Biology subjects

Sluetter, B.

Publications and source records attributed to Sluetter, B..

3 recordsLinked to original sources

bioRxiv2026

CD8+ T-cells protect against experimental atherosclerosis through antigen specific interactions in the plaque

Atherosclerosis is a chronic inflammatory disease with a significant adaptive immune component. CD8+ T cells accumulate in plaques and display signatures of antigen-specific activation. However, whether this accumulation is driven by local antigen recognition and what functional consequences follow, remains poorly understood. Here we address this gap of knowledge using loss- and gain-of-function experiments. Atherosclerotic Rag-/-Ldlr-/- mice received adoptively transferred wildtype or antigen-restricted CD8+ T cells alongside CD4+ T cells to distinguish antigen-specific from antigen-independent responses. In a complementary model, ApobOVA-TGxLdlr-/- mice, expressing an ovalbumin-tagged variant of the atherosclerosis-associated ApoB100 protein, enabled OT-I CD8+ T cells to function as atherosclerosis-antigen-specific CD8+ T cells. T-cell distribution, activation and phenotype were assessed systemically and within lesions, plaque burden and composition were quantified histologically. Wildtype CD8+ T cells accumulated significantly more in aortic lesions compared to antigen-restricted CD8+ T cells, and exhibited increased activation, exhaustion and cytokine secretion, indicating that plaque-infiltrating T cells are predominantly antigen-specific. Perturbing antigen-specific CD8+ T-cell interactions significantly decreased plaque stability index, suggesting a protective role for antigen-specific CD8+ T cells. In ApobOVA-TGxLdlr-/- mice, OT-I T cells accumulated at high frequency in the liver, consistent with hepatic ApoB100-expression, and were found in circulation and aorta. Histological analysis revealed reduced plaque burden in OT-I recipients, reproducing an atheroprotective effect of antigen-specific CD8+ T-cell responses. Plaque reduction coincided with reduced TUNEL, but similar Caspase 3 staining, suggesting OT-I transfer results in reduced secondary necrosis. In line with this, CD47 expression in OT-I recipient mice was reduced and in vitro, OT-I but not antigen non-specific CD8+ T cells reduced expression of CD47 on OVA-presenting foam cells. CD8+ T-cell accumulation in experimental atherosclerosis is driven primarily by antigen-specific interactions and such responses are associated with plaque stabilization and reduced lesion formation, potentially through induction of apoptosis and prevention of secondary necrosis

pathology↗

bioRxiv2026

Stereochemical identity of lipid nanoparticles modulates protein expression via internal lipid organization

Stereochemistry plays a crucial role in how molecules interact with complex physiological environments, affecting pharmacokinetics, pharmacodynamics, efficacy, and toxicity. Although these effects are well studied for small-molecular drugs, they are largely overlooked for supramolecular assemblies used in drug delivery. Even for lipid nanoparticles (LNPs)--the most advanced RNA delivery platform--stereochemical effects are rarely investigated and, when considered, are typically limited to the ionizable lipid rather than the overall stereochemical identity of the LNP. Here we separate the ionizable lipid cKK-E12 into its two stereoisomers (trans: R,S/S,R; cis: R,R/S,S), which are normally used as a mixture. LNPs containing the cis isomer exhibit improved physicochemical properties, stability, and protein expression. By systematically varying the stereochemistry of the ionizable lipid, phospholipid, and cholesterol, we reveal stereochemistry-dependent differences in uptake and protein expression across six cell lines and in vivo in zebrafish embryos and mice. AI-assisted cryo-TEM analysis and SAXS link enhanced protein expression to structural differences, demonstrating control over internal lipid phases (lamellar and inverse hexagonal), influencing sample uniformity, and identifying stereochemical identity as a key determinant of functional RNA delivery.

pharmacology and toxicology↗

bioRxiv2026

A single-nucleotide change in the Kozak sequence enhances protein expression

In vitro-transcribed messenger RNA (IVT mRNA) has emerged as a versatile protein expression platform with broad clinical potential. Current optimization strategies for IVT mRNA focus on untranslated regions (UTRs), mRNA stability, and codon usage, often guided by massively parallel screening and machine learning approaches. In contrast, the Kozak sequence, a key determinant of translation initiation, is often inconsistently incorporated into synthetic 5' UTR design, and its contribution to translation efficiency remains poorly defined. Here, we systematically varied the Kozak sequence across diverse UTR contexts and performed combinatorial optimization using synthetic, established, and viral UTRs to identify design principles for enhanced translation. We show that a single-nucleotide deviation from the consensus Kozak sequence consistently enhances protein expression across UTR contexts and coding sequences. This effect is conserved across in vitro and in vivo models, highlighting the generalizability of the optimized Kozak sequence. These findings redefine the role of the Kozak sequence in synthetic mRNA design and demonstrate its substantial contribution to translation efficiency when optimized, enabling improved mRNA-based therapeutics.

bioengineering↗