Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.06.15.732353

Sequential and coordinated control of human plasma cell differentiation by IRF4 and BLIMP1 utilizing a discriminating ISRE/EICE motif lexicon

Lau, L. C.·Lal, S.·Fan, J.·Pease, N.·Singh, H.
View original source ↗Export metadata ↓

Abstract

The transcription factors IRF4 and BLIMP1 (PRDM1) promote plasma cell (PC) differentiation by repressing B cell identity genes while inducing the unfolded protein response, ER/Golgi biogenesis, and immunoglobulin secretion. How IRF4 and BLIMP1 partition and coordinate their genomic activities during plasma cell differentiation remains unresolved. Using naive human B cells and a stepwise in vitro differentiation system, we performed CRISPR/Cas9 perturbations of IRF4 or PRDM1 in plasma cell precursors followed by single-cell RNA sequencing. Despite their mutually reinforced expression and shared recognition of related IRF-family motifs (ISREs and EICEs), loss of IRF4, but not of BLIMP1, yielded a stunted intermediate with incomplete silencing of B cell identity genes and defective induction of the secretory program. Multiome profiling, base-pair-resolution motif modeling, CUT&RUN, and DNA-binding assays identified non-conserved nucleotides within ISRE/EICE motifs that discriminate IRF4 from BLIMP1 binding. These findings reveal a motif-lexicon-dependent IRF4-BLIMP1 interplay, in which IRF4 first acts independently and then in concert with BLIMP1. This regulatory logic may also underlie programming of additional lymphocyte effector states.

Explore related subjects

immunologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Lau, L. C., Lal, S., Fan, J., Pease, N., Singh, H.. 2026-06-19. Sequential and coordinated control of human plasma cell differentiation by IRF4 and BLIMP1 utilizing a discriminating ISRE/EICE motif lexicon. https://doi.org/10.64898/2026.06.15.732353

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

KEEP EXPLORING

Related preprints

bioRxiv2026

Melanoma suppresses galectin-9-glycan axis in dendritic cells and galectin-9 restoration limits T regulatory cell expansion

Dendritic cells (DCs) are key orchestrators of anti-tumor adaptive immune responses. Their function is tightly regulated by galectins, a family of carbohydrate-biding proteins that decode extracellular glycans into intracellular signaling. Here, we show that exposure to melanoma-conditioned media (CM) induces loss of galectin-9 (gal-9) at the DC surface. Notably, gal-9 loss, independent of transcriptional regulation, was associated with the acquisition of an immunosuppressive phenotype in CD14cDC2 cells following tumor exposure, with higher-molecular weight fractions of the melanoma secretome as mediators. Notably, gal-9 depletion was mirrored with a reduction in gal-9 ligands on the cell surface, particularly GalNAc-containing glycoepitopes, pointing towards a melanoma-exploited gal-9-glycan axis as a DC-evasive strategy. Interestingly, restoring gal-9 surface levels in CM-exposed CD14cDC2 cells prevented the expansion of regulatory T cells (Tregs), postulating gal-9 as a novel immunomodulatory molecule in DC-mediated Treg induction during melanoma progression. Altogether, our data suggest that melanoma-derived factors remodel the DC glycan-gal-9 axis to enhance T cell differentiation towards regulatory phenotypes and dampen anti-tumor immunity. This identifies the gal-9/glycan axis in CD14cDC2 cells as a vulnerable node in melanoma immune evasion and as a potential therapeutic target.

immunology↗
bioRxiv2026

Repeated shrimp allergen exposure drives 5-lipoxygenase-dependent avoidance and selective gut-brain activation

Peripheral immune processes can shape animal behavior, yet how noninfectious inflammatory reactions affect neural activity and behavioral outputs remains poorly understood. We developed an optimized murine model of shrimp allergy using whole shrimp extract to examine how a complex dietary allergen elicits integrated immune, neural, and behavioral responses. Sensitized mice received repeated oral shrimp challenges and were assessed for allergic pathology, food preference, affective-like behaviors, and neuronal activation in the brain. Repeated exposure increased total IgE and shrimp-specific IgG1, induced mast cell activation, accelerated gastrointestinal transit, caused mild hypothermia consistent with oral anaphylaxis, and increased intestinal length. Shrimp-sensitized mice did not avoid shrimp solution after sensitization alone. Instead, avoidance emerged only after repeated oral challenges and strengthened over time. This delayed aversion occurred without detectable changes in locomotor activity or measures of anxiety-like or depressive-like behavior at the time points tested. Repeated shrimp exposure increased cFOS expression in the area postrema, nucleus of the tractus solitarius, central amygdala, and paraventricular nucleus of the thalamus, implicating brainstem and limbic-thalamic pathways involved in visceral sensing and aversion. Pharmacological inhibition of 5-lipoxygenase partially reversed avoidance and reduced circulating mast cell protease-1 in allergic mice. These findings establish a robust whole-shrimp allergy model and show that a complex food allergen engages gut-brain pathways to promote 5-lipoxygenase-dependent avoidance. The delayed, selective nature of this response supports immune-mediated food aversion as a shared output of food allergy, while suggesting that its kinetics and neural recruitment vary with allergen identity and inflammatory context.

immunology↗
bioRxiv2026

Targeting IL-2 to inflamed tissues via oxidation-specific epitopes enables third-generation bispecific IL-2 therapeutics

Interleukin-2 (IL-2) is essential for the survival and activation of regulatory T cells (Tregs). Low-dose native IL-2 (IL-2LD) therapy restores immune regulation in vivo and has shown reproducible clinical benefit across multiple autoimmune, inflammatory, and neuroimmune diseases. Attempts to improve IL-2 through engineered variants (muteins) have mainly focused on enhancing Treg selectivity by reducing IL-2 receptor {beta}-chain binding, but this strategy profoundly diminishes biological potency, likely contributing to the limited clinical efficacy of IL-2 muteins. Here, we develop a ''third-generation IL-2'' that combines site-specific targeting and bifunctionality. We generated a bivalent fusion protein linking IL-2 to a single-chain antibody recognizing oxidation-specific epitopes (OSEs), which are abundantly expressed at inflamed sites. Targeting OSEs provides not only site-specific localization, but also true bifunctionality as both anti-OSE antibodies and IL-2LD independently show therapeutic benefit in limiting inflammation. We first show that IL-2IT has bifunctional biological activities in vitro. In vivo, IL-2IT had increased specificity for Treg over Teff activation, which we attribute to a conformation-dependent modulation of IL-2 receptor engagement. Importantly, IL-2IT provided precise delivery to inflamed tissues in models of psoriasis and colitis. Altogether, this resulted in superior therapeutic benefit in multiple clinical settings, including in atherosclerosis models. Thus, our strategy illustrates a generalizable approach to cytokine engineering that preserves native signaling while achieving spatial control. Specifically, our findings validate OSE targeting as an efficient strategy to guide therapeutics to sites of inflammation and establish OSE-IL-2 as a promising bispecific Treg engager for treating inflammation.

immunology↗