Abstract 5400
Background
Type 1 regulatory (Tr1) T cells, like every effector T cells, arise from stimulation of naïve T cell precursor and enter a long term memory pool. While they can adapt their function to specific environmental cues, sometimes called plasticity, their phenotype remains broadly fixed. Unlike natural T regulator cells that emerge from the thymus with a defined phenotype (CD4+CD25hiCD127loFoxP3+), there is uncertainty over the characterisation of inducible Tr1 cells.
Methods
In this study we stimulated human total CD4+ T cells with PMA/ Ionomycin and also demonstrated that these cells respond specifically to costimulation via CD97-CD55. Dual cell surface capture (CSA) was used to assay for IL-10 and IFN-γ and intracellular staining for Tr1 markers.
Results
A small (<5%) population were IL-10+ IL-4-, IFN-γ- and expressed other markers commonly associated with Tr1-like cells. These included; CD49b, LAG-3, CD226, PD-1, CTLA-4, and TIM-3. However they were negative for FoxP3 expression, and expressed Cmaf, which is thought to be responsible for the transcriptional events within this population. Furthermore, we show that these Tr1-like cells form part of the immunological memory and reside predominantly within the effector memory (CD62L- CD45RO+, TEM) pool. Unlike the majority of other studies where Tr1 is generated by chronic stimulation of PBMCs in the presence of recombinant IL-10 for several days, as far as we are aware, this is the first report characterising Tr1 directly ex vivo from human peripheral blood.
Conclusions
We have also demonstrated that these cells respond specifically to costimulation via CD97-CD55 to drive proliferation and maintain the IL-10 single positive, Tr1 phenotype outlined above. This supports the idea that once differentiated from naïve precursors, Tr1-like cells respond to CD55 costimulation to maintain a small (<5%) pool with a committed IL-10+ IL-4-IFN-γ- phenotype.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The University of Nottingham.
Funding
The Commonwealth Scholarships Commission, London.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
785 - JAK-STAT inhibitor overcomes interferon γ-reduced, NK cell-mediated cytotoxicity in non-small-cell lung cancer cells
Presenter: Riki Okita
Session: Poster Display session 1
Resources:
Abstract
2326 - Low LATS2 expression is associated with poor prognosis in non small cell lung cancer
Presenter: Si-hyong Jang
Session: Poster Display session 1
Resources:
Abstract
5960 - Application of ESCAT and OncoKB scales in Liquid biopsy (LB) in Advanced NSCLC patients (pts): Is it feasible and reliable?
Presenter: Michael McCusker
Session: Poster Display session 1
Resources:
Abstract
4855 - IDH1R132H mutation induces a less aggressive phenotype of glioma cells and affects the radiosensitivity by interacting with Wnt/β-catenin signaling
Presenter: Xuetao Han
Session: Poster Display session 1
Resources:
Abstract
2641 - Impact of Angiopoietin-2 on glioblastoma response to combined chemo-radiotherapy
Presenter: Charly Helaine
Session: Poster Display session 1
Resources:
Abstract
5743 - The Discovery of RNA-aptamers That Selectively Bind and Inhibit Glioblastoma Stem Cells by targeting EphA2
Presenter: Alessandra Affinito
Session: Poster Display session 1
Resources:
Abstract
4160 - Impact of tumor reoxygenation by nanoparticles on Tumor Associated Macrophages (TAMs)
Presenter: Aurélie Ferré
Session: Poster Display session 1
Resources:
Abstract
2474 - Prognostic significance of c-Rel/p50 heterodimer in the tumor microenvironment of uveal melanoma
Presenter: Seema Kashyap
Session: Poster Display session 1
Resources:
Abstract
1769 - Synergistic role of BAP1 and DNA damage response pathway in uveal melanoma and its prognostic significance.
Presenter: JAYANTI JHA
Session: Poster Display session 1
Resources:
Abstract
5037 - CXCR4, CCR2 and CCR5 expression in subsets of tumor cells with stem and/or EMT features
Presenter: Olga Savelieva
Session: Poster Display session 1
Resources:
Abstract