IL-5 production by peripheral blood Th cells of adult asthma patients in response to Candida albicans allergen

Fungi composition in settled dust associated with fractional exhaled nitric oxide in school children with asthma

Fungi exposure has been significantly linked to respiratory illness. However, numerous fungi taxa that are potentially allergenic still undocumented and leave a barrier to establishing a clear connection between exposure and health risks. This study aimed to evaluate the association of fungi composition in settled dust with fractional exhaled nitric oxide (FeNO) levels among school children with doctor-diagnosed asthma. A cross-sectional study was undertaken among secondary school students in eight schools in the urban area of Hulu Langat, Selangor, Malaysia. A total of 470 school children (aged 14 years old) were randomly selected and their FeNO levels were measured and allergic skin prick tests were conducted. The settled dust samples were collected and analysed by using metagenomic technique to determine the fungi composition. The general linear regression with complex sampling was employed to determine the interrelationship. In total, 2645 fungal operational taxonomic units (OTUs) were characterised from the sequencing process which belongs to Ascomycota (60.7 %), Basidiomycota (36.4 %), Glomeromycota (2.9 %) and Chytridiomycota (0.04 %). The top five mostly abundance in all dust samples were Aspergillus clavatus (27.2 %), followed by Hyphoderma multicystidium (12.2 %), Verrucoconiothyrium prosopidis (9.4 %), Ganoderma tuberculosum (9.2 %), and Heterochaete shearii (7.2 %). The regression results indicated that A. clavatus, Brycekendrickomyces acaciae, Candida parapsilosis, Hazslinszkyomyces aloes, H. multicystidium, H. shearii, Starmerella meliponinorum, V. prosopidis were associated in increased of FeNO levels among the asthmatic group at 0.992 ppb (95 % CI = 0.34-1.68), 2.887 ppb (95 % CI = 2.09-3.76), 0.809 ppb (95 % CI = 0.14-1.49), 0.647 ppb (95 % CI = 0.36-0.94), 1.442 ppb (95 % CI = 0.29-2.61), 1.757 ppb (95 % CI = 0.59-2.87), 1.092 ppb (95 % CI = 0.43-1.75) and 1.088 ppb (95 % CI = 0.51-1.62), respectively. To our knowledge, this is a new finding. The findings pointed out that metagenomics profiling of fungi could enhance our understanding of a complex interrelation between rare and unculturable fungi with airway inflammation.

Relationships Between Oral Microecosystem and Respiratory Diseases

Oral microecosystem is a very complicated ecosystem that is located in the mouth and comprises oral microbiome, diverse anatomic structures of oral cavity, saliva and interactions between oral microbiota and between oral microbiota and the host. More and more evidence from studies of epidemiology, microbiology and molecular biology is establishing a significant link between oral microecosystem and respiratory diseases. Microbiota settling down in oral microecosystem is known as the main source of lung microbiome and has been associated with the occurrence and development of respiratory diseases like pneumonia, chronic obstructive pulmonary disease, lung cancer, cystic fibrosis lung disease and asthma. In fact, it is not only indigenous oral microbes promote or directly cause respiratory infection and inflammation when inhaled into the lower respiratory tract, but also internal environment of oral microecosystem serves as a reservoir for opportunistic respiratory pathogens. Moreover, poor oral health and oral diseases caused by oral microecological dysbiosis (especially periodontal disease) are related with risk of multiple respiratory diseases. Here, we review the research status on the respiratory diseases related with oral microecosystem. Potential mechanisms on how respiratory pathogens colonize oral microecosystem and the role of indigenous oral microbes in pathogenesis of respiratory diseases are also summarized and analyzed. Given the importance of oral plaque control and oral health interventions in controlling or preventing respiratory infection and diseases, we also summarize the oral health management measures and attentions, not only for populations susceptible to respiratory infection like the elderly and hospitalized patients, but also for dentist or oral hygienists who undertake oral health care. In conclusion, the relationship between respiratory diseases and oral microecosystem has been established and supported by growing body of literature. However, etiological evidence on the role of oral microecosystem in the development of respiratory diseases is still insufficient. Further detailed studies focusing on specific mechanisms on how oral microecosystem participate in the pathogenesis of respiratory diseases could be helpful to prevent and treat respiratory diseases.

Utility of immunology, microbiology, and helminth investigations in clinical assessment of severe asthma

OBJECTIVE

Systematic assessment of patients with potential severe asthma is key to identification of treatable traits and optimal management. Assessment of antimicrobial immune function is part of that assessment at many centers although there is little evidence-base on its added value in clinical assessment of this patient group. As part of reviewing our local pathway, we have retrospectively reviewed these tests in 327 consecutive referrals to our severe asthma service, in an evaluation to describe the utility of these tests and allow refinement of the local guideline for patient assessment.

METHODS AND RESULTS

Serum immunoglobulin concentrations were in the normal range in most patients though 12 patients had serum IgG < 5.5 g/L and many had suboptimal anti-Haemophilus (127 of 249 patients tested) and anti-Pneumococcal (111 of 239) immune responses. As expected many patients had evidence of sensitization to Aspergillus although specific IgG was not confined to those with evidence of allergic sensitization/allergic bronchopulmonary aspergillosis (ABPA). Eighteen of 277 patients tested had serological evidence of Strongyloides infection. Bacteria and/or yeast were cultured from the sputum in 76 out of 110 patients productive of sputum, and the most common microbes cultured were Candida sp. (44 patients), Staphylococcus aureus (21 patients), Haemophilus influenzae (18 patients).

CONCLUSIONS

Many patients had evidence of infection, colonization, or sensitization to potential pathogens relevant to asthma. Strongyloides infection was evident in several patients, which may be a major issue when considering the risk of hyper-infection following immunosuppression and supports our local screening strategy.

Delayed type of allergic skin reaction to Candida albicans in eosinophilic rhinosinusitis cases

OBJECTIVE

Eosinophilic chronic rhinosinusitis (ECRS) is frequently complicated by asthma, and recognized as refractory and persistent rhinosinusitis. However, the detailed pathophysiology of ECRS has not been elucidated yet. In this study, we investigated the association between recurrent ECRS and intradermal testing to multi-antigens including Candida albicans.

METHODS

The subjects were 49 cases of bilateral chronic rhinosinusitis including 24 ECRS cases. They underwent endoscopic sinus surgery and submitted to pathological examination. Prior to surgery, peripheral blood eosinophil count, total and antigen-specific IgE levels (11 categories), and intradermal tests (5 categories) were carried out in all patients. These patients were followed-up for longer than 3 months. We compared the results of preoperative and postoperative clinical examination data between ECRS and non-ECRS (NECRS) cases.

RESULTS

Positive reaction of the delayed type of intradermal testing to C. albicans was significantly more often observed in ECRS than NECRS cases. (P<0.01) Additionally, these positive reaction cases exhibited significantly higher recurrence of nasal polyps and symptoms of ECRS (P<0.05).

CONCLUSION

These results suggest the involvement of (Coombs) type IV allergic reaction to C. albicans in the pathophysiology of ECRS.

Cytokine responses of peripheral blood mononuclear cells to allergen do not identify asthma or asthma phenotypes

BACKGROUND

Asthmatic patients are often differentiated based on their atopic status (atopic or nonatopic) and type of bronchitis (eosinophilic, neutrophilic, both, or neither). There is evidence supporting a central role for the T cell in asthma, but the role of allergen-induced T cell cytokines in driving disease in different asthma phenotypes remains unclear.

OBJECTIVE

To investigate the hypothesis that peripheral blood mononuclear cells (PBMCs) from asthma patients with different phenotypes would react characteristically to a panel of common aeroallergens.

METHODS

We incubated PBMCs from 41 asthma patients and 8 healthy controls with allergen and assessed PBMC proliferation by (3) H-thymidine incorporation and the production of the cytokines IL-5, IL-17A, IL-23, IL-10, and IFN-γ by ELISA.

RESULTS

No differences in PBMC proliferation or cytokine production were found in patients with asthma, compared with healthy controls, or between patients with different asthma phenotypes.

CONCLUSIONS AND CLINICAL RELEVANCE

Peripheral blood mononuclear cell cytokine responses to allergen are not able to assist in the discrimination between disease state, atopic status, or type of bronchitis in asthma.

Secondary cutaneous candidiasis with eosinophilia

Cutaneous candidiasis is a common skin infection caused by the Candida species, especially in intertriginous areas, and neutrophils usually infiltrate histopathologically. We describe a case of secondary cutaneous candidiasis which spread extensively to the trunk and extremities and showed marked dermal eosinophilia. This case and a similar reported case suggest that Candida can sometimes cause cutaneous inflammation predominantly composed of eosinophils.

Candida soluble cell wall beta-glucan facilitates ovalbumin-induced allergic airway inflammation in mice: Possible role of antigen-presenting cells

BACKGROUND

Although fungi have been implicated as initiating/deteriorating factors for allergic asthma, their contributing components have not been fully elucidated. We previously isolated soluble beta-glucan from Candida albicans (CSBG) (Ohno et al., 2007). In the present study, the effects of CSBG exposure on airway immunopathology in the presence or absence of other immunogenic allergen was investigated in vivo, and their cellular mechanisms were analyzed both in vivo and in vitro.

METHODS

In vivo, ICR mice were divided into 4 experimental groups: vehicle, CSBG (25 microg/animal), ovalbumin (OVA: 2 microg/animal), and CSBG + OVA were repeatedly administered intratracheally. The bronchoalveolar lavage cellular profile, lung histology, levels of cytokines and chemokines in the lung homogenates, the expression pattern of antigen-presenting cell (APC)-related molecules in the lung digests, and serum immunoglobulin values were studied. In vitro, the impacts of CSBG (0-12.5 microg/ml) on the phenotype and function of immune cells such as splenocytes and bone marrow-derived dendritic cells (BMDCs) were evaluated in terms of cell proliferation, the surface expression of APC-related molecules, and OVA-mediated T-cell proliferating activity.

RESULTS

In vivo, repeated pulmonary exposure to CSBG induced neutrophilic airway inflammation in the absence of OVA, and markedly exacerbated OVA-related eosinophilic airway inflammation with mucus metaplasia in mice, which was concomitant with the amplified lung expression of Th2 cytokines and IL-17A and chemokines related to allergic response. Exposure to CSBG plus OVA increased the number of cells bearing MHC class II with or without CD80 in the lung compared to that of others. In vitro, CSBG significantly augmented splenocyte proliferation in the presence or absence of OVA. Further, CSBG increased the expression of APC-related molecules such as CD80, CD86, and DEC205 on BMDCs and amplified OVA-mediated T-cell proliferation through BMDCs.

CONCLUSION

CSBG potentiates allergic airway inflammation with maladaptive Th immunity, and this potentiation was associated with the enhanced activation of APCs including DC.

Exogenous farnesol interferes with the normal progression of cytokine expression during candidiasis in a mouse model

Candida albicans, a dimorphic fungus composed of yeast and mycelial forms, is the most common human fungal pathogen. Th1 cytokines such as interleukin-2 (IL-2), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha), which are induced by macrophage IL-12, are critical to resistance against systemic candidiasis, while Th2 cytokines such as IL-4 and IL-5 are less critical. Farnesol is a quorum-sensing molecule produced by C. albicans that controls the formation of mycelia but is also a virulence factor. To determine whether farnesol enhances the virulence of C. albicans by modulating the production of Th1 and Th2 cytokines, mice were pretreated with farnesol prior to intravenous infection with a sublethal dose of farnesol-producing C. albicans. Production of IL-2, IL-4, IL-5, TNF-alpha, IFN-gamma, and IL-12 was evaluated by bead-array flow cytometry and enzyme-linked immunosorbent assay. Mice exhibited an elevation in serum TNF-alpha levels at 48 h and an elevation in IFN-gamma and IL-12 levels at 6 to 12 h after infection with C. albicans. Pretreatment with farnesol significantly reduced the elevation of both IFN-gamma and IL-12 but not TNF-alpha. In contrast, mice pretreated with farnesol exhibited an unexpected elevation in IL-5 levels. To determine whether farnesol has a direct effect on macrophage production of IL-12, peritoneal macrophages were pretreated with farnesol prior to stimulation with IFN-gamma plus lipopolysaccharide (LPS). Farnesol inhibited production of both IL-12 p40 and p70 from IFN-gamma/LPS-stimulated macrophages. Therefore, the role of farnesol in systemic candidiasis is likely due to its ability to inhibit the critical Th1 cytokines IFN-gamma and IL-12 and perhaps to enhance a Th2 cytokine, IL-5.

Acute eosinophilic pneumonia caused by Candida albicans

A 36-year-old man was transferred to the hospital for further evaluation of pulmonary infiltration. A diagnosis of acute eosinophilic pneumonia (AEP) was confirmed by clinical symptoms, bronchoalveolar lavage, and computed tomography findings. Skin tests with fungal antigens were performed by intradermal injection. Both the Arthus (8 h) and delay (24 h)-type skin tests were positive for only Candida albicans. A lymphocyte-stimulating test was also positive for C. albicans. The etiology of the AEP was confirmed by a C. albicans inhalation provocation test. In addition, peripheral blood mononuclear cells obtained from the patient produced Interleukin-5 following C. albicans stimulation. This is the first report of C. albicans as a probable cause of AEP. Evaluation of allergy to C. albicans should be performed in AEP before diagnosing the cause as idiopathic.

Churg-Strauss syndrome presenting with conjunctival nodules in association with Candida albicans and ankylosing spondylitis

Churg-Strauss syndrome is a rare diffuse vasculitis of which the ocular manifestations have been well documented. However, reports of conjunctival involvement in Churg-Strauss syndrome are scarce. Such a presentation is described in a man with Candida albicans infection as well as ankylosing spondylitis, and a possible aetiological linkage is established amongst all three.

Adenoid-derived TH2 cells reactive to allergen and recall antigen express CC chemokine receptor 4

BACKGROUND

Interrupting recruitment of allergen-specific T(H)2 cells to the airway is an attractive potential therapeutic strategy for allergic disease. CC chemokine receptor 4 (CCR4) is preferentially expressed on T(H)2 cells, and CCR4-expressing cells have been described at sites of allergic inflammation. However, whether selective recruitment of allergen-specific T(H)2 cells to the airways occurs through CCR4 or other chemokine receptors remains controversial.

OBJECTIVE

We investigated the expression of the T(H)2-associated chemokine receptors (CCR3, CCR4, and CCR8) by primary antigen-specific human airway T(H)2 cells.

METHODS

Children undergoing elective adenoidectomy were recruited, and their atopic status was determined. Adenoid cells were cultured with allergen or recall antigen. Flow cytometric analyses permitted identification of T(H) cells proliferating in response to antigen and characterization of chemokine receptor and cytokine expression.

RESULTS

An increased proportion of airway CD4(+) T cells proliferated to allergen in atopic children (n = 6, of which 4 were given diagnoses of asthma or rhinitis) compared with nonatopic children (P =.0004). These cells were 44.7% (32.6% to 50.0%) IL-4(+) and only 2.5% (0.6% to 3.3%) IFN-(gamma) and showed a greater than 5-fold upregulation of CCR4 expression to 54.0% (40.7% to 67.8%) after culture, whereas CCR3 was expressed on 9.7% (7.4% to 18.9%) of allergen-reactive cells and CCR8 on less than 1%. Interestingly, increased expansion of recall antigen-specific cells was also seen in atopic children, and these cells were also predominantly of a T(H)2 CCR4(+) phenotype.

CONCLUSION

We conclude that airway allergen-specific T(H)2 cells are CCR4(+), but in the atopic child CCR4 does not distinguish between recall antigen and allergen specificity.