bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roles of glycosylation and redox states on SARS-CoV-2 spike protein actions
Authors: Bejoy Jennyfer , Brelidze Tinatin I , Suzuki Yuichiro J 
Published: August 2023

Abstract
The pandemic of Coronavirus Disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The viral fusion protein, spike protein, binds to its receptor Angiotensin-Converting Enzyme 2 (ACE2) to enter host cells. Further, the S1 subunit of the spike protein may be cleaved off the virus and affect various organs. In addition to tightly binding to ACE2, S1 spike protein also enhances the peptidase activity of ACE2 and activate cell signaling. The present study compared effects of recombinant S1 spike proteins expressed in HEK cells and in E. coli. The spike protein expressed in HEK cells is heavily glycosylated and binds strongly to ACE2, while the protein expressed in E. coli is not glycosylated and exhibits no ACE2 binding. The SulfoBiotics Protein Redox State Monitoring assay determined that cysteine residues of the spike protein expressed in HEK cells are fully oxidized, while those of the protein expressed in E. coli are reduced. The deglycosylation of the protein expressed in HEK cells by Glycopeptidase F attenuates the ACE2 binding, although not completely, and the oxidation of the E. coli protein by hydrogen peroxide enhances the binding. In contrast to the highly distinct ACE2 binding capacities of spike proteins expressed in HEK cells and in E coli, spike proteins expressed in both systems enhance the ACE2 peptidase activity and promote cell signaling. These results suggest that the glycosylated state contributes to the binding of the spike protein to ACE2 and introduce a new concept of the regulation of the spike protein-ACE2 binding by redox mechanisms. Glycosylation and redox states, however, do not define the abilities of the spike protein to enhance the ACE2 enzyme activity or promote cell signaling.
Supported by grants from NIH (R03 AG71596, R21 AG73919)
The role of immune boosting and waning in shaping dengue epidemic dynamics
Authors: Aogo Rosemary , Zambrana Jose Victor , Kuan Guillermina , Balmaseda Angel , Sanchez Nery , Ojeda Sergio , Gordon Aubree , Harris Eva , Katzelnick Leah 
Published: August 2023

Abstract
Infection with one of the four dengue viruses (DENV1-4) induces both virus-specific and broadly reactive antibodies that may either provide protection or increase the severity of disease during secondary infection. Re-exposure in those with multiple prior DENV infections may boost immunity and reduce dengue risk and transmission; however, longitudinal studies investigating re-exposure and protective immunity for dengue epidemic dynamics are still lacking. For instance, does the interaction between long-term waning of immunity between infections and re-exposure to DENV or Zika virus (ZIKV) contribute to the epidemic periodicity? Since measuring re-exposure in highly immune individuals is difficult, previous studies have explored the role of boosting in protection against dengue disease but not using longitudinal measures of herd immunity. Here, we utilize both a longitudinal dataset of antibody titers to DENV and ZIKV measured annually in a Nicaraguan cohort from 2004–2021 and a mathematical model incorporating individual antibody boosting, antibody-dependent enhancement and waning to study the role of boosting on dengue transmission dynamics. Our results support our hypothesis that boosts in highly immune individuals contribute to herd immunity, delaying their contribution into the susceptibles and lowering the rate of dengue cases in future epidemics. However, as their immunity wanes due to lower transmission intensity, the susceptible fraction builds up until a major epidemic that includes re-infection of those with high titers. Our study highlights the interaction of immune boosting and waning in highly exposed adults in shaping dengue epidemics and inform vaccine efforts to maintain immunity over the life-course.
Supported by the Intramural Research Program of the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health & by grants from NIH (P01AI106695)
Coronavirus spike protein vaccination history affects SARS-CoV-2 receptor-binding domain-specific memory response in a mouse model
Authors: Brice David , McGargill Maureen A 
Published: August 2023

Abstract

Background
Previous exposure to human common cold coronaviruses (hCCCoVs) has been shown to affect immune responses to SARS-CoV-2. Since most humans have been infected with different hCCoVs throughout their lives, determining exactly how previous immunity to hCCoVs affects anti-SARS-CoV-2 responses, especially to the Spike (S) protein and its receptor-binding domain (RBD), has proven difficult. We, therefore, used a mouse model to investigate how exposure to different coronavirus S alters the immune response to SARS-CoV-2 S vaccination.

Methods
C57BL/6 mice were vaccinated intramuscularly with 30 μg of full-length S from several coronaviruses: hCCCoVs, SARS-CoV, or SARS-CoV-2. All mice were then vaccinated with SARS-CoV-2 full-length S 33 days later. Sera from all mice were collected at multiple timepoints after vaccinations and analyzed by ELISA and microneutralization assays.

Results
Initial SARS-CoV S vaccination, surprisingly, led to significantly higher levels of anti-RBD IgG antibodies compared to SARS-CoV-2 vaccination. Boosting with SARS-CoV-2 S increased SARS-CoV-2 S IgG and IgM levels, regardless of previous vaccination, but increased RBD IgG responses more in SARS-CoV and SARS-CoV-2 S mice and only previous SARS-CoV S vaccination increased in anti-RBD IgM levels. Microneutralization assay results of each timepoint significantly correlated with combined anti-RBD IgG and IgM levels.

Conclusions
SARS-CoV S vaccination leads to more robust anti-SARS-CoV-2 RBD antibody levels in both naïve and SARS-CoV-2 S-vaccinated mice than other coronaviruses studied. Further investigation will help explore which aspects of this SARS-CoV S vaccination could lead to an increased RBD-focused immune response.

David C. Brice was supported through The American Association of Immunologists Intersect Fellowship Program for Computational Scientists and Immunologists.
Unveiling the antiviral activity of interferon epsilon in respiratory infections
Authors: Martinez-Espinoza Ivan , Guerrero-Plata Antonieta 
Published: August 2023

Abstract
Type I interferons (IFN-I), including IFN-α and IFN-β, have demonstrated efficacy in treatments against some viral infections but with a considerable amount of undesirable side effects. IFN-ɛ, a recently discovered member of the IFN-I family, has been found to be expressed constitutively in several tissues, including the lung. However, the antiviral effect of IFN-ɛ against respiratory viral infections is largely unknown. Human respiratory syncytial virus (RSV) is the most important agent responsible for acute lower respiratory tract diseases in infants worldwide. Each year in the United States, RSV leads to approximately 2.1 million outpatient (non-hospitalization) visits among children younger than five years old, with a considerable number of hospitalizations among children younger than five years old and adults 65 years and older. Currently, no vaccine is available to prevent this respiratory tract infections, and new strategies are necessary to treat patients. Therefore, in this study, we aimed to investigate the antiviral effect of IFN-ɛ against respiratory viruses, such as RSV. Using a human epithelial cell line, we assessed the expression, susceptibility, and antiviral effect of IFN-ɛ on RSV infection. Our results demonstrate that RSV is capable of inducing IFN-ɛ. Moreover, RSV is susceptible to the antiviral activity of the rhIFN-ɛ, reducing the number of infected cells as well as the viral replication. That effect is due to the induction of the expression of ISGs with a low inflammatory profile. Overall, our findings demonstrate that RSV is susceptible to the effect of IFN-ɛ, suggesting a potential therapeutic effect of this novel member of the IFN-I family to treat respiratory viral infections.
This work was funded in part by a Louisiana State University School of Veterinary Medicine Competitive Research Program Award
Cytotoxic T cells targeting spike glycoprotein are associated with hybrid immunity to SARS-CoV-2
Authors: Phan Jolie M , Layton Erik D , Yu Krystle K Q , Aguilar Melissa S , Golez Inah , Franko Nicholas M , Logue Jennifer K , Rodda Lauren B , Howard Christian A , Pepper Marion , Gale Michael , Chu Helen Y , Seshadri Chetan 
Published: August 2023

Abstract
mRNA vaccination of individuals with prior SARS-CoV-2 infection provides superior protection against breakthrough infections with variants of concern compared to vaccination in the absence of prior infection. However, the immune mechanisms by which this ‘hybrid immunity’ is generated and maintained are unknown. While genetic variation in spike glycoprotein effectively subverts neutralizing antibodies, spike-specific T cells are generally maintained against SARS-CoV-2 variants. Thus, we comprehensively profiled T cell responses against the S1 and S2 domains of spike glycoprotein in a cohort of SARS-CoV-2-naïve (n = 13) or convalescent (n = 17) individuals who received two-dose mRNA vaccine series and were matched by age, sex, and vaccine type. Using flow cytometry, we observed that the overall functional breadth of CD4 T cells as well as polyfunctional Th1 responses were similar between the two groups. However, polyfunctional cytotoxic CD4 T cell responses against both S1 and S2 domains trended higher among convalescent subjects. Multi-modal single-cell RNA sequencing revealed diverse functional programs in spike-specific CD4 and CD8 T cells in both groups. However, convalescent individuals displayed enhanced cytotoxic and antiviral CD8 T cell responses to both S1 and S2 in the absence of cytokine production. Taken together, our data suggest that cytotoxic CD4 and CD8 T cells targeting spike glycoprotein may partially account for hybrid immunity and protection against breakthrough infections with SARS-CoV-2.
In the absence of DEC-205, Enhanced inflammation in the CNS is Associated with Reduced numbers of IL-10-producing CD4+ T-cells During WNV encephalitis.
Authors: Ristic Fiona Marie , Ramos Damian Stone , Durrant Douglas M 
Published: August 2023

Abstract
West Nile Virus (WNV), a mosquito-borne single-stranded RNA flavivirus, can cause significant human morbidity and mortality. Previous studies have shown that dendritic cells (DCs) within the central nervous system (CNS) are required to reactivate antiviral effector T-cell responses that restrict WNV replication and limit immunopathology within the CNS. Among these DCs, one subset expressing DEC-205 accumulates within the CNS during WNV encephalitis. DEC-205, an endocytic receptor highly expressed on conventional DCs (cDCs), mediates the efficient processing and presentation of antigens in vivo, leading to either tolerance or immunity depending on DC maturation status, suggesting that DEC-205+ DCs play an immunoregulatory role in the CNS during WNV infection. However, the contributions of CNS-localized DEC-205+ DCs in programming WNV-specific T-cell immunity remains poorly understood. In preliminary experiments, WNV-infected DEC-205−/− mice exhibited increased susceptibility to WNV infection, more severe clinical signs of disease, and loss of virologic control with early entry into the CNS despite the increased trafficking, activation, and effector response of CD4+ and CD8+ T cells. We found that this uncontrolled inflammatory response was associated with a lack of IL-10-expressing CD4+ T regulatory cell (T reg) expansion that occurs typically during acute WNV infection. Thus, the enhanced inflammatory response in the absence of DEC-205 was coupled with a failure to protect against WNV infection and neuroinvasive disease. Taken together, DEC-205-expressing DCs regulate the degree and balance of the antiviral immune response to WNV infection within the CNS by activating T regs.
NIH SC3GM130472
Molecular characterization of influenza-specific memory B cell subsets residing in human tissues
Authors: Owiredu Eddie-Williams , Killian John T , King Rodney G , Akther Jobaida , Mousseau Betty , Zumaquero Esther , Zhou Fen , Chen Suki , Nellore Anoma , Rosenberg Alexander , Lund Frances E 
Published: August 2023

Abstract
B cells can be divided into distinct subsets based on origin, activation history and functional attributes. Most human studies, which have characterized bulk polyclonal populations of circulating B cells, suggest heterogeneity between the different B cell subsets. Indeed, we showed that memory B (Bmem) and plasma cells from the blood of the same donor exhibit distinct patterns of isotype distribution, mutational burden and have relatively limited clonal sharing. However, this heterogeneity may not extend to comparisons between the same B cell subset found within different tissues or cells that share the same reactivity. To test this, we examined influenza hemagglutinin (HA)-specific Bmem in multiple donor-matched tissues. We first generated a high-throughput bead array displaying HAs from the seasonal (H1, H3) and pandemic (H2, H5, H7, H9) flu strains and screened the serum from &gt;80 brain-dead human tissue donors. All the donors exhibited high serum IgG reactivity against the circulating strains. We also identified serum reactivity in some donors for HAs that are not circulating in humans, suggesting that these donors likely have HA-specific IgG that are potentially broadly reactive and may have cross-reactive B cells. To directly identify B cells with cross-reactive potential, we enumerated H1 (CA09) and H2 (NETH1999) specific Bmem by flow cytometry. We show that Bmem specific for H1 or H2 are found in the spleen and blood whereas Bmem specific for both H1 and H2 are present in the mediastinal lymph node (LN), spleen and mesenteric LN. The data suggest that the repertoire of HA specific Bmem likely differ between tissues. Going forward, we will characterize the repertoire and molecular signatures of these HA-specific Bmem populations.
Supported by grants from NIH (U19 AI142737,)
IFN-γ mediated epithelial injury during influenza pathogenesis
Authors: Navaeiseddighi Zahrasadat , Schmit Taylor , Guo Kai , Khan Nadeem 
Published: August 2023

Abstract
Influenza pneumonia is developed due to an exuberant host response accompanied by an impaired repair, causing profound airway lung and vascular injuries that impact gas exchange and require hospitalization. However, a significant knowledge gap remains in delineating the host response mechanisms regulating the intricate inflammatory balance in the lung that either favor viral clearance or develops into immune-mediated lung pathology. Substantial emerging data reveal that dysregulated interferon (IFN) signaling, including excessive IFN-II (IFN-g) production, promotes lung injury and impairs lung repair during influenza pathogenesis. In our ongoing work, we have discovered that IFN-g exerts a direct pathologic effect by promoting epithelial injury resulting in the exacerbation of pulmonary inflammation and loss of barrier integrity during influenza. The notable findings from our study are as follows. a.IFN-g causes the cell death of infected (IAV) and un-infected (bystander) alveolar epithelial cells at a comparable rate, contributing to the disruption of pulmonary barrier. b.Molecularly, we identified that IFN-g suppressed IL6-STAT3 axis, which exerts a protective effect against influenza epithelial injury. c.Notably, the protective effect of IFN-g deficiency was abrogated by neutralizing IL-6. d. Finally, using in vitro human and mouse alveolar epithelial cells we show that IL-6 treatment can ameliorate IFN-g mediated injury of IAV-infected or un-infected epithelial cells (bystander injury). Our data is the first to demonstrate suppression of the IL-6-STAT3 axis as a potential molecular basis of pathologic IFN-g response in lung inflammation and repair to the best of our understanding.
National Institute of Health
Vitamin A deficient mice exhibit impaired viral clearance, increased inflammation and altered immune response during respiratory viral infection
Authors: Pritchett Maisie , Ebert Emily , Teague Ryan M , Shornick Laurie P 
Published: August 2023

Abstract
Vitamin A deficiency (VAD) is prevalent in developing countries and is associated with increased mortality after respiratory viral infections. Vitamin A can only be acquired through the diet, and millions of pregnant women and young children are deficient; however, the effects of VAD on the immune response are not completely understood. Pregnant C57BL/6 mice were placed on a VAD diet at gestational day five, pups remained on this diet after birth. At 8 weeks of age, control and VAD mice were infected intranasally with a sub-lethal dose of Sendai Virus (SeV), a natural mouse pathogen. Body weight loss in control mice peaked at day 7 post-infection, while VAD mice continued to lose weight until day 11 post-infection. This was associated with delayed clearance of virus, elevated cytokines TNFα, IL-4, and IL-17, and increased numbers of inflammatory cells in the VAD lungs. Flow cytometry showed significantly increased percentages of neutrophils on days 7 and 21, increased NK cells on day 7, increased macrophages on day 7 and increased MHC Class IIhi macrophages on days 7 and 21. In the adaptive response, CD4+ and CD8+ T cells were decreased on day 7 and increased on day 21. CD4+ T cell subsets showed increased CD4+Foxp3+ T cells on day 7 and increased CD4+Tbet+ T cells on day 21. B lymphocytes were lower at all time points. Together, this suggests that VAD affects multiple cell populations in both the innate and adaptive immune responses to viral infection in the lung,
Supported by Grants from Sigma Xi Grant in Aid of Research, Saint Louis University College of Arts and Sciences Knoedler Award, and Saint Louis University College of Arts and Sciences Graduate Undergraduate Award.
Tuft cell tropism enables norovirus evasion of CD8+ T cells and viral persistence
Authors: Strine Madison S , Filler Renata , Alfajaro Mia Madel , Damo Martina , Gonzalez David , Haberman Ann Marie , Joshi Nikhil , Wilen Craig 
Published: August 2023

Abstract
Human norovirus (HNV) is a leading cause of viral gastroenteritis. Infection fails to elicit durable immunity and can cause chronic asymptomatic shedding. It is not known how norovirus escapes the adaptive immune response, and rigorous studies of the host and viral determinants underlying immune evasion are impeded by the lack of scalable cell culture systems and reverse genetic tools. Murine norovirus (MNV) recapitulates many aspects of HNV and enables studying norovirus biology in vitro and in vivo. MNVCW3 causes non-persistent infection with long-lasting immune memory, whereas MNVCR6 causes persistent infection despite inducing functional MNV-specific CD8+ T cells. We recently identified that MNVCR6 and other persistent MNV strains require tuft cells for chronic enteric infection. Tuft cells are rare, chemosensory epithelial cells with roles in pathogen surveillance, epithelial repair, and tumorigenesis. To interrogate tuft cell interactions with CD8+ T cells, we adoptively transferred JEDI (Just EGFP Death Inducing) CD8+ T cells that detect EGFP200–208 presented on H2-Kd into tuft cell reporter mice (Gfi1b-GFP). Surprisingly, tuft cells at steady state can resist JEDI CD8+ T cell-mediated killing despite normal levels of surface MHC-I. In contrast, Lgr5+ intestinal stem cells and extraintestinal tuft cells are highly susceptible to clearance by JEDI CD8+ T cells. We further find that JEDI CD8+ T cells cannot clear nor prevent MNVCR6 infection of tuft cells, suggesting that tuft cells offer a replicative niche for immune escape and viral persistence. Whether HNV infects tuft cells during chronic asymptomatic infection and whether tuft cell-derived cancers can evade CD8+ T cells will warrant further exploration in the future.
Supported by grants from the NIH (K08 A1128043, R01 AI148467) and the NSF (DGE1752134)
Inhibition of SARS-CoV-2-mediated thromboinflammation by CLEC2.Fc
Authors: Hsieh Shie-Liang 
Published: August 2023

Abstract
Thromboinflammation is the major cause of morbidity and mortality in COVID-19 patients, and post-mortem examination demonstrates the presence of platelet-rich thrombi and microangiopathy in lung and other visceral organs. Moreover, persistent microclots were detected in both acute COVID-19 and long COVID plasma samples. However, the molecular mechanism of SARS-CoV-2-induced thromboinflammation is still unclear. We found that the spleen tyrosine kinase (Syk)-coupled C-type lectin member 2 (CLEC2), which was highly expressed in platelets, interacted with the receptor-binding domain (RBD) of SARS-CoV-2 spike protein (SARS-CoV-2 RBD) directly. Unlike the thread-like NETs, SARS-CoV-2-induced aggregated NET formation in the presence of wild-type (WT), but not CLEC2-deficient platelets. Furthermore, SARS-CoV-2 spike pseudotyped lentivirus was able to induce NET formation via CLEC2, indicating SARS-CoV-2 RBD engaged CLEC2 to activate platelets to enhance NET formation. Administration of CLEC2.Fc inhibited SARS-CoV-2-induced NET formation and thromboinflammation in AAV-ACE2-infected mice. Thus, CLEC2 is a novel pattern recognition receptor for SARS-CoV-2, and CLEC2.Fc is a promising therapeutic agent to inhibit SARS-CoV-2-induced thromboinflammation and reduced the risk of post-acute sequelae of COVID (PASC) in the future.
Translational Medical Research Program (AS-TM-108-02-10), Biotechnology Research Park Translational Project (AS-BRPT-110-02), Academia Sinica
Th1-guided de novo Th17 response alleviates lung inflammation through IL-17-EGFR-TRAF4 signaling cascade in severe influenza
Authors: Dutta Avijit , Hung Chen-Yiu , Hsiao Sung-Han , Chen Tse-Ching , Chang Chia-Shiang , Huang Yu-Lin , Lin Yung-Chang , Lin Chun-Yen , Huang Ching-Tai 
Published: August 2023

Abstract
Excessive inflammation is a postulated cause of severe disease and death in respiratory virus infections. In response to severe influenza virus infection, adoptively transferred naïve hemagglutinin-specific CD4+ T cells from CD4+ TCR-transgenic 6.5 mice drive an IFN-γ-producing Th1 response in wild-type mice. It helps in virus clearance but also causes collateral damage and disease aggravation. The donor 6.5 mice have all the CD4+ T cells with TCR specificity toward influenza hemagglutinin. Still, the infected 6.5 mice do not suffer from robust inflammation and grave outcome. The initial Th1 response wanes with time, and a prominent Th17 response of recent thymic emigrants alleviates inflammation and bestows protection in 6.5 mice. The severe disease in older than younger adult 6.5 mice with aging-related thymic involution and waning Th17 response further supports the protective role of the de novo Th17 response in severe influenza. Our results suggest that viral neuraminidase-activated TGF-β of the Th1 cells guides the Th17 evolution. IL-17 up-regulates and phosphorylates the non-canonical IL-17 receptor EGFR, activates the scaffold protein TRAF4, and promotes the translocation of TRAF4 to the EGFR signaling complex. Taken together, Th1-guided de novo Th17 response alleviates lung inflammation through the IL-17-EGFR-TRAF4 signaling cascade in severe influenza.
The Research Center for Emerging Viral Infections receives support from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE), Taiwan and NSTC 111-2634-F-182-001 from the National Science and Technology Council, Taiwan. This work was supported by Projects MOST 111-2314-B-182-029 (AD) and MOST-105-2321-B-182A-003-MY3 (AD) from the National Science and Technology Council, Taiwan, and by CMRPG3L1671 (CTH), CMRPVVJ0052 (CTH), and CMRPG3J1771 (CYH) from the Medical Research Project Fund, Chang Gung Memorial Hospital, Taiwan.