scholarly journals Broad human and animal coronavirus neutralisation by SARS-CoV-2 S2-targeted vaccination

2021 ◽  
Author(s):  
Kevin W. Ng ◽  
Nikhil Faulkner ◽  
Katja Finsterbusch ◽  
Mary Wu ◽  
Ruth Harvey ◽  
...  

AbstractSeveral common-cold coronaviruses (HCoVs) are endemic in humans and several variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged during the current Coronavirus disease 2019 (COVID-19) pandemic. Whilst antibody cross-reactivity with the Spike glycoproteins (S) of diverse coronaviruses has been documented, it remains unclear whether such antibody responses, typically targeting the conserved S2 subunit, contribute to or mediate protection, when induced naturally or through vaccination. Using a mouse model, we show that prior HCoV-OC43 S immunity primes neutralising antibody responses to otherwise subimmunogenic SARS-CoV-2 S exposure and promotes S2-targeting antibody responses. Moreover, mouse vaccination with SARS-CoV-2 S2 elicits antibodies that neutralise diverse animal and human alphacoronaviruses and betacoronaviruses in vitro, and protects against SARS-CoV-2 challenge in vivo. Lastly, in mice with a history of SARS-CoV-2 Wuhan-based S vaccination, further S2 vaccination induces stronger and broader neutralising antibody response than booster Wuhan S vaccination, suggesting it may prevent repertoire focusing caused by repeated homologous vaccination. The data presented here establish the protective value of an S2-targeting vaccine and support the notion that S2 vaccination may better prepare the immune system to respond to the changing nature of the S1 subunit in SARS-CoV-2 variants of concern (VOCs), as well as to unpredictable, yet inevitable future coronavirus zoonoses.

2021 ◽  
Author(s):  
Fatima Amanat ◽  
Shirin Strohmeier ◽  
Wen-Hsin Lee ◽  
Sandhya Bangaru ◽  
Andrew B Ward ◽  
...  

After first emerging in December 2019 in China, severe acute respiratory syndrome 2 (SARS-CoV-2) has since caused a pandemic leading to millions of infections and deaths worldwide. Vaccines have been developed and authorized but supply of these vaccines is currently limited. With new variants of the virus now emerging and spreading globally, it is essential to develop therapeutics that are broadly protective and bind conserved epitopes in the receptor binding domain (RBD) or the whole spike of SARS-CoV-2. In this study, we have generated mouse monoclonal antibodies (mAbs) against different epitopes on the RBD and assessed binding and neutralization against authentic SARS-CoV-2. We have demonstrated that antibodies with neutralizing activity, but not non-neutralizing antibodies, lower viral titers in the lungs when administered in a prophylactic setting in vivo in a mouse challenge model. In addition, most of the mAbs cross-neutralize the B.1.351 as well as the B.1.1.7 variants in vitro.


1988 ◽  
Vol 118 (3) ◽  
pp. 351-356 ◽  
Author(s):  
S.M. Filteau ◽  
Bill Woodward

Abstract. T3 supplements enhance splenic primary thymus-independent antibody responses in the mouse in vivo. The purpose of the present investigation was to determine whether this effect may be mediated, in part, by direct influences on the lymphocytes and/or accessory cells involved in the response. A range of T3 levels (3 × 10−10 to 10−5 mol/l) was tested in microcultures of separated spleen cells from CBA/J mice 33 days of age. The immune reaction examined in vitro was the primary antibody response to trinitrophenylated Brucella abortus (TNP-BA). T3 was without influence, throughout the concentration range tested, on the number of anti-TNP plasma cells generated per culture. This result was obtained using splenocytes either from well-nourished or from malnourished mice, and using both optimal and suboptimal numbers of TNP-BA. On the basis of the present results and a reinterpretation of previous published work, it is concluded that the influence of T3 supplements on splenic antibody responses in vivo is mediated indirectly. Direct influences of T3 on the T-independent antibody response, if such occur, must be maximized by subphysiological levels of the hormone.


2021 ◽  
Author(s):  
Fatima Amanat ◽  
Shirin Strohmeier ◽  
Philip Meade ◽  
Nicholas Dambrauskas ◽  
Barbara Mühlemann ◽  
...  

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been highly efficient in protecting against coronavirus disease 2019 (COVID-19). However, the emergence of viral variants that are more transmissible and, in some cases, escape from neutralizing antibody responses has raised concerns. Here, we evaluated recombinant protein spike antigens derived from wild type SARS-CoV-2 and from variants B.1.1.7, B.1.351 and P.1 for their immunogenicity and protective effect in vivo against challenge with wild type SARS-CoV-2 in the mouse model. All proteins induced high neutralizing antibodies against the respective viruses but also induced high cross-neutralizing antibody responses. The decline in neutralizing titers between variants was moderate, with B.1.1.7 vaccinated animals having a maximum fold reduction of 4.8 against B.1.351 virus. P.1 induced the most cross-reactive antibody responses but was also the least immunogenic in terms of homologous neutralization titers. However, all antigens protected from challenge with wild type SARS-CoV-2 in a mouse model.


2021 ◽  
Vol 8 (6) ◽  
pp. 110
Author(s):  
Nathalie Meijerink ◽  
Jean E. de Oliveira ◽  
Daphne A. van Haarlem ◽  
Guilherme Hosotani ◽  
David M. Lamot ◽  
...  

Restrictions on the use of antibiotics in the poultry industry stimulate the development of alternative nutritional solutions to maintain or improve poultry health. This requires more insight in the modulatory effects of feed additives on the immune system and microbiota composition. Compounds known to influence the innate immune system and microbiota composition were selected and screened in vitro, in ovo, and in vivo. Among all compounds, 57 enhanced NK cell activation, 56 increased phagocytosis, and 22 increased NO production of the macrophage cell line HD11 in vitro. Based on these results, availability and regulatory status, six compounds were selected for further analysis. None of these compounds showed negative effects on growth, hatchability, and feed conversion in in ovo and in vivo studies. Based on the most interesting numerical results and highest future potential feasibility, two compounds were analyzed further. Administration of glucose oligosaccharide and long-chain glucomannan in vivo both enhanced activation of intraepithelial NK cells and led to increased relative abundance of lactic acid bacteria (LAB) amongst ileum and ceca microbiota after seven days of supplementation. Positive correlations between NK cell subsets and activation, and relative abundance of LAB suggest the involvement of microbiota in the modulation of the function of intraepithelial NK cells. This study identifies glucose oligosaccharide and long-chain glucomannan supplementation as effective nutritional strategies to modulate the intestinal microbiota composition and strengthen the intraepithelial innate immune system.


Author(s):  
Darja Kanduc

AbstractBy examining the issue of the thromboses and hemostasis disorders associated with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) through the lens of cross-reactivity, it was found that 60 pentapeptides are shared by SARS-CoV-2 spike glycoprotein (gp) and human proteins that— when altered, mutated, deficient or, however, improperly functioning— cause vascular diseases, thromboembolic complications, venous thrombosis, thrombocytopenia, coagulopathies, and bleeding, inter alia. The peptide commonality has a relevant immunological potential as almost all of the shared sequences are present in experimentally validated SARS-CoV-2 spike gp-derived epitopes, thus supporting the possibility of cross-reactions between the viral gp and the thromboses-related human proteins. Moreover, many of the shared peptide sequences are also present in pathogens to which individuals have previously been exposed following natural infection or vaccinal routes, and of which the immune system has stored imprint. Such an immunological memory might rapidly trigger anamnestic secondary cross-reactive responses of extreme affinity and avidity, in this way explaining the thromboembolic adverse events that can associate with SARS-CoV-2 infection or active immunization.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xuejie Gao ◽  
Bo Li ◽  
Anqi Ye ◽  
Houcai Wang ◽  
Yongsheng Xie ◽  
...  

Abstract Background Multiple myeloma (MM) is a highly aggressive and incurable clonal plasma cell disease with a high rate of recurrence. Thus, the development of new therapies is urgently needed. DCZ0805, a novel compound synthesized from osalmide and pterostilbene, has few observed side effects. In the current study, we intend to investigate the therapeutic effects of DCZ0805 in MM cells and elucidate the molecular mechanism underlying its anti-myeloma activity. Methods We used the Cell Counting Kit-8 assay, immunofluorescence staining, cell cycle assessment, apoptosis assay, western blot analysis, dual-luciferase reporter assay and a tumor xenograft mouse model to investigate the effect of DCZ0805 treatment both in vivo and in vitro. Results The results showed that DCZ0805 treatment arrested the cell at the G0/G1 phase and suppressed MM cells survival by inducing apoptosis via extrinsic and intrinsic pathways. DCZ0805 suppressed the NF-κB signaling pathway activation, which may have contributed to the inhibition of cell proliferation. DCZ0805 treatment remarkably reduced the tumor burden in the immunocompromised xenograft mouse model, with no obvious toxicity observed. Conclusion The findings of this study indicate that DCZ0805 can serve as a novel therapeutic agent for the treatment of MM.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Poushali Chakraborty ◽  
Sapna Bajeli ◽  
Deepak Kaushal ◽  
Bishan Dass Radotra ◽  
Ashwani Kumar

AbstractTuberculosis is a chronic disease that displays several features commonly associated with biofilm-associated infections: immune system evasion, antibiotic treatment failures, and recurrence of infection. However, although Mycobacterium tuberculosis (Mtb) can form cellulose-containing biofilms in vitro, it remains unclear whether biofilms are formed during infection in vivo. Here, we demonstrate the formation of Mtb biofilms in animal models of infection and in patients, and that biofilm formation can contribute to drug tolerance. First, we show that cellulose is also a structural component of the extracellular matrix of in vitro biofilms of fast and slow-growing nontuberculous mycobacteria. Then, we use cellulose as a biomarker to detect Mtb biofilms in the lungs of experimentally infected mice and non-human primates, as well as in lung tissue sections obtained from patients with tuberculosis. Mtb strains defective in biofilm formation are attenuated for survival in mice, suggesting that biofilms protect bacilli from the host immune system. Furthermore, the administration of nebulized cellulase enhances the antimycobacterial activity of isoniazid and rifampicin in infected mice, supporting a role for biofilms in phenotypic drug tolerance. Our findings thus indicate that Mtb biofilms are relevant to human tuberculosis.


Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 298
Author(s):  
Daniele Focosi ◽  
Angelo Genoni ◽  
Ersilia Lucenteforte ◽  
Silvia Tillati ◽  
Antonio Tamborini ◽  
...  

Antibody-dependent enhancement (ADE) of severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) infection has been hypothesized. However, to date, there has been no in vitro or in vivo evidence supporting this. Cross-reactivity exists between SARS CoV-2 and other Coronaviridae for both cellular and humoral immunity. We show here that IgG against nucleocapsid protein of alphacoronavirus NL63 and 229E correlate with the World Health Organization’s (WHO) clinical severity score ≥ 5 (incidence rate ratios was 1.87 and 1.80, respectively, and 1.94 for the combination). These laboratory findings suggest possible ADE of SARS CoV-2 infection by previous alphacoronavirus immunity.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii413-iii413
Author(s):  
Maggie Seblani ◽  
Markella Zannikou ◽  
Katarzyna Pituch ◽  
Liliana Ilut ◽  
Oren Becher ◽  
...  

Abstract Diffuse intrinsic pontine glioma (DIPG) is a devastating brain tumor affecting young children. Immunotherapies hold promise however the lack of immunocompetent models recreating a faithful tumor microenvironment (TME) remains a challenge for development of targeted immunotherapeutics. We propose to generate an immunocompetent DIPG mouse model through induced overexpression of interleukin 13 receptor alpha 2 (IL13Rα2), a tumor-associated antigen overexpressed by glioma cells. A model with an intact TME permits comprehensive preclinical assessment of IL13Rα2-targeted immunotherapeutics. Our novel model uses the retroviral avian leucosis and sarcoma virus (RCAS) for in vivo gene delivery leading to IL13Rα2 expression in proliferating progenitor cells. Transfected cells expressing IL13Rα2 and PDGFB, a ligand for platelet derived growth factor receptor, alongside induced p53 loss via the Cre-Lox system are injected in the fourth ventricle in postnatal pups. We validated the expression of PDGFB and IL13Rα2 transgenes in vitro and in vivo and will characterize the TME through evaluation of the peripheral and tumor immunologic compartments using immunohistochemistry and flow cytometry. We confirmed expression of transgenes via flow cytometry and western blotting. Comparison of survival dynamics in mice inoculated with PDGFB alone with PDGFB+IL13Rα2 demonstrated that co-expression of IL13Rα2 did not significantly affect mice survival compared to the PDGFB model. At time of application, we initiated experiments to characterize the TME. Preliminary data demonstrate establishment of tumors within and adjacent to the brainstem and expression of target transgenes. Preclinical findings in a model recapitulating the TME may provide better insight into outcomes upon translation to clinical application.


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