Biology subjects

Ferraro, M. J.

Publications and source records attributed to Ferraro, M. J..

4 recordsLinked to original sources

bioRxiv2026

Vesicle architecture licenses antigen-specific memory T cell immunity after mucosal immunization with infection-derived vesicles

Small extracellular vesicles (sEVs) released by infected cells carry microbial antigens together with host immunomodulatory molecules, yet whether their structural integrity governs the durability of protective immunity is unknown. Using Salmonella infection as a model, we show that sEVs isolated from infected macrophages act as potent antigen carriers for intranasal immunization. In BALB/c mice, intact sEVs elicited antigen-specific serum IgG responses comparable in magnitude to those induced by live attenuated aroA Salmonella. Immunization further increased fecal IgA binding to Salmonella following lethal challenge and generated serum capable of enhancing macrophage-mediated bacterial uptake. Single-cell RNA sequencing of mesenteric lymph nodes revealed enrichment of mature B cells, effector CD8 T cells, and central memory-like CD4 T cells expressing CD69, CD44, CCR7, and Sell/CD62L, while defined recombinant sEV-associated antigens drove IFN-gamma and IL-2 production by memory T cells ex vivo. Disrupting vesicle architecture by sonication left total IgG and IgG1 induction intact but selectively impaired IgG2a responses and antigen-specific T-cell recall; intact sEVs, by contrast, drove greater dendritic-cell CD80 expression, IL-2 production by cocultured CD69+ CD4 T cells, and prolonged survival after lethal challenge. These findings establish that vesicle integrity is dispensable for the overall magnitude of antibody induction but is required to instruct dendritic-cell costimulation, Th1-associated IgG2a class switching, and durable memory T-cell recall after mucosal immunization, identifying infection-derived sEVs as structurally organized immunogens rather than passive antigen reservoirs.

immunology↗

bioRxiv2025

Cannabinoid receptor deficiencies drive immune response dynamics in Salmonella infection

This study investigated the roles of cannabinoid receptors 1 and 2 (CB1R and CB2R) in regulating host responses to Salmonella Typhimurium in C57BL/6 mice. The absence of both receptors significantly impaired host resilience, as evidenced by increased weight loss, deteriorated body condition, and reduced survival following infection. Notably, CB1R deficiency resulted in more pronounced weight loss and heightened susceptibility to bacterial proliferation, as demonstrated by increased Salmonella dissemination to organs. In addition, both CB1R and CB2R knockout mice exhibited alterations in immune cell recruitment and cytokine production. CB1R-KO mice displayed increased T cell and macrophage populations, whereas CB2R-KO mice showed a reduction in NK cells, indicating receptor-specific effects on immune cell mobilization. Cytokine profiling of macrophages post-infection revealed that CB1R-KO mice had reduced IL-10 levels, along with increased IL-6 and TGF-{beta}, suggesting a dysregulated polarization state that combines pro-inflammatory and regulatory elements. In contrast, CB2R-KO mice exhibited a profile consistent with a more straightforward pro-inflammatory shift. Furthermore, microbiota analysis demonstrated that CB2R-KO mice experienced significant gut dysbiosis, including reduced levels of beneficial Lactobacillus and Bifidobacterium species and an increase in pro-inflammatory Alistipes species post-infection. Functional microbiome analysis further indicated declines in key metabolic pathways, such as the Bifidobacterium shunt, L-glutamine biosynthesis, and L-lysine biosynthesis, suggesting microbiota-driven immune dysregulation. Together, these findings highlight the distinct, non-redundant roles of CB1R and CB2R in modulating innate immunity, host defense, and microbiota composition during bacterial infections. Significance StatementUnderstanding the role of cannabinoid receptors in immune regulation is important for identifying new therapeutic targets for bacterial infections. Our study demonstrates that CB1R and CB2R play distinct, non-redundant roles in host defense against Salmonella Typhimurium. The absence of these receptors impairs host resilience, increases bacterial dissemination, and alters immune cell recruitment and cytokine production. Notably, CB1R deficiency leads to enhanced weight loss, increased bacterial spread, and a dysregulated macrophage cytokine profile--characterized by reduced IL-10 and elevated IL-6 and TGF-{beta}--while CB2R deficiency is associated with reduced NK cell numbers and a more pronounced pro-inflammatory cytokine profile. These findings reveal a receptor-specific balance in immune responses, suggesting that cannabinoid signaling modulates infection outcomes. Targeting CB1R and CB2R pathways may offer novel strategies to enhance host immunity and improve treatments for bacterial infections in the future.

microbiology↗

bioRxiv2025

Targeting deubiquitinating enzymes (DUBs) and ubiquitin pathway modulators to enhance host defense against bacterial infections

The rise of antibiotic-resistant bacterial pathogens poses a critical global health challenge, necessitating innovative therapeutic approaches. This study explores host-targeted therapies (HTTs) by focusing on deubiquitinating enzymes (DUBs), essential modulators of the ubiquitin-proteasome system (UPS) that regulate host-pathogen interactions during many bacterial infections. Using Salmonella-infected macrophages as a model, we identified UPS modulators that enhance bacterial clearance and observed significant changes in DUB expression, particularly USP25, USP46, and Otud7b. The small-molecule DUB inhibitor AZ-1 significantly reduced intracellular bacterial loads in vitro and mitigated early disease severity in a murine model by decreasing fecal bacterial loads and preserving host weight. However, AZ-1 alone did not achieve complete clearance of Salmonella and required combination with extracellular-targeting antibiotics for optimal efficacy. Notably, AZ-1 demonstrated broad-spectrum activity against multidrug-resistant pathogens, including Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. Transcriptomic analyses revealed infection-induced DUB regulation and highlighted pathways modulating immune responses, including TNF- secretion. These findings highlight the potential of targeting the UPS as a host-directed antimicrobial strategy and provide a foundation for developing innovative therapies to combat antimicrobial resistance.

microbiology↗

bioRxiv2021

Inter-species geographic signatures for tracing horizontal gene transfer and long-term persistence of carbapenem resistance

BackgroundCarbapenem-resistant Enterobacterales (CRE) are an urgent global health threat. Inferring the dynamics of local CRE dissemination is currently limited by our inability to confidently trace the spread of resistance determinants to unrelated bacterial hosts. Whole genome sequence comparison is useful for identifying CRE clonal transmission and outbreaks, but high-frequency horizontal gene transfer (HGT) of carbapenem resistance genes and subsequent genome rearrangement complicate tracing the local persistence and mobilization of these genes across organisms. MethodsTo overcome this limitation, we developed a new approach to identify recent HGT of large, near-identical plasmid segments across species boundaries, which also allowed us to overcome technical challenges with genome assembly. We applied this to complete and near-complete genome assemblies to examine the local spread of CRE in a systematic, prospective collection of all CRE, as well as time- and species-matched carbapenem susceptible Enterobacterales, isolated from patients from four U.S. hospitals over nearly five years. ResultsOur CRE collection comprised a diverse range of species, lineages and carbapenem resistance mechanisms, many of which were encoded on a variety of promiscuous plasmid types. We found and quantified rearrangement, persistence, and repeated transfer of plasmid segments, including those harboring carbapenemases, between organisms over multiple years. Some plasmid segments were found to be strongly associated with specific locales, thus representing geographic signatures that make it possible to trace recent and localized HGT events. Functional analysis of these signatures revealed genes commonly found in plasmids of nosocomial pathogens, such as functions required for plasmid retention and spread, as well survival against a variety of antibiotic and antiseptics common to the hospital environment. ConclusionsCollectively, the framework we developed provides a clearer, high resolution picture of the epidemiology of antibiotic resistance importation, spread, and persistence in patients and healthcare networks.

genomics↗