A PATHOGENIC NFKB2 VARIANT CAUSES COMBINED IMMUNODEFICIENCY WITH THYMIC AND PERIPHERAL LYMPHOID DEFECTS IN RATS
- 1CR2TI UMR 1064, INSERM
Abstract
The non-canonical NF-kappa B pathway, in which NFKB2 plays a central role, is critical for lymphoid organ development and immune homeostasis. Pathogenic NFKB2 variants have been strongly associated with a broad spectrum of human pathologies, notably immunodysregulation syndromes, characterized by recurrent infections, autoantibody production and endocrine abnormalities. The mechanisms underlying the resulting immune defects remain incompletely understood. In the present study, we characterized the immune phenotype of a novel rat model harboring a Nfkb2 non-sense mutation located in the c-terminal region of the gene (c.2602T>A; p.Tyr867*, Nfkb2p.Tyr867*). This variant has been identified in patients with a familial form of common variable immunodeficiency (CVID) presenting with autoimmunity manifestations. Using this model, we demonstrate that mutated NFKB2 resulted in profound alterations of the thymic microenvironment, including reduced K5+ medullary thymic epithelial cells and decreased AIRE expression, accompanied by altered thymocyte development and impaired thymic regulatory T populations. Peripheral lymphoid organization was also profoundly affected, with absence of lymph nodes, defects in the splenic marginal zone, and alterations of CD4+ and CD8+ T-cell homeostasis, including impaired Treg populations and reduced ICOS expression on CD4+ T cells. The B-cell compartment was markedly altered, with impaired B-cell maturation, characterized by accumulation of IgM+IgD- transitional cells and a marked reduction of IgD+ mature B cells. These abnormalities were associated with impaired humoral immunity and complete absence of circulating immunoglobulins. Collectively, our findings define a systemic combined immunodeficiency phenotype in the Nfkb2-mutated rat, highlighting its utility for studying the role of non-canonical NF-kB signaling in immune system organization and adaptative immunity.
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BibTeX
@misc{remy2026pathogenic,
title = {{A PATHOGENIC NFKB2 VARIANT CAUSES COMBINED IMMUNODEFICIENCY WITH THYMIC AND PERIPHERAL LYMPHOID DEFECTS IN RATS}},
author = {S. Remy and L. Tesson and C. Usal and M. Massoda and S. Menoret and I. Proekt and D. Yu and A. You and M. Giraud and M. S. Anderson and I. Anegon},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.02.756202},
url = {https://www.biorxiv.org/content/10.64898/2026.10.02.756202v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - A PATHOGENIC NFKB2 VARIANT CAUSES COMBINED IMMUNODEFICIENCY WITH THYMIC AND PERIPHERAL LYMPHOID DEFECTS IN RATS
AU - S. Remy
AU - L. Tesson
AU - C. Usal
AU - M. Massoda
AU - S. Menoret
AU - I. Proekt
AU - D. Yu
AU - A. You
AU - M. Giraud
AU - M. S. Anderson
AU - I. Anegon
PY - 2026
DA - 2026/10/02
PB - bioRxiv
DO - 10.64898/2026.10.02.756202
UR - https://www.biorxiv.org/content/10.64898/2026.10.02.756202v1
AB - The non-canonical NF-kappa B pathway, in which NFKB2 plays a central role, is critical for lymphoid organ development and immune homeostasis. Pathogenic NFKB2 variants have been strongly associated with a broad spectrum of human pathologies, notably immunodysregulation syndromes, characterized by recurrent infections, autoantibody production and endocrine abnormalities. The mechanisms underlying the resulting immune defects remain incompletely understood. In the present study, we characterized the immune phenotype of a novel rat model harboring a Nfkb2 non-sense mutation located in the c-terminal region of the gene (c.2602T>A; p.Tyr867*, Nfkb2p.Tyr867*). This variant has been identified in patients with a familial form of common variable immunodeficiency (CVID) presenting with autoimmunity manifestations. Using this model, we demonstrate that mutated NFKB2 resulted in profound alterations of the thymic microenvironment, including reduced K5+ medullary thymic epithelial cells and decreased AIRE expression, accompanied by altered thymocyte development and impaired thymic regulatory T populations. Peripheral lymphoid organization was also profoundly affected, with absence of lymph nodes, defects in the splenic marginal zone, and alterations of CD4+ and CD8+ T-cell homeostasis, including impaired Treg populations and reduced ICOS expression on CD4+ T cells. The B-cell compartment was markedly altered, with impaired B-cell maturation, characterized by accumulation of IgM+IgD- transitional cells and a marked reduction of IgD+ mature B cells. These abnormalities were associated with impaired humoral immunity and complete absence of circulating immunoglobulins. Collectively, our findings define a systemic combined immunodeficiency phenotype in the Nfkb2-mutated rat, highlighting its utility for studying the role of non-canonical NF-kB signaling in immune system organization and adaptative immunity.
ER -