bluuebunny/crossref_metadata_2025_split huggingface dataset:
EAE symptoms are enhanced by gammaherpesvirus latenlty infetected memory B cells (VIR1P.1143)
Authors: Marquez Ana , Casiraghi Costanza , Shanina Iryina , Horwitz Marc 
Published: January 2023

Abstract
While the description of the genetic and environmental factors responsible for the onset of Multiple Sclerosis has remained elusive, it is believed that previous infection with Epstein Barr Virus (EBV) plays an important role in the development of MS. Our lab has hypothesized that latent EBV infection alters the immune system’s response in genetically predisposed individuals, thereby exacerbating autoimmunity. The study of this relationship is difficult, however, since EBV only infects humans. To address this question we previously developed a murine model where latent infection with gamma herpesvirus 68 (γHV-68), the murine homolog to EBV, enhances the symptoms of experimental autoimmune encephalomyelitis (EAE), which closely resembles human MS pathogenesis. These enhanced symptoms are driven by the upregulati/on of CD40 on dendritic cells in latently infected mice, which drives the priming of a strong Th1 response as well as a decrease in Treg frequencies. Latency of γHV-68 mainly occurs in memory B cells. Here, we demonstrate that latently infected memory B cells are capable of enhancing EAE symptoms when transferred from mice latently infected with γHV-68 into uninfected mice. To understand the impact of γHV-68 on B cells, we propose a mechanism where type 1 interferons play an important role in skewing a Th1 response in latently infected mice. This is a novel mechanism that describes how EBV latency can spur the onset of MS and potentially other autoimmune diseases.
Greater avidity and phagocytic activity of HIV gp41-specific serum IgA antibodies in elite controllers compared to subjects on antiretroviral therapy (VIR1P.1144)
Authors: Nabi Rafiq , Wei Qing , Moldoveanu Zina , Durkin Helen , Greenblatt Ruth , Herold Betsy , Nowicki Marek , Young Mary , Golub Elizabeth , Landay Alan , Mestecky Jiri , Kozlowski Pamela 
Published: January 2023

Abstract
Identification of the mechanisms of natural control of HIV replication in elite controllers (EC) may inform approaches for prevention of HIV. We investigated whether EC produce envelope-specific serum IgA responses of greater magnitude, avidity and function compared to subjects on combination antiretroviral therapy (cART). Serum was obtained from age- and race-matched HIV-uninfected women and infected women classified as EC or cART controllers (HC) or noncontrollers (HN). The EC and HC had undetectable viremia and CD4 T cell counts &gt; 450/µl. The HN had high viremia and CD4 T cells &lt; 250/µl. Concentrations and avidity of IgA and IgG against Clade B consensus gp120 and gp41BAL proteins were determined using ELISA. THP-1 monocytes and fluorescent beads coated with gp120 or gp41 were used to evaluate phagocytosis in whole serum and in IgA- or IgG-depleted serum. The magnitude of IgA and IgG responses to gp120 and gp41 was not found to differ between groups. Also, no differences were observed for avidity and phagocytic activity of gp120-specific antibodies. However, avidity and phagocytic activity of the anti-gp41 IgA in EC was significantly greater (p = 0.0186 or p = 0.0054 compared to HC or HN; p = 0.0474 compared to HC, respectively). These data indicate that, in EC, affinity maturation of IgA antibodies to gp41 may occur to a greater extent, resulting in gp41-specific IgA with greater antiviral function. Induction of gp41-specific IgA should be considered in vaccine design.
Inhibition of T follicular helper cells mediated immune evasion in Japanese encephalitis virus infection (VIR1P.1146)
Authors: Cui Min , Wang Chong , Yuan Jiaolong , Wang Kunlong 
Published: January 2023

Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne neurotropic virus, which can escape from the peripheral immune response resulting in serious neuroinflammation. However, the mechanism of JEV immune evasion still remains unclear. In our study, it was found that both CD3+ and CD4+ T cell population dramatically decreased in the early stage of infection. And, T Follicular Helper Cell (TFH) counts reduced obviously accompanied with the decline of B cells, following the CD4+CD25+FoxP3+ regulatory T cells (Tregs) increased in the peripheral immune organs and blood after JEV infection. Co-inhibitory molecules CD279 (PD-1) and CD272 (BTLA) were upregulated on CD4+ T cells in JEV infected mouse, while CD274 (PD-1 ligand 1) was also upregulated on dendritic cells accordingly. IL-10, which indicating the immunosuppression, also dramatically increased in the whole process. Collectively, we hypothesis that there are two strategies involved in the JEV mediated immune evasion. On the one side, upregulation of the co-inhibitory molecules on T cells and APCs induces cell apoptosis of the CD3+ T cells, CD4+ T cells and TFH cells; on the other side, IL-10 may regulate TFH cells and Tregs differentiation. As a consequence, JEV evades from immune clearance and gains entry into the CNS leading to neuropathogenisis.
Maintenance of multiple Nef functions limits and dictates pathways of immune escape (VIR1P.1147)
Authors: Maness Nicholas , Das Arpita , Weiler Andrea , Friedrich Thomas 
Published: January 2023

Abstract
CD8+ T lymphocytes (CD8TL) can effectively control SIV and HIV replication. CD8TL targeting of particular regions in the Nef globular core is associated with control of both viruses suggesting common mechanisms of control. Deep sequencing of SIV from nine Mamu-B*017:01+ macaques revealed distinct selection patterns in two Nef epitopes. Functional assays revealed that acute escape in one epitope impacted a conserved structural face of the Nef core and reduced MHC-I downregulation, rendering infected cells more susceptible to CD8TL against other epitopes. In contrast, acute mutations in a nearby epitope impacted Nef’s ability to downregulate Tetherin and CD28, both of which are modulated via Nef interactions with host clathrin adaptor proteins, with mutations impacting MHC-I anchor residues being most destructive. In fact, anchor residues in both epitopes are almost entirely conserved throughout primate lentiviral history, spanning more than 40 millennia suggesting selection for maintenance of function. These data suggest mechanisms by which Nef targeting CD8TL can contribute to viral control; by targeting conserved epitopes involved in fuctions that are critical for high-level viral replication in vivo. Our approach to understanding T cell mediated control of SIV revealed novel insights into Nef structure:function relationships and suggest that particular regions of the Nef protein might be attractive components of vaccines designed to induce potent CD8TL responses.
Dengue virus infection elicits highly polarized CX3CR1+ cytotoxic CD4+ T cells associated with protective immunity (VIR1P.1126)
Authors: Weiskopf Daniela , Bangs Derek , Sidney John , Kolla Ravi , de Silva Aruna , de Silva Aravinda , Crotty Shane , Peters Bjorn , Sette Alessandro 
Published: January 2023

Abstract
The frequency of infection with any of the four dengue viruses (DENV 1-4) has increased dramatically in the last few decades, and the lack of a vaccine has led to significant morbidity and mortality worldwide. Dengue virus is a pathogen with unusual pathogenesis and protective immunity is poorly understood. While DENV-specific CD8+ T cell responses have been extensively studied, the breadth and specificity of CD4+ T cell responses remains to be defined. In effort to define HLA-restricted CD4+ T cell responses resulting from natural infection with DENV, we endeavored to map T cell responses in individuals from Sri Lanka where DENV is hyper-epidemic. Characterization of the phenotype of the responding CD4+ T cells revealed a DENV specific T cell subset that is specifically expanded in donors carrying an allele associated with protection from severe DENV disease. Analysis of DENV-specific CD4+ T cells revealed that the virus specific cells were highly polarized, with a strong bias towards a CX3CR1+ Eomes+ Tbet+ perforin+ granzyme B+ CD45RA+ CD4 CTL phenotype. Importantly, frequency of these cells correlated with a protective HLA DR allele and we demonstrate these cells have direct DENV-specific cytolytic activity. We speculate that cytotoxic dengue-specific CD4+ T cells may play a role in control of dengue infection in vivo, and this immune correlate may be a key target for dengue virus vaccine development.
SIV-specific rhesus CD4 T cells expressing African green monkey TRIM5α exhibit prolonged persistence and enhanced antiviral function. (VIR1P.1153)
Authors: Jain Sumiti , Trivett Matthew , Ayala Victor , Coren Lori , Barsov Eugene , Ohlen Claes , Ott David 
Published: January 2023

Abstract
Infection of CD4 T cells by HIV/SIV inhibits the formation of robust antiviral responses. Furthermore, HIV-specific CD4 T cells are preferentially infected and eliminated in vivo. This highlights the importance of protecting virus-specific CD4 T cells to effectively study their antiviral mechanisms. In this study, we have shown that African green monkey (Agm) TRIM5α restricts SIVmac239 replication in primary rhesus macaque CD4 T cells and synergizes with an intrinsic resistance present in some CD4 T-cell clones. Importantly, AgmTRIM5α-transduced effector CD4 T cells exhibit an increased ability to suppress viral replication in infected target cells. This increase in antiviral effector function was strongly linked to decreased infection and prolonged persistence of the AgmTRIM5α-expressing effectors. Hence, AgmTRIM5α restriction in rhesus CD4 T cells offers an approach to evaluate their anti-SIV effector functions. Currently, we are pursuing studies to determine the effectiveness of SIV-specific CD8 and CD4 T cells in controlling infection in an adoptive transfer model, where the genetically modified CD4 T-cell clones express AgmTRIM5α to prolong their persistence in vivo.
Stress perception alters cellular and molecular immunity in the immune response in the brain to a neurotropic viral pathogen (VIR1P.1154)
Authors: Steel Christina , Machida Mayumi , Lundberg Patric , Wellman Laurie , Yu Maureen , Kennedy Krista , Yanev Petar , Vonu Peter , Sanford Larry , Ciavarra Richard 
Published: January 2023

Abstract
Vesicular stomatitis virus (VSV) applied intranasally produces a well-characterized encephalitis. However, mice that experienced controllable stress via an escapable foot-shock (ES) demonstrated an enhanced immune response relative to mice that experienced uncontrollable stress (inescapable foot shock, IS) or non-stressed control mice (NS). These differences began as early as 1 day post-infection, where IS mice show a more robust cytokine response than ES or NS mice. By 3 days post-infection, however, ES mice showed enhanced inflammatory cytokine responses in the olfactory bulb. We used the Ingenuity Pathways Analysis (IPA) platform to identify regulatory genes responsible for the differences. IPA identified miRNA146a as an upstream regulator of the antiviral response and qPCR found elevated levels (~5-fold) of miRNA146a in the olfactory bulb from ES versus IS mice. miRNA levels in the non-stressed group were below detectable limits. These results suggested increased inflammation in the brains of ES mice, which were supported by more aggressive weight loss in ES mice compared to IS or NS mice as the encephalitis progressed. By 28 days post-infection, surviving mice subjected to ES continue to show increased immune activation as evidenced by increased leukocyte infiltration and enhanced production or infiltration of CD103+ (memory phenotype) T cells relative to IS or NS mice.
Evaluation of bone marrow in cowpox virus infection in cynomolgus macaques (VIR1P.1127)
Authors: Josleyn Nicole , Yellayi Srikanth , Martinez Mark , Janosko Krisztina , Adams Ricky , Burdette Tracey , Cohen Melanie , Zhang Tengfei , Jahrling Peter , Johnson Reed 
Published: January 2023

Abstract
Evaluation of countermeasures against variola virus, the causative agent of smallpox, must be performed through extrapolation from suitable animal models of human smallpox. In previous studies, the gross and histopathological findings of nonhuman primates intravenously (IV) infected with Cowpox Brighton Red (CPXV) included the presence of necrotic areas of bone marrow that were orthopox-viral antigen positive by immunohistochemistry (IHC). Here, we describe changes in bone marrow in regards to cellular composition, orthopox-viral antigen positivity, viral load, and histological findings during a serial disease progression study of cynomolgus macaques following IV inoculation of CPXV. Our results demonstrate infectious CPXV as early as day 3 post inoculation in the bone marrow. Flow cytometry and histological analysis indicate changes in bone marrow composition. Furthermore, flow cytometry analysis indicates many cell populations including monocytes, CD34+ stem cells, and neutrophils were orthopox-viral antigen positive, while mesenchymal stromal cells were not. We have previously shown immunopositivity in the bone marrow by IHC. Flow cytometry revealed no significant differences in early or late apoptosis between CPXV- and mock-infected NHPs. These data indicate an important role for bone marrow function during the progression of disease in the CPXV- nonhuman primate model of smallpox.
IL-10 inhibits neuraminidase activated-TGF-β and facilitates Th1 phenotype during early phase of infection (VIR1P.1129)
Authors: Huang Ching-Tai , Dutta Avijit , Chen Tse-Ching , Lin Chun-Yen , Chiu Cheng-Hsun , Lin Yung-Chang , Chang Chia-Shiang , He Yueh-Chia 
Published: January 2023

Abstract
Th1 cells control their activity by producing regulatory IL-10. Here we report that Th1 cell-derived IL-10 facilitates their expansion and in addition, augments Th1 cell production of IFN-γ, TNF-α, and IL-2 during the early phase of influenza. In our antigen-specific mouse experimental system, influenza hemagglutinin-specific CD4+ T cells respond to infection with the induction of T-bet, and produce both IFN-γ and IL-10. In the early phase of infection, an abundance of viral neuraminidase causes TGF-β activation of hemagglutinin-specific CD4+ T cells. CD4+ T cell-derived IL-10 inhibits neuraminidase-driven TGF-β activation and counteracts the virus-mediated immune suppression. As the host eradicates the virus, neuraminidase activity wanes and IL-10 receptors are up-regulated on CD4+ T cells in the late phase of infection. IL-10 then suppresses immune activation and aids in recovery from infection and inflammation. These results reveal a previously unrecognized function of Th1 cell-derived IL-10 in vivo.
LCMV-specific CD4 T cells induce immunopathology and impair immune protection following chronic LCMV infection (VIR1P.1132)
Authors: Penaloza-MacMaster Pablo , Barber Daniel , Wherry E. , Provine Nicholas , Teigler Jeffrey E. , Parenteau Lily , Blackmore Stephen , Borducchi Erica , Larocca Rafael , Yates Kathleen , Shen Hao , Haining W. , Sommerstein Rami , Pinschewer Daniel , Ahmed Rafi , Barouch Dan 
Published: January 2023

Abstract
CD4 T cells promote memory immune responses, but it is unclear whether vaccine-induced CD4 T cells contribute to immune protection. We interrogated if virus-specific CD4 T cells would protect mice against infection with chronic lymphocytic choriomeningitis virus (LCMV). Immunization with vaccines that induced CD4 T cell responses resulted in mortality following infection with persistent strains of LCMV. Immunopathology was associated with high levels of virus-specific CD4 T cells, generalized inflammation and collapse of adaptive immunity. Interestingly, virus-specific CD8 T cells or antibodies abrogated these lethal effects of CD4 T cell vaccines. Our data demonstrate the importance of tightly regulating CD4 T cell responses following vaccination, and suggest that CD4 T cells in the absence of effective antiviral immune responses could induce lethal immunopathology.
Rapid recovery from severe H7N9 disease requires a diversity of response mechanisms driven by CD8+ T cells (VIR2P.1162)
Authors: Xu Jianqing 
Published: January 2023

Abstract
The avian origin A/H7N9 influenza virus causes high admissions rates (&gt;99%) and mortality (&gt;30%), with ultimately favorable outcomes ranging from rapid recovery to prolonged hospitalisation. Using a novel multi-colour assay for monitoring adaptive and innate immunity, we dissected the kinetic emergence of different effector mechanisms across the spectrum of H7N9 disease and recovery, to find that a diversity of response mechanisms contribute to resolution and survival. Patients discharged within 2-3 weeks had an early peak in H7N9-specific CD8+ T-cell responses, while individuals with prolonged hospital stays had late recruitement of CD8+/CD4+ T cells and antibodies simultaneously (recover by week 4), augmented even later by prominent NK cell responses (recovery &gt;30 days). In contrast, those who succumbed had minimal influenza-specific immunity and little evidence of T-cell activation. Our study illustrates the importance of robust CD8+ T-cell memory for protection against severe influenza disease caused by newly-emerging influenza A viruses.
Bundibugyo ebolavirus replicates to lower viral titer in innate immune cells (VIR2P.1171)
Authors: Versteeg Krista , Mire Chad , Geisbert Thomas 
Published: January 2023

Abstract
The current Zaire ebolavirus (ZEBOV) epidemic in West Africa reinforces the need for effective vaccines and therapeutics that protect against all species of ebolavirus (EBOV). To achieve this, we characterized the effect of virus infection of macrophages and dendritic cells using the recently discovered Bundibugyo ebolavirus (BEBOV). BEBOV infection of humans and nonhuman primates has a lower case fatality rate, differing clinical presentations, and longer time to death compared to ZEBOV. More importantly, survivors and non-survivors of BEBOV have detectable antibodies against BEBOV, indicating that BEBOV interaction with immune cells may differ from ZEBOV. To better understand BEBOV pathogenicity and determine the effects of BEBOV on macrophages and dendritic cells, we performed growth curves and cell characterization in monocyte-derived dendritic cells and PMA-induced THP-1 macrophage-like cells. Over 96 hours, virus production was measured by virus titer, flow cytometry, and qRT-PCR. During monocyte derived dendritic cell experiments, cell surface markers were characterized over time to determine changes induced by EBOV infection. In all cell types tested, BEBOV grows to a lower viral titer. This may play an important role in the overall pathogenesis of BEBOV. Understanding the systemic immune response to BEBOV will aid in determining the mechanism of decreased pathogenesis and identify antiviral targets to be used in developing broad spectrum EBOV therapeutics.
Generation and evaluation of simian-human immunodeficiency virus subtype AE challenge stocks (VIR2P.1166)
Authors: Tartaglia Lawrence , Chang Hui-Wen , Lee Benjamin , Abbink Peter , Whitney James , Lim So-Yon , Sanisetty Srisomya , Lavine Christy , Seaman Michael , Barouch Dan 
Published: January 2023

Abstract
The majority of preclinical and clinical human immunodeficiency virus type 1 (HIV-1) vaccine development efforts have focused on HIV-1 subtype B strains from the western world. However, the overwhelming majority of HIV/AIDS-related deaths occur in the developing world and are from other HIV-1 subtype strains. Therefore, we sought to develop and generate the first mucosally transmissible simian-human immunodeficiency virus (SHIV) challenge stocks from HIV-1 subtype AE env sequences. The sequences were identified from acutely infected HIV-1 individuals from Southeast Asia. The challenge stocks efficiently infected rhesus monkeys, replicated to high levels during acute infection, and established chronic setpoint viremia. The SHIV challenge stocks should facilitate the evaluation of vaccines and other interventions aimed at controlling the spread of HIV-1 subtype AE infection.
T cell-mediated protection and epitope mapping with a trivalent alphavirus-like replicon particle vaccine (VIR2P.1167)
Authors: Cohen Courtney , Morazzani Elaine , Kalinyak Laura , Glass Pamela 
Published: January 2023

Abstract
Venezuelan (VEEV), eastern (EEEV) and western (WEEV) equine encephalitis viruses cause debilitating and sometimes fatal illness. These pathogens are highly infectious when aerosolized, and thus favorable candidates for weaponization, yet no licensed vaccines exist. In a subcutaneous model of infection protection correlates with neutralizing antibody response, but studies suggest that protection from aerosol challenge is partially mediated by cellular immunity. We have previously shown that a trivalent (VEEV/EEEV/WEEV) virus-like replicon particle (triVRP) vaccine protected mice against lethal aerosol challenge. To investigate the cell-mediated response, splenocytes from triVRP- and mock-vaccinated mice were cultured for 6 days ex vivo in the presence of VEEV, EEEV or WEEV peptides. Fifteen-mer peptide pool libraries against E1 and E2 glycoproteins were used for T cell epitope mapping. Splenocytes were analyzed via flow cytometry for T cell-specific markers and cytokine production. Restimulation with specific regions of the VEEV E2 protein induced a memory CD8+CD44+ T cell response, as well as an increase in proliferating, non-cytokine producing CD8+CD44+ T cells. Thus, triVRP-vaccinated mice developed a cell-mediated, peptide-specific memory response. Studies are ongoing to precisely map T cell epitopes within VEEV, EEEV and WEEV glycoproteins. Future studies will evaluate the importance of these responses to protection from lethal aerosol alphavirus challenge.
Comparative analysis of CTL-repertoires induced by different vaccine vectors
Authors: Bernhard Caroline Andrée 
Published: January 2023

Abstract
Dendritic cells (DCs) are considered the most potent antigen-presenting cells (APCs), which directly prime or cross-prime MHCI-restricted cytotoxic T cells (CTLs). Although we know much about the molecular mechanism of cross-presentation, its actual contribution to cytotoxic T cell (CTL) immunity under physiological conditions in vivo is still unclear. Cross-presentation is based on the idea that DCs are the only professional antigen-presenting cells able to prime naïve T cells. However, recent evidence suggests the existence of other, as-yet unidentified APCs also able to prime T cells. To identify those APCs, we used adenoviral (rAd) vectors, which do not infect DCs but selectively accumulate in CD169+ macrophages (MPs). In mice that lack DCs, infection of CD169+ MPs was sufficient to prime CTLs specific for all epitopes tested. In contrast, CTL responses relying exclusively on cross-presenting DCs were biased to selected strong MHC I-binding peptides only. When both DCs and MPs were absent, no CTL responses could be elicited. Therefore CD169+ MPs can be considered APCs that significantly contribute to CTL responses. However, other vaccine vectors, such as Modified Vaccinia Ankara (MVA), seem to have different APC-requirements to be efficient. Side-by-side comparison of CTL responses initiated by different APC types and vaccines might greatly advance our knowledge for vaccine development.