Purification of Bioactive Natural Antibodies to PD-1 Known as Regulatory Rheumatoid Factor from Human Blood Plasma.
- 1Laboratory of Molecular and Cellular Immunology, Department of Immunology and Cell Biology, Udmurt State University, 1 Universitetskaya St, Izhevsk 426034, Russia.
- 2Department of Physical and Colloid Chemistry, Peoples' Friendship University of Russia Named After Patrice Lumumba (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia.
- 3Laboratory of Biocompatible Materials, Udmurt Federal Research Center UB RAS, 34 T. Baramzinoy St, Izhevsk 426067, Russia.
Abstract
Background/objectives
Regulatory rheumatoid factor (regRF) is a recently discovered population of natural anti-idiotypic antibodies carrying a shared paratope specific to the PD-1 molecule. Normally, regRF exerts a cytotoxic effect on PD-1-expressing T lymphocytes, including autoreactive ones, thereby controlling their expansion. The specificity for PD-1 indentifies regRF as a promising therapeutic agent for suppressing autoimmune reactions via the PD-1 pathway. The aim of this study was to develop gentle methods for regRF isolation from healthy blood plasma, which would preserve the bioactivity of regRF.Methods
Ammonium sulfate precipitation was used for crude regRF purification. A search for suitable affinity sorbents was carried out. The purified regRF was tested for its bioactivity.Results
Ammonium sulfate precipitation at 35% saturation, followed by extraction with 28% saturated ammonium sulfate solution, allowed the separation of regRF from a portion of non-target IgG and high-molecular-weight fibrinogen. RegRF showed high affinity for Cibacron Blue and no binding to Protein A. Sequential affinity chromatography on immobilized Cibacron Blue and Protein A enabled the purification of regRF from non-target immunoglobulins and low-molecular-weight fibrinogen. The purified regRF samples showed binding to PD-1 and reduced the PD-1+CD4+ T lymphocyte count in vitro.Conclusions
Thus, we have identified sorbents and conditions for the purification of biologically active regRF.
Related
- Positivity Rates and Serum Levels of Antibodies Against Histone H3 Lysine 9 and Its Lactylated Form in Rheumatoid Arthritis and Its Mimics
- CD3-engaging bispecific antibodies convert human regulatory T cells into cytotoxic effectors
- Identification of Plasmodium falciparum var1CSA and var2CSA domains that bind IgM natural antibodies
- Evolving role of Anti-CD20 monoclonal antibodies in rheumatoid arthritis: efficacy, safety, economic perspectives, and future directions-a narrative review.
- Injectable bioactive glass hydrogels orchestrate metalloimmunotherapy by depleting pathogenic B cells and rescuing bone in rheumatoid arthritis
BibTeX
@article{menshikova2026purification,
title = {{Purification of Bioactive Natural Antibodies to PD-1 Known as Regulatory Rheumatoid Factor from Human Blood Plasma.}},
author = {Daria Menshikova and Alexey Terentiev and Pavel Ivanov and Alexandr Cherednichenko and Liubov Beduleva},
journal = {Antibodies (Basel, Switzerland)},
year = {2026},
month = oct,
doi = {10.3390/antib15050098},
url = {https://europepmc.org/article/MED/42930040},
note = {CC BY},
}
RIS
TY - JOUR
TI - Purification of Bioactive Natural Antibodies to PD-1 Known as Regulatory Rheumatoid Factor from Human Blood Plasma.
AU - Daria Menshikova
AU - Alexey Terentiev
AU - Pavel Ivanov
AU - Alexandr Cherednichenko
AU - Liubov Beduleva
PY - 2026
DA - 2026/10/19
JO - Antibodies (Basel, Switzerland)
DO - 10.3390/antib15050098
UR - https://europepmc.org/article/MED/42930040
AB - Background/objectives Regulatory rheumatoid factor (regRF) is a recently discovered population of natural anti-idiotypic antibodies carrying a shared paratope specific to the PD-1 molecule. Normally, regRF exerts a cytotoxic effect on PD-1-expressing T lymphocytes, including autoreactive ones, thereby controlling their expansion. The specificity for PD-1 indentifies regRF as a promising therapeutic agent for suppressing autoimmune reactions via the PD-1 pathway. The aim of this study was to develop gentle methods for regRF isolation from healthy blood plasma, which would preserve the bioactivity of regRF.Methods Ammonium sulfate precipitation was used for crude regRF purification. A search for suitable affinity sorbents was carried out. The purified regRF was tested for its bioactivity.Results Ammonium sulfate precipitation at 35% saturation, followed by extraction with 28% saturated ammonium sulfate solution, allowed the separation of regRF from a portion of non-target IgG and high-molecular-weight fibrinogen. RegRF showed high affinity for Cibacron Blue and no binding to Protein A. Sequential affinity chromatography on immobilized Cibacron Blue and Protein A enabled the purification of regRF from non-target immunoglobulins and low-molecular-weight fibrinogen. The purified regRF samples showed binding to PD-1 and reduced the PD-1+CD4+ T lymphocyte count in vitro.Conclusions Thus, we have identified sorbents and conditions for the purification of biologically active regRF.
SN - 2073-4468
ER -