Traditional Chinese medicine commands a unique position among all traditional medicines because of its 5000 years of history. Our own interest in natural products from traditional Chinese medicine ...was triggered in the 1990s, by artemisinin-type sesquiterpene lactones from Artemisia annua L. As demonstrated in recent years, this class of compounds has activity against malaria, cancer cells, and schistosomiasis. Interestingly, the bioactivity of artemisinin and its semisynthetic derivative artesunate is even broader and includes the inhibition of certain viruses, such as human cytomegalovirus and other members of the Herpesviridae family (e.g., herpes simplex virus type 1 and Epstein-Barr virus), hepatitis B virus, hepatitis C virus, and bovine viral diarrhea virus. Analysis of the complete profile of the pharmacological activities and molecular modes of action of artemisinin and artesunate and their performance in clinical trials will further elucidate the full antimicrobial potential of these versatile pharmacological tools from nature.
IMPORTANCE: B-cell–depleting therapies may affect the development of a protective immune response following vaccination. Understanding the ability to develop vaccine-specific immunity to COVID-19 in ...patients with multiple sclerosis (MS) treated with B-cell–depleting therapy is of importance for clinical decisions. OBJECTIVE: To assess SARS-CoV-2 vaccine-specific humoral and cellular responses in patients treated with ocrelizumab compared with healthy controls. DESIGN, SETTING, AND PARTICIPANTS: This single-center study performed at Hadassah Medical Center in Jerusalem, Israel, included patients with MS treated with ocrelizumab, healthy controls, and untreated patients with MS. Vaccination occurred between December 2020 and April 2021. Participants donated blood 2 to 4 and 2 to 8 weeks after the second vaccine dose for antibody and T-cell assessments, respectively. EXPOSURES: All participants received 2 doses of BNT162b2 vaccine (Pfizer/BioNTech) and completed the study. MAIN OUTCOMES AND MEASURES: Proportion of patients treated with ocrelizumab with SARS-CoV-2–specific serology and/or T-cell responses following vaccination. All participants underwent SARS-CoV-2 antibody testing; 29 patients treated with ocrelizumab and 15 healthy controls had evaluation of SARS-CoV-2–specific T-cell responses. RESULTS: Of 112 participants, 49 (43.8%) had MS and were treated with ocrelizumab (33 67.3% female; mean SD age, 47.9 13.3 years), 23 (20.5%) had MS and were not treated with disease-modifying therapies (18 78.3% female; mean SD age, 49 13.4 years), and 40 (35.7%) were healthy controls (25 62.5% female; mean SD age, 45.3 16 years). Twenty-six of 29 patients (89.7%) treated with ocrelizumab and 15 of 15 healthy controls (100%) had SARS-CoV-2–specific T cells following vaccination at similar levels (mean SD, 15.4 7.6 and 14.3 6.3 spot-forming cells, respectively). Mean antibody titers and positive serology rate were lower in the group of patients treated with ocrelizumab (mean SD antibody titers and positive serology rate, 26.2 49.2 and 376.5 907.6 AU/mL; 10 of 40 25% and 20 of 49 40.8% for S1/S2 and receptor-binding domain, respectively) compared with healthy controls (mean SD antibody titers and positive serology rate, 283 100 and 12 712 9114 AU/mL; 100% S1/S2 and receptor-binding domain) and untreated patients (mean SD antibody titers and positive serology rate, 288.3 113.8 and 10 877 9476 AU/mL; 100% S1/S2 and receptor-binding domain), with positive association to time from ocrelizumab infusion (S1/S2: r = 0.7, P < .001; receptor-binding domain: r = 0.4, P = .04). CONCLUSION AND RELEVANCE: In this study, patients with MS who were treated with ocrelizumab generated comparable SARS-CoV-2–specific T-cell responses with healthy controls and had lower antibody response following vaccination. Given the potential role of T cells in protection from severe disease, this is reassuring and will help physicians develop consensus guidelines regarding MS treatment in the era of the COVID-19 pandemic.
Abstract
Maternal and cord blood sera were collected from 20 parturients who received the BNT162b2 vaccine. All women and infants were positive for anti S- and anti-receptor binding domain ...antibody–specific immunoglobulin G. Cord blood antibody concentrations were correlated to maternal levels and to time since vaccination. Antenatal severe acute respiratory syndrome coronavirus 2 vaccination may provide maternal and neonatal protection.
The nasal mucosa constitutes the primary entry site for respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While the imbalanced innate immune response of ...end-stage coronavirus disease 2019 (COVID-19) has been extensively studied, the earliest stages of SARS-CoV-2 infection at the mucosal entry site have remained unexplored. Here, we employed SARS-CoV-2 and influenza virus infection in native multi-cell-type human nasal turbinate and lung tissues
, coupled with genome-wide transcriptional analysis, to investigate viral susceptibility and early patterns of local mucosal innate immune response in the authentic milieu of the human respiratory tract. SARS-CoV-2 productively infected the nasal turbinate tissues, predominantly targeting respiratory epithelial cells, with a rapid increase in tissue-associated viral subgenomic mRNA and secretion of infectious viral progeny. Importantly, SARS-CoV-2 infection triggered robust antiviral and inflammatory innate immune responses in the nasal mucosa. The upregulation of interferon-stimulated genes, cytokines, and chemokines, related to interferon signaling and immune-cell activation pathways, was broader than that triggered by influenza virus infection. Conversely, lung tissues exhibited a restricted innate immune response to SARS-CoV-2, with a conspicuous lack of type I and III interferon upregulation, contrasting with their vigorous innate immune response to influenza virus. Our findings reveal differential tissue-specific innate immune responses in the upper and lower respiratory tracts that are specific to SARS-CoV-2. The studies shed light on the role of the nasal mucosa in active viral transmission and immune defense, implying a window of opportunity for early interventions, whereas the restricted innate immune response in early-SARS-CoV-2-infected lung tissues could underlie the unique uncontrolled late-phase lung damage of advanced COVID-19.
In order to reduce the late-phase morbidity and mortality of COVID-19, there is a need to better understand and target the earliest stages of SARS-CoV-2 infection in the human respiratory tract. Here, we have studied the initial steps of SARS-CoV-2 infection and the consequent innate immune responses within the natural multicellular complexity of human nasal mucosal and lung tissues. Comparing the global innate response patterns of nasal and lung tissues infected in parallel with SARS-CoV-2 and influenza virus, we found distinct virus-host interactions in the upper and lower respiratory tract, which could determine the outcome and unique pathogenesis of SARS-CoV-2 infection. Studies in the nasal mucosal infection model can be employed to assess the impact of viral evolutionary changes and evaluate new therapeutic and preventive measures against SARS-CoV-2 and other human respiratory pathogens.
NK cells are innate lymphocytes that participate in many immune processes encompassing cancer, bacterial and fungal infection, autoimmunity, and even pregnancy and that specialize in antiviral ...defense. NK cells express inhibitory and activating receptors and kill their targets when activating signals overpower inhibitory signals. The NK cell inhibitory receptors include a uniquely diverse array of proteins named killer cell immunoglobulin-like receptors (KIRs), the CD94 family, and the leukocyte immunoglobulin-like receptor (LIR) family. The NK cell inhibitory receptors recognize mostly major histocompatibility complex (MHC) class I (MHC-I) proteins. Zika virus has recently emerged as a major threat due to its association with birth defects and its pandemic potential. How Zika virus interacts with the immune system, and especially with NK cells, is unclear. Here we show that Zika virus infection is barely sensed by NK cells, since little or no increase in the expression of activating NK cell ligands was observed following Zika infection. In contrast, we demonstrate that Zika virus infection leads to the upregulation of MHC class I proteins and consequently to the inhibition of NK cell killing. Mechanistically, we show that MHC class I proteins are upregulated via the RIGI-IRF3 pathway and that this upregulation is mediated via beta interferon (IFN-β). Potentially, countering MHC class I upregulation during Zika virus infection could be used as a prophylactic treatment against Zika virus.
NK cells are innate lymphocytes that recognize and eliminate various pathogens and are known mostly for their role in controlling viral infections. NK cells express inhibitory and activating receptors, and they kill or spare their targets based on the integration of inhibitory and activating signals. Zika virus has recently emerged as a major threat to humans due to its pandemic potential and its association with birth defects. The role of NK cells in Zika virus infection is largely unknown. Here we demonstrate that Zika virus infection is almost undetected by NK cells, as evidenced by the fact that the expression of activating ligands for NK cells is not induced following Zika infection. We identified a mechanism whereby Zika virus sensing via the RIGI-IRF3 pathway resulted in IFN-β-mediated upregulation of MHC-I molecules and inhibition of NK cell activity. Countering MHC class I upregulation and boosting NK cell activity may be employed as prophylactic measures to combat Zika virus infection.
We aimed to assess the impact of early versus late third-trimester maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on transplacental transfer and neonatal levels of ...SARS-CoV-2 antibodies.
Maternal and cord blood sera were collected following term delivery after antenatal SARS-CoV-2 BNT162b2 mRNA vaccination, with the first vaccine dose administered between 27 and 36 weeks of gestation. SARS-CoV-2 spike protein (S) and receptor-binding domain (RBD) -specific, IgG levels and neutralizing potency were evaluated in maternal and cord blood samples.
The study cohort consisted of 171 parturients—median age 31 years (interquartile range (IQR) 27–35 years); median gestational age 39+5 weeks (IQR 38+5–40+4 weeks)–83 (48.5%) were immunized in early thrird-trimester (first dose at 27–31 weeks) and 88 (51.5%) were immunized in late third trimester (first dose at 32–36 weeks). All mother–infant paired sera were positive for anti S- and anti-RBD-specific IgG. Anti-RBD-specific IgG concentrations in neonatal sera were higher following early versus late third-trimester vaccination (median 9620 AU/mL (IQR 5131–15332 AU/mL) versus 6697 AU/mL (IQR 3157–14731 AU/mL), p 0.02), and were positively correlated with increasing time since vaccination (r = 0.26; p 0.001). Median antibody placental transfer ratios were increased following early versus late third-trimester immunization (anti-S ratio: 1.3 (IQR 1.1–1.6) versus 0.9 (IQR 0.6–1.1); anti-RBD-specific ratio: 2.3 (IQR 1.7–3.0) versus 0.7 (IQR 0.5–1.2), p < 0.001). Neutralizing antibodies placental transfer ratio was greater following early versus late third-trimester immunization (median 1.9 (IQR 1.7–2.5) versus 0.8 (IQR 0.5–1.1), p < 0.001), and was positively associated with longer duration from vaccination (r = 0.77; p < 0.001).
Early compared with late third-trimester maternal SARS-CoV-2 immunization enhanced transplacental antibody transfer and increased neonatal neutralizing antibody levels. Our findings highlight that vaccination of pregnant women early in the third trimester may enhance neonatal seroprotection.
Significance
We present a generic methodology that extracts structural data from living, intact cells for any protein of interest. Application of this methodology to different viral proteins resulted ...in significant cross-link sets that revealed the connectivity within their structures. Importantly, we show that these cross-link sets are detailed enough to enable the integrative modeling of the full-length protein sequence. Consequently, we report the global structural organization of Nsp2 and the dimer of the nucleocapsid protein. We foresee that similar applications will be highly useful to study other recalcitrant proteins on which the mainstream structural approaches currently fail.
Atomic structures of several proteins from the coronavirus family are still partial or unavailable. A possible reason for this gap is the instability of these proteins outside of the cellular context, thereby prompting the use of in-cell approaches. In situ cross-linking and mass spectrometry (in situ CLMS) can provide information on the structures of such proteins as they occur in the intact cell. Here, we applied targeted in situ CLMS to structurally probe Nsp1, Nsp2, and nucleocapsid (N) proteins from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and obtained cross-link sets with an average density of one cross-link per 20 residues. We then employed integrative modeling that computationally combined the cross-linking data with domain structures to determine full-length atomic models. For the Nsp2, the cross-links report on a complex topology with long-range interactions. Integrative modeling with structural prediction of individual domains by the AlphaFold2 system allowed us to generate a single consistent all-atom model of the full-length Nsp2. The model reveals three putative metal binding sites and suggests a role for Nsp2 in zinc regulation within the replication–transcription complex. For the N protein, we identified multiple intra- and interdomain cross-links. Our integrative model of the N dimer demonstrates that it can accommodate three single RNA strands simultaneously, both stereochemically and electrostatically. For the Nsp1, cross-links with the 40S ribosome were highly consistent with recent cryogenic electron microscopy structures. These results highlight the importance of cellular context for the structural probing of recalcitrant proteins and demonstrate the effectiveness of targeted in situ CLMS and integrative modeling.
Abstract
Background
Coronavirus disease 2019 (COVID-19) during pregnancy and early infancy can result in severe disease. Evaluating the effect of gestational age at the time of severe acute ...respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on maternal antibody levels and transplacental antibody transfer has important implications for maternal care and vaccination strategies.
Methods
Maternal and cord blood sera were collected from mother–newborn dyads (n = 402), following term delivery after antenatal 2-dose SARS-CoV-2 BNT162b2 mRNA vaccination. SARS-CoV-2 spike protein (S) and receptor binding domain (RBD)–specific IgG levels were evaluated in the samples collected.
Results
Median anti-S and anti–RBD-specific IgG levels in maternal sera at the time of delivery were lowest following first-trimester vaccination (n = 90; anti-S IgG: 76 AU/mL; anti–RBD-specific IgG: 478 AU/mL), intermediate in those vaccinated in the second trimester (n = 124; anti-S IgG: 126 AU/mL; anti–RBD-specific IgG: 1263 AU/mL), and highest after third-trimester vaccination (n = 188; anti-S IgG: 240 AU/mL; anti–RBD-specific IgG: 5855 AU/mL). Antibody levels in neonatal sera followed a similar pattern and were lowest following antenatal vaccination in the first trimester (anti-S IgG: 126 AU/mL; anti–RBD-specific IgG: 1140 AU/mL). In a subgroup of parturients vaccinated in the first trimester (n = 30), a third booster dose was associated with significantly higher maternal and neonatal antibody levels.
Conclusions
These results suggest a considerable antibody waning throughout pregnancy in those vaccinated at early gestation. The observed boosting effect of a third vaccine dose hints at its potential benefit in those who completed the 2-dose vaccine series at early pregnancy or before conception. The impact of antenatal immunization timing on SARS-CoV-2 transplacental antibody transfer may influence neonatal seroprotection.
Lower antibody titers were found after maternal vaccination at early pregnancy, suggesting considerable antibody waning throughout gestation, with a potential role of a third vaccine dose. The effect of immunization timing on the transplacental antibody transfer may influence neonatal seroprotection.
Herpes simplex virus 1 (HSV1) is a ubiquitous human pathogen that utilizes variable mechanisms to evade immune surveillance. The glycosylphosphatidylinositol (GPI) anchoring pathway is a multistep ...process in which a myriad of different proteins are covalently attached to a GPI moiety to be presented on the cell surface. Among the different GPI-anchored proteins there are many with immunological importance. We present evidence that the HSV1-encoded miR H8 directly targets PIGT, a member of the protein complex that covalently attaches proteins to GPI in the final step of GPI anchoring. This results in a membrane down-modulation of several different immune-related, GPI-anchored proteins, including ligands for natural killer-activating receptors and the prominent viral restriction factor tetherin. Thus, we suggest that by utilizing just one of dozens of miRNAs encoded by HSV1, the virus can counteract the host immune response at several key points.
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•HSV1 miR H8 targets PIGT of the GPI anchoring pathway•Expression of the anti-viral protein tetherin is reduced and viral spread enhanced•Expression of GPI-anchored activating NK cell ligands is reduced•Recognition and elimination by NK cells decrease
Herpes simplex virus 1 is a ubiquitous human pathogen and the cause of several ailments. Enk et al. found that the HSV1-encoded miR H8 targets the GPI anchoring pathway, reducing expression of several immune-modulating proteins, thus enhancing viral spread and enabling evasion of natural killer cell elimination.
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