunohistochemistry, we were able to detect immunoreactive CD40 protein in a variety of cell types in the polyp stroma, but primarily in eosinophils. These observations suggest previously unforeseen interactions between eosinophils and cells expressing the CD40 ligand and, thus, novel pathways by which eosinophils may contribute to the regulation of airway inflammation.

Gene transfer for cytokine functional studies in the lung: the multifunctional role of GM-CSF in pulmonary inflammation

Using adenoviral-mediated gene transfer techniques, the murine granulocyte-macrophage colony-stimulating factor (GM-CSF) transgene is efficiently targeted to and highly expressed by the respiratory epithelium of rat lung. This lung tissue-directed expression of GM-CSF induces accumulation of both eosinophils and macrophages at early stages and an irreversible fibrotic reaction at later stages. These tissue responses to GM-CSF appear to be distinct from those induced by other proinflammatory cytokines, interleukin (IL)-5, IL-6, macrophage inflammatory protein-2 (MIP-2), or RANTES overexpressed in the lung. These findings clearly demonstrate that GM-CSF is more than a hematopoietic cytokine in the lung and may play a pivotal role in the multiple pathological processes underlying numerous respiratory illnesses, including asthma. In this overview, the differences in tissue responses induced by GM-CSF and other individual cytokines are highlighted. In addition, the mechanisms by which GM-CSF and other individual cytokines are highlighted. In addition, the mechanisms by which GM-CSF contributes to the development of eosinophilia, macrophage granuloma, and fibrosis are discussed in conjunction with the recent findings from us and others.

[A study of CD23 expression and regulation in the patients with asthma]

To study the pathogenesis of asthma, we examined the CD23 expression on peripheral blood mononuclear cells (PBMC) from 25 healthy donors and 28 asthmatic patients with APAAP test. The results demonstrated that CD23 antigen expressed strongly on PBMC from patients and their PBMC correlated positively with their IgE level (r = 0.78 P < 0.01). We investigated the regulation of CD23 expression by IL-4 and IFN-gamma in vitro, the results demonstrated that IFN-gamma could inhibit spontaneous and IL-4 induced expression of CD23. It was suggested that the analysis of the percentage of positive CD23 expression is useful for making diagnosis and assessing severity of asthma and is of significance in elucidating the pathogenesis of the asthma.

Transfer of granulocyte-macrophage colony-stimulating factor gene to rat lung induces eosinophilia, monocytosis, and fibrotic reactions

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic cytokine whose expression is increased in numerous respiratory diseases, particularly in asthma. However, the role of GM-CSF in the pathogenesis of these conditions in vivo remains unclear. Here, we report the functional activities of GM-CSF highly expressed in rat lung after intrapulmonary transfer of the gene coding for murine GM-CSF by using an adenoviral vector. This high, transient expression of GM-CSF led to the sustained but self-limiting accumulation of eosinophils and macrophages associated with tissue injury in the lung followed by varying degrees of irreversible fibrotic reactions observed in later stages. These results suggest that GM-CSF plays a previously unrealized role in the development of respiratory conditions characterized by eosinophilia, granuloma and/or fibrosis and provide the rationale for targeting this molecule in these diseases.

[Manufacture of computer-based testing and analyzing system for measuring step-through performance]

The computer-Based Testing and Analysing System for measuring Step-Through (avoiding darkness) performance (CTASS) has been developed. The system is based on the infrared beams which transfer actions of mice inside the boxes into signals of voltage. The signals are fed into the computer through A/D converter to computer for software processing. The functions which have been realized include, but not limited to: signal sampling and data curve displaying; intelligent identification and elimination of jamming signal; auto-calculation of number of errors (No) in all channels, latent period (LP) of entering into the light chamber, total time of mice staying in the light chamber (safty place Tl) and dark chamber (error place Td); hardcopy of screen graphics and resulting output by various printers. The CATSS system was applied to test normal mice and the cognition-deficient mice induced by anisodine, a M-Cholinergic antagonist at a dose of 1-10 mg/kg i.p. The data collected by the system were compared and proved to be consistent with those acquired by manual labour. The system has produced refined and accurate information refined to a maximum extent and guaranteed scientifically sound experimental results. It is foreseable that introducing the computer into pharmacological researches will update and advance their methodology.

Adenovirus vectors for cytokine gene expression

Recombinant Adenovirus type 5 constructs containing IL-6 cDNA can be used to infect cells in vitro and obtain a high level of IL-6 expression and secretion into culture media. Furthermore, Ad5-IL-6 viruses can also be used to infect Balb/c mice or Sprague-Dawley rats and obtain a high level of IL-6 expression that is sustained over a period of 3-5 days. Intratracheal infection was accompanied by dramatic increases in virus-encoded IL-6 mRNA levels in rat lung tissue, raised levels of IL-6 detected in bronchoalveolar lavage fluids and in serum, and IL-6-dependent sequelae such as liver acute phase responses. This occurs in a tissue-specific manner, depending on routes of infection by the virus. Rat lungs showed a prominent expansion (10 fold in numbers) of all classes of lymphocytes, including B cells, T helper cells (CD4+) and CTL (CD8+) at day 7 after infection which resolved significantly by day 12. Thus the associated biological effects of viral vector mediated IL-6 over-expression was also transient in nature. Other tissues can be infected with Ad5 and thus can also be induced to express selected genes in a transient fashion. We are currently examining the potential for Ad recombinant cytokine vectors in therapy for cancer and for bone marrow reconstitution after transplantation. Thus the use of recombinant Ad5 vectors may have a broad application in the study of cytokine function and possibly in future therapy as a transient gene transfer approach.

[The cytotoxicity of malignant pleural effusion lymphocytes and LAK cells against autologous tumor cells]

In malignant pleural effusion, lymphocytes (MPEL) and autologous tumor cells (ATC) were obtained by centrifugation on discontinuous density gradients from 16 patients with malignant pleural effusion. The cytotoxicity of MPEL against ATC were compared with that of peripheral blood lymphocytes (PBL). It was demonstrated that the results for separation with 100%: 60% Ficoll-Hypaque which formed a discontinuous density gradients were the best in three sets of discontinuous density gradients. The cytotoxicity of PBL was higher than that of MPEL (P < 0.001), but the cytotoxicity and expansion of MPEL-activated by rIL2 was much higher than that of PBL-activated by rIL2 (LAK cells) (P < 0.001). This shows that local immune reaction within pleural cavity of patients with malignant pleural effusion was in the state of suppression, but the state could be improved by using rIL2. Therefore, we consider that MPEL could be the better effector cells than LAK cells in tumor adoptive immunotherapy.

Macrophage engulfment of apoptotic neutrophils contributes to the resolution of acute pulmonary inflammation in vivo

For resolution of inflammation to occur, it is necessary both to limit leukocyte influx and to clear now redundant cells from the tissues. Recent evidence from in vitro studies suggests that clearance may be an active process, accomplished in part by macrophage engulfment of intact cells that have undergone programmed cell death or apoptosis. However, the kinetics of these events and their association with the resolution of acute inflammatory responses in vivo remain to be elucidated. To investigate these events, we examined an animal model of acute, limited, neutrophilic pulmonary inflammation. Cells were obtained by bronchoalveolar lavage (BAL) of rats at various time points after intratracheal administration of lipopolysaccharide (LPS). Apoptotic neutrophils were rarely seen in BAL from control animals but were detected after neutrophil influx had occurred in response to LPS challenge. Macrophage engulfment of these cells was identified at light microscopy and confirmed at electron microscopy. The proportion of macrophages that had engulfed apoptotic neutrophils was maximal 24 h after LPS challenge and declined thereafter as total neutrophil numbers fell. During the resolution phase, the alveolar macrophages became positive for peroxidase, indicating the presence of neutrophil granule contents in their cytoplasm. These observations demonstrate that apoptosis of leukocytes indeed occurs during the course of an acute inflammatory response in vivo and that the emergence of apoptotic neutrophils and macrophage engulfment of these cells are temporally correlated with the resolution of acute inflammation.

Antiviral activity of RNA molecules containing self-releasing ribozymes targeted to lymphocytic choriomeningitis virus

Ribozymes catalytically cleave substrate RNA molecules in a sequence-specific manner. Engineered ribozymes can be developed and introduced into tissue culture cells to regulate gene expression and to inhibit viral replication. We have previously reported on the construction of cell lines that constitutively express a single antiviral ribozyme embedded in a lengthy RNA transcript. These cells exhibited a marked reduction in their ability to support viral infection. Here we report the construction of RNA molecules that contain one or two antiviral ribozymes, each specific for a different cleavage site on the genome of the target virus, lymphocytic choriomeningitis virus (LCMV), and each contained in a self-cleavage cassette comprising cis-acting ribozymes designed to release the antiviral molecules from the transcript. In vitro studies showed that both antiviral ribozymes were released properly from the RNAs following cleavage by the flanking ribozymes and that these released ribozymes functioned as expected in cleaving the target virus RNA. These self-cleaving cassettes have been clones into a retroviral vector downstream of, but in the same transcript as, the chloramphenicol acetyltransferase (CAT) gene. Thus, we hoped to employ CAT as a surrogate marker of ribozyme transcription. Stably transformed cell lines were established. Cleavage by the cis-acting ribozymes was incomplete, as assessed by Northern blot analysis and by the ability of transformed cells to produce infectious retroviral particles. Nevertheless, the antiviral ribozyme sequences exerted effects in tissue culture. LCMV RNA levels in ribozyme-expressing cells were suppressed, and infectious virus yields were decreased by up to 95% compared with normal cells and with cells expressing inverted ribozymes. The antiviral effects correlated with CAT levels, but there was no significant difference between cell lines expressing a single ribozymes and those expressing two.

Adenovirus-mediated cytokine gene transfer at tissue sites. Overexpression of IL-6 induces lymphocytic hyperplasia in the lung

The biologic function of cytokines may be best studied in the context of a defined tissue site. To establish a model for studying the function of IL-6 at local tissue sites, we targeted the IL-6 transgene into the bronchial epithelium in the lung of Sprague-Dawley rats by intratracheal administration of a recombinant human type 5 adenovirus with rat IL-6 cDNA incorporated into the E3 region of the viral genome. This approach led to a highly compartmentalized overexpression of the IL-6 transgene and production of bioactive protein within the lung for about 7 days post-infection. Associated with this overexpression of IL-6 was the development of profound local lymphocytic hyperplasia around day 7, characterized by the dramatic expansion of bronchial associated lymphoid aggregates and massive lymphocytic infiltration in the pulmonary parenchyma. Concurrently, there were strikingly increased numbers of lymphocytes in bronchoalveolar lavage fluids. The majority of these lymphocytes were found to be CD3+CD8+ cytotoxic T and CD3+CD4+ helper T cells with the remaining being primarily a small number of CD45R+ B cells. In addition, there was moderate bronchial and alveolar epithelial hyperplasia associated with lymphocytic hyperplasia. However, all of these changes subsided concomitant with the decrease in IL-6 expression and the lung seemed normal at 12 to 14 days post-infection. Thus, our study provides a tissue-specific transient transgene model for investigating cytokine functions in vivo and demonstrates that IL-6 has a profound stimulatory effect on the local lymphoid tissue in the lung.

Adenovirus-mediated cytokine gene transfer at tissue sites. Overexpression of IL-6 induces lymphocytic hyperplasia in the lung

The biologic function of cytokines may be best studied in the context of a defined tissue site. To establish a model for studying the function of IL-6 at local tissue sites, we targeted the IL-6 transgene into the bronchial epithelium in the lung of Sprague-Dawley rats by intratracheal administration of a recombinant human type 5 adenovirus with rat IL-6 cDNA incorporated into the E3 region of the viral genome. This approach led to a highly compartmentalized overexpression of the IL-6 transgene and production of bioactive protein within the lung for about 7 days post-infection. Associated with this overexpression of IL-6 was the development of profound local lymphocytic hyperplasia around day 7, characterized by the dramatic expansion of bronchial associated lymphoid aggregates and massive lymphocytic infiltration in the pulmonary parenchyma. Concurrently, there were strikingly increased numbers of lymphocytes in bronchoalveolar lavage fluids. The majority of these lymphocytes were found to be CD3+CD8+ cytotoxic T and CD3+CD4+ helper T cells with the remaining being primarily a small number of CD45R+ B cells. In addition, there was moderate bronchial and alveolar epithelial hyperplasia associated with lymphocytic hyperplasia. However, all of these changes subsided concomitant with the decrease in IL-6 expression and the lung seemed normal at 12 to 14 days post-infection. Thus, our study provides a tissue-specific transient transgene model for investigating cytokine functions in vivo and demonstrates that IL-6 has a profound stimulatory effect on the local lymphoid tissue in the lung.

Interleukin 10 inhibits lipopolysaccharide-induced survival and cytokine production by human peripheral blood eosinophils

In this study we have investigated the effects of interleukin 10 (IL-10) on human peripheral blood eosinophils stimulated with granulocyte/macrophage colony stimulating factor (GM-CSF) and lipopolysaccharide (LPS). We show that LPS was able to enhance eosinophil survival in a dose-dependent manner, as well as release of the cytokines GM-CSF, tumor necrosis factor alpha, and IL-8. LPS-induced eosinophil survival was largely inhibited by an anti-GM-CSF neutralizing antibody and completely blocked by polymyxin B, suggesting GM-CSF involvement in the survival enhancing mechanism and LPS specificity, respectively. IL-10 significantly inhibited survival of, and cytokine production from, eosinophils induced by LPS, but did not inhibit the survival induced by GM-CSF. These observations suggest a novel activation mechanism of eosinophils and, also, that IL-10 may participate in the regulation of diseases characterized by eosinophil infiltration.

A role for CD4+ T cells in the pathogenesis of skin fibrosis in tight skin mice

The tight skin (Tsk/+) mouse represents a murine model of heritable fibrosis with some similarities to the skin fibrosis seen in human scleroderma. Tsk/+ animals display alterations in connective tissue in some internal organs. Skin fibrosis can be adoptively transferred to normal recipients with Tsk/+ bone marrow or spleen cells and older Tsk/+ animals develop autoantibodies against topoisomerase suggesting that some of the pathogenesis in the Tsk/+ mouse may be mediated by autoimmunity. To determine the role of T cell subsets in the pathogenesis of fibrotic disease, Tsk/+ mice were bred with CD4- and CD8-deficient (CD4-/- and CD8-/-) mice. Tsk/+ CD4-/- mice showed a marked reduction in skin fibrosis as well as decreased cellularity and only mild collagen disorganization as compared to Tsk/+ CD4+ CD8+ control mice yet did not differ from Tsk controls in the level of serum anti-topoisomerase activity. In contrast, Tsk/+ CD8-/- mice exhibited the same histology in the skin as Tsk/+ controls yet had significantly reduced levels of serum anti-topoisomerase activity. Lung pathology, i.e. emphysema, was unaffected by both the CD4 or CD8 mutations. These data show that only some of the pathological effects of the Tsk mutation are T cell dependent and that different T cell subsets affect different parameters in this multi-organ model of fibrotic disease.

Direct interaction of v-Src with the focal adhesion kinase mediated by the Src SH2 domain

The recently described focal adhesion kinase (FAK) has been implicated in signal transduction pathways initiated by cell adhesion receptor integrins and by neuropeptide growth factors. To examine the mechanisms by which FAK relays signals from the membrane to the cell interior, we carried out a series of experiments to detect potential FAK interactions with proteins containing Src homology 2 (SH2) domains that are important intracellular signaling molecules. Using v-Src-transformed NIH3T3 cells, we showed that FAK was present in the immune-complex precipitated by anti-Src antibody, suggesting potential interaction of FAK with v-Src in vivo. We also showed potentially direct interaction of FAK with v-Src in vivo using the yeast two-hybrid system. Using recombinant FAK expressed in insect cells and bacterial fusion proteins containing Src SH2 domains, we showed direct binding of FAK to the Src SH2 domain but not to the SH3 domain in vitro. A kinase-defective mutant of FAK, which is not autophosphorylated, did not interact with the Src SH2 domain under the same conditions, suggesting the involvement of the FAK autophosphorylation sites. Treatment of FAK with a protein-tyrosine phosphatase decreased its binding to the Src SH2 domain, whereas autophosphorylation in vitro increased its binding. These results confirm the importance of FAK autophosphorylation sites in its interaction with SH2 domain-containing proteins. Taken together, these results suggest that FAK may mediate signal transduction events initiated on the cell surface by kinase activation and autophosphorylation that result in its binding to other key intracellular signaling molecules.

Cytokine expression by neutrophils and macrophages in vivo: endotoxin induces tumor necrosis factor-alpha, macrophage inflammatory protein-2, interleukin-1 beta, and interleukin-6 but not RANTES or transforming growth factor-beta 1 mRNA expression in acute lung inflammation

Using a rat model of acute lung inflammation induced by intratracheal instillation of lipopolysaccharide (LPS), we investigated the kinetics of mRNA expression and the potential cellular sources of tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2), interleukin (IL)-1 beta, IL-6, RANTES, and transforming growth factor-beta 1 (TGF-beta 1). By Northern blot analysis, TNF-alpha and MIP-2 mRNAs in total lung tissue increased markedly by 30 min and peaked by 1 h after LPS exposure, whereas expression of IL-1 beta and IL-6 was not detected until 1 h and peaked within 6 h. In contrast, neither RANTES nor TGF-beta 1 mRNA was induced by LPS throughout 72 h, although a basal expression was detected in both saline- and LPS-treated lung tissues. At 1 h after LPS, the bronchoalveolar lavage (BAL) fluid contained about 98% alveolar macrophages (AM), whereas by 6 or 12 h, 88% of BAL cells were polymorphonuclear neutrophils (PMN). Upon extraction of total RNA after separation of AM from PMN in BAL, Northern analysis showed that at 1 h, AM expressed pronounced signals for TNF-alpha, MIP-2, IL-1 beta, and IL-6. At 6 and 12 h, however, while cytokine transcripts decreased in AM, PMN exhibited strong signals for these cytokines. A low basal noninducible signal for TGF-beta 1 but not RANTES was detected in both AM and PMN. Finally, by in situ hybridization techniques, PMN in the lung tissue, particularly those located in the vicinity of the bronchiole and vasculature, were demonstrated to localize MIP-2 mRNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Preliminary observation of the thymus as a privileged site for parathyroid gland allotransplantation in rats

Twenty Wistar rats were divided into two groups. In the control group parathyroid allografts were transplanted into the kidney subcapsule. In the experimental group parathyroid allografts were transplanted into the thymus. The results showed a statistically significant difference in mean allograft survival times between the two groups.

Polymorphonuclear leukocytes as a significant source of tumor necrosis factor-alpha in endotoxin-challenged lung tissue

The kinetic expression and potential cellular source of tumor necrosis factor-alpha (TNF-alpha) in lipopolysaccharide-(LPS) induced acute lung inflammation was investigated using a rat model by Northern blot analysis, in situ hybridization and immunohistochemistry. LPS induced a polymorphonuclear leukocyte infiltrate in the lung that peaked between 6 and 24 hours. TNF-alpha messenger (m)RNA was strongly induced by LPS in whole lung tissues shown by Northern analysis. Both alveolar macrophages and polymorphonuclear leukocytes (PMNs), purified from bronchoalveolar lavage fluids of LPS-treated rats, were shown to express TNF-alpha mRNA by Northern analysis. However, PMNs displayed several times more TNF-alpha mRNA, relative to actin mRNA, than alveolar macrophages at 6 and 12 hours. By in situ hybridization, most of the cells positive for TNF-alpha mRNA at 6 and 12 hours seemed to be PMNs located within the tissue near bronchioles or vessels. By immunohistochemistry, TNF-alpha protein was localized mainly to alveolar macrophages at early times (1 to 3 hours) after LPS challenge, and thereafter, PMNs seemed to be the predominant source of TNF-alpha protein as more than 90% of total intraalveolar positive cells at 6 and 12 hours were PMN. Thus, our data provide the first in vivo evidence that PMNs can serve as a significant source of TNF-alpha at sites of acute inflammation.

Lipopolysaccharide induces expression of granulocyte/macrophage colony-stimulating factor, interleukin-8, and interleukin-6 in human nasal, but not lung, fibroblasts: evidence for heterogeneity within the respiratory tract

Fibroblasts play an indirect augmenting effector role in the inflammatory response by releasing growth and differentiation factors and other inflammatory mediators after activation by inflammatory cytokines such as interleukin (IL)-1, but whether direct activation occurs by exogenous agents such as endotoxin (lipopolysaccharide, LPS) remains controversial. Using a number of primary human airways tissue-derived fibroblast lines, we demonstrate that in contrast to IL-1 alpha, LPS significantly induced gene expression and production of granulocyte/macrophage colony-stimulating factor (GM-CSF), IL-8, and IL-6 only in nasal but not bronchial or lung tissue-derived fibroblasts. Enhanced expression was dose- and time-dependent, and the minimal stimulatory dose was 10 ng LPS/ml. Polymyxin B entirely abrogated increased cytokine expression by LPS. Actinomycin D treatment largely inhibited expression, and LPS markedly increased an IL-6 gene promoter-driven luciferase reporter response in transfected nasal fibroblasts, suggesting enhanced expression may involve transcriptional regulation. Secondary protein or IL-1 synthesis requirement seemed unlikely since cycloheximide superinduced LPS-stimulated cytokine expression and anti-IL-1 alpha/beta antibodies failed to abrogate the response. Thus our data show that GM-CSF, IL-8, and IL-6 are directly inducible in nasal fibroblasts by LPS, and establish heterogeneous responsiveness to LPS by different fibroblast populations in the airways.

An anti-lymphocytic choriomeningitis virus ribozyme expressed in tissue culture cells diminishes viral RNA levels and leads to a reduction in infectious virus yield

Ribozymes, RNA molecules which cleave RNA in a sequence-specific manner, are a promising tool in the development of specific antiviral therapies. The viruses most susceptible to ribozymes may be those in which all aspects of the viral life cycle depend on RNA, with no DNA intermediate. Consequently, we have chosen as a model one such virus, the arenavirus lymphocytic choriomeningitis virus (LCMV), and have previously reported the design of specific anti-LCMV ribozymes (Z. Xing and J. L. Whitton, J. Virol. 66:1361-1369, 1992). Here we describe the establishment of several cell lines, each stably expressing an antiarenaviral ribozyme of different specificity. Expression of a single ribozyme leads to a reduction in LCMV RNA levels, and stimulation of ribozyme transcription amplifies the effect. Target site selection may be an important determinant of antiviral effectiveness, since the extent of the antiviral effect, measured by assay of viral RNA, varies with the specificity of the antiviral ribozyme expressed. Furthermore, infectious virus production is reduced approximately 100-fold. This effect is LCMV specific, as yield of a related arenavirus is not similarly curtailed. We are currently investigating the mechanism underlying the ribozyme-mediated antiviral effect.

Intra-hepatic-arterial infusion of misonidazole--an experimental study of regional radiosensitisation by intraarterial embolisation

The purpose of this study was to generate a selective radiosensitising effect by the intra-hepatic-arterial infusion of misonidazole (MISO). MISO (10 mg) was infused after transcatheter hepatic-arterial embolisation into the livers of rabbits bearing VX2 liver cancer. This procedure was followed by 15 Gy electron irradiation. Evaluation of tumour volume and histological examination was carried out on the 7th day after treatment. The greatest tumour response was obtained in the group which received MISO followed by radiation and was characterised by extensive fibrosis around the tumour and nearly complete tumour necrosis. Liver cell regeneration was also noted in adjacent liver tissue. The advantages of regional infusion of MISO following hepatic-arterial embolisation are: (1) Selectivity increased radiosensitivity of liver cancer alongside very low drug concentration in the plasma. (2) Reduced or absent deleterious side effects of MISO with higher tumour/normal tissue ratios of drug concentration. (3) Reduced cost due to the lower dosage of MISO required for regional infusion.

IL-1 beta and IL-6 gene expression in alveolar macrophages: modulation by extracellular matrices

Interleukin-1 (IL-1) and interleukin-6 (IL-6) are two cytokines involved in a variety of host inflammatory reactions. The alveolar macrophage (AM), a predominant cell source for IL-1 and IL-6, exists in a microenvironment in which there are abundant extracellular matrix (ECM) components, and it is likely that ECM may participate in the inflammatory response in the lung by modulating the effector activities of AMs. To investigate this hypothesis, we cultured rat AMs on different substrates including plastic, collagen, and airways fibroblast-derived ECM (fECM) and assessed IL-1 beta and IL-6 gene expression in these cells. Our study demonstrates that cytokine gene expression in AMs is affected by the conditions of culture. IL-1 gene expression is stimulated by adherence to plastic and exposure to endotoxin, whereas IL-6 mRNA is detectable only in the cells stimulated by endotoxin. Coating the plastic with collagen or fECM modifies cytokine gene expression. At early time points, collagen enhances gene expression. At later times (5 days), actin and cytokine gene expression are predominantly maintained in the endotoxin-stimulated cells cultured on fECM. These findings suggest an extracellular environment-directed mechanism of regulation of cytokine expression in alveolar macrophages.

Ribozymes which cleave arenavirus RNAs: identification of susceptible target sites and inhibition by target site secondary structure

The development of safe and effective antiviral agents has been a slow process, largely because of the difficulty in distinguishing between virus and host functions; materials toxic to the virus are frequently harmful also to the host in which the agent resides. Recently, techniques which target nucleic acid sequences as a means of reducing gene expression have emerged. This antisense armamentarium includes ribozymes, RNA enzymes which cleave other RNA molecules in a sequence-specific manner. We wish to assess the ability of ribozymes to control animal virus infection. Reasoning that the viruses most vulnerable to ribozyme intervention will be those whose complete life cycle is based on RNA (with no DNA stage), we have begun to develop ribozymes directed toward lymphocytic choriomeningitis virus (LCMV), the prototype of the arenavirus family. Using ribozymes of the hammerhead variety, we have identified several sites on the LCMV genome which can be efficiently cleaved in trans. The efficiency of cleavage is site dependent, and we demonstrate that secondary structure at the target site can abolish ribozyme cleavage. Computer-assisted analysis indicates that much of the LCMV genome may be involved in base pairing, which may render it similarly resistant to ribozyme attack. The few remaining open regions of LCMV lack a GUC target site, on which most studies to date have relied. Here we show that AUC, CUC, and AUU are alternative sites which can be cleaved by trans-acting ribozymes. This finding is important given the aforementioned restriction of available sites, imposed by secondary structure.

Human upper airway structural cell-derived cytokines support human peripheral blood monocyte survival: a potential mechanism for monocyte/macrophage accumulation in the tissue

A central feature of chronic airway inflammation is accumulation of monocyte/macrophages in the tissue. It is well known that circulating monocytes are short-lived cells whereas tissue macrophages are longer-lived cells. One mechanism that may account for accumulation of inflammatory cells includes enhanced survival and/or differentiation of these cells. Recent studies imply that signals released by tissue structural cells may be crucial in these events. To investigate this notion, human blood monocytes were cultured with either culture medium alone as a control, human nasal epithelial cell-conditioned medium (EpCM), or fibroblast-conditioned medium (FCM) for more than 1 wk. Survival of monocytes in medium alone was 17% at day 7, whereas survival of those cultured with 50% of EpCM or FCM was 62% and 64%, respectively. The effect of EpCM and FCM was dose dependent. Preincubation of either conditioned medium (CM) with an antibody against granulocyte/macrophage colony-stimulating factor (GM-CSF) or an antibody against macrophage colony-stimulating factor (M-CSF) resulted in a partial abrogation of the survival-enhancing effect, to an average of 50% and 30%, respectively. Complete inhibition was obtained by preincubation of the CM with a combination of both antibodies. The effect of CM represented true survival because CM only induced a low profile of [3H]thymidine incorporation and, furthermore, less than 0.3% of the cells cultured with CM underwent DNA synthesis as assessed by autoradiography. In addition, ultrastructural observations demonstrated that most monocytes cultured with either CM but not with control culture medium assumed ultrastructural features of macrophages by day 8 of culture.(ABSTRACT TRUNCATED AT 250 WORDS)

[The preparation of highly purified insulin and its clinical use. Insulin Cooperative Study Group]

Antigenicity of insulin preparations is obviously related to their purity. The average contents of proinsulin, glucagon and pancreatic polypeptide in highly purified insulin (HP-I) produced by us are 76.0, 2.11 and 0.11 ppm respectively. These results are superior to those for domestic conventional crystalline insulin and single peak insulin (SP-I). The antibodies to insulin, proinsulin and pancreatic polypeptide in serum were examined in 24 diabetic patients treated with HP-I for more than 6 months. The positive rates for the above three antibodies were 37.5%, 0% and 0% respectively. The results showed that the antigenicity of HP-I was much lower than that of domestic conventional crystalline insulin and almost the same as that of MC-I from Nordisk, Denmark.