bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeted delivery of antigens to CD11b+ cells via nanobodies induces strong antigen-specific T cell and anti-tumor responses
Authors: Woodham Andrew W. , Cheloha Ross W. , Ling Jingjing , Rashidian Mohammad , Kolifrath Stephen C. , Mesyngier Maia , Duarte Joao N. , Bader Justin M. , Skeate Joseph G. , Da Silva Diane M. , Kast W. Martin , Ploegh Hidde L. 
Published: January 2023

Abstract
The variable regions of camelid heavy chain-only antibodies (nanobodies or VHHs) are the smallest antibody fragments that retain full antigen binding. Owing to their small size, ease of expression, and high tissue penetration, VHHs that recognize cell surface proteins on antigen-presenting cells (APCs) can serve as targeted delivery vehicles for antigens conjugated to them. We site-specifically attached antigens to the C-terminus of an anti-CD11b VHH (VHHCD11b), and then investigated the ability of the VHH-antigen conjugates to elicit antigen-specific T cell and anti-tumor responses in a mouse model of human papillomavirus (HPV)-induced cancer. This VHH had high affinity for CD11b+ dendritic cells (apparent KD = 204 ± 90 pM), and enhanced cross-presentation of a conjugated antigen (OVA257–264) in vitro. Mice immunized with the VHH conjugated to an immunodominant HPV16 E7 epitope (E749–57) had more E7-specific cytotoxic T cells compared to mice immunized with E7 peptide alone, conferring protection against HPV16 E7+ tumor cell challenge. Therapeutically, VHHCD11b-E7 vaccination resulted in greater numbers of CD8+ tumor infiltrating lymphocytes compared to mice receiving E7 peptide alone in HPV16+ tumor-bearing mice, as measured by in vivo non-invasive VHH-based positron emission tomography (PET), which correlated with tumor regression and increased survival. Thus, targeting CD11b for the delivery of antigens via VHHs may be a promising cancer immunotherapeutic strategy.
Recovery of HIV-mediated Immune Aging of T Cells in Virologically Controlled HIV-Infected Patients on Antiretroviral Therapy
Authors: Bradley Nicole Elizabeth , Wertheimer Anne , Klotz Stephen , Nikolich-Zugich Janko , Ahmad Nafees 
Published: January 2023

Abstract
Several studies have shown that HIV infection induces an accelerated aging of T cells, immunosenescence, and alterations in T cell homeostasis resulting in dysregulation of T cell function and rapid HIV disease progression in infected individuals. We have investigated whether long term antiretroviral therapy (ART), which successfully controls viremia and restores CD4 T cell counts in HIV-infected individuals, is correlated with reversal of immunosenescence and/or improved homeostasis of T cells in 100 virologically controlled HIV-infected individuals. We show that the median frequencies of immunosenescence of T cells (CD4+/CD8+ CD28−, CD27−, CD57+ and CD28−CD57+ T cells), were higher in the HIV-infected cohort than the uninfected cohort, however, senescent T cells significantly decreased with increasing CD4 T cell counts in HIV-infected individuals. Although overall levels of naïve CD4+ and CD8+ T cells were lower in HIV-infected than uninfected individuals, there was a significant increase in both CD4+ and CD8+ naïve T cells with increasing CD4 T cell counts in HIV-infected individuals. In addition, the increase in naïve CD4+ and CD8+ T cells in HIV-infected individuals was due to recent thymic immigrants expressing CD31+ marker; however, with increasing CD4 T cells counts accumulation of CD4+CD31− T cells were seen. Moreover, the CD4+ T cells of HIV-infected individuals produced cytokines, including IL-2, IL-10 and IFN-g comparable to uninfected individuals. In conclusion, HIV-infected individuals with controlled viremia and restored CD4 T cell counts due to prolonged ART showed significant reduction in T cell immunoscenesce and improvement of T cell homeostasis and function.
Co-inhibitory receptor TIGIT inhibits CD8+T mediated hepatocellular carcinoma
Authors: Zong Lu , Li Fenglei , Wei Haiming , Sun Rui , Tian Zhigang 
Published: January 2023

Abstract
Chronic hepatitis B virus (HBV) pathogenesis is widely accepted as numerous immune response inducing prolonged inflammation, cirrhosis and lastly hepatocellular carcinoma(HCC). However, the potential theory of HBV tolerance and the immune-mediated HCC development has not been clearly defined currently. We found here that hepatic CD8+T cells of HBsAg-transgenic mice (HBs-tg) express remarkably high levels of co-inhibitory receptor T cell Ig and ITIM domain (TIGIT) with age. Co-inhibitory pathway blockade in HBs-tg mice initiated regional chronic inflammation sequentially inside the liver which reflected by gradually rising ALT level and hepatic fibrosis. TIGIT blockade gave rise to the emerging of HBsAg-specific CTLs and rescued CD8+T cells function by increased proliferation and interferon-γ(IFN-γ) and CD107a production in liver. Besides, HBsAg vaccination to TIGIT-blockade mice triggered the development of HCC. Breeding HBs-tg TIGIT−/−mice showed spontaneous chronic inflammation in life and got HCC toward HBsAg vaccination. CD8+T depletion during TIGIT blockade alleviates liver inflammation in HBs-tg mice. While depleting CD8+T cells start from the vaccination stage till harvest in TIGIT-blockade mice abolishes HCC formation.

Conclusion
High co-inhibitory receptor expression on CD8+T cell may be a contributing factor for HBV tolerance. Our studies reveal a new molecular pathway which causes chronic hepatic diseases.
Increased reactivation of murine gammaherpesvirus-68 during Heligmosomoides polygyrus infection
Authors: Zarek Christina M. , Reese Tiffany A. 
Published: January 2023

Abstract
A vast majority of people are infected with a herpesvirus. These viruses are double stranded DNA viruses that avoid eradication by the immune system by becoming latent. Certain signals, such as immune repression, can lead to reactivation of the virus. Reactivation of gamma herpesviruses is associated with pathologies, such as lymphomas and tumors. Past studies have shown that infection with helminths, extracellular parasitic worms, during gamma herpesvirus latency can cause reactivation. Helminths are known to secrete immunomodulatory factors that suppress host inflammation. The aim of the current study is to determine how prior helminth infection leads to increased reactivation of murine gammaherpesvirus-68 (MHV68). In this study, mice were or were not infected with Heligmosomoides polygyrus (HP), and then infected with MHV68. We found that infection with HP increased the reactivation of virus and the number of infected cells. However, there was no difference in acute replication of the virus between HP infected mice and HP uninfected mice. This suggests that the helminth infection specifically alters viral reactivation. The increased reactivation was only seen in a conventional mouse facility, but not in a barrier mouse facility, suggesting dependence on a microbiota component. Further work is required to determine how HP infection alters immune signals, such as IL-4 and STAT6 signaling, to cause increased MHV68 reactivation. Whether HP alters the permissiveness of cells to MHV68 infection should also be explored.
Development of an in vitro cell culture model to investigate HCMV priming of CD8+ T cells
Authors: Abad Maria , Lenarcic Erik , Xu Yinyan , Wong Jason , Clutton Genevieve , Warren Joanna A. , Savoldo Barbara , Moorman Nathaniel J. , Goonetilleke Nilu 
Published: January 2023

Abstract
Human cytomegalovirus (HCMV)-specific CD8+ T cells are characterized by an unique, non-exhausting, effector memory phenotype. How HCMV induces this phenotype is poorly characterized. We hypothesized that HCMV may skew T cell priming producing functionally distinct CD8+ T cells.
To investigate this question, we have established an autologous 3-cell culture system using human umbilical tissue in which naïve CD8+ T cells are isolated from cord blood, myeloid DCs (mDCs) are generated from cord blood CD34+ precursor cells and fibroblasts, which are a primary target of HCMV infection, are generated from matching umbilical cord (UC-F).
Previous studies have reported IFN-γ treatment of fibroblasts induces MHC-II expression, leading to suggestions that fibroblasts can acquire APC-like activity. To investigate this, we used flow cytometry to examine the effects of HCMV infection +/− IFN-γ on MHC-II, CD40, CD80 and CD86 surface expression on fibroblasts. HCMV alone did not induce MHC-II or costimulatory molecules. HCMV infection +/− IFN-γ induced MHC-II but costimulatory molecules remained undetectable. This suggests HCMV-infected fibroblasts do not acquire APC-like phenotype and that fibroblasts mediate T cell priming through cross-presentation.
Fibroblasts release extracellular vesicles (EVs), which are important mediators of cell signaling, including antigen cross-presentation. We used electron microscopy to confirm that fibroblasts release EVs. Following AD169-GFP infection, 5.5–8% of EV collected were GFP-positive by ImageStream. Future studies will investigate whether UC-F modulate mDC priming of CD8+ T cells through direct cell-cell contact and/or indirectly, including through the release of EVs.
Defining the mechanisms responsible for the induction of cytotoxic CD4 T cell responses during viral infection
Authors: Knudson Cory , Kappes Dietmar , Sigal Luis J. 
Published: January 2023

Abstract
Induction of cytolytic lymphocytes is a core aspect of the anti-viral immune response. While NK and CD8 T cells are most often associated with the job of directly eliminating virus-infected cells, cytotoxic CD4 T cells can also be a major contributor. Cytotoxic CD4 T cell responses have been observed during a multitude of virus infections in both humans and mice including HIV, cytomegalovirus (CMV), herpes simplex virus, influenza virus, ectromelia virus (ECTV), and lymphocytic choriomeningitis virus. It has been previously demonstrated that the absence of a cytotoxic CD4 T cell response following ECTV infection of mice results in significantly greater viral burden. Runx3, the main transcription factor responsible for induction of cytolytic genes in NK and CD8 T cells, was also upregulated in cytotoxic CD4 T cells as compared to other activated or naive CD4 T cells following ECTV infection. Isolation of CD4 T cells expressing Runx3 revealed upregulated expression of cytolytic genes granzyme B and perforin. This suggests that Runx3 may play a critical role in the induction of cytotoxic effector functions in CD4 T cells. In addition, mice lacking expression of MHC class II on either CD11c+ or monocytic cells had significantly impaired cytotoxic CD4 T cell responses following ECTV infection. Challenge of mice with a mutant strain of ECTV that cannot spread from the footpad does not induce a cytotoxic CD4 T cell response, indicating that viremia or local replication is necessary. Our results highlight cell intrinsic and extrinsic mechanisms that are critical for the induction of the cytotoxic CD4 T cell response during viral infection.
Delayed and highly specific antibody response to nonstructural protein 1 (NS1) revealed during natural ZIKV infection by NS1-based capture ELISA
Authors: Yu Lei , Gao Xiujie , Wen Yingfen , Wang Jian , Hong Wenxin , Li Chunlin , Zhao Lingzhai , Yin Chibiao , Jin Xia , Zhang Fuchun 
Published: January 2023

Abstract
The high degree of cross-reactivity of Envelope (E) protein specific antibody responses between ZIKV and DENV made it difficult to perform differential diagnosis between the two infections using standard ELISA method for E protein. The analyses of the sequential serum samples from ZIKV infected individuals showed NS1 specific Abs appeared two weeks later than E specific Abs. Notably, there is none cross-reactivity to NS1 proteins from all four DENV serotypes in human sera from ZIKV infection. Furthermore, four out of five NS1-specific monoclonal antibodies (mAbs) isolated from ZIKV infected individuals did not bind to DENV NS1 proteins. Only limited cross-binding to ZIKV NS1 was displayed in 108 DENV1 immune sera at 1:100 dilution. The high degree of NS1-specific Abs in both ZIKV and DENV infection revealed here suggest that NS1-based diagnostics would significantly improve the differential diagnosis between DENV and ZIKV.
Determinants of CD8+ T Cell Immunodominance in Acute HIV-1 Infection
Authors: Warren Joanna A. , Xu Yinyan , Constanzo Margaret , Whale Victoria , Liu Michael , Thomas Rasmi , Tovanabutra Sodsai , Kijak Gustavo H. , Eller Leigh A. , Rolland Morgane , Michael Nelson L. , Robb Merlin L. , Eller Michael A. , Goonetilleke Nilu 
Published: January 2023

Abstract
CD8+T cells detect and clear virus-infected cells. During human immunodeficiency virus-1 (HIV-1) infection, different HIV-specific CD8+ T cell populations are expanded, each targeting a discreet epitope. These different HIV-specific CD8+ T cell populations do not arise equally, and instead establish a hierarchy (immunodominance) based on strength of T cell response to a given viral epitope. Our previous work has shown that immunodominance is a major determinant of the rate at which HIV can mutate to escape T cell immune pressure. The precise mechanism of how the first CD8+ T cell response to HIV is generated, and which factors determine T cell dominance is unclear. To investigate determinants of T cell immunodominance in acute HIV-1 infection (~45 days after infection), we determined all primary HIV-1 specific CD8+ T cell responses in 10 individuals from the RV217 early acute HIV-1 cohort. Participants are high-risk volunteers from Kenya and Thailand, and acute HIV-1 infection was determined from twice-weekly blood draws using a nucleic acid test. T cell responses were mapped against the unique infecting HIV-1 virus/es in each individual using IFN-γ ELISpot. Across participants, the immunodominant T cell response mostly targeted the Env, Gag and Pol proteins of the HIV-1 genome. We detected a wide (4–14 epitopes) breadth of T cell response across our cohort, with all HIV-1 proteins targeted and different rates of virus escape observed. The summed magnitude of response ranged from 1,388–16,044 SFU/106 cells. Ongoing studies are focusing on better understanding how factors, such as T cell receptor repertoire, avidity, antigen presentation and function contribute to T cell immunodominance, which in turn will inform HIV-1 vaccine design.
Biochemical and structural characterization of a host protein that binds Ebola VP30
Authors: Liu Dandan , Small Gabe , Hultquist Judd , Krogan Nevan , Batra Joyti , Basler Christopher , Leung Daisy , Amarasinghe Gaya 
Published: January 2023

Abstract
Ebola and Marburg viruses are negative sense RNA viruses that can cause high case fatality rates during outbreaks. Approximately 19 kb genome encodes for 7 open reading frames. During virus replication, 7–10 multifunctional proteins are expressed, but viral replication and pathogenesis also require numerous cellular proteins. While the need for host factors in virus replication and pathogenesis has been long appreciated, our understanding of key host-virus interactions during filoviral infection and replication remain incomplete. In order to address this limitation, our collaborators recently performed a proteomic analysis, which identified RBBP6, an E3 ubiquitin ligase, as a cellular interactor of Ebola VP30 (eVP30). eVP30 is a viral protein critical for transcription initiation. In this study, we generated a series of recombinant RBBP6 and eVP30 truncation constructs. We performed in vitro pull-down assays to validate the initial proteomic identification of the eVP30/RBBP6 protein-protein interaction and defined key regions within RBBP6 that are critical for eVP30 binding. Furthermore, using purified eVP30 protein, we generated crystals with a RBBP6 binding peptide and refined X-ray diffraction data to define a series of key residues on the interface of eVP30/RBBP6. Hence, this study provides insights on host-viral interface that modulates viral pathogenesis and defines a novel target for potential development of antiviral therapeutics that target filoviruses.
Lack of T-cell mediated IL2 and TNFa production is linked with the decreased CD58 expression in intestinal tissue during acute simian immunodeficiency virus infection
Authors: Pahar Bapi , Pan Diganta , Srivastav Sudesh K. , Lackner Andrew A. , Das Arpita 
Published: January 2023

Abstract
Human immunodeficiency virus type 1 (HIV-1)/simian immunodeficiency virus (SIV) infection causes a progressive impairment of the immune system characterized by massive CD4+ T-cell loss, CD8+ T-cell expansion and sustained immune activation and inflammation. Our data also suggest that pathogenic SIVMAC251 infection in rhesus macaques (RMs) leads to decreased production of several T-helper 1 (TH1) and TH2 cytokines and increased production of IL-17, IFNg, CCL4 and GM-CSF by intestinal CD8+ T-cells 21 days after infection. For an effective T-cell activation and response, costimulation is required in addition to the antigen-specific signal from their antigen receptors. The CD2/CD58 interaction is considered as one of the important T-cell costimulatory pathway for T-cell activation and proliferation. Intestinal lamina propria T cells were reported to be highly responsive to a stimulus delivered by CD2 pathway compared to the conventional CD3/TCR pathway. The role of CD2/CD58 in regulating intestinal T-cell function of acute and chronic SIV infected RMs is poorly documented. Here, we demonstrated a significant reduction of CD58 expression in both T- and B-cell population during acute SIV infection along with the loss of intestinal CD4+ T-cells and high plasma viral load compared to SIV-uninfected normal RMs. The reduction of CD58 expression in T-cells was positively correlated with the reduced expression of T-cell mediated IL2 and TNFa production. Together, these results indicate that the reduction in CD2/CD58 interaction pathway in mucosal lymphocytes might play a crucial role in mucosal T-cell dysfunction during acute SIV/HIV infection.
Autoimmune Risk Allele of PTPN22 influences early events post viral infection
Authors: Willenbring Robin , Pratumchai Isaraphorn , Marquardt Kristi , Mowen Kerri A. , Teijaro John R. , Sherman Linda A. 
Published: January 2023

Abstract
The PTPN22 alternative allele, PTPN22 1858T, is present in 5–10% of the North American population and is considered the highest autoimmune, non-HLA, risk allele. Extensive work has been done to better understand this allele in the context of autoimmune disorders. However, the role of PTPN22 1858T in the context of viral infection remains incompletely defined. Our lab has previously defined a role for Ptpn22 in generating T cell exhaustion during chronic viral infection. Yet, the mechanism by which it is acting and how the alternative allele effects T cell exhaustion remains unknown. To directly determine this we used CRISPR/Cas9 technology to independently generate mice expressing the human-relevant Ptpn22 alternative allele. Using the well-established LCMV-cl13 infection model in our mice, we tested the hypothesis that pleiotropic effects of Ptpn22 contributes to T cell exhaustion and chronic viral infection. We address this through examination of the role of Ptpn22 in numerous immune cells contributing to viral clearance in vivo. Since early events post-infection drastically influence persistent viral infection we began our studies characterizing splenic organization, cytokines, immune cell infiltration of target organs, and viral load at 1 and 3 days post infection in our mice. Next, we further define how the Ptpn22 alternative allele effects APC functions required for proper anti-viral immune response. Lastly, we determine the state of viral clearance and T cell exhaustion at late time points post-infection in our system. Results of these studies give valuable insight into the role of Ptpn22 in multiple immune cell types that contribute to chronic viral infection and T cell exhaustion.
Dendritic cell intrinsic IRF4 expression regulates production of regulatory cytokines during influenza virus infection
Authors: Hatipoglu Ibrahim , Ainsua-Enrich Erola , Kadel Sapana , Turner Sean , Singh Simar , Kovats Susan 
Published: January 2023

Abstract
Lung resident dendritic cells (DCs) are a heterogeneous population with diverse roles in respiratory infection. The development and function of DC subsets are controlled by distinct transcription factors including IRF4, which regulates CD11b+ cDC2 development, migration, and function. CD11c-cre Irf4fl/fl mice (KO) with a deletion of Irf4 in DCs lack a subset (P1) of lung CD11b+ DCs while other DCs are present but lack IRF4. To test the hypothesis that DC intrinsic IRF4 regulates anti-viral responses, wild type (WT) and KO mice were infected with a sublethal dose of influenza A/PuertoRico/8/34. On days 3–8 post-infection, a novel flow cytometry scheme was used to assess numbers and functional responses of lung and mediastinal lymph node (mLN) DCs, including tissue DC subsets CD103+ and CD11b+ (P1, P2), and inflammatory monocyte-derived Ly6Chi DCs. In addition to lacking CD11b+P1 DCs, KO mice had increased numbers of lung CD103+DCs, a defect in migration of CD11b+P2 DCs to the mLN and reduced numbers of Ly6Chi DCs in the mLN. In WT mice, CD11b+P1 DCs mice produced IL-10, and CD103+DCs preferentially displayed a latent form of TGFβ (LAP) and expressed Itgb8 needed to retain surface LAP for TGFβ activation. KO CD103+DCs showed reduced expression of TGFβ-LAP and Itgb8. Thus, DC production of both IL-10 and TGFβ is deficient in infected KO mice. The reduction of regulatory cytokines is consistent with our earlier finding that infected KO mice harbor decreased numbers of Foxp3+ T regulatory and CD8+ T memory cells, yet greater numbers of effector IFNg+ influenza-specific CD8+ T cells. In sum, IRF4 differentially regulates lung DC subsets to promote regulatory cytokines, and this diversity balances the anti-viral immune response to influenza infection.
IFN-lambda regulates dendritic cell function to mediate protective immunity against influenza A virus infection
Authors: Hemann Emily A. , Green Richard , Langlois Ryan A. , Savan Ram , Gale Michael 
Published: January 2023

Abstract
Influenza A virus (IAV) is a public health threat with constant potential for pandemic outbreak in addition to causing annual, seasonal epidemics. While an IAV vaccine is available, it is rapidly subverted through viral genetic drift, necessitating strategies to limit IAV infection and drive robust, protective immune responses. Type III interferon (IFN), IFN-lambda (IFNλ), is the most highly produced IFN in the lung during IAV infection and restricts IAV in vitro and in vivo. Further, IFNλ influences CD4 T cell skewing following IAV vaccination, but the contribution of IFNλ to the critically protective CD8 T cell response against IAV has not been defined. Here we evaluated the role of IFNλ signaling in the development of CD8 T cell responses against IAV infection in a murine model. Our studies reveal that IFNλ signaling is essential to support cytokine-producing IAV-specific effector CD8 T cells as the CD8 T cell response against IAV is significantly reduced in IFNλ receptor knock out (IFNλR KO) mice. Importantly, IFNλR KO mice exhibited reduced immune protection upon heterologous IAV re-challenge that is dependent upon T cell responses. This immune defect was not T cell intrinsic but instead mapped to altered function and migration of dendritic cells (DCs) in IFNλR KOs, thus linking IFNλ signaling in DCs with modulation of the T cell response. Transcriptomic analysis of DCs revealed the dysregulation of a set of genes implicated in antigen uptake, processing and/or presentation, downstream of IFNλ, but not type I IFN. The function of these genes in the IFNλ response for programming CD8 T cells against IAV will be presented. Our findings reveal a unique role for IFNλ in the governance of DC function and subsequent downstream T cell function.