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Updated: Jun 27, 2026
Adenoviral Transduction of Naive CD4 T Cells to Study Treg Differentiation
Published on: August 13, 2013
In vitro induction of T cells that are resistant to A2 adenosine receptor-mediated immunosuppression
Akio Ohta1, J Kjaergaard, S Sharma
1New England Inflammation and Tissue Protection Institute, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA. a.ohta@neu.edu
Background And Purpose:
The increased levels of extracellular adenosine in inflamed tissues down-regulate activated immune cells via the A(2A) adenosine receptor. This A(2A) adenosine receptor-mediated immunosuppression is a disqualifying obstacle in cancer immunotherapy as it protects cancerous tissues from adoptively transferred anti-tumour T cells. The aim of this study was to test whether the negative selection of T cells will produce T cells that are resistant to inhibition by extracellular adenosine.
Experimental Approach:
Cytotoxic T lymphocytes (CTL) were developed by mixed lymphocyte culture in the presence or absence of the adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA). The sensitivity of CTL to adenosine analogues was characterized by cAMP induction, interferon-gamma production and cytotoxicity.
Key Results:
CTL that could proliferate even in the presence of NECA were less susceptible to inhibition by A(2A) adenosine receptor agonists, as shown by a much smaller accumulation of cAMP and less inhibition of interferon-gamma production compared with control CTL. The successful protocol to produce CTL that are both resistant to adenosine-mediated immunosuppression and maintain strong cytotoxicity and interferon-gamma secretion required NECA to be added only during the expansion stage after the establishment of CTL. In contrast, the priming of resting T cells in the presence of NECA resulted in T cells with impaired effector functions.
Conclusions And Implications:
Adenosine-resistant effector T cells were successfully obtained by exposure of activated T cells to NECA. These in vitro studies form the basis for future attempts to produce anti-tumour T cells that are more effective in adoptive immunotherapy.
Insights
Researchers developed adenosine-resistant T cells to overcome immunosuppression in cancer immunotherapy. This approach enhances the effectiveness of anti-tumour T cells for adoptive immunotherapy by making them resistant to adenosine inhibition.
Area of Science:
- Immunology
- Cancer Research
- Pharmacology
Background:
- Extracellular adenosine in inflamed tissues suppresses immune cells via the A(2A) adenosine receptor.
- This immunosuppression hinders cancer immunotherapy by protecting tumors from anti-tumor T cells.
Purpose of the Study:
- To investigate if T cells can be made resistant to extracellular adenosine inhibition.
- To develop T cells that can overcome adenosine-mediated immunosuppression in cancer immunotherapy.
Main Methods:
- Cytotoxic T lymphocytes (CTL) were cultured with or without the adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA).
- Sensitivity to adenosine was assessed by measuring cAMP induction, interferon-gamma production, and cytotoxicity.
- Optimized protocol involved NECA addition during the expansion stage of activated T cells.
Main Results:
- CTLs expanded with NECA showed reduced susceptibility to A(2A) adenosine receptor agonists.
- These cells exhibited less cAMP accumulation and preserved interferon-gamma production compared to controls.
- Adding NECA during T cell priming impaired effector functions, while adding it during expansion yielded resistant CTLs.
Conclusions:
- Adenosine-resistant effector T cells were successfully generated by exposing activated T cells to NECA.
- These findings support the development of more effective anti-tumor T cells for adoptive immunotherapy.
