bluuebunny/crossref_metadata_2025_split huggingface dataset:
Indoleamine 2,3-dioxygenase during acute toxoplasmosis and the hyporesponsiveness of splenocytes
Authors: Ufermann Christoph-Martin , Eller Silvia , Domröse Andreas , Spekker-Bosker Katrin , Däubener Walter 
Published: January 2023

Abstract
Toxoplasma gondii (T. gondii) is an obligate intracellular parasite of medical and veterinary importance. Major mediators of defense to a T. gondii infection are interferon-gamma induced effector mechanisms, e.g. inducible nitric oxide synthase, immunity related GTPases and indoleamine 2,3-dioxygenase (IDO). Suppression of T cell responses – that diminish after several weeks post infection – is observed during acute toxoplasmosis as well as in other infectious diseases. IDO catalyzes the rate limiting step of the kynurenine pathway by utilizing tryptophan. Furthermore, IDO activity has been described to possess antimicrobial and immunoregulatory properties, but its role during acute toxoplasmosis and the altered T cell responsiveness is obscure.
To investigate this part, WT (C57BL/6) and IDO-deficient mice were infected intraperitoneally with T. gondii ME49 tachyzoites. Parasite burden, IDO expression as well as tryptophan and kynurenine concentrations were analyzed. During murine T. gondii infection tryptophan depletion and kynurenine detection was clearly measureable. Since the role of IDO in the T cell hyporesponsiveness during acute toxoplasmosis is incompletely understood, primed and unprimed splenocytes were isolated from infected and naïve mice, respectively. Proliferative responses of the splenocytes to ex vivo mitogen stimulation were measured by detection of incorporated 3H-thymidine. Cell sorting and subsequent cell mixing experiments as well as supernatant transfer experiments were used to break down the mode of action. The observed hyporesponsiveness was independent of IDO. We suggest that the hyporesponsiveness is influenced by nitric oxide synthase and regulatory T cells.
The gut microbiome can contribute to colon tumor susceptibility via an effect on CD8+ T cell responses
Authors: Yu Amy I-Wen , Ho Sharon , Chen Jiachen , Koumpouras Charles , Zhao Lili , Schloss Patrick D , Eaton Kathryn A , Chen Grace Y 
Published: January 2023

Abstract
There is increasing evidence that colorectal cancer patients have altered gut microbiomes compared to healthy controls, but the mechanisms by which the microbiota contribute to colon carcinogenesis remain to be fully elucidated. Using the azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model of inflammation-associated colon tumorigenesis, our lab discovered two colonies of specific pathogen free (SPF) C57BL/6J wild type (WT) mice housed in the same mouse room that develop differential tumor burdens. Mice from the “WT1” colony developed five tumors on average while mice from the “WT2” colony developed 15 tumors on average. The increased tumor susceptibility in WT2 mice can be directly attributed to the gut microbiome as germ-free (GF) mice colonized with WT2 bacteria developed more tumors compared to that of GF mice colonized with WT1 bacteria. Additionally, 16S rRNA gene sequencing of fecal bacteria from WT1 and WT2 mice revealed distinct microbiomes with certain bacteria consistently associated with high or low tumor numbers. Furthermore, naïve and acutely-inflamed (day 10 of AOM/DSS) WT2 mice have increased colon lamina propria CD8+ IFNγ+ T cells compared to WT1 mice as measured by flow cytometry. However, in tumor-bearing WT2 mice, there was decreased tumor-infiltrating CD8+ T cells with reduced IFNγ production, possibly due to T cell exhaustion. GF Rag1−/− mice as well as SPF CD8−/− mice inoculated with WT2 gut microbiota developed fewer tumors than SPF WT2 mice, suggesting that the WT2 gut microbiome increases tumor susceptibility, in part, through an effect on CD8+ T cells. Altogether, our data reveal a potential novel role of microbiota in altering colon CD8+ T cell function that ultimately impacts colon cancer risk.
HHLA2 Expression in Human Clear Cell Renal Cell Carcinoma is Significantly Associated with Patient’s Prognosis and Promotes Cancer Progression
Authors: Chen Lujun , Jiang Jingting 
Published: January 2023

Abstract
HHLA2, a recently reported member of B7 family, plays an important role in the functional inhibition of T cells. Herein, we found that higher HHLA2 mRNA expression level in human ccRCC tissues compared with that in adjacent normal tissues based on TCGA data, and the HHLA2 mRNA level was positively and significantly correlated with PD-L1, PD-L2, B7-H6, but negatively and significantly correlated with B7-H3. Moreover, our immunohistochemistry study showed that HHLA2 staining intensity in human ccRCC tissues was significantly higher than that in normal tissues, and higher HHLA2 expression was significantly correlated with poorer survival of the patients. Higher HHLA2 expression in ccRCC tissues was positively and significantly associated with larger tumor size, advanced pathological stage, and advanced TNM stage. COX model revealed that the parameters including patient’s age, TNM stage and HHLA2 expression level could serve as independent risk factors for prognostic prediction of the patients. Furthermore, our cellular study showed that upon knockdown of HHLA2 expression in human ccRCC cell lines, the cell viability, migration and invasion ability were significantly inhibited, while the cell cycle arrest at G1 phase was induced and the expressions of Cyclin D1, c-Myc and Cyclin E1 were decreased. In addition, based on the microarray analysis data, we also confirmed that the expressions of epithelia-to-mesenchymal transition markers, such as E-cadherin, N-cadherin and Vimentin, were significantly decreased after knockdown of HHLA2 expression. Collectively, our findings indicated that HHLA2 was involved in the progression of human ccRCC and could be used as an important prognostic predictor for this malignancy.
CD4 T Cells modulate the protective vs. pathologic response of CD8 T cells during viral infection
Authors: Luna Evelyn 
Published: January 2023

Abstract
Vaccines expressing pathogen T cell epitopes have been a widely pursued strategy for improving the efficacy of vaccines against persistent viral infections such as HIV. However, selectively engaging T cells also has the potential to increase rather than prevent pathology, consequently shifting a mild disease to a lethal one after subsequent infection. Thus, determining the immune and viral parameters that lead to protection versus those that mediate pathology is critical for developing a safe and effective vaccine against persistent viral infections. Using lymphocytic choriomeningitis virus (LCMV) and an in vivo adoptive transfer mouse model, we investigated how the precursor frequency of CD8 T cells affected the balance of protection vs. pathology during chronic viral infection. We found that the balance is based largely on the number of T cells responding to the pathogen. Intermediate numbers of responding CD8 T cells results in maximum pathology while high numbers provide full protection. We also looked at CD4 T cells and unlike CD8 T cells, increasing the number of pathogen specific CD4 T cells never provides a protective response and instead leads to high host mortality. We have now begun to study the interaction of CD8 and CD4 T cells simultaneously during viral infection to determine the effects of CD4 T cells on CD8 T cell protective versus pathologic vaccine-induced immunity and what exactly mediates such responses.
Raising Endogenous Anti-HMGB1 IgM Antibody for Athero-Protection in the Apoe−/− Mouse Model of Atherosclerosis
Authors: Hariharasubramanian Anjhana , Elangovan Ramya , Shankar Archana , Giacobazzi Mario , Broski Annalisa , Panicker Anjali , Shin Soomin , Chen Aoshuang , Zheng Guoxing 
Published: January 2023

Abstract
Atherosclerosis is driven partly by inflammation, mediated mainly by pro-inflammatory mediators/cytokines. Previous studies have revealed the role of HMGB1, a prototypic DAMP (damage-associated molecular pattern) molecule, in atherogenesis. Recently, we have found that there is a spontaneous production of a neutralizing anti-HMGB1 IgM antibody in the Apoe−/− mouse model of atherosclerosis and healthy humans. In the present study, we have determined whether raising the anti-HMGB1 IgM, via immunization targeting HMW4 (a dominant epitope of HMGB1), reduces atherosclerosis. We first showed that the immunization of 8-week-old Apoe−/− C57BL/6 mice increased the HMW4-specific B-1 cells (which produce anti-HMW4 IgM), identified by HMW4-tetramer staining/flow cytometry. Next, we assessed the anti-atherogenic efficacy of the immunization. To the end, 8-week-old Apoe−/− mice were divided into 4 groups (n = 10/group). Each group was treated with: 1) HMW4 (“test”); 2) raHMW4 (randomized control peptide) (“control”); 3) depletion of the HMW4-specific B cells (to prevent the production of anti-HMW4 IgM), followed by the immunization (control for B cell dependence); or 4) none. At 12 weeks of age, mice were fed a western type diet (WTD) for 12 weeks. Lesions in treated mice were then quantified, by both en face analysis of the aortic arch and morphometric analysis of ORO-stained sections of the aortic root. The “test” group showed reduction in atherosclerosis (by ~40%), when compared to the “control” group (p = 0.006) or non-treated group (p = 0.01). Such reduction was diminished when the anti-HMW4 IgM-producing B cells were depleted (p = 0.02). This study raises the possibility to amplify the anti-HMGB1 IgM response to reduce atherosclerosis.
CD40 ligand (CD40L) multi-trimer antigen fusion protein (MagaVax) as a vaccine design for high-level CD8+ T cell responses
Authors: Kornbluth Richard S , Adase Christopher , Hamilton Victoria Snarsky , Studer Sean 
Published: January 2023

Abstract
Dendritic cells (DCs) can take up antigen via a number of routes. Of these, several studies have shown antigen uptake via the CD40 receptor generates some of the strongest CD8+ T cell responses. At the same time, stimulation through CD40 activates DCs for cross-presentation and heightened antigen presentation. Consequently, it is desirable to combine the CD40 targeting of antigen and a CD40 stimulant into a single vaccine formulation. When the CD40 stimulant is CD40 ligand (CD40L, CD154), it is important to use a multi-trimer complex that clusters CD40 in the DC membrane, thereby engaging downstream signaling pathways. Such a multi-trimer form of CD40L can be provided by fusing the extracellular domain of CD40L with the body of surfactant protein D (SPD), a self-assembling 12-chain soluble molecule with 4 trimeric “arms.” When an antigen sequence is included within the SPD arm, the entire protein complex is termed “Multi-trimer AntiGen Adjuvant Vaccine (Vax)” or “MagaVax.” Studies in mice have shown that MagaVax elicits very high levels of antigen-specific CD8+ T cells with high TCR avidity and functional activity. MagaVax can be effectively delivered as a DNA vaccine i.m. and even more effectively using an adenoviral (Ad5) vector. For a MagaVax encoding HIV-1 Gag, vaccination with Ad5-MagaVax-Gag led to complete protection (“sterilizing immunity”) from Vaccinia-Gag challenge (i.e., 7 log reduction of tissue virus). Thus far, MagaVax formulations have been made for HIV-1 Gag, Ebola, malaria, hepatitis B virus (HBV), and tumor-specific neoantigens. In all of these cases, there may be a clinical benefit for a vaccine that elicits very strong CD8+ T cell responses.
Per oral inoculation with live or killed Chlamydia muridarum induces protection against per-vaginal C. muridarum challenge
Authors: Shillova Nita , Howe Savannah E , Konjufca Vjollca H 
Published: January 2023

Abstract
In addition to infecting the female reproductive tract (FRT), Chlamydia spp. infect the gastro-intestinal (GI) tract of animals and humans. In the GI tract Chlamydia spp. persists without causing pathology, is more resistant to azithromycin treatment, and can be a reservoir for reinfection of the FRT. To date no effective vaccines have been licensed for use in humans. We have found that sIgA responses in the FRT mirror the responses in the GI tract following feeding with a high dose soluble Ova, leading us to hypothesize that immunity in the FRT may be induced via per-oral (PO) antigen administration. To test this hypothesis, 6 week-old C57BL/6 mice were PO or sub-cutaneously (SC) primed with live or killed C. muridarum, then 28 days later SC boosted with killed C. muridarum. At day 42 mice were per vaginally challenged with 2×105 IFUs of C. muridarum and six weeks following challenge mice were euthanized for determination of hydrosalpinx severity and C. muridarum tissue loads. PO inoculation with live or killed C. muridarum followed by SC boosting significantly reduced hydrosalpinx pathology and C. muridarum titers in ovaries, uterus, and vaginal swabs compared to unimmunized controls and to mice primed and boosted SC with killed EBs. Neither form of immunization affected C. muridarum titers in the GI tract, in spite of relatively high Chlamydia-specific sIgA titers. Further analysis revealed that intestinal sIgA are almost exclusively specific for a single antigen (HSP60, a cytoplasmic antigen), while serum antibodies recognize multiple antigens. Our results indicate that while mucosal priming is essential for induction of protective immunity in the FRT, colonization of the GI tract by live Chlamydia is not necessary for mucosal priming.
HIV-1 envelope glycan composition influences virus-host interaction
Authors: Hioe Catarina E , Jan Muzafar , Feyznezhad Roya , Itri Vincenza , Liu Xiaomei , Upadhyay Chitra 
Published: January 2023

Abstract
HIV-1 envelope (Env) is densely shrouded with oligomannose- and complex-type glycans. These glycans interact with lectins, a family of carbohydrate-recognizing proteins. We evaluated lectins for the ability to block infection of HIV-1 isolates that differ in their sensitivity to neutralizing antibodies. The antibody-sensitive tier 1 viruses were blocked by lectins more easily than the resistant tier 2 viruses. When tier 2 viruses were produced with glycosidase inhibitors to express homogenously oligomannose-type glycans, they became more sensitive to mannose-binding lectins (GNA, GRFT, CVN), suggesting that glycan homogeneity increases virus sensitivity to antibodies and lectins. Further, we tested the effect of glycan content on HIV-1 capture and transmission via DC-SIGN, a C-type lectin expressed by macrophages and dendritic cells. While the capture of virus enriched with high-mannose glycans was enhanced, transmission was diminished due to increased degradation. Under a biologically relevant setting, glycan composition was influenced by the Env signal sequence (SS), and SS mutations altered DC-SIGN-mediated virus transmission. The SS mutants also displayed altered sensitivity to inhibition by lectins GNA and GRFT. Mutations in gp120 did not have these effects. Env SS sequences and glycan compositions also vary among HIV-1 strains, leading to differences in their interactions with and sensitivity to lectins. These phenotypes were associated with the amounts of terminating Manα1–3 vs Manα1–2 residues on the Env oligosaccharides and their recognition by DC-SIGN, GNA, and GRFT. These data demonstrate the importance of the Env sugar contents for HIV-1 interactions with lectins expressed by the host immune cells.
Filovirus glycoprotein glycosylation analysis and effects on immunogenicity
Authors: Martinez Britney , Bradfute Steven 
Published: January 2023

Abstract
Filoviruses are hemorrhagic fever viruses that are some of the deadliest pathogens in the world with a fatality rate up to 90%. Symptoms include fever, vomiting, diarrhea, headache, weakness and can lead to hemorrhaging, multiple organ failure and death. Experimental vaccines use filovirus Surface glycoproteins (GPs) as immunogens to induce protective immune responses. Our laboratory studies the glycosylation patterns of different filovirus GPs to develop improved vaccines. Mammalian 293T cells have more complex N-linked glycosylation machinery compared to Sf9 insect cells but both are capable of O-linked glycosylation. Differences in N- and O-linked glycans on filovirus GPs may induce different immune responses upon vaccination. However, the glycosylation patterns on the different filovirus GPs have not been thoroughly elucidated. Here we report purification and glycan analysis of GPs from filoviruses produced in 293T mammalian cells and Sf9 insect cells. We are currently assessing the effects of different glycosylation of the understudied Lloviu virus GP on immunogenicity in mice.
West-Nile virus replicon particles infect 293T cells expressing DC-SIGNR
Authors: Martinez Osvaldo , Kunkel Hannah , Ludwig Anika 
Published: January 2023

Abstract
West-Nile virus (WNV) is an arbovirus usually transmitted to humans via a mosquito vector. Infections commonly result in febrile symptoms while severe neuroinvasive cases may result in encephalitis or meningitis. Studies have shown that WNV infection efficiency is enhanced by expression of DC-SIGNR on target cells, which normally do not express DC-SIGNR. To investigate WNV tropism, we established 293T kidney epithelial cell lines that stably express vector or DC-SIGNR. We demonstrate uniformly high levels of DC-SIGNR expression in selected cells. Virus replicon particles (VRPs), replication-incompetent viral particles containing necessary structural proteins for infection and a viral plasmid including a GFP reporter are used to safely and conveniently study viral entry. Entry assays using WNV (NY99) VRPs as well as a variant of WNV (NY99) which contains the beta-lactamase enzyme show significant entry into DC-SIGNR expressing cell lines, but not in controls that do not express DC-SIGNR. Future studies will focus on discovering which regions of the DC-SIGNR surface glycoprotein are required for WNV entry.
Differential gene expression profile analysis of RIG-I- versus type I IFN-stimulated primary human nasal epithelial cells and protection from influenza virus replication
Authors: Hartmann Evelyn , von Lilien Waldau Vanessa , Stümpel Jan Phillip , Ludwig Janos , Schlee Martin , Coch Christoph , Hartmann Gunther 
Published: January 2023

Abstract
Nasal mucosa is a key barrier against upper airway infection including influenza. Trained innate antiviral immunity has the potential to broadly protect the host from a variety of respiratory viruses. Although exposure of cells to type I IFN confers some degree of protection, direct stimulation of innate immune sensors may induce a more effective and longer lasting antiviral immunity.
In the present study we analysed the gene expression profile and functional consequence of direct activation of RIG-I by its specific ligand 5′-triphosphate RNA (3pRNA) in primary human nasal epithelial cells, and compared these effects to stimulation of other innate receptors and stimulation by type I IFN. Gene expression analysis was carried out by Lexogen QuantSeq 3′mRNA sequencing. For functional analysis, epithelial cells were exposed to H1N1 influenza virus strain A/PR/8/34. Viral replication was analysed by qPCR.
Gene set enrichment analysis revealed upregulation of pathways related to antiviral immune response and type I Interferon signaling. Activation of RIG-I in epithelial cells induced a broad panel of antiviral defense mechanisms which extends beyond those stimulated by recombinant type I IFN. RIG-I-stimulated cells were completely protected from influenza viral replication, while viability of the cells was not reduced. Recombinant IFN-b resulted in lower protection against viral replication compared to 3pRNA, demonstrating that RIG-I induces additional functional antiviral activities not induced by exogenous type I IFN acting alone.
Thus, our findings support the concept that stimulation of RIG in epithelial cells is a promising strategy to protect cells from viruses including emerging viral infections of the respiratory tract.
Unveiling the functional role of hsa-miR-4634 in the innate immunity against respiratory pneumovirus infection
Authors: Uche Ifeanyi Kingsley , Guerrero-Plata Maria Antonieta 
Published: January 2023

Abstract
Human metapneumovirus (HMPV) is a clinically important single stranded RNA virus that belongs to the genus Metapneumovirus in the new virus family, Pneumoviridae. HMPV is among the major causes several respiratory infections such as bronchiolitis and pneumonia worldwide. The lack of vaccine for this respiratory pathogen warrants further research toward understanding the host immune response induced by this pneumovirus. In fact, the molecular mechanisms regulating the antiviral response against this virus is still unclear, specifically miRNAs in HMPV infection are poorly understood. We have recently demonstrated that HMPV induces predominant expression of hsa-miR-4634 in infected cells. However, the functional role of this miRNA during HMPV infection is unknown. To determine the role of hsa-miR-4634 in HMPV infection, we use an in vitro model of human epithelial cells. Our results show that inhibition of hsa-miR-4634 significantly increased the induction of type I and III IFN responses. In addition, overexpression of hsa-miR-4634 led to an increased viral gene expression with concurrent lower expression of IRF7 and Mx1. Furthermore, based on predicted target for hsa-miR-4634, we explored the effect of hsa-miR-4634 on TLR8 activation and the role of TLR8 in HMPV infection. Using an engineered TLR8 knock out cells, we observed that TLR8 is necessary for an adequate IFN response in HMPV-infected cells. Overall, our data strongly suggest that hsa-miR-4634 impairs the innate immune response to HMPV infection. These studies contribute to our understanding of host-pneumovirus interaction, which is critical to design future therapeutic approaches against HMPV and other highly relevant viral infections.
Pro-autoimmune genetic risk variant, PTPN22 1858C&gt;T accelerates formation of tertiary lymphoid structures in a mouse model of Type 1 Diabetes
Authors: Schmiel Shirdi E , Marquardt Kristi , Sherman Linda A 
Published: January 2023

Abstract
Protein tyrosine phosphatase non-receptor type 22 (PTPN22) encodes a lymphoid tyrosine phosphatase adaptor molecule involved in many biological pathways. Studies have shown an association with the minor allelic variant of PTPN22, R620W, and increased incidence of numerous autoimmune disorders, including type 1 diabetes (T1D). The exact mechanisms by which this pro-autoimmune risk allele enhances the incidence of T1D is unknown. To examine the immunological pathways altered by this risk variant, our lab introduced the murine ortholog of the human R620W allele, R619W, into the endogenous locus of Non-obese diabetic (NOD) mice that develop spontaneous T1D. NOD mice harboring this mutation (NOD 619W/W) demonstrated a similar phenotype seen in affected humans with accelerated onset of T1D and enhanced anti-islet autoantibodies (IAA). Preliminary data generated in our lab show enhanced islet infiltration in the pancreata of NOD 619 W/W compared to wild type NOD mice starting at 4–5 weeks of age. Studies have shown that infiltrating lymphocytes can organize into tertiary lymphoid structures (TLS) at the insulitis lesions of pre-diabetic mice. In addition to enhanced infiltration, NOD 619W/W pancreata also show characteristics of TLO formation at the sites of insulitis. Studies have shown that TLOs contribute to disease manifestation and prevention of TLO formation in the pancreas can prevent pathogenesis. Therefore, we are actively examining the immune cell types and pathways altered by the PTPN22 risk allele that may enhance early islet infiltration and promote the formation of TLOs in the pancreata of NOD 619 W/W hosts.