Beyond Exosomes: Ultrapurified Phospholipoproteic Complex (PLPC) as a Scalable Immunomodulatory Platform to Reprogram Immune Suppression in Metastatic Cancer

• DOI: 10.20944/preprints202504.0471.v1
• Publication Date: 2025-04-10T00:46:11Z
• Authors: Ramon Gutierrez-S...; Francisco Gutiérr...; Natalia Muñoz-Godoy; Ider Rivadeneira; Adolay Sobarzo; Jordan Iturra; Francisco Krakowiak; Luis Alarcón; Wilson Dorado; Andy Lagos; Diego Montenegro; Ignacio Muñoz; Rodrigo Aguilera; Andres Toledo

Dendritic exosomes (DEX) have demonstrated immunostimulatory potential in can-cer immunotherapy, but their clinical translation remains limited due to cryodepend-ence, heterogeneity, and poor scalability. To overcome these challenges, we developed a phospholipoprotein complex (PLPC), derived from dendritic cell secretomes and sta-bilized via ultracentrifugation and lyophilization. This study characterizes PLPC’s structural, immunological, and functional properties compared to conventional secre-tome formats. Secretomes were processed under four conditions: fresh, concentrated, cryopreserved, and lyophilized (PLPC). Proteomic profiling using LC-MS/MS revealed that PLPC exhibited superior protein stability, enrichment of immunoregulatory pro-teins (e.g., QSOX1, CCL22, SDCBP), and consistent preservation of post-translational modifications. Functional assays in PBMC co-cultures demonstrated strong induction of IFN-γ, TNF-α, and IL-6 with concurrent IL-10 suppression, yielding an IFN-γ/IL-10 ratio >3.5. Flow cytometry confirmed robust activation of CD4+ and CD8+ T cells (CD69+, CD25+), and selective cytotoxicity assays showed ≥55% apoptosis in tumor lines without affecting non-tumor cell viability (>92%). In functional ex vivo models, PLPC consistently reprogrammed the immune profile toward a Th1-polarized state. Notably, its mechanism of action supports immune reconditioning of suppressive mi-croenvironments, including those found in metastatic niches refractory to conventional therapies. These findings establish PLPC as a next-generation, vesicle-based immuno-modulator with high reproducibility, tumor selectivity, and GRAS-compatible formu-lation. Its stability and suitability for non-invasive delivery position it as a scalable and clinically integrable alternative to DEX, with unique potential in treating advanced and metastatic cancers.