bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcriptional regulation of proteolytic enzymes in dendritic cells by effector versus regulatory T cells: a new mechanism of maintaining peripheral tolerance (52.15)
Authors: Marvel Douglas , Finn Olivera 
Published: January 2023

Abstract
MUC1.Tg mice express the human tumor associated antigen MUC1 in a physiological pattern that is analogous to its expression on normal human epithelial cells and tumors. Vaccine-induced responses to MUC1 peptide in these animals are weak compared to WT mice. Gene expression profiling post vaccination revealed differential regulation in spleen dendritic cells (DC) of several proteolytic enzymes that were previously thought to function exclusively in pancreatic catabolism (i.e. Trypsin-1, Trypsin-4, Carboxypeptidase B1). These enzymes were upregulated in DC when WT mice were vaccinated with the MUC1 peptide (more foreign) and highly downregulated after the same vaccination in MUC1.Tg mice (more self). Using an in vitro co-culture system, we show that this regulation is dependent on CD4 T cell interactions with DC, such that activated effector T cells (Teff), but not TLR agonists, upregulate these enzymes, whereas activated regulatory T cells (Treg) actively suppress their expression. Cell-cell contact appears to be necessary. The Treg mediated suppression is dominant and it occurs even when DC are cultured simultaneously with Treg and Teff. We propose a new mechanism of maintaining peripheral tolerance whereby self-antigen specific Treg recognize the presence of antigen on a few DC and temporarily shut down antigen processing by all DC to avoid efficient priming of effector T cells.
Prime and pull: establishing protective immunity in restrictive tissues (52.16)
Authors: Shin Haina , Iijima Norifumi , Iwasaki Akiko 
Published: January 2023

Abstract
Some of the world’s most pressing health concerns include sexually transmitted infections such as HIV and HSV. Thus far, vaccines against these pathogens, even those that elicit robust systemic cytotoxic responses, have been unsuccessful. The genital tract is a highly restrictive tissue that does not allow entry of activated CD8 T cells in the absence of infection or inflammation. Thus, it is possible that the failure of previous vaccination attempts reflects an inability to establish a tissue-resident population of cytotoxic T cells at the front line of infection within the genital tract. Thus, to address this issue, we have designed a novel vaccination method called ‘prime and pull’ to recruit antigen-specific effector CD8 T cells into the vaginal mucosa. After subcutaneous immunization (prime), very few effector CD8 T cells are observed in the genital tissue. However, a single topical application of the chemokines CXCL9 and CXCL10 in the vagina (pull) leads to robust recruitment of effector CD8 T cells, which is independent of CD4 T cell help. Furthermore, our ‘prime and pull’ method may generate a long-term population of memory CD8 T cells within the tissue that appears to enhance viral control after a lethal challenge. Thus, our studies suggest that ‘prime and pull’ is a promising method not only for providing protection against sexually transmitted infections, but also for directing immune responses to other restrictive microenvironments such as tumors.
The histone deacetylase inhibitor, Trichostatin A, decreases TLR-mediated cytokine production in human plasmacytoid dendritic cells by negatively affecting IRF-7 phosphorylation and nuclear translocation (52.24)
Authors: Descalzi Dante , Dai Jihong , Bocarsly-Fitzgerald Patricia 
Published: January 2023

Abstract
pDC produce high levels of IFN-α and TNF-α upon TLR7/9 stimulation and express high constitutive levels of the transcription factor IRF-7, which is required for IFN-α induction. Histone deacetylases (HDAC) are enzymes shown to regulate protein function by removing acetyl groups from nuclear and cytoplasmic targets. HDAC inhibitors are used clinically as cancer therapeutics and are being considered as potential anti-inflammatory agents. Our purpose was to characterize the effects of TSA, a class I/II HDAC inhibitor, on pDC cytokine production and IRF-7 protein regulation and activation. TSA treatment strongly inhibited the induction of both IFN-α and TNF-α by pDC upon stimulation with CpG-A, HSV-1, HIV-1, or Flu, as shown by intracellular flow cytometry and ELISA. TSA treatment did not induce pDC apoptosis, nor did it negatively affect cell number, arguing against general toxicity of the drug. Interestingly, although basal IRF-7 levels were not affected by TSA, upregulation of pDC IRF-7 protein expression in response to rIFN-α was inhibited. Moreover, TSA treatment inhibited virus-induced IRF-7 activation, as demonstrated by BD Phosphoflow, and nuclear translocation of IRF-7, as demonstrated by ImageStream imaging flow cytometry. These findings suggest a potential impact of acetylation on the activation and protein expression of IRF-7 in pDC and highlight a possible mechanism of cytokine inhibition by TSA in these cells.
Toll like receptor agonists stabilize MHC-II expression in macrophages thereby enhancing peptide presentation by BCG infected macrophages (52.30)
Authors: Bakhru Pearl , Sirisaengtaksin Natalie , Estrella Jaymie , Khan Arshad , Jagannath Chinnaswamy 
Published: January 2023

Abstract
BCG is the only human-approved vaccine used to protect against childhood tuberculosis although it fails to protect against adult tuberculosis. BCG vaccine localizes to an immature phagosomal compartment and avoids lysosomal fusion. Furthermore, it reduces the expression of MHC-II in macrophages in vitro and in phagocytic cells of mice after infection. We hypothesized that immunogenicity of BCG is reduced because of reduced MHC-II expression by APCs and the addition of Toll-like receptor (TLR) - ligands will strengthen and prolong immunity conferred by BCG vaccine and perhaps protect against adult disease. Since TLR ligands activate macrophages, we tested their effect on MHC-II expression. BCG infection down regulated the expression of MHC-II while a combination of BCG vaccine with ligands for TLR-7, and 9 markedly induced an up-regulation that correlated with the ability of macrophages to present antigens to T cells. Furthermore, we identified that TLR-7, and 9 but not TLR-1/2, TLR-3 or TLR-5 induced a down regulation of the ubiquitin ligase MARCH1 that in turn correlated with a decreased ubiquitination and enhanced clearance of MHC-II from macrophages. These data suggest that BCG down regulates immune responses while TLR-ligands can be used to up regulate MHC-II contributing to a novel mode of adjuvant action.
Immunization with a synthetic peptide vaccine directed against the loop neutralizing determinant from domain 2 of protective antigen formulated with human use adjuvants protects rabbits from inhalation anthrax (53.13)
Authors: Oscherwitz Jon , Yu Fen , Cease Kemp 
Published: January 2023

Abstract
The current vaccines for anthrax in the U.S. and U.K. are efficacious in the two most accepted animal models of inhalation anthrax, non-human primates and rabbits, but require intensive immunization protocols.We previously demonstrated that a multiple antigenic peptide (MAP) vaccine comprising a heterologous T cell epitope from Plasmodium falciparum colinearly synthesized with a cryptic loop neutralizing determinant (LND) from domain 2 of Bacillus anthracis protective antigen can completely protect rabbits from an aerosol challenge with B. anthracis Ames strain spores when formulated with CFA. In the current study, we evaluated whether immunization of rabbits with a mixture of two MAPs, each comprising the LND peptide colinearly synthesized with one of two different heterologous T cell epitopes, could stimulate protective immunity using CFA, and in a subsequent study, using adjuvants currently evaluated for use in humans.In the initial study, all rabbits (7/7) immunized five times with the MAP vaccine formulated with CFA/IFA were completely protected from a 200 LD50-target dose of B. anthracis Ames strain. When tested with human use adjuvants, 100% (9/9), 89% (8/9), 89% (8/9) or 67% (6/9) of rabbits immunized with the MAP vaccine formulated with lipid A monophosphoryl/Alhydrogel, CpG/Alhydrogel, QS-21/Alhydrogel or Alhydrogel alone, respectively, were protected from aerosol challenge. The LND MAP vaccine may represent an adjunctive or alternative vaccine for anthrax.
Characterizing the primary B cell antibody response to HIV (53.18)
Authors: Pujanauski Lindsey , Pelanda Roberta , Torres Raul 
Published: January 2023

Abstract
Most individuals infected with the human immunodeficiency virus (HIV) make neutralizing antibodies (nAbs) to the virus, but this response is delayed and consequently not protective. Some nAbs that have been characterized are described as polyreactive and slightly autoreactive, two attributes of Abs produced by marginal zone (MZ) B cells. Thus, B cells capable of producing nAbs early in infection may not participate, possibly because of tolerance mechanisms. To directly examine the components of the primary Ab response to the HIV envelope protein gp120, we use a mouse model and HIV viral-like particles (VLPs). Our studies focus on the quantity and quality of the anti-HIV responses from different B cell subsets. We have found that naïve follicular (FO) and MZ B cells are both capable of producing anti-gp120 IgM in culture. Additionally, we have examined the VDJ rearrangements of gp120-reactive Abs from different populations in both the naïve and VLP-challenged repertoire. So far, it seems that there may be a preferred VDJ recombination event that is over-represented in the MZ B cell compartment. This VDJ rearrangement has not yet been found in responding cells of VLP-immunized mice, indicating that MZ B cells may not be participating in the VLP response. Abs from these subsets are being further characterized with HIV-neutralization studies. It is expected that the results from these experiments will prove informative for the development of a protective HIV vaccine.
Blockage of CD59 diminishes infectivity of HIV-1-positive plasma in vitro and in vivo (53.21)
Authors: Amet Tohti , Hu Sishun , Byrd Daniel , Yu Andy Qigui 
Published: January 2023

Abstract
Numerous vaccination trials have been conducted to induce neutralizing antibodies (nAbs) against HIV-1. However, high levels of Abs, including nAbs and non-nAbs, mount in vast majority of HIV-1 infected subjects, yet fail to control virus proliferation or protect patients from developing AIDS, indicating that HIV-1 virions can escape Ab immunity. Recent studies have shown that regulators of complement activation (RCA) including CD59 present on the viral envelope (Env) confer resistance to Ab-dependent complement-mediated lysis (ADCML), which may explain why HIV-1 is not neutralized or lysed even in the presence of high titer of anti-Env Abs. Here, we report that blockage of CD59 on HIV-1 Env in infected patient plasma by BRIC229, a widely used CD59-blocking Ab, or rILYd4, a novel CD59 inhibitor derived from bacterial toxin intermedilysin domain 4, significantly reduces infectivity of HIV-1-positive plasma in vitro (H9 cells) and in vivo (SCID mice reconstituted with human peripheral blood mononuclear cells or PBMCs). Similarly, BRIC229 and rILYd4 significantly enhanced ADCML of HIV-1-infected H9 cells and HIV-1-bound erythrocytes in the presence of patient plasma as a source of both complement and anti-HIV-1 Env Abs. All plasma samples from 7 HIV-1-infected patients examined contained high titer of anti-HIV-1 Env Abs. Our data suggest that blockage of CD59 on the surface of HIV-1 virions and infected cells represents a novel therapeutic approach to combat HIV-1/AIDS pandemic.
A novel combination vaccine for HIV-1 and tuberculosis is safe and immunogenic in infant rhesus macaques (53.25)
Authors: Jensen Kara , Ranganathan Uma , Van Rompay Koen , Abbott Zack , Larsen Michelle , Fennelly Glenn , Abel Kristina 
Published: January 2023

Abstract
Despite improved therapies, breast milk transmission of HIV to newborns does not decline. In many resource-poor countries, these infants are also at risk for Mycobacterium tuberculosis infection. We hypothesized that a highly attenuated Mtb with improved safety and similar immunogenicity to the current BCG vaccine, but modified to harbor HIV genes, could protect infants against both HIV and Tb. We have tested 3 different rAMtb-SIV vectors in infant rhesus macaques. Vaccine safety was evaluated by immunizing 1-week old SIV-infected macaques orally (PO) and intradermally (ID) with rAMtb. Next, we tested the immunogenicity of (1) a PO prime/ID boost rAMtb-SIV, (2) a PO rAMtb-SIV prime/IM Ad5-SIV boost, and (3) an ID rAMtb-SIV prime/IM Ad5-SIV boost vaccine regimen. Our studies show that rAMtb-SIV does not cause rAMtb dissemination, even when given to immunocompromised SIV infected infants. Further, our data confirm that the oral route of immunization is effective in infant macaques. Vaccinated animals showed increased dendritic cell responsiveness to in vitro TLR stimulation, supporting our hypothesis that rAMtb is highly immunogenic in infants. While all vaccine regimens elicited cellular and humoral Mtb-specific immune responses, SIV-specific responses were greatly enhanced by the heterologous boost. Thus, rAMtb-HIV should be further developed as a pediatric combination vaccine. We will test vaccine efficacy against multiple oral SIV challenges and against Mtb exposure.
Dimeric 2G12 as a potent protection against HIV-1 (53.26)
Authors: Luo Xin , Ouyang Yong , West Anthony , Keeffe Jennifer , Gnanapragasam Priyanthi , Bjorkman Pamela , Baltimore David 
Published: January 2023

Abstract
We previously showed that broadly neutralizing anti-HIV-1 antibody 2G12 (human IgG1) naturally forms dimers that are more potent than monomeric 2G12 in in vitro neutralization of various strains of HIV-1. Recently, we also investigated the protective effects of monomeric versus dimeric 2G12 against HIV-1 infection in vivo using a humanized mouse model. We showed that passively transferred, purified 2G12 dimer is more potent than 2G12 monomer at preventing CD4 T cell loss and suppressing the increase of viral load following HIV-1 infection of humanized mice. In addition, we found that 2G12 dimer does not favor mutations of the HIV-1 envelope that would cause the virus to completely escape 2G12 neutralization. These results suggest dimeric 2G12 as a potent prophylactic reagent against HIV-1 in vivo, which could be used as part of an antibody cocktail to prevent HIV-1 infection. We are currently investigating whether the protective effect of 2G12 dimer against HIV-1 in humanized mice requires antibody-dependent cellular cytotoxicity (ADCC) using mutated 2G12 dimers where the ADCC function is either abolished or enhanced. Our results will suggest a mechanism of action underlying the protective effect of dimeric 2G12 against HIV-1 in vivo.
Reversal of human papillomavirus-mediated suppression of Langerhans cells function with the TLR3 agonist Poly-ICR (53.7)
Authors: Da Silva Diane , Koopman Maaike , Brand Heike , McKee Gregory , Kast W. Martin 
Published: January 2023

Abstract
The human papillomavirus (HPV) family of viruses establishes persistent infections because it has evolved mechanisms that allow it to evade the human immune system. We have identified HPV-mediated suppression of antigen presentation by Langerhans cells (LC) as a key mechanism through which HPV evades immune surveillance. PolyICR is a stable TLR3 agonist that is a broad inducer of innate immunity and is being developed as a vaccine adjuvant and antitumor agent. An important feature of PolyICR is its ability to functionally activate dendritic cells to induce antigen-specific T cells. In this study, we determined whether PolyICR can overcome HPV-induced immune suppression by functionally activating human LC in the presence of HPV16 and inducing HPV16-specific T cells. PolyICR was able to activate LC that had been pre-exposed to HPV16 VLP such that expression of MHC and costimulatory molecules were highly upregulated and LC secreted high amounts of Th1 and inflammatory cytokines and chemokines. Upregulation of CCR7 resulted in a significant increase in migration capacity. LC incubated with HPV16 VLP and treated with PolyICR induced an HPV16-specific CD8+ T cell response detected by interferon gamma Elispot that was absent when LC were exposed to VLP alone. These data suggest that the TLR3 agonist PolyICR is a promising therapeutic molecule that can overcome HPV-induced immune suppression of LC and result in an LC capable of stimulating an anti-HPV T-cell mediated immune response.
Antigen presentation by dendritic cells in the aortic wall triggers T helper immune responses in atherosclerosis (54.16)
Authors: Koltsova Ekaterina , Garcia Zacarias , Landau Michael , Scott Spencer , von Vietinghoff Sibylle , Galkina Elena , Acton Scott , Ley Klaus 
Published: January 2023

Abstract
Atherosclerosis is an immune-mediated disease associated with lipid accumulation and formation of atherosclerotic plaques in the major arteries of the body. Vascular dendritic cells (DC) are present throughout the adventitia of the normal mouse aorta and expand under atherosclerotic conditions, but their function remains incompletely understood. To test whether DC can mediate productive antigen presentation directly in the aortic wall, we used two-photon microscopy. CD11cYFP tagged DC were motile in mouse aortas and interacted with T cells in an antigen dependent manner. In atherosclerotic Apoe-/- CD11cYFP mice, DC interacted with transferred T cells from Apoe-/-, but not C57BL/6 mice. Interaction with DC decreased T cell migration velocity and induced secretion of IFN-γ, TNF-α and IL-17, which enhanced oxLDL uptake by primary macrophages. Using flow cytometry of digested whole aorta from C57BL/6 and Apoe-/- mice fed either Western diet or regular chow diet, we found CD11b+CD11c+ and CD11b-CD11c+ DC in the aortic wall of C57BL/6 mice, and this population expanded in Apoe-/- mice on western diet. Under these conditions, CD8a+ and CD103 DC appear among the CD11c+ DC population. Taken together, our data show the emergence of distinct subsets of DC in the mouse aorta during the progression of atherosclerosis and demonstrate that the aortic wall can be a site of active antigen presentation leading to the induction of a pro-atherogenic immune response.
Multicolor flow cytometry analysis of peripheral blood lymphocytes in pediatric patients with inflammatory bowel disease (54.7)
Authors: Abramson Tzvia , Tarlton Nicole , Green Caroline , Jandu Jagmohan , Abramson Oren , Wong Anthony , Lazarus Nicole , Rott Lusijah , Ulloa E. , Butcher Eugene 
Published: January 2023

Abstract
While the etiology and mechanism of Inflammatory Bowel Disease (IBD) is not fully understood, immunologic abnormalities play a role in these diseases. Monitoring of disease progression and response to therapeutics is typically invasive and lacking. Increased recruitment of lymphocytes to the gut has been demonstrated in IBD, leading to inflammation and ultimately to gut tissue damage. Lymphocyte circulation is tightly controlled by trafficking receptors (TRs) that act in combination to govern migration to the target organ. Plasmablasts (PBs) are immature circulating B cells that may reflect tissue localized plasma cells. We hypothesize that the PB blood levels and trafficking patterns can inform on the location of tissue damage and the clinical condition of the patients. Using multicolor flow cytometry we examined PB (IgA+/CD38high) and memory B cell (IgA+/CD19+) blood levels, and TRs expressed on these cells. We show that an increase in IgA+ PB blood levels reflect an aggravated clinical state, and a significantly greater amount of these cells in ulcerative colitis patients express colon associated TRs (CCR10+) as opposed to small intestine associated TRs (CCR9+). Additionally, these trafficking patterns are more evident on IgA+ PBs rather than memory B cells. This work in progress suggests that the analyses of the TR phenotype of circulating immature and mature B lymphocytes may provide valuable information for monitoring disease progression via a less invasive process.
Hydrogen sulfide: improved hemodynamics and mitigation of ischemia-reperfusion injury in a large animal model (54.8)
Authors: Satterly Steven , Salgar S. , Stallings J. , Martin M. 
Published: January 2023

Abstract
Hemorrhagic shock can lead to ischemia-reperfusion (IR) injury followed by multi-organ failure and death. We tested intravenous Hydrogen sulfide (H2S) in a porcine hemorrhagic shock-resuscitation model evaluating IR injury. Experimental design: Sham (n=3); H2S untreated group (n=5); and H2S treated group (n=14). Animals were splenectomized, induced 35% hemorrhage and ischemia by cross-clamping the supraceliac aorta for 50 minutes. Intravenous fluid and H2S were administered at cross-clamp. Serial hemodynamic measurements and blood plasma analysis were followed for 6 h post-cross clamp release. The mean lactate levels (a measure of injury) were markedly lower in H2S group (7.0±1.6 mmol/L) compared to untreated group (9.3±1.2 mmol/L). Epinephrine requirement was significantly (P&lt;0.05) lower in H2S group (727±645 µg) compared to untreated group (3052±1700 µg). Cardiac output was significantly (P&lt;0.05) lower in H2S treated pigs. The intravenous fluid, hematocrit, and body temperature did not differ significantly (P&lt;0.05). Blood plasma pro-inflammatory cytokines (IL1-β, IL-6, IFN-γ, TNF-α) at 6 h post-cross clamp release were significantly lower (P&lt;0.05) compared to baseline in both H2S treated (n=4) and untreated groups (n=3). Organ (liver, kidney, heart, lung, small bowel, aorta) histopathology and gene expression (iNOS, eNOS, HO-1, HIF-1α, TNFα, IL-6, IFN-γ, IL1-β, etc.,) analyses are in progress. H2S improved hemodynamics and appears to be protective against IR injury.
Chronic estradiol exposure in oophorectomized mice induces a systemic inflammatory disorder that is mediated via TNFα. (54.9)
Authors: Halder Ramesh , Shinyashiki Brenda , Chaudhuri Gautam , Singh Ram 
Published: January 2023

Abstract
Estradiol (E2) administration to oophorectomized (Ovx) mice has been shown to induce the expression of IL-1β, IL-6 and TNFα and inducible NO synthase mRNA in macrophages. Here, we investigated the effect of chronic E2 supplementation on immune responses and cytokines. We found that long-term E2 exposure in Ovx mice led to a marked increase in granulocytes in the liver and spleen. Although, E2 exposed Ovx mice had reduced total cellularity of thymus and spleen and reduced CD4+ and CD8+ T cells in the spleen, more splenic T cells from these mice produced IFN-γ and IL-17 as compared to sham-operated and placebo-treated Ovx mice. IFN-γ and IL-17 were also abundantly made by T, NK and NKT cells in the liver of E2-exposed Ovx mice compared to animals in the other two groups. Intriguingly, E2 exposure in Ovx mice led to significant weight loss as compared to sham-operated mice and placebo-treated Ovx mice. Strikingly, the pro-inflammatory cytokine (IFN-γ and IL-17) response, granulocyte accumulation in liver, and weight loss elicited by chronic E2 exposure in Ovx mice were largely abolished by TNFα deficiency. Finally, 54% of chronically E2-exposed Ovx wild-type B6 mice, as compared to none of sham and placebo-Ovx wild-type mice and none of E2-exposed Ovx TNFα-/- mice, died during the study period. Thus, chronic E2 exposure in Ovx mice elicits an inflammatory condition that is mediated, at least in part, by TNFα.