Effectiveness of Soluble CTLA-4-Fc in the Inhibition of Bone Marrow T-Cell Activation in Context of Indoleamine 2.3-Dioxygenase (IDO) and CD4+Foxp3+ Treg Induction

Magdalena Massalska; Marzena Ciechomska; Ewa Kuca-Warnawin; Tomasz Burakowski; Anna Kornatka; Anna Radzikowska; Dariusz Pawlak; Barbara Muz; Adrianna Loniewska-Lwowska; Andrzej Palucha; Pawel Maldyk; Wlodzimierz Maslinski

doi:10.2147/JIR.S359775

Effectiveness of Soluble CTLA-4-Fc in the Inhibition of Bone Marrow T-Cell Activation in Context of Indoleamine 2.3-Dioxygenase (IDO) and CD4⁺Foxp3⁺ Treg Induction

J Inflamm Res. 2022 Dec 22:15:6813-6829. doi: 10.2147/JIR.S359775. eCollection 2022.

Affiliations

¹ Department of Pathophysiology and Immunology, National Institute of Geriatrics, Rheumatology, and Rehabilitation (NIGRiR), Warsaw, 02-637, Poland.
² Department of Pharmacodynamics, Medical University of Bialystok, Bialystok, 15-222, Poland.
³ Department of Radiation Oncology, Cancer Biology Division, Washington University School of Medicine, St. Louis, MO, 63108, USA.
⁴ Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, 02-106, Poland.
⁵ Genomed S.A. Ponczowa 12, Warsaw, 02-971, Poland.
⁶ Department of Rheumoorthopaedic Surgery, National Institute of Geriatrics, Rheumatology, and Rehabilitation (NIGRiR), Warsaw, 02-637, Poland.
⁷ Clinical Department of Orthopaedic and Traumatology of Locomotor System, Enfant-Jesus Clinical Hospital, Warsaw, 02-005, Poland.

Abstract

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease with systemic inflammation finally resulting in damaged joints. One of the RA development models suggests bone marrow (BM) as a place of inflammation development further leading to disease progression. We aimed to investigate the potential of CTLA-4-Fc molecule in inducing tolerogenic milieu in BM measured as indoleamine 2,3-dioxygenase (IDO) expression, CD4⁺Foxp3⁺ Treg induction, and T cell activation control. The expression of IDO-pathway genes was also examined in monocytes to estimate the tolerogenic potential in the periphery.

Methods: Bone marrow mononuclear cells (BMMC) were stimulated by pro-inflammatory cytokines and CTLA-4-Fc. Next IDO expression, CD4⁺CD69⁺ and CD4⁺Foxp3⁺ percentage were estimated by PCR and FACS staining, respectively. Enzymatic activity of IDO was confirmed by HPLC in BM plasma and blood plasma. Genes expressed in IDO-pathway were analyzed by NGS in peripheral monocytes isolated from RA patients and healthy controls.

Results: We found that CTLA-4-Fc and IFN-γ stimulation results in IDO production by BMMC. CTLA-4-Fc induced tryptophan catabolism can inhibit mitogen-induced CD4⁺ T cells activation without influencing CD8⁺ cells, but did not control CD25 nor Foxp3 expression in BM cells. Significantly higher expression of selected IDO-pathway genes was detected on peripheral monocytes isolated from RA as compared to healthy controls.

Conclusion: This study sheds light on some immunosuppression aspects present or induced in BM. The potential of IDO-mediated pathways were confirmed in the periphery, what may represent the promising candidates for therapeutic strategies in RA.

Keywords: CD4+Foxp3+; CTLA-4-Fc; bone marrow; indoleamine 2,3- dioxygenase; monocytes; rheumatoid arthritis.

Grants and funding

This work was supported by the core grant No S/9 National Institute of Geriatrics, Rheumatology, and Rehabilitation from the Polish Ministry of Science and Higher Education and grant No 2018/30/E/NZ5/00104 from the National Science Centre (M.C.).