Biology subjects

Puth, S.

Publications and source records attributed to Puth, S..

3 recordsLinked to original sources

bioRxiv2026

Single-Particle STORM Imaging Quantifies Coating Heterogeneity Among Cell Membrane-Coated Nanoparticles

Cell membrane-coated nanoparticles (CNPs) are a potentially transformative biomimetic targeted-delivery platform, which can engage therapeutic targets through source-cell membrane protein functions or homotypic interactions. However, their therapeutic development is limited by the current inability to accurately resolve membrane coating completeness, and CNP particle-to-particle variation. Here, we introduce a STochastic Optical Reconstruction Microscopy (STORM)-based approach that resolves population composition and quantifies membrane coating coverage at the single-particle level. Applying it to dendritic cell membrane- and HeLa cell membrane-coated nanoparticles (DCmPs and HeLamPs), we revealed substantial heterogeneity within both particle types and a cell-type dependence of coating outcomes, corroborated by confocal imaging and flow cytometry. We also quantified membrane protein composition, including peptide major histocompatibility complex class I (pMHC-I) among DCmPs, and confirmed that DCmPs preferentially engaged antigen-specific T cells in coculture. This single-particle framework establishes a quantitative standard for CNP characterization, providing a foundation for quality control and rational design.

bioengineering↗

bioRxiv2025

Development of Dendritic Cell Membrane-Coated Nanoparticles for Antigen-Specific T Cell Engagement

Dendritic cell (DC) membrane-coated nanoparticles (DCmPs) hold significant potential for antigen-specific therapies. DCmPs carry key DC membrane proteins that facilitate DC-T cell interaction, such as major histocompatibility complex (MHC), costimulatory CD80/86, and adhesive molecules ICAM-1. However, our current understanding of the impact of the coating processes and the composition of the final products is very limited, significantly hindering the development of DCmP-based therapy. Here, using DC2.4 cell membrane proteins and poly (lactic-co-glycolic acid) (PLGA) nanoparticles, we comprehensively characterized and compared the compositions and functions of DCmPs produced using sonication, extrusion, and a newly developed combined coating approach (sonication coating following by extrusion process). The combined coating approach achieved relatively high level of protein coating and exerted superior control over the diameter and uniformity of DCmPs relative to sonication and extrusion. We also developed a characterization strategy by leveraging the homotypic interactions between DCmPs and DC2.4 cells and determined that about 80% of PLGA particles are coated with membrane proteins and both unbound proteins and uncoated particles similarly present in the final products after the three coating processes. Because DC2.4 cells exclusively express MHC class I molecules, DCmPs showed preferentially bind to cognate B3Z CD8+ T cells over DOBW CD4+ T cells, confirming that DCmPs bind to T cells in an antigen-specific fashion. Furthermore, we demonstrated that DCmPs can activate B3Z CD8+ T cells in vitro, similar to DC2.4 cells. These findings demonstrate a new coating approach that potentially improves size control over membrane-coated particles and a characterization strategy for detailed analysis of coated particle composition, having important and broad implications for the therapeutic development of DCmPs and other membrane-coated particle technology.

bioengineering↗

bioRxiv2019

A stealth adhesion factor contributes to Vibrio vulnificus pathogenicity: Flp pili play roles in host invasion, survival in the blood stream and resistance to complement activation

The tad operons encode the machinery required for adhesive Flp (fimbrial low-molecular-weight protein) pili biogenesis. Vibrio vulnificus, an opportunistic pathogen, harbors three distinct tad loci. Among them, only tad1 locus was highly upregulated in in vivo growing bacteria compared to in vitro culture condition. To understand the pathogenic roles of the three tad loci during infection, we constructed single, double and triple tad loci deletion mutants. Interestingly, only the{Delta} tad123 triple mutant cells exhibited significantly decreased lethality in mice. Ultrastructural observations revealed short, thin filamentous projections disappeared on the{Delta} tad123 mutant cells. Since the pilin was paradoxically non-immunogenic, a V5 tag was fused to Flp to visualize the pilin protein by using immunogold EM and immunofluorescence microscopy. The{Delta} tad123 mutant cells showed attenuated host cell adhesion, delayed RtxA1 exotoxin secretion and subsequently impaired translocation across the intestinal epithelium compared to wild type, which could be partially complemented with each wild type operon. The{Delta} tad123 mutant was susceptible to complement-mediated bacteriolysis, predominantly via the alternative pathway, suggesting stealth hiding role of the Tad pili. Taken together, all three tad loci cooperate to confer successful invasion of V. vulnificus into deeper tissue and evasion from host defense mechanisms, ultimately resulting in septicemia.\n\nAuthor SummaryTo understand the roles of the three Tad operons in the pathogenesis of V. vulnificus infection, we constructed mutant strain with single, double and triple Tad loci deletions. Employing a variety of mouse infection models coupled with molecular genetic analyses, we demonstrate here that all three Tad operons are required for V. vulnificus pathogenicity as the cryptic pili contribute to host cell and tissue invasion, survival in the blood, and resistance to complement activation.

microbiology↗