bluuebunny/crossref_metadata_2025_split huggingface dataset:
MIF is necessary for late-stage melanoma patient MDSC immune suppression and differentiation
Authors: Yaddanapudi Kavitha , Rendon Beatriz , Rayyan Numan , Richie Jamaal , Kim Eun Jung , Wise Ashley , Mitchell Robert 
Published: January 2023

Abstract
Patients diagnosed with unresectable stage IV melanoma have an average survival of 6–10 months; a survival time that hasn’t changed significantly in the last 30 years. Despite some encouraging improvements in response rates and overall survival in patients receiving Ipilimumab (anti-CTLA-4) and/or Nivolumab (anti-PD-1) immunotherapies, the majority of patients will ultimately progress. Myeloid-derived suppressor cells (MDSCs) are potently immunosuppressive innate immune cells that accumulate in advanced cancer patients and actively inhibit anti-tumor T lymphocyte responses; therefore, can contribute to immunotherapeutic resistance. Increased circulating MDSCs in stage III/IV melanoma patients predict patient mortality and directly correlate with reduced melanoma antigen-specific T cells. Our results demonstrate that circulating monocytic MDSCs are found in significantly higher numbers in chemotherapy naïve late stage melanoma patients and the immunosuppressive activity of these cells is highly reliant upon the innate immunomodulatory cytokine, macrophage migration inhibitory factor (MIF). Moreover, inhibition of MIF results in a functional reversion from immune suppressive MDSC to an immunostimulatory dendritic cell (DC)-like phenotype that is at least partly due to reductions in MDSC prostaglandin E2 (PGE2). These findings indicate that monocyte-derived MIF is centrally involved in melanoma MDSC induction and immune suppressive function and that therapeutic targeting of MIF may provide a novel means of inducing anti-tumor immune responses in late stage melanoma patients.
ubiquitinated proteins enriched by Vx3 conjugated Alpha-alumina nanoparticles induce efficient anti-tumor response
Authors: jinjin zhao , Shen Yanfei , Wang Lixin 
Published: January 2023

Abstract
Weak and ineffective therapy of malignant tumor threatened thousands of people. Immune therapy is one of the most promising methods for tumor treatment due to little side effects. Our previous study has shown that ubiquitinated proteins from tumor cells enriched by Vx3 (A7) protein have an effective anti-tumor efficacy through establishing mice tumor models. However, it was difficult to enrichment ubiquitinated proteins in this methods. Here, we reported that such kind of problem could be solved through a microparticle precipitate method by using a-Al2O3 nanoparticles. Briefly, a-Al2O3 was first functionalized with (3-Aminopropyl) triethoxysilane, and subsequently with glutaraldehyde, as proved by the Fourier transform-infrared (FT-IR) analysis. Finally, the Vx3 (A7) protein was conjugated with the aldehyde-functionalized a-Al2O3 via Schiff ‘ s base reaction. Using Vx3 (A7) protein conjugated with a-Al2O3 could effectively enrich much more ubiquitinated proteins compared with our previous study as indicated by western blot. Interestingly, the ubiquitinated proteins that enriched by this new strategy show a high tumor specific immune response and an effective anti-tumor efficacy through in vivo experiments. It could be concluded that this ubiquitinated-protein conjugated to a-Al2O3 nanoparticles are considered to be a good choice in cancer immunotherapy.
Rapamycin directly inhibits T cell lymphoma proliferation at high doses and facilitates immune-independent toxin-mediated killing at a low dose in vivo.
Authors: Liu Yang , Pandeswara Srilakshmi , Dao Vinh A , Padrón Álvaro , Hurez Vincent , Curiel Tyler J 
Published: January 2023

Abstract
Hyperactive mammalian target of rapamycin (mTOR) signaling that drives tumor growth makes mTOR inhibition an attractive cancer therapeutic strategy. mTOR inhibitors are approved to treat certain carcinomas, but effects on T cell hematologic malignancies, which also express hyper-activated mTOR, are less reported. We studied effects of the mTOR inhibitor rapamycin (Rapa) in mouse EL4 T cell lymphoma. Typical pharmacologic Rapa doses (1–8 mg/kg) significantly reduced tumor burden and improved survival in subcutaneous EL4 challenge independent of interferon (IFN)-γ or host T cells which we showed was by direct suppression of tumor cell proliferation. Though we found EL4 refractory to many anti-cancer immunotherapies, its growth was significantly slowed by regulatory T cell depletion with denileukin diftitox (DD) in vivo in a T cell-dependent fashion. However, typical Rapa doses inhibited T cell activation and tumor infiltration in vivo and failed to boost DD treatment effects as expected. Low dose (LD, 75 μg/kg) Rapa reportedly improves anti-tumor immunity and we found it increased potentially beneficial CD8+ T cells with a central memory phenotype (CD44hiCD62L+) in EL4 challenge, but without clinical effect. LD Rapa significantly enhanced DD treatment efficacy, but surprisingly, DD + LD Rapa treatment effects were independent of T cells, IFN-γ or perforin. Instead, Rapa up-regulated EL4 IL-2 receptor expression (DD binding site) in vitro and in vivo, apparently facilitating direct DD tumor cell killing. We thus show an unexpected mechanism for mTOR inhibitor in cancer immunotherapy and show distinct, biphasic mechanisms of action at typical pharmacologic doses versus LD Rapa that can be exploited clinically.
The clinical-stage TLR5 agonist, Entolimod, mediates antimetastatic activity by stimulating a CXCR3-dependent NK-DC-CD8+ T cell axis
Authors: Brackett Craig M , Kojouharov Bojidar M. , Gollnick Sandra O. , Burdelya Lyudmila G. , Abrams Scott I , Gudkov Andrei V. 
Published: January 2023

Abstract
Activation of an anticancer innate immune response is an attractive immunotherapeutic opportunity that is challenged by insufficient safety of systemically administered innate immune modulators. Unusual tissue specificity of expression of TLR5 determines a uniquely safe profile of cytokines induced by the sole TLR5 agonist flagellin. Entolimod, a pharmacologically optimized flagellin derivative, was initially developed to treat and prevent acute radiation syndrome with demonstrated efficacy in rodents and non-human primates and safety in human healthy volunteers. In addition, Entolimod demonstrated antitumor effects in mouse models of uveal melanoma, lymphoma, breast, and colorectal carcinoma. Entolimod’s mechanism of action involves activation of NF-κB-, AP-1-, and STAT-3-driven immunomodulatory pathways in hepatocytes that initiates a cascade of cell-cell signaling events that mobilize innate and adaptive immunity to the liver. This includes CXCR3-dependent blood-borne NK cell homing followed by DC activation and antitumor CD8+ T cell memory formation. These results define systemically administered TLR5 agonists as an organ-specific immunoadjuvant enabling efficient antitumor vaccination that does not depend on identification of tumor-specific antigens. Therefore, Entolimod has strong promise as a safe, effective and broadly applicable immunotherapeutic agent against liver metastases, which are currently a major cause of cancer-associated mortality. Recent completion of a phase I trial of Entolimod in patients with advanced metastatic solid tumors has opened the opportunity to test whether efficacy demonstrated in animal cancer models could be translated into immunotherapy of human tumors.
Vaccines Bearing Engineered HIV-1 gp41 Transmembrane and Cytoplasmic-tail Domains Elicit Rare Reactivities Targeting the C-terminal Subdomain of the MPER
Authors: Scott Jamie Kathleen 
Published: January 2023

Abstract
Numerous vaccine strategies have failed to induce neutralizing (Nt) antibodies (Abs) against the HIV-1 gp41 MPER, the target of several broadly NtAbs. Factors contributing to this include an incomplete understanding of native MPER structure, and restricted/transient exposure of key Nt sites. Here, we describe novel MPER DNA and MPER-peptide liposome vaccines (PLVs) that best elicit Abs against N- and C-terminal (N- & C-) subdomains of the MPER; these subdomains are targeted by the 2F5 and 4E10/10E8 NtAbs, respectively. DNA-prime, PLV-boost immunization of rabbits and guinea pigs (GPs) with vaccines that optimize exposure of the N-terminal subdomain, elicited low-level 2F5-like reactivities that were moderately elevated with boosting. Co-immunization with the vaccines increased durability of these responses, with preliminary results showing moderate Nt activity from GPs (but not rabbits; however, GP pre-immune sera exhibited high Nt background). DNA and PLV vaccines were optimized to expose both the N- and C-subdomains. DNA vaccines were engineered to (i) encode an N-terminal coiled-coil to support a trimeric structure, (ii) express the native gp41 TMD, and (iii) truncate the cytoplasmic tail. Lipids and peptides for PLVs were designed to optimally expose the C-subdomain. Prime-boost and co-immunization of rabbits with the DNA vaccines and mixed N- and C-subdomain PLVs elicited Abs targeting both Nt sites of the MPER, but no Nt activity. Similar immunizations are underway in GPs. Together, our results illustrate the importance of (i) the TMD in eliciting Abs against the C-subdomain, (ii) co-immunization, and (iii) perhaps of GPs as a model, for eliciting NtAb responses.
Lipid nanoparticles incorporated with Ebola glycoprotein for induction of humoral immunity against Ebola infection.
Authors: Bazzill Joseph D , Cooper Christopher L , Fan Yuchen , Bavari Sina , Moon James J 
Published: January 2023

Abstract
The recent outbreaks of Ebola virus in Africa and isolated incidents in the U.S. have increased global attention and concern for this pathogen. The highly contagious nature and severe mortality rate of Ebola infection highlight the urgent need for an effective vaccine. To cull its spread, many vaccines are currently being tested in pre-clinical and clinical settings. Here, we report the development of a vaccine nanoparticle system that can safely elicit antibody responses and protect animals against Ebola viral challenge. We incorporated Ebola glycoprotein (GP) into lipid-based nanoparticles, called Interbilayer-crosslinked multilamellar vesicles (ICMVs), that were produced by fusing and crosslinking functionalized phospholipids. The resulting nanoparticles exhibited GP loading efficiency of 45–60 % with the particle diameter of approximately 350 nm. We observed strong binding of the murine mAbs 6D8 and 13C6, recognizing GP epitopes, on GP-ICMVs, indicating surface-bound GP in its natural configuration on ICMVs. C57BL/6 mice were immunized on days 0 and 21with 10 ug GP plus 2.5 ug monophosphoryl lipid A, a Toll-like receptor 4 agonist, in either ICMV or soluble formulations. Compared with the soluble GP+MPLA control, GP-ICMVs elicited 10-fold and 3-fold higher GP-specific IgG sera titers at two weeks post prime and boost, respectively. Vaccinated mice were challenged with 1000 p.f.u. of mouse adapted Ebola virus on day 28 after vaccination. All mice immunized with ICMVs survived up to 21 days post challenge, compared with 60 % survival for mice immunized with the GP+MPLA formulation. These preliminary experiments show strong elicitation of protective immunity however more research is needed to determine real world efficacy.
Evaluating the immunostimulatory characteristics of LicKM, a novel carrier protein.
Authors: Parent Michelle A , Chabot Ashley , Chichester Jessica 
Published: January 2023

Abstract
The key objective of vaccination is the induction of an effective pathogen-specific immune response that leads to protection against infection and/or disease caused by that pathogen. New vaccine technologies have resulted in second-generation recombinant vaccines containing highly purified antigens with improved tolerability and safety profiles. Unfortunately, the immune responses they induce are suboptimal without the help of adjuvants. Here, utilizing a non-toxic bacterial carrier molecule from Clostridium thermocellum a modified Lichenase (LicKM) and based upon preliminary results we hypothesize, that this serves a dual purpose; as both a mechanism to carrier dominant immunogenic epitopes for presentation to antigen presenting cells during vaccination and as an adjuvant enhancing immunity. This thermostable enzyme contains a catalytic domain loop structure separating it into two regions; an N-terminal and C-terminal region. Target protein sequences are expressed as either N or C terminal fusions; and this molecule, LicKM, may contain a single or double fusion. Currently, we are investigating the mechanism by which this molecule enhances the host humoral and cell-mediated response to vaccination. At this time, we have determined that LicKM physically binds to cells associated with the immune response. Additionally, murine vaccination in the presence of LicKM enhances antibody isotype titer production and possibly enhances the cellular responses. Our goal is to understand the immunostimulatory capability of this protein for its possible use to enhance future vaccination protocols.
Increased protection and decreased lung immunopathology induced by the ID93/GLA-SE vaccine candidate following infection with Mycobacterium tuberculosis HN878.
Authors: Baldwin Susan L , Reese Valerie A. , Huang Po-wei D. , Beebe Elyse A. , Podell Brendan K. , Reed Steven G. , Coler Rhea N. 
Published: January 2023

Abstract
Mycobacterium tuberculosis (M. tuberculosis) HN878 causes death and extensive lung pathology in infected C57BL/6 mice. A clinically relevant isolate of M. tuberculosis increases the possibilities of assessing the efficacy of experimental TB vaccines against human TB strains in a relatively inexpensive and immunologically intact small animal model. This model will also allow for the measurement of survival in mice and hence the determination of long-lived effects of M. tuberculosis vaccines. In this study, we show that the ID93/GLA-SE tuberculosis vaccine candidate elicits protection against M. tuberculosis HN878 by reducing the bacterial burden in the lung and spleen, and prevents the extensive lung pathology that is induced by M. tuberculosis HN878 in C57BL/6 mice. Future studies utilizing this model will allow the use of specific knock-out mice on the C57BL/6 mouse background to critically examine key immunological factors that are responsible for long-lived, vaccine-induced immunity and prevention of pulmonary immunopathology induced by a virulent clinical isolate of M. tuberculosis.
Modulation of Protective Efficacy of Fracisella tularensis Immunogens by Differential Cultivation in Mueler Hinton Broth Versus Brain Heart Infusion Medium
Authors: Kumar Sudeep , Sunagar Raju , Pham Giang , Franz Brian J , Gosselin Edmund J 
Published: January 2023

Abstract
Francisella tularensis (Ft) can survive in a variety of habitats with a remarkable ability to adapt to changing environmental conditions. For example, Ft expresses a distinct set of antigens (Ags) in the macrophage, which are not expressed in Ft grown in vitro with Mueler Hinton Broth (MHB) medium. In contrast, Ft grown in Brain Heart Infusion (BHI) medium exhibits an antigenic profile more closely resembling that of in vivo growth conditions. In addition, studies also suggest an alteration in immunological properties of Ft when grown in BHI versus MHB medium. Thus, we investigated the protective efficacy of BHI and MHB-grown Ft, when inactivated and used as an immunogen to protect against Ft LVS challenge. Inactivated Ft (iFt) generated in MHB (iFt-MHB) was found to have superior protective efficacy as compared to that of the iFt generated in BHI (iFt-BHI). The enhanced protection generated by iFt- MHB-immunized mice was also associated with lower bacterial burden and sepsis-like conditions in the lungs and spleens of iFt-MHB versus iFt-BHI-immunized mice. Further evaluation of early immunological events revealed, in the case of iFt-MHB immunogen, superior Ag binding to Ag-presenting dendritic cells (DCs), increased MHC class II expression by DCs, and enhanced Ag presentation by DCs, as apposed to the use of iFt-BHI. Also, iFt-MHB induced increased levels of Ft-specific IgG as well as IFNg and IL17 production versus that of iFt-BHI. These studies thus demonstrate the critical importance of considering bacterial growth medium in Ft vaccine development.
Increase in Incidence of Clostridium Difficile infection in aged models and the need for novel vaccines for the prevention of disease
Authors: Kutzler Michele A. , Baliban Scott M , Bernui Mariana 
Published: January 2023

Abstract
Clostridium difficile associated disease (CDAD) constitutes a large majority of nosocomial diarrhea cases and is mediated by the effects of two secreted toxins, toxin A (TcdA) and toxin B (TcdB). Key toxin-neutralizing epitopes have been discovered within the carboxy-terminal receptor-binding domain (RBD) of the toxins, which has generated interest in developing the RBD as a vaccine target. The elderly mount an impaired humoral response to C. difficile toxins leading to more severe and recurrent disease; however, it has yet to be determined what underlying mechanisms lead to lower anti-toxin titers, thus higher incidence of severe and recurrent disease. While numerous platforms have been studied, very few data describe the potential of DNA vaccination against CDAD. We created highly optimized plasmids encoding the RBD from TcdA and TcdB and immunized C57BL/6 mice and rhesus macaques intramuscularly followed by in vivo electroporation. In these animal models, vaccination induced significant levels of anti-RBD antibodies within the serum and feces that could neutralize toxins in an in vitro cytotoxicity assay. Moreover, mice that were actively immunized with the DNA vaccine or given passive transfer of immunized non-human primate sera were protected from a lethal intraperitoneal challenge of purified C. difficile toxins. Finally, immunized mice were significantly protected following orogastric challenge with strains of C. difficile spores that were homologous (VPI 10463; n=10/10) and heterologous (hypervirulent UK1; n=4/8) strains to our vaccine antigens. These data demonstrate the robust immunogenicity and efficacy of a TcdA/B RBD-based DNA vaccine in preclinical models of acute toxin-associated disease.
Guinea pig infection with the intracellular pathogen Rhodococcus equi
Authors: Bordin Angela Ilha , Gressler Leticia Trevisan , Sule Preeti , Alexander Ellen Ruth , Conner Meagan , Brake Courtney , Edwards John , Cirillo Jeffrey , McMurray David , Cohen Noah 
Published: January 2023

Abstract
Rhodococcus equi is an opportunistic intracellular pathogen that causes pyogranulomatous pneumonia in foals and immunocompromised people, and is clinically and microbiologically similar to tuberculosis (TB). Currently, no model exists of R. equi pneumonia other than intra-bronchial infection of foals with R. equi. Because infection of foals is labor-intensive and costly, a guinea pig (GP) model of R. equi pneumonia would be of great benefit for evaluating novel approaches for control and prevention of this disease (and possibly TB). Our objective in this study was to develop a GP model of R. equi pneumonia. Groups of 6 GPs were infected with either 101, 102, 103, or 104 CFU of virulent R. equi strain using a Madison aerosol chamber, and groups of 6 GPs were infected with either 106, 107, or 108 CFU of virulent R. equi intratracheally. GPs were observed daily for clinical signs of pneumonia, and were euthanized on days 1, 3, 7, 14, or 35 post-infection (PI). Necropsy was performed and lungs were weighed, homogenized with PBS, and plated onto selective agar to determine bacterial load. No clinical signs of the disease or gross pathologic changes were observed regardless of the inoculum or mode of infection; histopathological findings of lungs are pending. Viable bacteria recovered from the lungs increased on day 3 PI, but decreased on day 7. No bacteria were recovered from animals euthanized either 2 or 5 weeks PI. Despite being highly susceptible to the agent of TB, GPs appear to be resistant to pulmonary infection with virulent R. equi at high doses. These remarkable findings suggest that this model might reveal novel mechanisms of resistance to natural infection with R. equi, which could inform the development of prophylactic or therapeutic approaches.
A Critical Combination of Bacterial Dose and Virus-Induced Alveolar Macrophage Depletion Leads to Pneumococcal Infections During Influenza
Authors: Smith Amber M 
Published: January 2023

Abstract
Coinfection with pneumococcus during influenza A virus infection is characterized by rapid, uncontrolled bacterial growth, a rebound in viral titers, and a robust inflammatory response. Several factors contribute to influenza-pneumococcal pathogenicity, including aberrant immune responses, tissue destruction, and pathogen strain and dose. By analyzing pathogen kinetics with a mathematical model, we predicted that bacterial establishment and growth is driven by a defect in clearance by alveolar macrophages (AMs), the first line of defense against pneumococcal invasion. This prediction was tested and confirmed in an experimental study, which suggested that these cells are depleted during influenza. Remarkably, both our model prediction and the follow-up experiments agreed that the AM population is reduced by ~85–90% 7d post-influenza infection (pii). Analyzing our coinfection model in more depth allowed us to quantify an initial dose threshold for successful bacterial infection that depends on the level of AM depletion and predict how the threshold changes throughout an influenza virus infection. To validate this prediction, we infected groups of mice with pneumococcus at 1, 3, 5, 7, 9, or 11d pii and at a dose either higher or lower than the predicted threshold. Within 4h after inoculation, bacterial loads decline for doses below the threshold, increase for doses above the threshold, and are dichotomous for doses close to the threshold. These results give insight into the conditions necessary for a secondary bacterial infection to establish during influenza infection and the probability of a successful secondary bacterial infection occurring with seasonal and pandemic influenza virus strains.
Differential Tbet, Gata3 and RORγt expression in mature and neonatal regulatory T cells during influenza virus infection
Authors: Heil Luke , Oliphant Samantha , Hollifield Melissa , Garvy Beth A 
Published: January 2023

Abstract
Neonates respond poorly to influenza infection and have trouble clearing the virus. In contrast to adult mice, pups display reduced cytokine production and poor migration of cells into the alveolar space during infection, resulting in an interstitial pneumonia and delayed clearance of virus. Pups also have a large population of regulatory T cells (Tregs) in their lungs compared to adults. Tregs suppress immune reactions and their abundance in pups could explain the poor response to infection. However, we found that pups that lacked Tregs failed to clear influenza infection, suggesting that pups require Tregs to clear the virus. We hypothesize that there is a functional difference between adult and pup Tregs that may explain this finding.
Tregs express the transcription factor Foxp3, and it is essential for their function, but they may also express T helper subset transcription factors such as Tbet, Gata3 or RORγt. The function of this co-expression is incompletely understood, but they may play a role in establishing functional subsets of Tregs. We investigated whether Tregs from adult mice expressed different transcription factors than Tregs from pups during infection.
We performed flow cytometry on cells from the lungs of neonatal and adult mice infected with influenza virus to examine the prevalence of Tregs that co-expressed Foxp3 with Tbet, Gata3 or RORγt. We found that Tregs in pups tended to express Gata3 more frequently than Tregs from adults. In contrast, adult Tregs were more likely to express Tbet or RORγt than pups. We are investigating whether this differential expression of transcription factors has functional consequences in modulating the response to influenza virus.