Resveratrol-mediated gamma interferon reduction prevents airway inflammation and airway hyperresponsiveness in respiratory syncytial virus-infected immunocompromised mice

Respiratory syncytial virus (RSV) is the most important cause of severe, lower respiratory tract infections in infants, and RSV infections have been associated with chronic wheezing and asthma during childhood. However, the mechanism of RSV-induced airway inflammation and airway hyperresponsiveness (AHR) is poorly understood. Furthermore, there are presently neither effective vaccines nor drugs available for the prevention or treatment of RSV infections. In this study, we investigated the effect of the plant extract resveratrol as a means of preventing airway inflammation and attenuating RSV-induced AHR. Our data showed that resveratrol reduced RSV lung titers and the number of infiltrating lymphocytes present in bronchoalveolar lavage fluid (BALF) and reduced inflammation. Furthermore, resveratrol attenuated airway responses to methacholine following RSV infection and significantly decreased gamma interferon (IFN-γ) levels in BALF of RSV-infected mice. Data presented in this report demonstrated that resveratrol controlled Toll-like receptor 3 (TLR3) expression, inhibited the TRIF signaling pathway, and induced M2 receptor expression following RSV infection. These data support a role for the use of resveratrol as a means of reducing IFN-γ levels associated with RSV-mediated airway inflammation and AHR, which may be mediated via TLR3 signaling.     

Recurrent respiratory syncytial virus infections in allergen-sensitized mice lead to persistent airway inflammation and hyperresponsiveness

Respiratory syncytial virus (RSV) infection is considered a risk factor for bronchial asthma; however, the synergy between allergen sensitization and RSV infection in the development of pulmonary inflammation and asthma has been controversial. In this study the effects of primary and recurrent RSV infection on allergic asthma were examined in a group of control, RSV-infected, Dermatophagoides farinae (Df) allergen-sensitized, and Df allergen-sensitized plus RSV-infected BALB/c mice. Primary RSV infection in Df-sensitized mice transiently increases airway responsiveness, which is accompanied by increases in eosinophilic infiltration, the expression of ICAM-1, and macrophage inflammatory protein-1alpha (MIP-1alpha) in the lung tissue. A secondary RSV infection persistently enhances airway responsiveness in Df-sensitized mice, with a concomitant increase in MIP-1alpha and RSV Ag load in lung tissues. Bulk cultures of thoracic lymph node mononuclear cells demonstrate that acute RSV infection augments both Th1- and Th2-like cytokines, whereas secondary and tertiary infections shift the cytokine profile in favor of the Th2-like cytokine response in Df-sensitized mice. The elevated total serum IgE level in the Df-sensitized mice persists following only RSV reinfection. Thus, recurrent RSV infections in Df-sensitized mice augment the synthesis of Th2-like cytokines, total serum IgE Abs, and MIP-1alpha, which are responsible for persistent airway inflammation and hyperresponsiveness, both of which are characteristics of asthma.     

Respiratory syncytial virus predisposes mice to augmented allergic airway responses via IL-13-mediated mechanisms.

The development of severe childhood asthma may be influenced by several factors including environmental and infectious stimuli. The causal relationship between infectious viral responses, such as respiratory syncytial virus (RSV), and severe asthma during early childhood is unclear. In these studies, the ability for an initial RSV infection to exacerbate and promote a more severe asthmatic-type response was investigated by combining established murine models of disease. We examined the ability of RSV to induce exacerbation of allergic disease over a relatively long period, leading to development of severe airway responses including airway inflammation and hyperreactivity. The preferential production of IL-13 during a primary RSV infection appears to play a critical role for the exacerbation of cockroach allergen-induced disease. The depletion of IL-13 during RSV infections inhibited the exacerbation and acceleration of severe allergen-induced airway hyperreactivity. This was indicated by decreases in airway hyperreactivity and changes in lung chemokine production. These data suggest that the airway responses during asthma can be greatly affected by a previous RSV infection, even when infection occurs before allergen sensitization. Overall, infection of the airways with RSV can induce an IL-13-dependent change in airway function and promotes an environment that contributes to the development of severe allergic asthmatic responses.     

Sustained Protein Kinase D Activation Mediates Respiratory Syncytial Virus-Induced Airway Barrier Disruption

Understanding the regulation of airway epithelial barrier function is a new frontier in asthma and respiratory viral infections. Despite recent progress, little is known about how respiratory syncytial virus (RSV) acts at mucosal sites, and very little is known about its ability to influence airway epithelial barrier function. Here, we studied the effect of RSV infection on the airway epithelial barrier using model epithelia. 16HBE14o- bronchial epithelial cells were grown on Transwell inserts and infected with RSV strain A2. We analyzed (i) epithelial apical junction complex (AJC) function, measuring transepithelial electrical resistance (TEER) and permeability to fluorescein isothiocyanate (FITC)-conjugated dextran, and (ii) AJC structure using immunofluorescent staining. Cells were pretreated or not with protein kinase D (PKD) inhibitors. UV-irradiated RSV served as a negative control. RSV infection led to a significant reduction in TEER and increase in permeability. Additionally it caused disruption of the AJC and remodeling of the apical actin cytoskeleton. Pretreatment with two structurally unrelated PKD inhibitors markedly attenuated RSV-induced effects. RSV induced phosphorylation of the actin binding protein cortactin in a PKD-dependent manner. UV-inactivated RSV had no effect on AJC function or structure. Our results suggest that RSV-induced airway epithelial barrier disruption involves PKD-dependent actin cytoskeletal remodeling, possibly dependent on cortactin activation. Defining the mechanisms by which RSV disrupts epithelial structure and function should enhance our understanding of the association between respiratory viral infections, airway inflammation, and allergen sensitization. Impaired barrier function may open a potential new therapeutic target for RSV-mediated lung diseases.     

Mixed infection and clonal representativeness of a single sputum sample in tuberculosis patients from a penitentiary hospital in Georgia

Background

Respiratory syncytial virus (RSV) is the most common cause of acute bronchiolitis in infants and the elderly. Furthermore, epidemiological data suggest that RSV infection during infancy is a potent trigger of subsequent wheeze and asthma development. However, the mechanism by which RSV contributes to asthma is complex and remains largely unknown. A recent study indicates that the age of initial RSV infection is a key factor in determining airway response to RSV rechallenge. We hypothesized that severe RSV infection during neonatal development significantly alters lung structure and the pulmonary immune micro-environment; and thus, neonatal RSV infection is crucial in the development of or predisposition to allergic inflammatory diseases such as asthma.

Methods

To investigate this hypothesis the present study was conducted in a neonatal mouse model of RSV-induced pulmonary inflammation and airway dysfunction. Seven-day-old mice were infected with RSV (2 × 10⁵ TCID₅₀/g body weight) and allowed to mature to adulthood. To determine if neonatal RSV infection predisposed adult animals to enhanced pathophysiological responses to allergens, these mice were then sensitized and challenged with ovalbumin. Various endpoints including lung function, histopathology, cytokine production, and cellularity in bronchoalveolar lavage were examined.

Results

RSV infection in neonates alone led to inflammatory airway disease characterized by airway hyperreactivity, peribronchial and perivascular inflammation, and subepithelial fibrosis in adults. If early RSV infection was followed by allergen exposure, this pulmonary phenotype was exacerbated. The initial response to neonatal RSV infection resulted in increased TNF-α levels in bronchoalveolar lavage. Interestingly, increased levels of IL-13 and mucus hyperproduction were observed almost three months after the initial infection with RSV.

Conclusion

Neonatal RSV exposure results in long term pulmonary inflammation and exacerbates allergic airways disease. The early increase in TNF-α in the bronchoalveolar lavage implicates this inflammatory cytokine in orchestrating these events. Finally, the data presented emphasize IL-13 and TNF-α as potential therapeutic targets for treating RSV induced-asthma.     

Respiratory Syncytial Virus Reverses Airway Hyperresponsiveness to Methacholine in Ovalbumin-Sensitized Mice

Each year, approximately 20% of asthmatics in the United States experience acute symptom exacerbations, which commonly result from pulmonary viral infections. The majority of asthma exacerbations in very young children follow infection with respiratory syncytial virus (RSV). However, pathogenic mechanisms underlying induction of asthma exacerbations by RSV are not well understood. We therefore investigated the effect of post-sensitization RSV infection on lung function in ovalbumin (OVA)-sensitized BALB/c mice as a model of RSV asthma exacerbations. OVA sensitization of uninfected female BALB/c mice increased bronchoalveolar lavage fluid (BALF) eosinophil levels and induced airway hyperresponsiveness to the muscarinic agonist methacholine, as measured by the forced-oscillation technique. In contrast, intranasal infection with replication-competent RSV strain A2 for 2–8 days reduced BALF eosinophil counts and reversed airway hyperresponsiveness in a pertussis toxin-sensitive manner. BALF levels of the chemokine keratinocyte cytokine (KC; a murine homolog of interleukin-8) were elevated in OVA-sensitized, RSV-infected mice and reversal of methacholine hyperresponsiveness in these animals was rapidly inhibited by KC neutralization. Hyporesponsiveness could be induced in OVA-sensitized, uninfected mice by recombinant KC or the Gαi agonist melittin. These data suggest that respiratory syncytial virus induces KC-mediated activation of Gαi, resulting in cross-inhibition of Gαq-mediated M₃-muscarinic receptor signaling and reversal of airway hyperresponsiveness. As in unsensitized mice, KC therefore appears to play a significant role in induction of airway dysfunction by respiratory syncytial virus. Hence, interleukin-8 may be a promising therapeutic target to normalize lung function in both asthmatics and non-asthmatics with bronchiolitis. However, the OVA-sensitized, RSV-infected mouse may not be an appropriate model for investigating the pathogenesis of viral asthma exacerbations.     

TH-, NPY-, SP-, and CGRP-immunoreactive nerves in interscapular brown adipose tissue of adult rats acclimated at different temperatures: an immunohistochemical study

Interscapular brown adipose tissue (IBAT), a site of nonshivering thermogenesis in mammals, is neurally controlled. The co-existence of sympathetic and peptidergic innervation has been demonstrated in different brown adipose depots. We studied the morphological profile of IBAT innervation and tested by immunohistochemical methods whether cold and warm stimulation are accompanied by modifications in the density of parenchymal noradrenergic nerve fibers. We also studied the immunoreactivity of afferent fibers—which contain calcitonin gene-related peptide (CGRP) and substance P (SP)<197>in different functional conditions. IBAT was obtained from adult rats (6 weeks old) acclimated at different temperatures (4°, 20°, and 28°C). Tissue activity was evaluated by studying the immunolocalization of uncoupling protein (UCP-1), a specific marker of brown adipose tissue. Noradrenergic and peptidergic innervation were seen to arise from morphologically different nerves. Fibers staining for tyrosine hydroxylase (TH) were thin, unmyelinated hilar nerves, and CGRP- and SP-positive fibers were in thick nerves containing both myelinated and unmyelinated fibers. Under cold stimulation, noradrenergic neurons produce greater amounts of TH, and their axons branch, resulting in increased parenchymal nerve fibers density. Neuropeptide Y (NPY) probably co-localizes with TH in noradrenergic neurons, but only in the perivascular nerve fiber network. The parenchymal distribution of NPY to interlobular arterioles and capillaries suggests that this peptide must have other functions besides that of innervating arteriovenous anastomoses, as hypothesized by other researchers. The different distribution of CGRP and SP suggests the existence of different sensory neuronal populations. The detection of CGRP at the parenchymal level is in line with the hypothesis of a trophic action of this peptide.     

Respiratory syncytial virus induces TLR3 protein and protein kinase R, leading to increased double-stranded RNA responsiveness in airway epithelial cells

Respiratory syncytial virus (RSV) preferentially infects airway epithelial cells, causing bronchiolitis, upper respiratory infections, asthma exacerbations, chronic obstructive pulmonary disease exacerbations, and pneumonia in immunocompromised hosts. A replication intermediate of RSV is dsRNA. This is an important ligand for both the innate immune receptor, TLR3, and protein kinase R (PKR). One known effect of RSV infection is the increased responsiveness of airway epithelial cells to subsequent bacterial ligands (i.e., LPS). In this study, we examined a possible role for RSV infection in increasing amounts and responsiveness of another TLR, TLR3. These studies demonstrate that RSV infection of A549 and human tracheobronchial epithelial cells increases the amounts of TLR3 and PKR in a time-dependent manner. This leads to increased NF-kappaB activity and production of the inflammatory cytokine IL-8 following a later exposure to dsRNA. Importantly, TLR3 was not detected on the cell surface at baseline but was detected on the cell surface after RSV infection. The data demonstrate that RSV, via an effect on TLR3 and PKR, sensitizes airway epithelial cells to subsequent dsRNA exposure. These findings are consistent with the hypothesis that RSV infection sensitizes the airway epithelium to subsequent viral and bacterial exposures by up-regulating TLRs and increasing their membrane localization.     

ITGB4 deficiency induces mucus hypersecretion by upregulating MUC5AC in RSV-infected airway epithelial cells

Respiratory syncytial virus (RSV) infection is the main cause of bronchiolitis in children. Excessive mucus secretion is one of the primary symbols in RSV related lower respiratory tract infections (RSV-related LRTI), which is closely associated with the occurrence and development of asthma in later life. Integrin β4 (ITGB4) is down-regulated in the airway epithelial cells (AECs) of asthma patients which plays a critical role in the pathogenesis of asthma. However, whether ITGB4 is involved in the pathological processes of RSV infection remains unclear. In this study, we found that decreased expression of ITGB4 was negatively correlated with the level of MUC5AC in childhood AECs following RSV infection. Moreover, ITGB4 deficiency led to mucus hypersecretion and MUC5AC overexpression in the small airway of RSV-infected mice. MUC5AC expression was upregulated by ITGB4 in HBE cells through EGFR, ERK and c-Jun pathways. EGFR inhibitors treatment inhibited mucus hypersecretion and MUC5AC overexpression in ITGB4-deficient mice after RSV infection. Together, these results demonstrated that epithelial ITGB4 deficiency induces mucus hypersecretion by upregulating the expression of MUC5AC through EGFR/ERK/c-Jun pathway, which further associated with RSV-related LRTI.     

Alteration of airway neuropeptide expression and development of airway hyperresponsiveness following respiratory syncytial virus infection

The mechanisms by which respiratory syncytial virus (RSV) infection causes airway hyperresponsiveness (AHR) are not fully established. We hypothesized that RSV infection may alter the expression of airway sensory neuropeptides, thereby contributing to the development of altered airway function. BALB/c mice were infected with RSV followed by assessment of airway function, inflammation, and sensory neuropeptide expression. After RSV infection, mice developed significant airway inflammation associated with increased airway resistance to inhaled methacholine and increased tracheal smooth muscle responsiveness to electrical field stimulation. In these animals, substance P expression was markedly increased, whereas calcitonin gene-related peptide (CGRP) expression was decreased in airway tissue. Prophylactic treatment with Sendide, a highly selective antagonist of the neurokinin-1 receptor, or CGRP, but not the CGRP antagonist CGRP(8-37), inhibited the development of airway inflammation and AHR in RSV-infected animals. Therapeutic treatment with CGRP, but not CGRP(8-37) or Sendide, abolished AHR in RSV-infected animals despite increased substance P levels and previously established airway inflammation. These data suggest that RSV-induced airway dysfunction is, at least in part, due to an imbalance in sensory neuropeptide expression in the airways. Restoration of this balance may be beneficial for the treatment of RSV-mediated airway dysfunction.     

Topography and distribution of nerve fibers in the posterior longitudinal ligament of the rat: an immunocytochemical and electron-microscopical study

The distribution and immunocytochemical characterization of nerve fibers and their terminals in the posterior longitudinal ligament of the rat lumbar vertebral column was studied in whole-mount preparations and serial semithin and ultrathin sections. Differences in the localization, distribution pattern and density of peptidergic and catecholaminergic nerve fibers were found in the vertebral and intervertebral regions of the posterior longitudinal ligament. For immunocytochemistry, free floating specimens were incubated with primary antibodies against protein gene product 9.5, substance P, calcitonin gene-related peptide, dopamine-beta-hydroxylase, vasoactive intestinal polypeptide and neuropeptide Y together with the avidin-biotin-peroxidase method. In whole-mount preparations, the neural marker protein gene product 9.5 is immunostained in all unmyelinated nerve fibers in the posterior longitudinal ligament, thus giving a panoramic view of the nerve fiber plexus. The most striking nerve fiber plexus is localized in the intervertebral region. In this region, the posterior longitudinal ligament is rich in capillaries that form a dense plexus within its ventral part and extend to the outer layer of the annulus fibrosus. The peptidergic and catecholaminergic innervation of the posterior longitudinal ligament is discussed in the context of pain syndromes related to the vertebral column and degenerative lumbar spine diseases.     

Innervation of the canine mammary gland: an immunohistochemical study

The distribution of peptidergic nerves in canine mammary tissues was studied by immunohistochemical techniques. In addition, the general and the noradrenergic innervations were demonstrated using protein gene product 9.5 and tyrosine hydroxylase immunoreactivities as markers, respectively. Tissue specimens from the caudal mammary glands were obtained from adult, non-lactating, female dogs. The overall innervation of the mammary gland tissue was sparse and primarily associated with the arterial vasculature. Nerve fibres positive for protein gene product 9.5 were rarely found in the secretory parenchyma. The nipple was not richly innervated, although it displayed a greater amount of nerve fibres than the mammary parenchyma. Nerve fibres supplying nonvascular structures of the nipple expressed immunoreactivity for the sensory neuropeptides calcitonin gene-related peptide, substance P and neuropeptide K, but not for vasoactive intestinal peptide, peptide histidine isoleucine and C-flanking peptide of neuropeptide Y. Somatostatin immunoreactivity was not detected in mammary gland tissue. Our results indicate that the innervation of the canine mammary gland is mainly affiliated with the vasculature and comprises peptidergic nerves which may be involved in the regulation of local blood flow. The presence of sensory neuropeptides in nerves supplying the mammary nipple suggest that these peptides may play a role in the afferent pathway of the milk ejection reflex.     

Changes in the peptidergic innervation in the carotid body of rats chronically exposed to hypercapnic hypoxia: an effect of arterial CO2 tension

The abundance of neuropeptide Y (NPY)-, vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibers in the carotid body was examined in chronically hypercapnic hypoxic rats (10% O2 and 6-7% CO2 for 3 months), and the distribution and abundance of these four peptidergic fibers were compared with those of previously reported hypocapnic- and isocapnic hypoxic carotid bodies to evaluate the effect of arterial CO2 tension. The vasculature in the carotid body of chronically hypercapnic hypoxic rats was found to be enlarged in comparison with that of normoxic control rats, but the rate of vascular enlargement was smaller than that in the previously reported hypocapnic- and isocapnic hypoxic carotid bodies. In the chronically hypercapnic hypoxic carotid body, the density per unit area of parenchymal NPY fibers was significantly increased, and that of VIP fibers was unchanged, although the density of NPY and VIP fibers in the previously reportetd chronically hypocapnic and isocapnic hypoxic carotid bodies was opposite to that in hypercapnic hypoxia as observed in this study. The density of SP and CGRP fibers was decreased. These results along with previous reports suggest that different levels of arterial CO2 tension change the peptidergic innervation in the carotid body during chronically hypoxic exposure, and altered peptidergic innervation of the chronically hypercapnic hypoxic carotid body is one feature of hypoxic adaptation.     

Changes in the immunoreactivity of substance P and calcitonin gene-related peptide in the laryngeal taste buds of chronically hypoxic rats

The distribution of substance P (SP)- and calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibers in the taste buds of the epiglottis and aryepiglottic folds was compared between normoxic control and chronically isocapnic hypoxic rats (10% O2 and 3-4% CO2 for 3 months). In the normoxic laryngeal taste buds, SP- and CGRP-immunoreactive fibers were detected within the taste buds, where they appeared as thin processes with many varicosities. Most CGRP fibers showed coexistence with SP, but a few fibers showed the immunoreactivity of CGRP only. The density of intra- and subgemmal SP and CGRP fibers penetrating into the laryngeal taste buds was significantly higher in chronically hypoxic rats than in normoxic control rats. Water intake in the hypoxic rats was significantly lower than in the normoxic rats. These results indicate that the increased density of SP- and CGRP-containing nerve fibers within the laryngeal taste buds is a predominant feature of hypoxic adaptation. The altered peptidergic innervation and reduced water intake support the hypothesis that the laryngeal taste buds are involved in water reception, and that the water reception may be under the control of peptidergic innervation.     

IkappaB kinase is a critical regulator of chemokine expression and lung inflammation in respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the major etiologic agent of severe epidemic lower respiratory tract infections in infancy. Airway mucosal inflammation plays a critical role in the pathogenesis of RSV disease in both natural and experimental infections. RSV is among the most potent biological stimuli that induce the expression of inflammatory genes, including those encoding chemokines, but the mechanism(s) that controls virus-mediated airway inflammation in vivo has not been fully elucidated. Herein we show that the inoculation of BALB/c mice with RSV results in rapid activation of the multisubunit IkappaB kinase (IKK) in lung tissue. IKK transduces upstream activating signals into the rate-limiting phosphorylation (and proteolytic degradation) of IkappaBalpha, the inhibitory subunit that under normal conditions binds to the nuclear factor (NF)-kappaB complex and keeps it in an inactive cytoplasmic form. Mice treated intranasally with interleukin-10 or with a specific cell-permeable peptide that blocks the association of the catalytic subunit IKKbeta with the regulatory protein NEMO showed a striking reduction of lung NF-kappaB DNA binding activity, chemokine gene expression, and airway inflammation in response to RSV infection. These findings suggest that IKKbeta may be a potential target for the treatment of acute or chronic inflammatory diseases of the lung.     

Incomplete regulation of NF-kappaB by IkappaBalpha during respiratory syncytial virus infection in A549 cells

Respiratory syncytial virus (RSV) infection of airway epithelial cells results in persistent NF-kappaB activation and NF-kappaB-mediated interleukin-8 production. Previous studies in airway epithelial cells demonstrated that tumor necrosis factor alpha (TNF-alpha)-induced NF-kappaB activation is transient due to regulation by IkappaBalpha. However, during RSV infection, IkappaBalpha has only a partial inhibitory effect on NF-kappaB activation. Studies presented here demonstrate that neither increased IkappaBalpha production which occurs as a result of RSV-induced NF-kappaB activation nor inhibition of proteasome-mediated IkappaBalpha degradation results in a reversal of RSV-induced NF-kappaB activation. Thus, while manipulation of IkappaBalpha results in reversal of TNF-alpha-induced NF-kappaB activation, manipulation of IkappaBalpha does not result in a reversal of RSV-induced NF-kappaB activation.     

The role of cytokines and chemokines in severe respiratory syncytial virus infection and subsequent asthma

Respiratory syncytial virus (RSV) is the primary cause of serious lower respiratory tract illness in infants and young children worldwide. The mechanism is largely unknown. RSV stimulates airway epithelial cells and resident leukocytes to release cytokines. Cytokines and chemokines involved in host response to RSV infection are thought to play a central role in the pathogenesis. In addition, RSV infection early in life has been associated with the development of asthma in later childhood. It is likely that the persistence of cytokines and chemokines in fully recovered patients with RSV in the long term can provide a substratum for the development of subsequent asthma. This review describes the genetic factors in cytokines and chemokines associated with severity of RSV disease, cytokines and chemokines synthesis in RSV infection, and the role of these innate immune components in RSV-associated asthma.     

IL-5 and eosinophils are essential for the development of airway hyperresponsiveness following acute respiratory syncytial virus infection

Viral respiratory infections can cause bronchial hyperresponsiveness and exacerbate asthma. In mice, respiratory syncytial virus (RSV) infection, which induces an immune response dominated by IFN-gamma, results in airway hyperresponsiveness (AHR) and eosinophil influx into the airways, both of which are prevented by pretreatment with anti-IL-5 Ab. To delineate the role of IL-5, IL-4, and IFN-gamma in the development of RSV-induced AHR and lung eosinophilia, we tested the ability of mice deficient in each of these cytokines to develop these symptoms of RSV infection. Mice deficient in either IL-5, IL-4, or IFN-gamma were administered infectious RSV intranasally, and 6 days later, airway responsiveness to inhaled methacholine was assessed by barometric body plethysmography, and numbers of lung eosinophils and production of IFN-gamma, IL-4, and IL-5 by mononuclear cells from peribronchial lymph nodes were monitored. RSV infection resulted in airway eosinophilia and AHR in both IL-4- and IFN-gamma-deficient mice, but not in IL-5-deficient mice. Reconstitution of IL-5-deficient mice with IL-5 restored these responses and enhanced the responses in IL-4-deficient mice. Anti-VLA-4 (very late Ag-4) treatment prevented lung eosinophilia and AHR following RSV infection and IL-5 reconstitution. We conclude that in response to RSV, IL-5 is essential for the influx of eosinophils into the lung and that eosinophils in turn are critical for the development of AHR. IFN-gamma and IL-4 are not essential for these responses to RSV infection.     

Cutaneous innervation in man visualized with protein gene product 9.5 (PGP 9.5) antibodies

Summary Using antibodies to the neuronal cytoplasmic protein, protein gene product 9.5 (PGP 9.5) the cutaneous innervation in man was investigated. The distribution of PGP 9.5 immunoreactive nerve fibers was compared with the distribution of nerve fibers immunoreactive to neuron specific enolase, neurofilament proteins, calcitonin gene related peptide, vasoactive intestinal polypeptide and neuropeptide Y. PGP 9.5 immunoreactive nerve fibers were found in the epidermis, dermis, in Meissner's corpuscles, innervating Merkel cells, around blood vessels, sweat glands and hair follicles. Merkel cells were also PGP 9.5 positive. The labelled nerve fibers included sensory and autonomic fibers, visualizing the whole innervation of the human skin. The number of positive fibers and the intensity of the fluorescence was greater with PGP 9.5 antibodies than with any of the other markers included. Thus, PGP 9.5 antibodies may serve as a tool for investigations of cutaneous innervation, reinnervation and nerve regeneration in different clinical conditions.     

Cutaneous innervation in man visualized with protein gene product 9.5 (PGP 9.5) antibodies

Using antibodies to the neuronal cytoplasmic protein, protein gene product 9.5 (PGP 9.5) the cutaneous innervation in man was investigated. The distribution of PGP 9.5 immunoreactive nerve fibers was compared with the distribution of nerve fibers immunoreactive to neuron specific enolase, neurofilament proteins, calcitonin gene related peptide, vasoactive intestinal polypeptide and neuropeptide Y. PGP 9.5 immunoreactive nerve fibers were found in the epidermis, dermis, in Meissner's corpuscles, innervating Merkel cells, around blood vessels, sweat glands and hair follicles. Merkel cells were also PGP 9.5 positive. The labelled nerve fibers included sensory and autonomic fibers, visualizing the whole innervation of the human skin. The number of positive fibers and the intensity of the fluorescence was greater with PGP 9.5 antibodies than with any of the other markers included. Thus, PGP 9.5 antibodies may serve as a tool for investigations of cutaneous innervation, reinnervation and nerve regeneration in different clinical conditions.