Posttranscriptional control of the B cell receptor by HuR is essential for innate B cell maintenance and function

D Dunja Capitan-Sobrino (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) M Mailys Mouysset (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) O Orlane Maloudi (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) Y Yann Aubert (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) I Ines C. Osma-Garcia (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) T Trang-My M. Nguyen (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) G Greta Dunga (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) M Maia Nestor-Martin (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) V Virginie Mieulet (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan) M Manuel D. Diaz-Muñoz (Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan)

Abstract

Innate B-1 cells constitute a self-maintained layer of defense for early detection of bacteria, clearance of apoptotic cell debris, and removal of autoantigens driving autoimmunity. B-1 cells are originated from fetal tissues, but, as opposed to B-2 cells, the molecular mechanisms behind their development and homeostatic maintenance remain largely unknown. Here, we demonstrate that posttranscriptional regulation by the RNA binding protein HuR is essential for the homeostatic self-replenishment of innate B-1a cells, the expansion of B-1 cell clones targeting self-antigens, and the production of natural autoantibodies. HuR KO B-1 cells fail to express the high levels of surface B-cell receptor (BCR), TACI, and BAFFR required for tonic signaling and cell survival. At the molecular level, HuR promotes the translation of messenger RNAs encoding the IgM heavy chain and modules, in a direct or indirect manner, the expression of TACI and BAFFR. In summary, we reveal the need for posttranscriptional regulation in BCR expression, tonic signaling, and homeostatic maintenance of functional innate B-1 cells.

Article Details

Volume / Issue Vol. 122, Issue 37
Published September 16, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (10)

D

Dunja Capitan-Sobrino

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

M

Mailys Mouysset

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

O

Orlane Maloudi

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

Y

Yann Aubert

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

I

Ines C. Osma-Garcia

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

T

Trang-My M. Nguyen

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

G

Greta Dunga

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

M

Maia Nestor-Martin

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

V

Virginie Mieulet

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan

M

Manuel D. Diaz-Muñoz

Toulouse Institute for Infectious and Inflammatory Diseases (INFINITY), Inserm UMR1291, CNRS UMR5051, University of Toulouse, Centre Hospitalier Universitaire (CHU) de Toulouse - Purpan