Biology subjects

Vantucci, C. E.

Publications and source records attributed to Vantucci, C. E..

4 recordsLinked to original sources

bioRxiv2022

Nanoparticle-delivered TLR4 and RIG-I agonists enhance immune response to SARS-CoV-2 subunit vaccine

Despite recent success in vaccinating populations against SARS-CoV-2, concerns about immunity duration, continued efficacy against emerging variants, protection from infection and transmission, and worldwide vaccine availability, remain. Although mRNA, pDNA, and viral-vector based vaccines are being administered, no protein subunit-based SARS-CoV-2 vaccine is approved. Molecular adjuvants targeting pathogen-recognition receptors (PRRs) on antigen-presenting cells (APCs) could improve and broaden the efficacy and durability of vaccine responses. Native SARS-CoV-2 infection stimulate various PRRs, including toll-like receptors (TLRs) and retinoic-acid-inducible gene I-like receptors (RIG-I). We hypothesized that targeting the same PRRs using adjuvants on nanoparticles along with a stabilized spike (S) protein antigen could provide broad and efficient immune responses. Formulations targeting TLR4 (MPLA), TLR7/8 (R848), TLR9 (CpG), and RIG-I (PUUC) delivered on degradable polymer-nanoparticles (NPs) were combined with the S1 subunit of S protein and assessed in vitro with isogeneic mixed lymphocyte reactions (iso-MLRs). For in vivo studies, the adjuvanted nanoparticles were combined with stabilized S protein and assessed using intranasal and intramuscular prime-boost vaccination models in mice. Combination NP-adjuvants targeting both TLR and RIG-I (MPLA+PUUC, CpG+PUUC, or R848+PUUC) differentially increased proinflammatory cytokine secretion (IL-1{beta}, IL-12p70, IL-27, IFN-{beta}) by APCs cultured in vitro, and induced differential T cell proliferation. When delivered intranasally, MPLA+PUUC NPs enhanced local CD4+CD44+ activated memory T cell responses while MPLA NPs increased anti-S-protein-specific IgG and IgA in the lung. Following intramuscular delivery, PUUC-carrying NPs induced strong humoral immune responses, characterized by increases in anti-S-protein IgG and neutralizing antibody titers and germinal center B cell populations (GL7+ and BCL6+ B cells). MPLA+PUUC NPs further boosted S-protein-neutralizing antibody titers and T follicular helper cell populations in draining lymph nodes. These results suggest that SARS-CoV-2-mimicking adjuvants and subunit vaccines could lead to robust and unique route-specific adaptive immune responses and may provide additional tools against the pandemic. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=58 SRC="FIGDIR/small/478507v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@7b8174org.highwire.dtl.DTLVardef@701721org.highwire.dtl.DTLVardef@feb860org.highwire.dtl.DTLVardef@fae094_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2020

Effects of osteogenic ambulatory mechanical stimulation on early stages of BMP-2mediated bone repair

Mechanical loading of bone defects through rehabilitation is a promising therapeutic approach to stimulate repair and reduce the risk of non-union; however, little is known about how therapeutic mechanical stimuli modulate early stages of repair before mineralized bone formation. In a previous study, we established an osteogenic mechanical loading protocol using early ambulatory rehabilitation and a compliant, load-sharing fixator in a rat model of BMP-2 mediated bone defect repair. The objective of this study was to investigate the early effects of osteogenic loading on cytokine expression, tissue composition, and angiogenesis during the first 3 weeks of repair in this model. Using a wireless implantable strain sensor for local measurements of mechanical boundary conditions, finite element simulations showed that osteogenic mechanical loading increased mean compressive strain in defect soft tissue during rehabilitative ambulation at 1 week (load-sharing: -1.54 {+/-} 0.17% vs. load-shielded: -0.76 {+/-} 0.06%), and that strain was amplified in remaining soft tissue regions at 3 weeks as mineralization progressed (load-sharing: -1.89 {+/-} 0.35% vs. load-shielded: -1.38 {+/-} 0.35%). Multivariate analysis of multiplex cytokine arrays revealed that loading significantly altered cytokine expression profiles in the defect tissue at 2 weeks compared to load-shielded defects. Specifically, loading reduced VEGF and increased CXCL5 (LIX) levels. Subsequently, vascular volume in loaded defects was reduced relative to load-shielded defects but similar to intact bone at 3 weeks. Endochondral bone repair was also observed histologically in loaded defects only at 3 weeks. Together, these results demonstrate that moderate ambulatory strains previously shown to stimulate functional bone regeneration significantly alter early angiogenic and cytokine signaling and may promote endochondral ossification in large segmental bone defects. Authors ContributionsB.S.K., N.J.W., and R.E.G. designed the research and performed surgeries; B.S.K., C.E.V., and J.K. performed experiments; B.S.K., C.E.V., J.K., and L.B.W., analyzed data; B.S.K., C.E.V., N.J.W., and R.E.G. wrote the manuscript; All authors interpreted data, critically edited, and have read and approved the final manuscript.

bioengineering↗

bioRxiv2020

Development of Systemic Immune Dysregulation in a Rat Trauma Model with Biomaterial-Associated Infection

Orthopedic biomaterial-associated infections remain a large clinical challenge, particularly with open fractures and segmental bone loss. Invasion and colonization of bacteria within immune-privileged canalicular networks of the bone can lead to local, indolent infections that can persist for years without symptoms before eventual catastrophic hardware failure. Host immunity is essential for bacterial clearance and an appropriate healing response, and recent evidence has suggested an association between orthopedic trauma and systemic immune dysregulation and immunosuppression. However, the impact of a local infection on this systemic immune response and subsequent effects on the local response is poorly understood and has not been a major focus for addressing orthopedic injuries and infections. Therefore, this study utilized a model of orthopedic biomaterial-associated infection to investigate the effects of infection on the long-term immune response. Here, despite persistence of a local, indolent infection lacking outward symptoms, there was still evidence of long-term immune dysregulation with systemic increases in MDSCs and decreases in T cells compared to non-infected trauma. Further, the trauma only group exhibited a regulated and coordinated systemic cytokine response, which was not present in the infected trauma group. Locally, the infection group had attenuated macrophage infiltration in the local soft tissue compared to the non-infected group. Our results demonstrate widespread impacts of a localized orthopedic infection on the systemic and local immune responses. Characterization of the immune response to orthopedic biomaterial-associated infection may identify key targets for immunotherapies that could optimize both regenerative and antibiotic interventions, ultimately improving outcomes for these patients.

bioengineering↗

bioRxiv2018

Effects of BMP-2 dose and delivery of microvascular fragments on healing of bone defects with concomitant volumetric muscle loss

Traumatic composite bone-muscle injuries, such as open fractures, often require multiple surgical interventions and still typically result in long-term disability. Clinically, a critical indicator of composite injury severity is vascular integrity; vascular damage alone is sufficient to assign an open fracture to the most severe category. Challenging bone injuries are often treated with bone morphogenetic protein 2 (BMP-2), an osteoinductive growth factor, delivered on collagen sponge. Previous studies in a composite defect model found that a minimally bridging dose in the segmental defect model was unable to overcome concomitant muscle damage, but the effect of BMP dose on composite injuries has not yet been studied. Here, we test the hypotheses that BMP-2-mediated functional regeneration of composite extremity injuries is dose dependent and can be further enhanced via co-delivery of adipose-derived microvascular fragments (MVF), which have been previously shown to increase tissue vascular volume. Although MVF treatment did not improve healing outcomes, we observed a significant BMP-2 dose-dependent increase in regenerated bone volume and biomechanical properties. While high dose BMP-2 delivery can induce heterotopic ossification (HO) and increased inflammation, the maximum 10 g dose used in this study did not result in HO and was associated with a lower circulating inflammatory cytokine profile than the low dose (2.5 g) group. These data support the potential benefits of an increased, though still moderate, BMP-2 dose for treatment of bone defects with concomitant muscle damage. Future work to improve vascularization may further improve healing.

bioengineering↗