bioRxiv Science⌕ Search

bioRxiv · 10.1101/2025.01.08.631945

SELECTION OF ANTI-NUCLEAR ANTIGEN (ANA) REACTIVE B CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS.

Abstract

ObjectiveAutoreactive B cells that recognize nuclear antigens are normally present in healthy individuals and patients with systemic lupus erythematosus (SLE), yet their activation and the production of IgG autoantibodies is a hallmark of SLE. The selection process and regulation of these cells in patients with SLE has not been completely understood. To gain insights into tolerance checkpoints and the developmental trajectories of autoreactive clones, we studied the BCR sequences from thousands of anti-nuclear antigen binding (ANA)+ and ANA-B cells from patients with SLE. MethodsFrom a cohort of 13 patients with SLE, we identified and isolated ANA+ and ANA-B cells by flow cytometry using a method based on their binding to nuclear extracts. We sequenced B cell receptor (BCR) heavy chain variable regions and investigated the features of the IgH repertoire of ANA+ and ANA-B cells from naive, memory and age-associated B cells (ABCs), and from total plasmablasts. ResultsThe frequency of ANA+ B cells was similar in ABCs and naive B cells and higher in both than in memory B cells. We observed preferential usage of some VH (IGHV1-18, IGHV3-21, IGHV3-23|3-23D, IGHV4-34, IGHV4-39 and IGHV4-59) and VJ genes (IGHJ4 and IGHJ6) in B cells from these patients. ANA+ naive and ANA+ ABCs used different gene segments and have longer CDR3 sequences than ANA+ memory B cells and ANA-subsets. ANA+ ABCs and memory B cells have a lower frequency of somatic hypermutation (SHM) and less activation induced deaminase (AID) targeting to WRC hotspots compared with their ANA-counterparts. Patients with active disease have a lower frequency of SHM in ANA+ ABCs and memory B cells and in ANA-ABCs. ConclusionCompared to memory B cells, ABCs are enriched in autoreactivity. Our results suggest that there is an immune checkpoint that restricts the differentiation of ANA+ naive B cells into memory B cells and that ANA+ ABCs originate from ANA+ naive B cells. Lower frequencies of SHM in antigen experienced ANA+ B cells, and particularly ANA+ ABCs, suggest that these cells might be generated through an extrafollicular (EF) pathway, and that in patients with active SLE there is more EF activation.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Atisha-Fregoso, Y., Meng, W., Rosenfeld, A., Liu, F., Feltman, S., Aranow, C., Mackay, M., Terestchenko, C., Dunn, M., Scharff, M., Prak, E. L., Diamond, B.. 2025-01-13. SELECTION OF ANTI-NUCLEAR ANTIGEN (ANA) REACTIVE B CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS.. https://doi.org/10.1101/2025.01.08.631945

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

CTR1-mediated copper uptake orchestrates metabolic-epigenetic regulation of pathogenic TH17 cells in autoimmune disease

Pathogenic T helper 17 (pTH17) cells are a subset of CD4+ T cells driving autoimmune diseases including multiple sclerosis (MS). Compared to homeostatic TH17 cells and other TH subsets, pTH17 have enhanced mitochondrial function and oxidative phosphorylation (OXPHOS) that supports their differentiation and pathogenic function. Here we identify Copper Transporter 1 (CTR1), encoded by Slc31a1, as essential for copper uptake in CD4+ T cells, OXPHOS and pTH17 cell differentiation and function. While copper levels are known to be higher in the cerebrospinal fluid of patients with MS compared to healthy individuals, and excess copper contributes to oligodendrocyte loss in murine models of MS, the effect of copper on T cell function and pathogenicity in MS are unclear. We demonstrate that deletion of Slc31a1 in CD4+ T cells decreased intracellular copper levels, disrupting mitochondrial respiration and rewiring metabolism. These changes altered the epigenetic landscape of pTH17 cells by impairing DNA demethylation capacity, leading to hypermethylated DNA and altered chromatin accessibility at key binding sites for AP-1 transcription factors essential for pTH17 differentiation. As a result, CTR1-deficient T cells showed defective differentiation into pTH17 cells, with decreased production of IL-17A and expression of TH17 signature genes, while the differentiation of other CD4+ T cell subsets remained largely unaffected. Moreover, T cell-specific deletion of Slc31a1 protected mice from central nervous system (CNS) inflammation in the experimental autoimmune encephalomyelitis (EAE) model of MS by suppressing clonal expansion of autoreactive CD4+ T cells. These findings establish copper as a critical regulator of pTH17 differentiation and function, revealing a previously unknown molecular link between copper homeostasis, metabolism and epigenetic regulation governing pTH17-mediated autoimmunity.

immunology↗

Fetal-intrinsic antiviral mechanisms emerge over the course of gestation

Congenital viral infections have variable effects on pregnancy outcomes with implications for maternal and fetal health. However, the maternal and fetal immune mechanisms that emerge over the course of gestation to determine protective or pathological outcomes remain poorly understood. Here, we use the emerging congenital pathogen Oropouche virus (OROV) to examine gestational stage-dependent differences in maternal and fetal outcomes in a mouse model of congenital infection. Pregnant mice (dams) infected during early gestation resist severe OROV disease, whereas mid-gestation-infected dams succumb to infection. In contrast, fetal pathology is substantial following early gestation infection but limited following infection during mid-gestation, revealing discordant maternal and fetal susceptibility across gestation. Mid-gestation fetal tissues effectively restricted vertical transmission compared to early gestation fetal tissues, corresponding with reduced fetal pathology. Moreover, both placental and fetal tissue cleared OROV RNA over the course of infection, independent of gestational stage, and failure to clear viral RNA was associated with severe fetal pathology. Spatial analysis of early gestation implantation sites further revealed distinct regional susceptibility to OROV infection across the maternal-fetal interface. We identified potential instances of placental-independent vertical transmission via direct fetal contact with highly infected regions of the contralateral maternal uterus. Finally, we uncovered an unexpected mechanism by which type I interferon signaling contributes to inter-fetal immune crosstalk to restrict both OROV vertical transmission and pathology. Together, these findings establish the fetus as an active participant in antiviral defense and reveal previously unrecognized mechanisms by which fetal-intrinsic antiviral immune responses limit congenital viral infection and disease.

immunology↗

Interferon lambda drives immunological maturation in the infant lung and protects against lethal Bordetella pertussis infection

Serious pertussis infections disproportionately affect infants but the biological basis for this age-dependent susceptibility remains unclear. Infant mouse models recapitulate features of severe human infant pertussis. We investigated the role of interferon lambda (IFN-{lambda}), a key regulator of mucosal immunity, in Bordetella pertussis infection of infant mice. While infected adult mice upregulate lung IFN-{lambda}, infant mice inoculated at P7 fail to upregulate IFN-{lambda} and succumb to infection. We hypothesized that failure to produce IFN-{lambda} during infection represents a critical immunological deficit in infant mice, and that restoring IFN-{lambda} signaling would improve survival outcomes. Whereas wild-type mice gained complete protection from lethal B. pertussis infection by P10, mice lacking the IFN-{lambda} receptor component IFNLR1 did not achieve full protection until P21. Loss of IFNLR1 was associated with enhanced bacterial dissemination to systemic organs. Infant mice possessed a functional IFN-{lambda} receptor in the lungs but failed to upregulate IFN-{lambda} during infection, and supplementing IFN-{lambda} exogenously extended survival. RNA sequencing of lung tissue from infected and uninfected wild-type and IFNLR1-deficient mice inoculated at different ages identified an immune transcriptional framework distinguishing susceptible from resistant animals at a systems level and revealed IFN-{lambda} signaling as a critical driver of immunological maturation in the infant lung. Infected infant IFNLR1-deficient mice had dysregulated immune cell recruitment to the lungs, indicating a quantitatively expanded but qualitatively impaired response. These findings demonstrate that IFN-{lambda} affects immune maturation accounting for a critical window of age-dependent resistance to lethal pertussis with novel therapeutic possibilities for human infants with this disease.

immunology↗