Biology subjects

Rodriguez, B. V.

Publications and source records attributed to Rodriguez, B. V..

4 recordsLinked to original sources

bioRxiv2025

Tuberculous meningitis alters the proteomic landscape of brain-derived extracellular vesicles

Tuberculous meningitis (TB meningitis), the deadliest form of Mycobacterium tuberculosis infection, leads to mortality and severe neurological disability despite standard therapy. Brain injury and microglial activation are major determinants of outcome, yet the mechanisms linking infection, inflammation and neuronal injury remain poorly understood. Extracellular vesicles (EVs), key mediators of cell-to-cell communication, have been investigated in pulmonary TB but their role in TB meningitis remains unexplored. We used our young rabbit model of TB meningitis to isolate pure, intact EVs from brain tissue (i.e., brain-derived EVs) from infected and uninfected rabbits and used nanoflow cytometry, transmission electron microscopy and protein quantification to characterize the EVs. Comparative proteomic profiling was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), followed by in silico pathway, cell-type and protein-protein interaction analyses using DAVID, Enrichr, and STRING databases. We found that EV isolation from fresh and frozen tissue was equivalent and demonstrated that M. tuberculosis infection activated EV biogenesis. Despite preserved vesicle morphology, EVs from infected brain showed a significant proteomic shift characterized by enrichment of TB host defense, microglial and immune activation, metabolic excitotoxicity, and neuronal injury. These proteome dysregulations suggest that infection reprograms brain EV cargo toward proinflammatory and metabolic stress responses while depleting neuronal and mitochondrial components. Collectively, these data demonstrate that M. tuberculosis infection alters the cargo and abundance of brain-derived EV, highlighting their potential as biomarkers and mediators of host-pathogen interactions in TB meningitis.

microbiology↗

bioRxiv2025

An ex vivo and in vitro investigation of extracellular vesicle interactions with B cells of Macaca nemestrina and humans

AbstractExtracellular vesicles may modify recipient cell behavior through multiple mechanisms, including interacting with the cell surface or internal membrane components and delivering luminal cargo to the cytoplasm. Here, we use a previously established ex vivo approach to investigate the cellular fate of EVs spiked into whole blood samples from nonhuman primate (NHP) and human donors and contrast these findings with results from in vitro assays. We report that EVs are internalized by NHP and human B cells while also associating to some degree with other PBMCs. EVs exhibit greater association with B cells in ex vivo whole blood compared to isolated B cells, suggesting that blood components may promote EV interactions or that cell isolation factors may inhibit this association. Cellular uptake of EVs involves clathrin-dependent endocytosis and may be aided by other pathways, including direct EV-cell membrane fusion. Overall, our data suggest that EV association, including uptake, by B cells occurs in at least two primate species. These findings highlight the potential to develop new strategies to either enhance or inhibit EV tropism toward B cells. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/637883v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@bd28e3org.highwire.dtl.DTLVardef@c76b28org.highwire.dtl.DTLVardef@4c2e44org.highwire.dtl.DTLVardef@1719771_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2023

An ex vivo model of interactions between extracellular vesicles and peripheral mononuclear blood cells in whole blood

Extracellular vesicles (EVs) can be loaded with therapeutic cargo and engineered for retention by specific body sites; therefore, they have great potential for targeted delivery of biomolecules to treat diseases. However, the pharmacokinetics and biodistribution of EVs in large animals remain relatively unknown, especially in primates. We recently reported that when cell culture-derived EVs are administered intravenously to Macaca nemestrina (pig-tailed macaques), they differentially associate with specific subsets of peripheral blood mononuclear cells (PBMCs). More than 60% of CD20+ B cells were observed to associate with EVs for up to 1 hr post-intravenous administration. To investigate these associations further, we developed an ex vivo model of whole blood collected from healthy pig-tailed macaques. Using this ex vivo system, we found that labeled EVs preferentially associate with B cells in whole blood at levels similar to those detected in vivo. This study demonstrates that ex vivo blood can be used to study EV-blood cell interactions.

immunology↗

bioRxiv2020

Staphylococcus aureus secretes immunomodulatory RNA and DNA via membrane vesicles

Bacterial-derived RNA and DNA can function as ligands for intracellular receptor activation and induce downstream signaling to modulate the host response to bacterial infection. The mechanisms underlying the secretion of immunomodulatory RNA and DNA by pathogens such as Staphylococcus aureus and their delivery to intracellular host cell receptors are not well understood. Recently, extracellular membrane vesicle (MV) production has been proposed as a general secretion mechanism that could facilitate the delivery of functional bacterial nucleic acids into host cells. S. aureus produce membrane-bound, spherical, nano-sized, MVs packaged with a select array of bioactive macromolecules and they have been shown to play important roles in bacterial virulence and in immune modulation through the transmission of biologic signals to host cells. Here we show that S. aureus secretes RNA and DNA molecules that are mostly protected from degradation by their association with MVs. Importantly, we demonstrate that MVs can be delivered into cultured macrophage cells and subsequently stimulate a potent IFN-{beta} response in recipient cells via activation of endosomal Toll-like receptors. These findings advance our understanding of the mechanisms by which bacterial nucleic acids traffic extracellularly to trigger the modulation of host immune responses.

microbiology↗