Identification of Tr1 Cells and Other CD4+ T Cell Subsets in Humans Using Mass Cytometry: A Tool for Understanding Asthma
Monday, March 7, 2016: 3:00 PM
Room 403A (Convention Center)
Mary Prunicki, PhD, MD, , , ,
Rationale: T cell subsets contribute to immune functioning and are critical for controlling allergic disease.  We studied asthmatic and non-asthmatic children to investigate the contributions of various T cell subsets.

Methods: Peripheral blood mononuclear cells (PBMCs) from healthy (n=10) and current asthmatic children (n=10) (based on Global Initiative for Asthma guidelines) were stained with 30 metal-conjugated antibodies for surface and intracellular targets. Plasma total IgE levels were measured. Pyrosequencing of the FoxP3 gene at 10 different CpG sites was also performed.

Results: T cell subsets (Tr1, Treg, Th1, Th2, Th17, TCRgd) were identified using both Flow-Jo and 2 dimensional display using viSNE. Methylation at 4 CpG sites in the promoter region was negatively correlated with the percentage of Tr1 cells (CpG -146, p<.01; CpG-133, p<.01; CpG -127, p<.03; CpG -83, p<.02).  IgE level negatively correlated with percentage of Treg cells (p<.05).  In addition, there was a trend for asthmatics to have fewer Tr1 cells than healthy controls (p<.08).

Conclusions: This study is the first to our knowledge to identify of all of these T cell subsets using mass cytometry.  Analysis at a single-cell level may be superior to flow cytometry, and elucidate more subtle findings, as reported here even with a limited sample size.  These preliminary data indicate that asthmatics may have a reduced amount of Tr1 cells in comparison to non-asthmatics.  Tr1 cells also correlate with FoxP3 methylation levels in the promoter region.  Finally, IgE levels are inversely related to the number of Treg cells.