Innate immunity in cystic fibrosis lung disease

Chronic lung disease determines the morbidity and mortality of cystic fibrosis (CF) patients. The pulmonary immune response in CF is characterized by an early and non-resolving activation of the innate immune system, which is dysregulated at several levels. Here we provide a comprehensive overview of innate immunity in CF lung disease, involving (i) epithelial dysfunction, (ii) pathogen sensing, (iii) leukocyte recruitment, (iv) phagocyte impairment, (v) mechanisms linking innate and adaptive immunity and (iv) the potential clinical relevance. Dissecting the complex network of innate immune regulation and associated pro-inflammatory cascades in CF lung disease may pave the way for novel immune-targeted therapies in CF and other chronic infective lung diseases.

Ursodeoxycholic acid therapy in cystic fibrosis liver disease--a retrospective long-term follow-up case-control study

BACKGROUND

The prevention and treatment of liver disease associated with cystic fibrosis remain a significant unresolved problem.

AIM

To assess the long-term effects of continuous ursodeoxycholic acid (UDCA) therapy in cystic fibrosis patients with constantly elevated serum liver enzymes.

METHODS

The primary endpoint was the incidence of overt liver disease. Between 1989 and 2005, UDCA treatment was started in 98 subjects from a cohort of 382 cystic fibrosis patients. These subjects were compared with a historic control group of 352 subjects who attended our centre between 1975 and 1989 before UDCA became standard treatment. For the long-term comparison of liver function and lung function tests, a group of 98 matched contemporary cystic fibrosis patients were compared with the 98 subjects treated with UDCA.

RESULTS

Overt liver disease developed in only one of the 382 patients who was treated with UDCA for increased serum liver enzymes compared with nine patients in the historic control group (P < 0.05). Serum liver enzyme levels declined in most patients receiving UDCA treatment during the 17-year follow-up (87/98, P < 0.05). No difference was seen in lung function between subjects with cystic fibrosis-related liver disease and the matched controls.

CONCLUSIONS

Regular and systematic screening for liver involvement enables early introduction of UDCA therapy in affected cystic fibrosis patients, reduces the development of severe liver disease and leads to a significant and persistent improvement in serum liver tests, without impairing long-term pulmonary outcome.

Ursodeoxycholic acid therapy in cystic fibrosis liver disease--a retrospective long-term follow-up case-control study

BACKGROUND

The prevention and treatment of liver disease associated with cystic fibrosis remain a significant unresolved problem.

AIM

To assess the long-term effects of continuous ursodeoxycholic acid (UDCA) therapy in cystic fibrosis patients with constantly elevated serum liver enzymes.

METHODS

The primary endpoint was the incidence of overt liver disease. Between 1989 and 2005, UDCA treatment was started in 98 subjects from a cohort of 382 cystic fibrosis patients. These subjects were compared with a historic control group of 352 subjects who attended our centre between 1975 and 1989 before UDCA became standard treatment. For the long-term comparison of liver function and lung function tests, a group of 98 matched contemporary cystic fibrosis patients were compared with the 98 subjects treated with UDCA.

RESULTS

Overt liver disease developed in only one of the 382 patients who was treated with UDCA for increased serum liver enzymes compared with nine patients in the historic control group (P < 0.05). Serum liver enzyme levels declined in most patients receiving UDCA treatment during the 17-year follow-up (87/98, P < 0.05). No difference was seen in lung function between subjects with cystic fibrosis-related liver disease and the matched controls.

CONCLUSIONS

Regular and systematic screening for liver involvement enables early introduction of UDCA therapy in affected cystic fibrosis patients, reduces the development of severe liver disease and leads to a significant and persistent improvement in serum liver tests, without impairing long-term pulmonary outcome.

Persistent disease and recurrence in differentiated thyroid cancer patients with undetectable postoperative stimulated thyroglobulin level

(131)I is given in differentiated thyroid cancer (DTC) without taking into account thyroglobulin (Tg) levels at the time of ablation, whereas 6-18 months later it is a major criterion for cure. This single-center retrospective study assessed the frequency and risk factors for persistent disease on postablation whole body scan (WBS) and postoperative neck ultrasonography (n-US) and for recurrent disease during the subsequent follow-up, in patients with DTC and undetectable TSH-stimulated Tg level (TSH-Tg) in the absence of Tg antibodies (TgAb) at the time of ablation. Among 1031 patients ablated, 242 (23%) consecutive patients were included. Persistent disease occurred in eight cases (3%) (seven abnormal WBS and one abnormal n-US), all with initial neck lymph node metastases (N1). N1 was a major risk factor for persistent disease. Among 203 patients with normal WBS and a follow-up over 6 months, TSH-Tg 6-18 months after ablation was undetectable in the absence of TgAb in 173 patients, undetectable with TgAb in 1 patient and equal to 1.2  ng/ml in 1 patient. n-US was normal in 152 patients and falsely positive in 3 patients. After a mean follow-up of 4 years, recurrence occurred in two cases (1%), both with aggressive histological variants. The only risk factor for recurrence was an aggressive histological variant (P = 0.03). In conclusion, undetectable postoperative TSH-Tg in the absence of TgAb at the time of ablation is frequent. In these patients, repeating TSH-Tg 6-18 months after ablation is not useful. (131)I ablation could be avoided in the absence of N1 and aggressive histological variant.

The role of matrix metalloproteinases in cystic fibrosis lung disease

Significant airway remodelling is a major component of the increased morbidity and mortality observed in cystic fibrosis (CF) patients. These airways feature ongoing leukocytic inflammation and unrelenting bacterial infection. In contrast to acute bacterial pneumonia, CF infection is not cleared efficiently and the ensuing inflammatory response causes tissue damage. This structural damage is mainly a result of free proteolytic activity released by infiltrated neutrophils and macrophages. Major proteases in this disease are serine and matrix metalloproteases (MMPs). While the role of serine proteases, such as elastase, has been characterised in detail, there is emerging evidence that MMPs could play a key role in the pathogenesis of CF lung disease. This review summarises studies linking MMPs with CF lung disease and discusses the potential value of MMPs as future therapeutic targets in CF and other chronic lung diseases.

Efficient and gentle siRNA delivery by magnetofection

Magnetic force combined with magnetic nanoparticles recently has shown potential for enhancing nucleic acid delivery. Achieving effective siRNA delivery into primary cultured cells is challenging. We compared the utility of magnetofection with lipofection procedures for siRNA delivery to primary and immortalized mammalian fibroblasts. Transfection efficiency and cell viability were analyzed by flow cytometry and effects of gene knockdown were quantified by real-time PCR. Lipofectamine 2000 and magnetofection achieved high transfection efficiencies comparable to similar gene silencing effects of about 80%; the cytotoxic effect of magnetofection, however, was significantly less. Magnetofection is a reliable and gentle alternative method with low cytotoxicity for siRNA delivery into difficult to transfect cells such as mammalian fibroblasts. These features are especially advantageous for functional end point analyses of gene silencing, e.g., on the metabolite level.

Innate immune receptors on neutrophils and their role in chronic lung disease

Neutrophils, the prototypic cells of the innate immune system, are recruited to infected sites to protect the human body from invading pathogens. To accomplish this function, neutrophils sense pathogens and endogenous damage-associated molecules via innate immune receptors, such as Toll-like receptors (TLRs) and other pattern recognition receptors. This defence function is essential for the pulmonary microenvironment where the host is faced with millions of particles and pathogens inhaled daily. Chronic lung diseases, such as cystic fibrosis or chronic obstructive pulmonary disease are characterized by a neutrophil accumulation and chronic bacterial colonization of the airways. Consequently, insights into the role of TLRs on neutrophils in chronic lung diseases are of high relevance for further diagnostic and therapeutic approaches. Here we summarize and discuss recent advances in the expression, regulation and functional role of TLRs on neutrophils in chronic lung diseases.

Inhibition of airway proteases in cystic fibrosis lung disease

Progressive lung disease determines the morbidity and mortality of cystic fibrosis (CF) patients. CF lung disease is characterised by endobronchial inflammation sustained by bacterial infections and an ongoing accumulation of airway neutrophils. Activated or necrotic neutrophils liberate proteases that cause damage to structural, cellular and soluble components of the pulmonary microenvironment. Among various proteases released by airway cells, elastase is considered to play the major role in CF lung disease. Based on this concept, several therapeutic approaches have been developed to inhibit free elastolytic activity, including small synthetic chemical compounds, semi-synthetic inhibitors and natural inhibitors of free elastase. The present review summarises and discusses the pathophysiological rationales, methodological requirements and clinical implications of inhibition of airway proteases in cystic fibrosis lung disease.

Differential effects of BMP-2 and TGF-beta1 on chondrogenic differentiation of adipose derived stem cells

OBJECTIVES

This article addresses the interaction of transforming growth factor beta1 (TGF-beta1) and bone morphogenic protein 2 (BMP-2) during osteo-chondrogenic differentiation of adipose-derived adult stem cells (ASC). TGF-beta1 was expected to modulate the BMP-2-induced effects through transcriptional regulation of Dlx-5, Msx-2 and Runx-2.

MATERIALS AND METHODS

Encapsulated ASC were cultured for 14 days in medium containing TGF-beta1 and/or BMP-2. mRNA expression of the extracellular matrix molecules col2a1, cartilage oligomeric matrix protein, col10a1, alkaline phosphatase (AP) and transcription factors Msx-2, Dlx-5 and Runx-2 was analysed. Release of glycosaminoglycans, collagen types II and X into the extracellular matrix was demonstrated.

RESULTS

BMP-2 and TGF-beta1 induced a chondrogenic phenotype in ASC. Combined growth factor treatment had a synergistic effect on col10a1 and an additive effect on col2a1 mRNA expression. Synthesis of glycosaminoglycans was enhanced by combined growth factor treatment. Addition of TGF-beta1 inhibited BMP-2 induced AP expression and activity and both proteins promoted chondrogenic maturation.

CONCLUSIONS

Prevention of BMP-2-induced osteogenic transdifferentiation by TGF-beta1 seemed not to be mediated by transcriptional regulation of Dlx-5. Due to these findings, simultaneous stimulation of ASC with BMP-2 and TGF-beta1 seemed to be beneficial for complete differentiation of ASC into chondrocytes.

Comparison of serum markers for allergic bronchopulmonary aspergillosis in cystic fibrosis

The diagnosis of allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF) is a challenge. Thymus- and activation-regulated chemokine (TARC) has recently been reported to play a role in ABPA. The aim of this study was to compare the diagnostic value of TARC with that of known serological markers for diagnosis of ABPA in CF patients. The present study longitudinally followed 48 CF patients, of whom 12 had a diagnosis of ABPA according to Nelson's criteria, for 1-8 yrs with repeated measurements of serum total immunoglobulin (Ig)E, specific Aspergillus fumigatus IgE and IgG, specific IgE against recombinant A. fumigatus allergens (rAsp f) 1, 3, 4 and 6, and TARC. Median (interquartile range) TARC levels were 589 (465-673) pg x mL(-1) in ABPA patients and 232 (189-289) pg x mL(-1) in non-ABPA patients. Receiver operating characteristic curves revealed that TARC was superior to the other markers for diagnosis of ABPA. Diagnostic accuracy was greater for TARC (93%) than for total IgE (74%), or rAsp f 4 (75%) or f 6 (79%). The present study indicates that thymus- and activation-regulated chemokine may be useful in the diagnosis of allergic bronchopulmonary aspergillosis in cystic fibrosis patients. However, larger studies are needed before thymus- and activation-regulated chemokine can routinely be used in diagnostic algorithms.

Comparison of cellular functionality of human mesenchymal stromal cells and PBMC

BACKGROUND

Human mesenchymal stromal cells (MSC) and PBMC play significant roles in repair processes following inflammation. Mechanisms of recruitment are still under investigation.

METHODS AND RESULTS

MIP-1alpha induced the chemotactic migration of MSC but not of PBMC. Correlating with this, 7.7% of MSC expressed the chemokine receptor CCR-1, as shown by FACS analysis. In contrast, PBMC did not express CCR-1 or CCR-2 but did express CXCR-4 (81.9%) and CCR-7 (42.2%). Setum induced the chemotaxis of both cell types, and zymosan activation increased the migration of PBMC but not of MSC. Corresponding with this, C5a induced the migration of PBMC but not of MSC. Dose-dependent and -specific adhesion to fibronectin, fibrinogen, collagen type I and collagen type II could be demonstrated for MSC; in contrast, PBMC did not adhere to any of the investigated proteins. Real-time PCR of receptor expression revealed a 12.2-fold higher expression of alphav in MSC compared with PBMC. Incubation of MSC with tumor necrosis factor-alpha (TNFalpha) induced NFkappaB activation and increased the chemotactic response to serum and adhesion to fibronedtin.

DISCUSSION

Chemotaxis and adhesion are crucial and differing cell fundtons of MSC and PBMC.

Surfactant protein A--from genes to human lung diseases

Surfactant associated protein-A (SP-A) is the most abundant pulmonary surfactant protein and belongs to the family of innate host defense proteins termed collectins. Besides pulmonary host defense, SP-A is also involved in the formation of pulmonary surfactant, as it is essential for the structure of tubular myelin. The human SP-A gene locus includes two functional genes, SFTPA1 and SFTPA2 which are expressed independently, and a pseudo gene. The largest amount of SP-A1 proteins assemble to larger molecular complexes, whereas SP-A2 forms mainly dimers and trimers. SP-A polymorphisms play a role in respiratory distress syndrome, allergic bronchopulmonary aspergillosis and idiopathic pulmonary fibrosis. The levels of SP-A are decreased in the lungs of patients with cystic fibrosis, respiratory distress syndrome and further chronic lung diseases. Future areas for clinical research include disease specific SP-A expression pattern and their functional consequences, the differential roles of SP-A1 and SP-A2 in human lung diseases, and therapeutical approaches to correct altered SP-A levels.

8-Isoprostane in nasally exhaled breath condensate in different pediatric lung diseases

OBJECTIVE

Increased levels of 8-isoprostane were found in various human lung diseases suggesting 8-isoprostane as a marker of pulmonary oxidative stress in vivo. The exact role in pediatric lung diseases has not been defined yet. The goal of this study was to clarify the role of 8-isoprostane in nasally exhaled breath condensate as possible marker of oxidative stress in children with different lung diseases.

METHODS

Levels of 8-isoprostane were measured in nasally exhaled breath condensate of 29 cystic fibrosis patients, 19 children with a history of wheezing episodes, 8 infants with acute respiratory tract infection and 53 healthy subjects using a specific enzyme immunoassay.

RESULTS

Levels of 8-isoprostane did neither discriminate between different disease groups nor correlate with lung function in cystic fibrosis patients.

CONCLUSIONS

Levels of 8-isoprostane in nasally exhaled breath condensate do not reflect oxidative stress in children with different lung diseases.

Genetic Diversity and Selection at the Plasmodium vivax Apical Membrane Antigen-1 (PvAMA-1) Locus in a Sri Lankan Population

Plasmodium vivax apical membrane antigen 1 (PvAMA-1) is an important malaria vaccine candidate. We present the first comprehensive analysis of nucleotide diversity across the entire PvAMA-1 gene using a single population sample from Sri Lanka. In contrast to what has been observed at the AMA-1 locus of Plasmodium falciparum, the signature of diversifying selection is seen most strongly in Domain II of PvAMA-1, indicating that the different domains in each species may be subject to varying selective pressures and functional constraints. We also find that recombination plays an important role in generating haplotype diversity at this locus, even in a region of low endemicity such as Sri Lanka. Mapping of diversity and recombination hotspots onto a 3-dimensional structural model of the protein indicates that one surface of the molecule may be particularly likely to bear epitopes for antibody recognition. Regions of this surface that show constrained variability may prove to be promising vaccine targets.

bFGF influences human articular chondrocyte differentiation

BACKGROUND

The possible functional role of basic fibroblast growth factor (bFGF) in regulating the mitotic and metabolic activity of primary human articular chondrocytes was investigated.

METHODS

[EF1]Chondrocytes were enzymatically isolated from femoral head cartilage, and were cultured in vitro in monolayer. bFGF-dependent cell proliferation, production of collagen type II and aggrecan were monitored 10 days after isolation. Furthermore, effect of bFGF on cell cycle, cell morphology, and mRNA expression of integrins and chondrogenic markers determined by real time PCR were analyzed.

RESULTS

bFGF concentrations in supernatants of primary human articular chondrocytes peaked immediately after isolation and then declined. In a dose-dependent manner, bFGF enhanced cell amplification and viability. BFGF induced a decrease in the apoptotic cell population, while the number of proliferating cells remained unchanged. Supplementation of cell culture with bFGF reduced collagen type II mRNA by 49%, but increased expression of the integrin alpha(2) by 70%. bFGF did not significantly regulate the integrins alpha(1), alpha(5), alpha(10), alpha(v) and type I collagen. bFGF reduced the amount of collagen type II by 53%, which was correlated with diminished mRNA production. Monolayer cultured chondrocytes secreted significant amounts of aggrecan that decreased over time. Secretion of this cartilage-specific marker was further reduced by the addition of bFGF.

DISCUSSION

These findings highlight the potential role of bFGF as an endogenous chondrocyte mediator that can enhance cell amplification and regulate cell differentiation.

Recurrent pericarditis in children: elevated cardiac autoantibodies

Recurrent pericarditis is a rare disease in childhood. Nevertheless, it may represent a challenge to the clinician due to its resistance to anti-inflammatory treatment. The initial etiology often remains unclear; specific laboratory parameters predicting the frequency or severity of the recurrences are lacking. We report on four patients with recurrent pericarditis in whom antimyolemmal antibodies (AMLAs) were detected. A prolonged persistence of IgM-type AMLAs was found in three patients: two of them presented with acute inflammation as the initial event and one with 48 recurrences during 5.5 years. The fourth patient showed a fast conversion from IgM to IgG-type AMLAs after a less acute initial presentation and showed 4 mild recurrences during the 48-month follow-up.

CONCLUSION

We were able to detect AMLAs in four children with recurrent pericarditis. This finding may be attributed to an auto-immunological disease following a first, acute event. We propose the detection of AMLAs in all children with unexplained recurrent pericarditis. Pediatric patients with a persistence of IgM-type AMLAs may face frequent recurrences and should be monitored therefore more closely. In addition, medical treatment may be changed in these patients with a slower tapering of the dosage of steroidal and non-steroidal antiinflammatory drugs.

1-Antitrypsin inhalation reduces airway inflammation in cystic fibrosis patients

The airways of cystic fibrosis (CF) patients are characterised by neutrophils that release high amounts of elastase overwhelming the local antiprotease shield. Inhalation of alpha(1)-antitrypsin (AAT) may restore the protease-antiprotease balance and attenuate airway inflammation in CF airways. The aims of the present study were: 1) to assess the best deposition region for inhaled AAT by two different inhalation strategies; and 2) to examine the effect of 4 weeks of AAT inhalation on lung function, protease-antiprotease balance and airway inflammation in CF patients. In a prospective, randomised study, 52 CF patients received a daily deposition by inhalation of 25 mg AAT for 4 weeks targeting their peripheral or bronchial compartment. The levels of elastase activity, AAT, pro-inflammatory cytokines, neutrophils, immunoglobulin G fragments and the numbers of Pseudomonas aeruginosa were assessed in induced sputum before and after the inhalation period. Inhalation of AAT increased AAT levels and decreased the levels of elastase activity, neutrophils, pro-inflammatory cytokines and the numbers of P. aeruginosa. However, it had no effect on lung function. No difference was found between the peripheral and bronchial inhalation mode. In conclusion, although no effect on lung function was observed, the clear reduction of airway inflammation after alpha(1)-antitrypsin treatment may precede pulmonary structural changes. The alpha(1)-antitrypsin deposition region may play a minor role for alpha(1)-antitrypsin inhalation in cystic fibrosis patients.

Long-term outcome of 444 patients with distant metastases from papillary and follicular thyroid carcinoma: benefits and limits of radioiodine therapy

AIM

The goal of this study was to estimate the cumulative activity of (131)I to be administered to patients with distant metastases from thyroid carcinoma.

METHODS

A total of 444 patients were treated from 1953-1994 for distant metastases from papillary and follicular thyroid carcinoma: 223 had lung metastases only, 115 had bone metastases only, 82 had both lung and bone metastases, and 24 had metastases at other sites. Treatment consisted of the administration of 3.7 GBq (100 mCi) (131)I after withdrawal of thyroid hormone treatment, every 3-9 months during the first 2 yr and then once a year until the disappearance of any metastatic uptake. Thyroxine treatment was given at suppressive doses between (131)I treatment courses.

RESULTS

Negative imaging studies (negative total body (131)I scans and conventional radiographs) were attained in 43% of the 295 patients with (131)I uptake; more frequently in those who were younger, had well-differentiated tumors, and had a limited extent of disease. Most negative studies (96%) were obtained after the administration of 3.7-22 GBq (100-600 mCi). Almost half of negative studies were obtained more than 5 yr after the initiation of the treatment of metastases. Among patients who achieved a negative study, only 7% experienced a subsequent tumor recurrence. Overall survival at 10 yr after initiation of (131)I treatment was 92% in patients who achieved a negative study and 19% in those who did not.

CONCLUSION

(131)I treatment is highly effective in younger patients with (131)I uptake and with small metastases. They should be treated until the disappearance of any uptake or until a cumulative activity of 22 GBq has been administered. In the other patients, other treatment modalities should be used when tumor progression has been documented.

Surfactant protein D in human lung diseases

The lung is continuously exposed to inhaled pollutants, microbes and allergens. Therefore, the pulmonary immune system has to defend against harmful pathogens, while an inappropriate inflammatory response to harmless particles must be avoided. In the bronchoalveolar space this critical balance is maintained by innate immune proteins, termed surfactant proteins. Among these, surfactant protein D (SP-D) plays a central role in the pulmonary host defence and the modulation of allergic responses. Several human lung diseases are characterized by decreased levels of bronchoalveolar SP-D. Thus, recombinant SP-D has been proposed as a therapeutical option for cystic fibrosis, neonatal lung disease and smoking-induced emphysema. Furthermore, SP-D serum levels can be used as disease activity markers for interstitial lung diseases. This review illustrates the emerging role of SP-D translated from in vitro studies to human lung diseases.

An equivalence principle for the incorporation of favorable mutations in asexual populations

Rapid evolution of asexual populations, such as that of cancer cells or of microorganisms developing drug resistance, can include the simultaneous spread of distinct beneficial mutations. We demonstrate that evolution in such cases is driven by the fitness effects and appearance times of only a small minority of favorable mutations. The complexity of the mutation-selection process is thereby greatly reduced, and much of the evolutionary dynamics can be encapsulated in two parameters-an effective selection coefficient and effective rate of beneficial mutations. We confirm this theoretical finding and estimate the effective parameters for evolving populations of fluorescently labeled Escherichia coli. The effective parameters constitute a simple description and provide a natural standard for comparing adaptation between species and across environments.