Biology subjects

Schultz, A. C.

Publications and source records attributed to Schultz, A. C..

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

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↗

bioRxiv2023

Lymphatic vessel transit seeds precursors to cytotoxic resident memory T cells in skin draining lymph nodes

Resident memory T cells (TRM) provide rapid, localized protection in peripheral tissues to pathogens and cancer. While TRM are also found in lymph nodes (LN), how they develop during primary infection and their functional significance remains largely unknown. Here, we track the anatomical distribution of anti-viral CD8+ T cells as they simultaneously seed skin and LN TRM using a model of skin infection with restricted antigen distribution. We find exquisite localization of LN TRM to the draining LN of infected skin. LN TRM formation depends on lymphatic transport and specifically egress of effector CD8+ T cells that appear poised for residence as early as 12 days post infection. Effector CD8+ T cell transit through skin is necessary and sufficient to populate LN TRM in draining LNs, a process reinforced by antigen encounter in skin. Importantly, we demonstrate that LN TRM are sufficient to provide protection against pathogenic rechallenge. These data support a model whereby a subset of tissue infiltrating CD8+ T cells egress during viral clearance, and establish regional protection in the draining lymphatic basin as a mechanism to prevent pathogen spread. One Sentence SummaryT cell egress out of virally infected skin via afferent lymphatic vessels seeds CD8+ resident memory T cells in the draining lymph node.

immunology↗

bioRxiv2021

Manganese transport by Streptococcus sanguinis in acidic conditions and its impact on growth in vitro and in vivo

Streptococcus sanguinis is an oral commensal and an etiological agent of infective endocarditis. Previous studies have identified the SsaACB manganese transporter as essential for endocarditis virulence; however, the significance of SsaACB in the oral environment has never been examined. Here we report that a {Delta}ssaACB mutant of strain SK36 exhibits reduced growth and manganese uptake under acidic conditions. Further studies revealed that these deficits resulted from the decreased activity of TmpA, shown in the accompanying paper to function as a ZIP-family manganese transporter. Transcriptomic analysis of fermentor-grown cultures of SK36 WT and {Delta}ssaACB strains identified pH-dependent changes related to carbon catabolite repression in both strains, though their magnitude was generally greater in the mutant. In strain VMC66, which possesses a MntH transporter, loss of SsaACB did not significantly alter growth or cellular manganese levels under the same conditions. Interestingly, there were only modest differences between SK36 and its {Delta}ssaACB mutant in competition with Streptococcus mutans in vitro and in a murine oral colonization model. Our results suggest that the heterogeneity of the oral environment may provide a rationale for the variety of manganese transporters found in S. sanguinis and point to strategies for enhancing the safety of oral probiotics. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=162 SRC="FIGDIR/small/446192v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@a5afa7org.highwire.dtl.DTLVardef@1af3cdforg.highwire.dtl.DTLVardef@1c58693org.highwire.dtl.DTLVardef@1063980_HPS_FORMAT_FIGEXP M_FIG Depiction of methods. Streptococcal strains used are depicted at the top. The four methods illustrated are: 1. S. sanguinis cells were grown in media at pH 7.3 and pH 6.2 and quantified by plating. 2. S. sanguinis cells were grown in a fermentor vessel for RNA-sequencing and metal analysis. 3. S. sanguinis and S. mutans cells were grown in 12-well plates singly or in competition, then plated and the pH of the media measured. 4. S. sanguinis and S. mutans cells were inoculated into the mouths of mice. Oral swabs and dental biofilms from molars were assayed for bacterial composition by qPCR. (Biorender) C_FIG

microbiology↗