Small Molecule CCR4 Antagonists Protect Mice from Aspergillus Infection and Allergy.

The ability to regulate the recruitment of immune cells makes chemokines and their receptors attractive drug targets in many inflammatory diseases. Based on its preferential expression on T helper type 2 (Th2) cells, C-C chemokine receptor type 4 (CCR4) has been widely studied in the context of allergic diseases, but recent evidence on the expression of CCR4 in other cell types has considerably expanded the potential applications of CCR4 antagonism. However, the current number of approved indications, as well as the portfolio of CCR4-targeting drugs, are still limited. In the present study, we have assessed the potential therapeutic efficacy of a CCR4 small molecule antagonist, SP50, discovered via an in silico-based approach, against a variety of pre-clinical settings of infection with the fungus Aspergillus fumigatus. We show that SP50 efficiently worked as prophylactic vaccine adjuvant in immunocompetent mice, protected against invasive aspergillosis in immunosuppressed mice. Further, the CCR4 antagonist prevented allergic bronchopulmonary aspergillosis in susceptible mice, and in a murine model of cystic fibrosis, a genetic disorder characterized by chronic pulmonary inflammation and recurrent infections. In conclusion, our results extend the potential applications of CCR4 antagonism and prompt for the development of novel compounds with the potential to progress to clinical trials.

Evaluation of mold exposure in cystic fibrosis patients' dwellings and allergic bronchopulmonary risk.

Very few studies have been conducted on cystic fibrosis (CF) patients' exposure to the indoor environment and, to our knowledge, there are no studies dealing with the link between specific fungal environmental exposure at home and fungal colonization resulting in allergic bronchopulmonary aspergillosis (ABPA). Fungal exposure of CF adult patients with ABPA (n=4) with fungal sensitization (n=7) and with no ABPA (n=5) was assessed in 16 homes by dust sampling with electrostatic dust fall collectors (EDCs). Aspergillus fumigatus was specifically quantified by real-time quantitative polymerase chain reactions (qPCRs), and A. fumigatus DNA concentrations were significantly higher in homes of ABPA patients (p<0.001). Results indicate that indoor fungal contamination could be a factor favoring ABPA and suggest that environmental surveys could help in preventing fungal risk in CF patients.

Axl receptor blockade protects from invasive pulmonary aspergillosis in mice.

Aspergillus fumigatus is a sporulating fungus found ubiquitously in the environment, which is quickly contained in the immunocompetent host but can cause lethal invasive aspergillosis in the immunocompromised host. We have recently demonstrated that Axl (one member of the Tyro3, Axl, Mertk receptor family) is a key regulator of antiviral immune responses in the lung. In this study, we investigated the role of Axl in antifungal immunity in a model of invasive pulmonary aspergillosis (IPA). In this model, Aspergillus fumigatus conidia were administered into the lungs of neutrophil-depleted mice, and the mice were monitored for survival, lung inflammatory response, and fungal clearance. The lethal effect of IPA was significantly reduced in anti-Axl mAb-treated mice compared with IgG control-treated mice. Targeting Axl significantly inhibited pulmonary inflammation, including the expression of IL-1ß, IL-6, TNF-α, and chitinase-like proteins in whole lung. Further, anti-Axl mAb treatment significantly increased M1 macrophages that highly expressed inducible NO synthase and decreased M2 macrophages that expressed Arginase 1 and were found in inflammatory zone protein (Fizz1). More importantly, anti-Axl mAb treatment significantly increased the number of IFN-γ-producing T cells and NK cells compared with the IgG control group during IPA. Together, our results demonstrate that the Axl mAb treatment is protective during invasive aspergillosis in neutropenic mice. Collectively, these data suggest a potential deleterious role for Axl during primary immune responses directed against A. fumigatus and novel therapeutic strategy for IPA.

Targeting ST2L potentiates CpG-mediated therapeutic effects in a chronic fungal asthma model.

IL-33 and its soluble receptor and cell-associated receptor (ST2L) are all increased in clinical and experimental asthma. The present study addressed the hypothesis that ST2L impairs the therapeutic effects of CpG in a fungal model of asthma. C57BL/6 mice were sensitized to Aspergillus fumigatus and challenged via i.t. instillation with live A. fumigatus conidia. Mice were treated with IgG alone, anti-ST2L monoclonal antibody (mAb) alone, CpG alone, IgG plus CpG, or anti-ST2L mAb plus CpG every other day from day 14 to day 28 and investigated on day 28 after conidia. Lung ST2L and toll-like receptor 9 protein expression levels concomitantly increased in a time-dependent manner during fungal asthma. Therapeutic blockade of ST2L with an mAb attenuated key pathological features of this model. At subtherapeutic doses, neither anti-ST2L mAb nor CpG alone affected fungal asthma severity. However, airway hyperresponsiveness, mucus cell metaplasia, peribronchial fibrosis, and fungus retention were markedly reduced in asthmatic mice treated with the combination of both. Whole lung CXCL9 levels were significantly elevated in the combination group but not in the controls. Furthermore, in asthmatic mice treated with the combination therapy, dendritic cells generated significantly greater IL-12p70 with CpG in vitro compared with control dendritic cells. The combination of anti-ST2L mAb with CpG significantly attenuated experimental asthma, suggesting that targeting ST2L might enhance the therapeutic efficacy of CpG during allergic inflammation.

Serum amyloid P attenuates M2 macrophage activation and protects against fungal spore-induced allergic airway disease.

BACKGROUND: Aspergillus fumigatus conidia aggravate asthmatic responses. Lung macrophages normally kill fungal conidia, but the presence of type 2 cytokines during asthma contributes to the alternative (or M2) activation of these cells, which secrete proallergic factors and exhibit impaired innate immunity. OBJECTIVE: Considering that pentraxins modulate macrophage function, we examined the effect of C-reactive protein (CRP) and serum amyloid P (SAP) in an experimental model of A fumigatus-induced allergic airway disease. METHODS: The effects of SAP and CRP on M2 macrophage differentiation were examined in vitro, and the in vivo effects of these pentraxins were analyzed in the asthma model. RESULTS: SAP inhibited the generation of M2 markers, such as arginase and the chitinase Ym-1, through an FcγR-dependent mechanism in cultured macrophages. This effect correlated with a decrease in signal transducer and activator of transcription 6 (STAT6) phosphorylation in SAP-treated M2 macrophages. In vivo treatment with SAP significantly decreased methacholine-induced bronchial resistance, mucus cell metaplasia, the number of "found in inflammatory zone 1" (FIZZ1)-positive cells in the lungs, and collagen deposition compared with the control group. CRP had a modest effect on M2 differentiation, and in vivo treatment with CRP had a minor effect or exacerbated A fumigatus-induced lung disease. Finally, the adoptive transfer of SAP-pretreated M2 macrophages into allergic mice significantly attenuated disease when compared with nontransferred or M2-transferred control groups. CONCLUSIONS: These findings demonstrate that SAP is a potent inhibitor of M2 macrophage differentiation and represents a novel therapy in A fumigatus-induced allergic disease.

Native valve Aspergillus endocarditis complicating lung transplantation.

We present 2 cases of Aspergillus endocarditis occurring in lung transplant recipients, both of whom were treated with early surgical intervention and triazole anti-fungal agents. Neither had evidence of airway colonization/infection with Aspergillus post-transplant, suggesting hematogenous spread of fungi at the time of surgery as a possible mechanism of infection. One case was successfully treated and discharged from the hospital, but, despite initial recovery, death occurred 10 months later due to a recurrence of Aspergillus endocarditis. Aspergillus endocarditis should be considered a relapsing disease and survivors of the condition should receive ongoing anti-fungal therapy.

Dendritic cells transduced with an adenovirus vector encoding interleukin-12 are a potent vaccine for invasive pulmonary aspergillosis.

Invasive pulmonary aspergillosis (IPA) is a common and devastating pneumonia. We developed a novel antiinfective vaccine that couples the potent Ag-presenting capacity of dendritic cells (DCs) with paracrine delivery of interleukin-12 (IL-12) to local immune response sites. Our results showed that DCs engulfed Aspergillus conidia through coiling phagocytosis. Transfection of DCs with adenovirus encoding the cDNA of IL-12 did not affect their morphology and capacity to engulf conidia. The transduced DCs secreted IL-12, which was biologically active, to induce the production of gamma interferon (IFN-gamma) from spleen cells. Adoptive transfer of DCs pulsed with heat-inactivated Aspergillus fumigatus (HAF) to naive mice induced the Ag-specific production of IFN-gamma; the transduced HAF-pulsed DCs augmented this immune response further. Animals receiving HAF-pulsed DCs had lower fungal burdens, a more than three-fold higher survival rate at day 3. This protection was associated with a pronounced enhancement in the Aspergillus-specific IFN-gamma response. IL-12-engineered DCs augmented this protection strikingly as judged by a higher survival, and almost no Aspergillus could be detected in the lung of mice that had received IL-12-transduced HAF-pulsed DCs. These results suggest that antigen-pulsed DCs and IL-12 gene therapy could be used as adjunct therapy for aspergillosis.

Novel inhalational murine model of invasive pulmonary aspergillosis.

We developed a novel model of invasive aspergillosis (IA) that recapitulates human disease. Mice were immunosuppressed with cyclophosphamide and cortisone acetate and then infected in an aerosol chamber. This procedure reproducibly delivered 1 x 10(3) to 3 x 10(3) conidia to the lungs. Lethal pulmonary IA developed over 2 weeks and was prevented by amphotericin B.

Guidelines for preventing health-care--associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee.

This report updates, expands, and replaces the previously published CDC "Guideline for Prevention of Nosocomial Pneumonia". The new guidelines are designed to reduce the incidence of pneumonia and other severe, acute lower respiratory tract infections in acute-care hospitals and in other health-care settings (e.g., ambulatory and long-term care institutions) and other facilities where health care is provided. Among the changes in the recommendations to prevent bacterial pneumonia, especially ventilator-associated pneumonia, are the preferential use of oro-tracheal rather than naso-tracheal tubes in patients who receive mechanically assisted ventilation, the use of noninvasive ventilation to reduce the need for and duration of endotracheal intubation, changing the breathing circuits of ventilators when they malfunction or are visibly contaminated, and (when feasible) the use of an endotracheal tube with a dorsal lumen to allow drainage of respiratory secretions; no recommendations were made about the use of sucralfate, histamine-2 receptor antagonists, or antacids for stress-bleeding prophylaxis. For prevention of health-care--associated Legionnaires disease, the changes include maintaining potable hot water at temperatures not suitable for amplification of Legionella spp., considering routine culturing of water samples from the potable water system of a facility's organ-transplant unit when it is done as part of the facility's comprehensive program to prevent and control health-care--associated Legionnaires disease, and initiating an investigation for the source of Legionella spp. when one definite or one possible case of laboratory-confirmed health-care--associated Legionnaires disease is identified in an inpatient hemopoietic stem-cell transplant (HSCT) recipient or in two or more HSCT recipients who had visited an outpatient HSCT unit during all or part of the 2-10 day period before illness onset. In the section on aspergillosis, the revised recommendations include the use of a room with high-efficiency particulate air filters rather than laminar airflow as the protective environment for allogeneic HSCT recipients and the use of high-efficiency respiratory-protection devices (e.g., N95 respirators) by severely immunocompromised patients when they leave their rooms when dust-generating activities are ongoing in the facility. In the respiratory syncytial virus (RSV) section, the new recommendation is to determine, on a case-by-case basis, whether to administer monoclonal antibody (palivizumab) to certain infants and children aged <24 months who were born prematurely and are at high risk for RSV infection. In the section on influenza, the new recommendations include the addition of oseltamivir (to amantadine and rimantadine) for prophylaxis of all patients without influenza illness and oseltamivir and zanamivir (to amantadine and rimantadine) as treatment for patients who are acutely ill with influenza in a unit where an influenza outbreak is recognized. In addition to the revised recommendations, the guideline contains new sections on pertussis and lower respiratory tract infections caused by adenovirus and human parainfluenza viruses and refers readers to the source of updated information about prevention and control of severe acute respiratory syndrome.

Masking of neutropenic patients on transport from hospital rooms is associated with a decrease in nosocomial aspergillosis during construction.

To prevent nosocomial pulmonary aspergillosis during hospital construction, neutropenic patients with hematologic malignancy were required to wear high-efficiency masks when leaving their rooms. The rate of nosocomial aspergillosis decreased from 0.73 per 1,000 hospital patient-days during fiscal years 1993 to 1996 to 0.24 per 1,000 hospital patient-days during fiscal years 1996 to 1999 (P < .001). High-efficiency masks reduced nosocomial aspergillosis during hospital construction.

Evidence for the involvement of two different MHC class II regions in susceptibility or protection in allergic bronchopulmonary aspergillosis.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a disease with uncertain pathology. Studies have suggested a pathogenic role for T(H)2 cells. Previously, we demonstrated, in a small group of patients, that T(H)2 reactivity to a major Aspergillus fumigatus antigen was restricted by HLA-DR2 or HLA-DR5 alleles. OBJECTIVES: We sought to confirm whether susceptibility to ABPA is exclusively associated with HLA-DR locus and to investigate the involvement of HLA-DQ genes in the development of ABPA. METHODS: Genomic DNA was extracted from patients with ABPA, patients without ABPA but with positive A fumigatus skin test responses and asthma or cystic fibrosis, and healthy control subjects. HLA-DR and HLA-DQ genes were detected by using low-resolution typing; high-resolution typing was done only on HLA-DR2- and HLA-DR5-positive individuals by using sequence-specific primers (PCR-SSP). RESULTS: A significantly higher frequency of HLA-DR2 was observed in patients with ABPA versus those without ABPA (corrected P <.01) or healthy control subjects (corrected P <.01). Genotype analysis revealed that susceptibility to ABPA is associated with HLA-DR2 alleles DRB1*1503 and DRB1*1501 and, to a lesser extent, with the HLA-DR5 allele DRB1*1104. The presence of DR4 or DR7 alleles in non-DR2/5 patients with ABPA suggests that these alleles may also be contributing factors in this disease. Another striking observation was the significantly high frequency of HLA-DQ2 in patients without ABPA (67. 4%) compared with patients with ABPA (20.5%) and normal control subjects (37.7%), suggesting that these alleles may confer protection in the population without ABPA. CONCLUSION: These genetic studies suggest that HLA-DR molecules DR2, DR5, and possibly DR4 or DR7 contribute to susceptibility while HLA-DQ2 contributes to resistance and that a combination of these genetic elements determines the outcome of ABPA in patients with cystic fibrosis and asthma.

Prophylactic use of itraconazole for the prevention of invasive pulmonary aspergillosis in high risk neutropenic patients.

Invasive pulmonary aspergillosis (IPA) is an increasing cause of morbidity and mortality in patients with hematologic malignancies. A major program of construction work close to our unit prompted us to evaluate the efficacy of itraconazole prophylaxis in preventing IPA in these patients. During September 1994 to December 1995, 77 patients undergoing 96 neutropenic episodes (mean duration, 19.3 days +/- 9.1) received itraconazole as antifungal prophylaxis. All patients were treated in laminar air flow rooms. Itraconazole was administered at a loading dose of 600mg/d, (day 1 to day 3) and 400mg/d on the following days, in 87 instances. In the remaining episodes, the daily dose was 200 or 400mg. Oral doses were adjusted to reach a plasma itraconazole level (PIL) above 1000ng/l. In cases of inadequate PIL or poor oral intake, IV AmphoB was started at a 20 mg daily dose. Five cases of IPA (proven n = 2, probable n = 3) were observed. This represents an incidence of 5.2% of the total number of episodes. One out of 67 (2%) treatment episodes with adequate PIL were associated with IPA as compared to 4 of 29 (14%) episodes with inadequate PIL, (p < 0.02). AmphoB was added in 28 cases because of low PIL (n = 25), and/or antibiotic-resistant fever persistent pulmonary infiltrate (n = 8). These results need to be interpreted with caution, because of the absence of randomization or a control group. The efficacy of Itraconazole in neutropenic patients with high risk IPA has to be confirmed on larger and prospective studies.

Liposomal amphotericin B as early empiric antimycotic therapy of pneumonia in granulocytopenic patients.

Twenty-three neutropenic patients with haematological malignancies and febrile pulmonary infiltrates were empirically treated with liposomal amphotericin B (AmBisome) in addition to broad-spectrum antibiotics. AmBisome was given on alternate days in two different dosages: 3 mg kg-1 in patients with pneumonia but without radiological signs or other evidence of Aspergillus infection and 5 mg kg-1 in pneumonia patients with suspected Aspergillus infection. The main objectives of this study were to compare the response and lethality of pneumonias treated early with empirically AmBisome with a historical group (treatment with conventional amphotericin B only in case of proven/highly probable aspergillosis) and to investigate the tolerability and efficacy of AmBisome 5 mg kg-1 in cases of proven/probable aspergilloses. Six out of seven (86%) patients without initially suspected aspergilloses receiving AmBisome 3 mg kg-1 responded completely. Twelve out of 16 patients with initial radiological signs of aspergillosis receiving AmBisome 5 mg kg-1 were evaluable. Body temperature normalized in 10/12 (83%) patients; eight experienced complete and two partial regression of their infiltrations and 9/10 patients with proven/probable aspergillosis responded. Acute AmBisome-related reactions were seen in three patients from each group; loss of potassium was noted in five subjects in each group and slightly increased plasma creatinine was found in two patients in the 5 mg kg-1 group. Altogether, the response of all pneumonia patients treated with early empirical AmBisome compared with the historical group was 17/19 vs. 49/72 (89% vs. 68%, NS); among those with proven/probable aspergilloses 11/12 vs. 7/17 (92% vs. 41%, P = 0.008) patients responded. Pneumonia lethality was 1/19 in the AmBisome-treated patients compared with 23/72 in the historical group (5% vs. 32%, P = 0.01); and among those with proven/probable aspergilloses it was 1/12 vs. 10/17 (8% vs. 59%, P = 0.008). In conclusion, early empiric treatment with AmBisome 3 mg kg-1 and 5 mg kg-1 on alternate days was well tolerated and greatly reduced the lethality of proven/probable Aspergillus pneumonias.

[Progress and problems in hospital infections: exemplified by pneumonia]. / Progrès et problèmes dans les infections hospitalières: l'exemple des pneumonies.

Nosocomial pneumonias have various etiologies and their development depends mainly on the underlying condition of the patients. Intubated patients are prone to development of bacterial pneumonia from the oropharyngeal or gastric flora. Prevention relies on reducing exogenous as well as endogenous colonization of the bronchotracheal tree: avoidance of cross-contamination, maintenance of a physiological gastric pH and, possibly, selective digestive decontamination. Neutropenic patients may develop invasive aspergillus infection. Prevention depends on appropriate air filtration. Patients with cellular immunodeficiency are susceptible to various agents. Prevention of legionella depends on control of the water and ventilation systems. The prevention of cytomegalovirus infection includes the screening of blood products for certain patients and, in some cases, the administration of hyperimmune gammaglobulins and possibly ganciclovir. Even though Pneumocystis carinii pneumonia is thought to be due to reactivation, recent evidence suggests that transmission may occur between patients and therefore appropriate respiratory isolation is advisable. Finally, nosocomial tuberculosis is an increasing problem in which control depends on early diagnosis and treatment of patients as well as on appropriate air exchange in particular rooms of the hospital. In conclusion, the prevention of nosocomial pneumonia includes numerous measures which largely depend on the type of microorganisms.

[Aspergillus fumigatus infection of the lung in cystic fibrosis (author's transl)]. / Aspergillus-fumigatus-Infektion der Lunge bei Mucoviscidose. Beitrag zur Diagnostik, Epidemiologie, Pathogenese und Prophylaxe.

In an 8-year-old girl with cystic fibrosis Aspergillus fumigatus infection of the lung was diagnosed. Pot-plant soil as reservior of Aspergillus fumigatus was shown to be the source of inhalable Aspergillus fumigatus units within the clinic. Cystic fibrosis mucus of the patient acted as nutritive substrate for Aspergillus fumigatus. Consequent exclusion of pot plants in housing and hospital rooms is considered necessary for prevention of Aspergillus fumigatus infection in patients with cystic fibrosis.

Filtering hospital air decreases Aspergillus spore counts.

We performed counts of airborne spores in a hospital with filtered air where a decrease in nosocomial infection with Aspergillus organisms had been documented. For comparison, similar studies were performed at a nearby general hospital in a ward with open windows. The total spore count inside the hospital with filtered air was significantly less than inside the ward with open windows. The total count of Aspergillus organisms in the filtered air was significantly less than that in the room with open windows. We conclude that the decrease in nosocomial infections with Aspergillus organisms in the hospital with filtered air is probably associated with fewer airborne spores.