Dataset DOI: 10.5061/dryad.0gb5mkmch

Description of the data and file structure

Study cohorts

A subset of school-age individuals (age range 7-13 years) from the Western Australian Twin Study of Child Health (WATCH). A total of 93 twin pairs (186 individuals) were included in the present study.

Clinical parameters

Atopy was defined as either (i) a positive skin prick test (SPT, wheal size ≥3mm) for any of the most common aeroallergens including house dust mite (HDM), cat dander, dog dander, fungi (Alternaria alternata, Aspergillus spp.), cockroach, perennial rye grass, mixed grass, and mixed mould or (ii) a total IgE level above 300 IU/mL as measured by a clinical pathology laboratory in Australia.

Flow cytometry analysis

Approximately 1x10^6 thawed PBMCs were stained. Briefly, thawed PBMC were washed using PBS supplemented with 0.5% BSA and 0.1% NaN3 (Flow buffer), incubated with the extracellular antibody mixture at 4 °C for 30 min, washed and incubated in fixation/permeabilised solution for 30 min at 4 °C (Thermo Fisher) followed by intracellular FoxP3-PE staining at 4 °C for 30 min, washed and resuspended in Flow buffer for flow cytometric data generation. Flow data were acquired using the LSR-Fortessa II with FACSDiva software (BD Bioscience). Processing of samples was block-randomised, ensuring that all twin pairs were processed in the same batch, this to reduce technical variation in the paired analysis.

Cell culture and cytokine quantification

Thawed PBMC were resuspended in RPMI + 10% FCS and cultured at 0.25x10^6 cells per well, in 250 mL, in round-bottom 96-well culture plates. Cells were stimulated with 1 μg/mL Phytohemagglutinin (PHA, Remel-Thermo), 25 pg/mL Lipopolysaccharide (LPS, Alexis-Enzo), or 0.5 mg/mL HDM (CSL) and incubated for 24 hours at 37 °C and 5% CO2. Following culture, supernatants were collected for cytokine assays and stored at -80 °C. From the HDM-stimulated cultures, cells were also washed and prepared for flow cytometry analysis, as above. For evaluation of cytokine content in cell supernatant, a 13-plexed cytokine panel (in-house) was used and analysed on a Luminex 100 System. Briefly, post-culture supernatants and in-house quality controls (one high and one low made from recombinant human standards) were diluted 1:2 in culture media. Pooled standards were also diluted in culture media, and cytokines were quantified as pg/mL concentration with reference to a standard curve. Antibodies were coupled to MagPlex beads (Luminex Corp), and the Luminex assay was performed using the manufacturer’s instructions. Standard curves and quantitation were determined using BioPlex Pro Manager software. In-house quality controls (high and low) were included across each plate and accepted if their values fell within 2 standard deviations of the mean.

Files and variables

File: ex_vivo.zip

Description: Flow cytometry data files on ex vivo samples. These can be linked using the “Ex vivo FCS file” variable in the metadata file.

File: HDM-stim.zip

Description: Flow cytometry data on samples stimulated in vitro with HDM. These can be linked using the “HDM-stim FCS file” variable in the metadata file.

File: Meta_data.csv

Description: Twin- and Atopy-specific parameters, as detailed in the variable section, and also including cytokine production following stimulation with PHA, LPS, and HDM, cytokine concentrations are depicted in pg/mL. As an example, “LPS [IFNg]” depicts the concentration of IFNg following stimulation with LPS.

Variables

• Subject ID (unique for each individual)
• Family ID (common for each twin pair)
• Zygosity (monozygotic and dizygotic)
• Sex (male or female)
• Age [yrs] (binned to avoid identification)

• Current Atopy (yes=1, no=0, based on definition as detailed above)
• HDM SPT+ (yes=1, no=0, skin-prick test positive for HDM)
• Technical Batch (batch in which samples were stained/cultured)
• total IgE [plasma] (in IU/mL)
• Ex vivo FCS file (file name to link with ex vivo flow cytometry data)
• HDM-stim FCS file (file name to link with HDM-stim flow cytometry data)
• LPS [IFNg]
• LPS [IL1b]
• LPS [IL5]
• LPS [IL6]
• LPS [IL8]
• LPS [IL9]
• LPS [IL10]
• LPS [IL12]
• LPS [IL13]
• LPS [IL18]
• LPS [IP10]
• LPS [MIP1a]
• LPS [TNF]
• PHA [IFNg]
• PHA [IL1b]
• PHA [IL5]
• PHA [IL6]
• PHA [IL8]
• PHA [IL9]
• PHA [IL10]
• PHA [IL12]
• PHA [IL13]
• PHA [IL18]
• PHA [IP10]
• PHA [MIP1a]
• PHA [TNF]
• HDM [IFNg]
• HDM [IL1b]
• HDM [IL5]
• HDM [IL6]
• HDM [IL8]
• HDM [IL9]
• HDM [IL10]
• HDM [IL12]
• HDM [IL13]
• HDM [IL18]
• HDM [IP10]
• HDM [MIP1a]
• HDM [TNF]

Access information

NA

Human subjects data

All participants have consented to that their research data will be published and the data has been de-identified prior to submission into the public domain.