Belinda Hales - Academia.edu (original) (raw)

Papers by Belinda Hales

International Journal of Molecular Sciences, 2021

The development of food allergy has been reported to be related with the changes in the gut micro... more The development of food allergy has been reported to be related with the changes in the gut microbiome, however the specific microbe associated with the pathogenesis of food allergy remains elusive. This study aimed to comprehensively characterize the gut microbiome and identify individual or group gut microbes relating to food-allergy using 16S rRNA gene sequencing with network analysis. Faecal samples were collected from children with IgE-mediated food allergies (n = 33) and without food allergy (n = 27). Gut microbiome was profiled by 16S rRNA gene sequencing. OTUs obtained from 16S rRNA gene sequencing were then used to construct a co-abundance network using Weighted Gene Co-expression Network Analysis (WGCNA) and mapped onto Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We identified a co-abundance network module to be positively correlated with IgE-mediated food allergy and this module was characterized by a hub taxon, namely Ruminococcaceae UCG-002 (phylum Firmicut...

Background: Human microbiota plays a fundamental role in modulating the immune response. Western ... more Background: Human microbiota plays a fundamental role in modulating the immune response. Western environment and lifestyle are envisaged to alter the human microbiota with a new microbiome profile established in Chinese immigrants, which fails to prime the immune system. Here, we investigated how differences in composition of oropharyngeal microbiome may contribute to patterns of interaction between the microbiome and immune system in Chinese immigrants living in Australia.Methods: We recruited 44 adult Chinese immigrants: newly-arrived (n=22, living in Australia <6 months) and long-term Chinese immigrants (n=22, living in Australia >5 years), with age and gender matched. Oropharyngeal swabs, serum and whole blood were collected. The 16s ribosomal RNA gene from the swabs was sequenced on the Illumina MiSeq platform. Innate immune responses were determined by 23 Toll-like receptors (TLR) pathway cytokines, while adaptive immune responses were determined by IgG-associated respon...

American Journal of Respiratory and Critical Care Medicine, 2020

Rationale: Individuals with asthma have heightened antibody responses to rhinoviruses (RVs), alth... more Rationale: Individuals with asthma have heightened antibody responses to rhinoviruses (RVs), although those specific for RV-C are lower than responses specific for RV-A, suggesting poor immunity to this species. Objectives: To ascertain and compare T-cell memory responses induced by RV-A and RV-C in children with and without asthma. Methods: Peripheral blood mononuclear cells from 17 children with asthma and 19 control subjects without asthma were stimulated in vitro with peptide formulations to induce representative speciesspecific responses to RV-A and RV-C. Molecular profiling (RNA sequencing) was used to identify enriched pathways and upstream regulators. Measurements and Main Results: Responses to RV-A showed higher expression of IFNG and STAT1 compared with RV-C, and significant expression of CXCL9, 10, and 11 was not found for RV-C. There was no reciprocal increase of T-helper cell type 2 (Th2) cytokine genes or the Th2 chemokine genes CCL11, CCL17, and CCL22. RV-C induced higher expression of CCL24 (eotaxin-2) than RV-A in the responses of children with and without asthma. Upstream regulator analysis showed both RV-A and, although to a lesser extent, RV-C induced predominant Th1 and inflammatory cytokine expression. The responses of children with asthma compared with those without asthma were lower for both RV-A and RV-C while retaining the pattern of gene expression and upstream regulators characteristic of each species. All groups showed activation of the IL-17A pathway. Conclusions: RV-C induced memory cells with a lower IFN-g-type response than RV-A without T-helper cell type 2 (Th2) upregulation. Children with asthma had lower recall responses than those without asthma while largely retaining the same gene activation profile for each species. RV-A and RV-C, therefore, induce qualitatively different Tcell responses.

Immunity, inflammation and disease, 2018

Infections by rhinovirus (RV) species A and C are the most common causes of exacerbations of asth... more Infections by rhinovirus (RV) species A and C are the most common causes of exacerbations of asthma and a major cause of exacerbations of other acute and chronic respiratory diseases. Infections by both species are prevalent in pre-school and school-aged children and, particularly for RV-C, can cause severe symptoms and a need for hospitalization. While associations between RV infection and asthma are well established, the adaptive immune-mechanisms by which RV infections influence asthma exacerbations are yet to be defined. The aim of this study was to characterize and compare T-cell responses between RV-A and RV-C and to test the hypothesis that T-cell responses would differ between asthmatic children and healthy controls. A multi-parameter flow cytometry assay was used to characterize the in vitro recall T-cell response against RV-A and RV-C in PBMCs from children with acute asthma (n = 22) and controls (n = 26). The responses were induced by pools of peptides containing species-...

Clinical & Experimental Allergy, 2015

Pneumonia, 2016

Background: Pneumococcal surface protein A (PspA), a conserved virulence factor essential for Str... more Background: Pneumococcal surface protein A (PspA), a conserved virulence factor essential for Streptococcus pneumoniae attachment to upper respiratory tract (URT) epithelia, is a potential vaccine candidate for preventing colonisation. Methods: This cohort study was conducted in the Asaro Valley in the Eastern Highlands Province of Papua New Guinea, of which Goroka town is the provincial capital. The children included in the analysis were participants in a neonatal pneumococcal conjugate vaccine trial (ClinicalTrials.gov NCT00219401) that was conducted between 2005 and 2009. We investigated the development of anti-PspA antibodies in the first 18 months of life relative to URT pneumococcal carriage in Papua New Guinean infants who experience one of the earliest and highest colonisation rates in the world. Blood samples and nasopharyngeal swabs were collected from a cohort of 88 children at ages 3, 9, and 18 months to quantify immunoglobulin G (IgG) levels to PspA families 1 and 2 using an enzyme-linked immunosorbent assay and to determine URT carriage. Results: Seventy-three per cent (64/88) of infants carried S. pneumoniae at age 3 months; 85 % (75/88) at 9 months, and 83 % (73/88) at 18 months. PspA-IgG levels declined between ages 3 and 9 months (p < 0.001), then increased between 9 and 18 months (p < 0.001). At age 3 months, pneumococcal carriers showed lower PspA1-IgG levels (geometric mean concentration [GMC] 602 arbitrary units [AU]/ml, 95 % confidence interval [CI] 497-728) than noncarriers (GMC 1058 AU/ml [95 % CI 732-1530]; p = 0.008), while at 9 months, PspA1-and PspA2-IgG levels were significantly higher in carriers (PspA1: 186 AU/ml, 95 % CI 136-256; PspA2: 284 AU/ml, 95 % CI 192-421) than in non-carriers (PspA1 87 AU/ml, 95 % CI 45-169; PspA2 74 AU/ml, 95 % CI 34-159) (PspA1: p = 0.037, PspA2: p = 0.003). Conclusion: Our findings confirm that PspA is immunogenic and indicate that natural anti-PspA immune responses are acquired through exposure and develop with age. PspA may be a useful candidate in an infant pneumococcal vaccine to prevent early URT colonisation.

Journal of virology, Jan 14, 2016

Rhinovirus (RV) species A and C are the most frequent cause of respiratory viral illness worldwid... more Rhinovirus (RV) species A and C are the most frequent cause of respiratory viral illness worldwide and RV-C has been linked to more severe exacerbations of asthma in young children. Little is known about the immune response against the different RV species, although studies comparing IgG1 antibody titers found impaired antibody responses to RV-C. Therefore, the aim of this study was to assess whether T-cell immunity to RV-C is similarly impaired. We measured T-cell proliferation to overlapping synthetic peptides covering the entire VP1 capsid protein of an RV-A and RV-C genotype for 20 healthy adult donors. Human leukocyte antigen (HLA) was typed in all donors in order to investigate possible associations between HLA type and RV peptide recognition. Total and specific IgG1 antibody titers to VP1 of both RV-A and RV-C were also measured to examine associations between the antibody and T-cell responses. We identified T-cell epitopes that are specific of, and representative for each RV...

Late-breaking abstract: Improving cell mediated immunity to non-typeable haemophilus influenzae in children with chronic suppurative lung disease

European Respiratory Journal, Sep 1, 2014

Finding an effective vaccine to protect against non-typeable Haemophilus influenzae (NTHi) is an ... more Finding an effective vaccine to protect against non-typeable Haemophilus influenzae (NTHi) is an important goal in bronchiectasis & chronic suppurative lung disease (CSLD). NTHi infection is common in both conditions and impaired cell-mediated immunity against NTHi has been documented. Aim: Determine if a H. influenzae protein D containing conjugate vaccine improves cytokine responses to NTHi in children with CSLD. Methods: 108 children with CSLD and 32 healthy children (median age 2 yrs) were included. Those who received the 10-valent pneumococcal H. influenzae protein D conjugate vaccine (PHiD-CV) were compared with those who received multi-valent pneumococcal vaccine without protein D. Blood mononuclear cells were cultured with live NTHi. Results: Cells from CSLD children who had received 3 doses of PHiD-CV produced significantly more interferon gamma (IFN median 939; IQ range 247-2142 pg/ml) than cells from children who had received the alternative vaccines (median 338; IQ range 108-938 pg/ml; p=0.007). Importantly, the amount of IFN produced by cells from CSLD children receiving 3 doses of PHiD-CV approached that seen with healthy children. Having received 3 doses of PHiD-CV was also associated with small but significant increases in IL-13 and IL-5 (p

World Allergy Organization Journal, 2015

Cell host & microbe, Jan 8, 2015

The nasopharynx (NP) is a reservoir for microbes associated with acute respiratory infections (AR... more The nasopharynx (NP) is a reservoir for microbes associated with acute respiratory infections (ARIs). Lung inflammation resulting from ARIs during infancy is linked to asthma development. We examined the NP microbiome during the critical first year of life in a prospective cohort of 234 children, capturing both the viral and bacterial communities and documenting all incidents of ARIs. Most infants were initially colonized with Staphylococcus or Corynebacterium before stable colonization with Alloiococcus or Moraxella. Transient incursions of Streptococcus, Moraxella, or Haemophilus marked virus-associated ARIs. Our data identify the NP microbiome as a determinant for infection spread to the lower airways, severity of accompanying inflammatory symptoms, and risk for future asthma development. Early asymptomatic colonization with Streptococcus was a strong asthma predictor, and antibiotic usage disrupted asymptomatic colonization patterns. In the absence of effective anti-viral therap...

Host Responses to Allergens

Allergy and Allergic Diseases

The nasopharynx (NP) is a reservoir for microbes associated with acute respiratory illnesses (ARI... more The nasopharynx (NP) is a reservoir for microbes associated with acute respiratory illnesses (ARI). The development of asthma is initiated during infancy, driven by airway inflammation associated with infections. Here, we report viral and bacterial community profiling of NP aspirates across a birth cohort, capturing all lower respiratory illnesses during their first year. Most infants were initially colonized with Staphylococcus or Corynebacterium before stable colonization with Alloiococcus or Moraxella, with transient incursions of Streptococcus, Moraxella or Haemophilus marking virus-associated ARIs. Our data identify the NP microbiome as a determinant for infection spread to the lower airways, severity of accompanying inflammatory symptoms, and risk for future asthma development. Early asymptomatic colonization with Streptococcus was a strong asthma predictor, and antibiotic usage disrupted asymptomatic colonization patterns.

PLoS ONE, 2014

Chronic suppurative lung disease (CSLD) is characterized by the presence of a chronic wet or prod... more Chronic suppurative lung disease (CSLD) is characterized by the presence of a chronic wet or productive cough and recurrent lower respiratory infections. The aim of this study was to identify features of innate, cell-mediated and humoral immunity that may increase susceptibility to respiratory infections in children with CSLD. Because non-typeable Haemophilus influenzae (NTHi) is commonly isolated from the airways in CSLD, we examined immune responses to this organism in 80 age-stratified children with CSLD and compared their responses with 51 healthy control children. Cytokines involved in the generation and control of inflammation (IFN-c, IL-13, IL-5, IL-10 at 72 hours and TNFa, IL-6, IL-10 at 24 hours) were measured in peripheral blood mononuclear cells challenged in vitro with live NTHi. We also measured circulating IgG subclass antibodies (IgG 1 and IgG 4) to two H. influenzae outer membrane proteins, P4 and P6. The most notable finding was that PBMC from children with CSLD produced significantly less IFN-c in response to NTHi than healthy control children whereas mitogen-induced IFN-c production was similar in both groups. Overall there were minor differences in innate and humoral immune responses between CSLD and control children. This study demonstrates that children with chronic suppurative lung disease have an altered systemic cell-mediated immune response to NTHi in vitro. This deficient IFN-c response may contribute to increased susceptibility to NTHi infections and the pathogenesis of CSLD in children.

PLoS ONE, 2011

We adapted DELFIA TM (dissociation-enhanced lanthanide fluoroimmunoassay), a time resolved fluore... more We adapted DELFIA TM (dissociation-enhanced lanthanide fluoroimmunoassay), a time resolved fluorescence method, to quantitate whole venom specific and allergenic peptide-specific IgE (sIgE), sIgG 1 and sIgG 4 in serum from people clinically allergic to Australian native ant venoms, of which the predominant cause of allergy is jack jumper ant venom (JJAV). Intraassay CV was 6.3% and inter-assay CV was 13.7% for JJAV sIgE. DELFIA and Phadia CAP JJAV sIgE results correlated well and had similar sensitivity and specificity for the detection of JJAV sIgE against intradermal skin testing as the gold standard. DELFIA was easily adapted for detecting sIgE to a panel of other native ant venoms.

European Respiratory Journal, 2010

Bacterial colonisation of the airways is associated with increased risk of childhood asthma. Immu... more Bacterial colonisation of the airways is associated with increased risk of childhood asthma. Immunoglobulin (Ig)E against bacterial antigens has been reported in some asthmatics, suggesting a role for bacterial-specific type-2 immunity in disease pathogenesis. We aimed to investigate relationships between bacterial-specific IgE amongst teenagers and asthma susceptibility. We measured titres of IgE against Haemophilus influenzae, Streptococcus pneumoniae and Staphylococcus aureus in 1,380 teenagers, and related these to asthma symptomatology and immunophenotypes. IgE titres against S. aureus-derived enterotoxins were highest amongst atopics and were associated with asthma risk. Surprisingly, IgE titres against H. influenzae and S. pneumoniae surface antigens were higher, not stratified by atopy and independently associated with decreased asthma risk. The positive association between type-2 immunity to S. aureus and asthma phenotypes probably reflects IgE-mediated effector cell activation via enterotoxin super antigens which are secreted in soluble form. The contrasting benign nature of type-2 immunity to H. influenzae and S. pneumoniae antigens may reflect their lower availability in soluble forms that can crosslink IgE receptors. We theorise that instead they may be processed by antigen presenting cells and presented to type-2 memory cells leading to mucosal secretion of interleukin (IL)-4/IL-13, a mechanism widely recognised in other tissues to attenuate T-helper-1 associated bacterialinduced inflammation.

Clinical & Experimental Allergy, 2009

Background Atopic sensitization to the house dust mite (HDM) is associated with altered antibody ... more Background Atopic sensitization to the house dust mite (HDM) is associated with altered antibody responses to the nasopharyngeal colonizing bacterium Haemophilus influenzae and children admitted to the emergency department for asthma exacerbation have reduced IgG responses to HDM allergens. Objective To investigate anti-bacterial and anti-allergen antibody responses during convalescence from asthma exacerbation and differences found in exacerbations associated with and without viral infection. Results IgE antibodies to the P6 bacterial antigen increased in 60% of sera during convalescence and for many children achieved titres as high as IgE titres to allergens. In contrast IgE anti-HDM titres declined during convalescence. The anti-bacterial IgE titres were the same in subjects with and without virus infection while the anti-HDM IgE declined more rapidly in virus-infected subjects. IgG titres to the major HDM allergens showed no consistent increase and the overall IgG anti-HDM titres even declined in subjects without a virus infection. Anti-bacterial IgG antibodies in contrast to IgE did not change. Patients with frequent episodic or persistent asthma had similar IgE anti-bacterial titres to patients with infrequent asthma during the acute phase, although they had reduced IgG titres to both the bacteria and the HDM. Conclusions During the period following an acute exacerbation of asthma there was a marked and specific increase in anti-bacterial IgE compared with a reduced IgE response to HDM. This provides further support for the concept of T-helper type 2 responses to bacterial antigens playing a role in asthma pathogenesis.

Inhalant allergen-specific T-cell reactivity is detectable in close to 100% of atopic and normal individuals: covert responses are unmasked by serum-free medium

Clinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, 1995

It is widely held that in vitro T cell responses to allergens are more prominent in atopic than i... more It is widely held that in vitro T cell responses to allergens are more prominent in atopic than in normal individuals, though this conclusion is based upon culture techniques which fail to detect proliferative responses in a significant minority of atopics and many normals. Study allergen-specific proliferative responses of T cells cultured in serum-free medium (SFM). Examine associations between atopic status, age and T cell reactivity. Initially, peripheral blood mononuclear cells were stimulated with allergens or antigens in SFM, and compared with cells cultured in RPMI + 10% fetal calf serum or human AB serum. Subsequently, T cell reactivity was studied in 34 adults (20-49 years), 27 children (2-13 years), and 19 infants (< or = 10 weeks) using SFM alone. Compared with serum-supplemented medium, SFM enhanced net T cell proliferation, both in bulk culture and when cloning at limiting dilution. In many subjects, SFM unmasked T cell reactivity to allergens which was not otherwise evident, and lowered the threshold allergen levels required for in vitro T cell triggering. For most allergens, T cell proliferative responses did not differ between adults who had specific IgE, and those who did not. The most vigorous responses observed were to ubiquitous inhalant allergens, which stimulated T cells from close to 100% of adults and children, and over 60% of infants. In contrast, responses to the 'vaccine' antigen tetanus toxoid were completely absent in the latter age group, but present in the majority of adults and children. These findings suggest that the extent of active T cell recognition of environmental allergens has been hitherto underestimated, and further that these responses may frequently be initiated in very early life. Additionally, these findings reinforce the notion that qualitative (as opposed to quantitative) variations in specific T cell reactivity ultimately determine allergen responder phenotype.

Clinical & Experimental Allergy, 2007

Background There is evidence that the specificity of the IgE binding in allergy tests can vary fo... more Background There is evidence that the specificity of the IgE binding in allergy tests can vary for different populations. Objective We aimed to examine the allergenic specificity of IgE binding in sera from house dust mite (HDM)-atopic subjects in a tropical Australian Aboriginal community. Methods Sera shown to contain IgE antibodies to an HDM extract of Dermatophagoides pteronyssinus were examined for IgE binding to a panel of nine purified HDM allergens from this mite species by quantitative microtitre assays. IgG antibody binding (IgG1 and IgG4) was also measured. Results The IgE-binding activity in the sera from the Aboriginal community was not directed to the expected major groups 1 and 2 HDM allergens but instead to the group 4 amylase allergen. There was also little IgE binding to the potentially cross-reactive tropomyosin (Der p 10) or arginine kinase (Der p 20) allergens. The IgG4 antibody was rarely detected and limited to the Der p 4 allergen. IgG1 antibody binding was frequently measured to all the allergens regardless of an individual's atopic status, whereas in urban communities it is restricted to the major allergens and to atopic subjects. Conclusion The high IgE anti-HDM response of Australian Aboriginals predominantly bound Der p 4 and not the Der p 1 and 2 allergens, showing a distinctive allergy that could affect the disease outcome and diagnosis.

BMC Pulmonary Medicine, 2012

Background Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are often linked... more Background Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are often linked to respiratory infections. However, it is unknown if COPD patients who experience frequent exacerbations have impaired humoral immunity. The aim of this study was to determine if antibodies specific for common respiratory pathogens are associated with AECOPD. Methods Plasma was obtained from COPD patients when clinically stable. AECOPD requiring hospitalisation were recorded. IgG1 antibodies to H. Influenzae outer membrane protein 6 (P6), pneumococcal surface protein C (PspC) and the VP1 viral capsid protein of rhinovirus were measured. Results COPD patients who had an AECOPD (n = 32) had significantly lower anti-VP1 IgG1 antibody levels when stable compared to COPD patients who did not have an AECOPD (n = 28, p = 0.024). Furthermore, the number of hospitalisations was inversely proportional to anti-VP1 antibody levels (r = −0.331, p = 0.011). In contrast, antibodies specific for P6 and...

The Journal of Immunology, 2009

Severe asthma exacerbations in children requiring hospitalization are typically associated with v... more Severe asthma exacerbations in children requiring hospitalization are typically associated with viral infection and occur almost exclusively among atopics, but the significance of these comorbidities is unknown. We hypothesized that underlying interactions between immunoinflammatory pathways related to responses to aeroallergen and virus are involved, and that evidence of these interactions is detectable in circulating cells during exacerbations. To address this hypothesis we used a genomics-based approach involving profiling of PBMC subpopulations collected during exacerbation vs convalescence by microarray and flow cytometry. We demonstrate that circulating T cells manifest the postactivated “exhausted” phenotype during exacerbations, whereas monocyte/dendritic cell populations display up-regulated CCR2 expression accompanied by phenotypic changes that have strong potential for enhancing local inflammation after their recruitment to the atopic lung. Notably, up-regulation of FcεR1...