scholarly journals Recombinant SARS-CoV-2 RBD molecule with a T helper epitope as a built in adjuvant induces strong neutralization antibody response

2020 ◽  
Author(s):  
Qiudong Su ◽  
Yening Zou ◽  
Yao Yi ◽  
Liping Shen ◽  
Xiangzhong Ye ◽  
...  

AbstractWithout approved vaccines and specific treatment, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spreading around the world with above 20 million COVID-19 cases and approximately 700 thousand deaths until now. An efficacious and affordable vaccine is urgently needed. The Val308 – Gly548 of Spike protein of SARS-CoV-2 linked with Gln830 – Glu843 of Tetanus toxoid (TT peptide) (designated as S1-4) and without TT peptide (designated as S1-5), and prokaryotic expression, chromatography purification and the rational renaturation of the protein were performed. The antigenicity and immunogenicity of S1-4 protein was evaluated by Western Blotting (WB) in vitro and immune responses in mice, respectively. The protective efficiency of it was measured by virus neutralization test in Vero E6 cells with SARS-CoV-2. S1-4 protein was prepared to high homogeneity and purity by prokaryotic expression and chromatography purification. Adjuvanted with Alum, S1-4 protein stimulated a strong antibody response in immunized mice and caused a major Th2-type cellular immunity compared with S1-5 protein. Furthermore, the immunized sera could protect the Vero E6 cells from SARS-CoV-2 infection with neutralization antibody GMT 256. The candidate subunit vaccine molecule could stimulate strong humoral and Th1 and Th2-type cellular immune response in mice, giving us solid evidence that S1-4 protein could be a promising subunit vaccine candidate.

2021 ◽  
Author(s):  
Cheng-Wei Chang ◽  
Yuchen Liu ◽  
Cheng Jiao ◽  
Hongwei Liu ◽  
Xiaochuan Chen ◽  
...  

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific cellular immune response may prove to be essential for long-term immune protection against the novel coronavirus disease 2019 (COVID-19). To assess COVID-19-specific immunity in the population, we synthesized selected peptide pools of SARS-CoV-2 structural and functional proteins, including Spike (S), Membrane (M), Envelope (E), Nucleocapsid (N) and Protease (P) as target antigens. Survey of the T cell precursur frequencies in healthy individuals specific to these viral antigens demonstrated a diverse cellular immunity, including high, medium, low and no responders. This was further confirmed by in vitro induction of anti-SARS-CoV-2 T cell immune responses using dendritic cell (DC)/T cell coculture, which supported the corresponding T cell precursor frequencies in each of the individuals tested. In general, the combination of all five viral antigen pools induced the strongest cellular immune response, yet individual donors responded differently to different viral antigens. Importantly, in vitro restimulation of the T cells with the DC-peptides induced increased anti-viral immune responses in all individuals even in the no responders, suggesting that repeated antigen stimulation could elicit a broad protection in immune naïve population. Our analysis recapitulates the critical role of cellular immunity in fighting COVID-19 and the importance of analyzing anti-SARS-CoV-2 T cell response in addition to antibody response in the population.ImportanceFacing the rapid evolving SARS-CoV-2 variants in the world, current emphasis on antibody-producing vaccines needs a quick revisit. The virus-specific cellular immunity may prove to be essential for long-term protection against COVID-19. This study designed a series of antigenic peptides encompassing the conserved and/or essential domains of Spike (S), Membrane (M), envelope (E), Nucleocapsid (N) and Protease (P) as targets to assess Covid-19-specific immunity in the population. The results demonstrated a diverse cellular immunity, including high, medium, low and no responders. This was verified by in vitro generation of anti-SARS-CoV-2 T-cells from these subjects. The study suggested that individuals responded differently to the different viral antigens, and importantly, repeated stimulation could produce virus specific T cells in all individuals, including the no responders. This study illustrates the needs for assessing anti-viral cellular immunity in addition to antibody response in the general population.


PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e93549 ◽  
Author(s):  
Alexandra Dostal ◽  
Mélanie Gagnon ◽  
Christophe Chassard ◽  
Michael Bruce Zimmermann ◽  
Liam O'Mahony ◽  
...  

2019 ◽  
Author(s):  
Ali Nazmi ◽  
Michael J. Greer ◽  
Kristen L. Hoek ◽  
M. Blanca Piazuelo ◽  
Joern-Hendrik Weitkamp ◽  
...  

AbstractIntestinal intraepithelial lymphocytes (IEL) comprise a diverse population of cells residing in the epithelium at the interface between the intestinal lumen and the sterile environment of the lamina propria. Because of this anatomical location, IEL are considered critical components of intestinal immune responses. Indeed, IEL are involved in many different immunological processes ranging from pathogen control to tissue stability. However, despite their critical importance in mucosal immune responses, very little is known about the homeostasis of different IEL subpopulations. The phosphoprotein osteopontin is important for critical physiological processes, including cellular immune responses such as survival of Th17 cells and homeostasis of NK cells, among others. Because of its impact in the immune system, we investigated the role of osteopontin in the homeostasis of IEL. Here, we report that mice deficient in the expression of osteopontin exhibit reduced numbers of the IEL subpopulations TCRγδ+, TCRβ+CD4+, TCRβ+CD4+CD8α+and TCRβ+CD8αα+cells in comparison to wild-type mice. For some IEL subpopulations the decrease in cells numbers could be attributed to apoptosis and reduced cell division. Moreover, we showin vitrothat exogenous osteopontin stimulates the survival of murine IEL subpopulations and unfractionated IEL derived from human intestines, an effect mediated by CD44, a known osteopontin receptor. We also show that iCD8α IEL, but not TCRγδ+IEL, TCRβ+IEL or intestinal epithelial cells, can promote survival of different IEL populations via osteopontin, indicating an important role for iCD8α cells in the homeostasis of IEL.Key PointsOsteopontin promotes homeostasis of mouse and human IEL, mediated by its ligand CD44iCD8α cells produce osteopontin which impacts the survival of other IELLack of osteopontin renders mice susceptible to intestinal inflammation


Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1408
Author(s):  
Qiao Li ◽  
Zhihua Liu ◽  
Yi Liu ◽  
Chen Liang ◽  
Jiayi Shu ◽  
...  

TFPR1 is a novel adjuvant for protein and peptide antigens, which has been demonstrated in BALB/c mice in our previous studies; however, its adjuvanticity in mice with different genetic backgrounds remains unknown, and its adjuvanticity needs to be improved to fit the requirements for various vaccines. In this study, we first compared the adjuvanticity of TFPR1 in two commonly used inbred mouse strains, BALB/c and C57BL/6 mice, in vitro and in vivo, and demonstrated that TFPR1 activated TLR2 to exert its immune activity in vivo. Next, to prove the feasibility of TFPR1 acting as a major component of combined adjuvants, we prepared a combined adjuvant, TF–Al, by formulating TFPR1 and alum at a certain ratio and compared its adjuvanticity with that of TFPR1 and alum alone using OVA and recombinant HBsAg as model antigens in both BALB/c and C57BL/6 mice. Results showed that TFPR1 acts as an effective vaccine adjuvant in both BALB/c mice and C57BL/6 mice, and further demonstrated the role of TLR2 in the adjuvanticity of TFPR1 in vivo. In addition, we obtained a novel combined adjuvant, TF–Al, based on TFPR1, which can augment antibody and cellular immune responses in mice with different genetic backgrounds, suggesting its promise for vaccine development in the future.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Reza Taherkhani ◽  
Fatemeh Farshadpour ◽  
Manoochehr Makvandi ◽  
Hamid Rajabi Memari ◽  
Ali Reza Samarbafzadeh ◽  
...  

Background.The aim of this study was to evaluatehepatitis E virus(HEV) specific cellular immune responses to truncated ORF2 protein in Iranian patients recovered from HEV infection. Information about HEV-specific immune responses could be useful in finding an effective way for development of HEV vaccine.Methods.A truncated form of HEV ORF2 protein containing amino acids 112-608 was used to stimulate peripheral blood mononuclear cells (PBMCs) separated from HEV-recovered and control groups. Finally, the levels of four cytokines, IFN-γELISPOT, and cell proliferative responses following stimulation with the truncated ORF2 protein were assessed in the both groups.Results.The truncated ORF2 protein was able to induce IFN-γELISPOT and cell proliferation responses and to produce significant amounts of IFN-γand IL-12 cytokines, but low amounts of IL-10 and IL-4 cytokinesin vitro. These responses were significantly higher in the recovered group compared to the control group. These results indicate the antigenic nature of the truncated ORF2 protein and production of T helper type 1 cytokines.Conclusion.The truncated ORF2 protein can effectively induce significant cellular immune responsesand can be introduced as a potential vaccine candidate. However, further studies are required to evaluate this proteinin vivo.


Author(s):  
Mario Giordano ◽  
Maria Elisabetta Baldassarre ◽  
Viviana Palmieri ◽  
Diletta D. Torres ◽  
Vincenza Carbone ◽  
...  

Shiga toxin-producing Escherichia Coli (STEC) infections routinely run as a common gastroenteritis, but in many cases they may evolve towards hemolytic uremic syndrome (HUS). HUS is a rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Gut microorganisms have a fundamental impact on human physiology, because they modulate normal intestinal functions and play a pivotal role in influencing the local and systemic immune responses. Despite surveillance established in many countries and major progresses in the understanding of STEC-HUS mechanisms, no specific treatment is currently available. Targeting the gut microbiota could represent a new potential therapeutic strategy in STEC infection. In this paper, we reviewed the current knowledge about microbiota characteristics of patients with STEC infections, as well as in vitro and in vivo evidence of probiotic supplementation in managing STEC gastroenteritis and in HUS onset prevention.


2020 ◽  
Vol 21 (13) ◽  
pp. 4660
Author(s):  
Hsin-Fang Chang ◽  
Marie-Louise Wirkner ◽  
Elmar Krause ◽  
Jens Rettig

Cytotoxic T lymphocytes (CTL) are an essential part of our immune system by killing infected and malignant cells. To fully understand this process, it is necessary to study CTL function in the physiological setting of a living organism to account for their interplay with other immune cells like CD4+ T helper cells and macrophages. The anterior chamber of the eye (ACE), originally developed for diabetes research, is ideally suited for non-invasive and longitudinal in vivo imaging. We take advantage of the ACE window to observe immune responses, particularly allorejection of islets of Langerhans cells by CTLs. We follow the onset of the rejection after vascularization on islets until the end of the rejection process for about a month by repetitive two-photon microscopy. We find that CTLs show reduced migration on allogeneic islets in vivo compared to in vitro data, indicating CTL activation. Interestingly, the temporal infiltration pattern of T cells during rejection is precisely regulated, showing enrichment of CD4+ T helper cells on the islets before arrival of CD8+ CTLs. The adaptation of the ACE to immune responses enables the examination of the mechanism and regulation of CTL-mediated killing in vivo and to further investigate the killing in gene-deficient mice that resemble severe human immune diseases.


Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 125 ◽  
Author(s):  
Entao Li ◽  
Feihu Yan ◽  
Pei Huang ◽  
Hang Chi ◽  
Shengnan Xu ◽  
...  

Middle East respiratory syndrome (MERS) is an acute, high-mortality-rate, severe infectious disease caused by an emerging MERS coronavirus (MERS-CoV) that causes severe respiratory diseases. The continuous spread and great pandemic potential of MERS-CoV make it necessarily important to develop effective vaccines. We previously demonstrated that the application of Gram-positive enhancer matrix (GEM) particles as a bacterial vector displaying the MERS-CoV receptor-binding domain (RBD) is a very promising MERS vaccine candidate that is capable of producing potential neutralization antibodies. We have also used the rabies virus (RV) as a viral vector to design a recombinant vaccine by expressing the MERS-CoV S1 (spike) protein on the surface of the RV. In this study, we compared the immunological efficacy of the vaccine candidates in BALB/c mice in terms of the levels of humoral and cellular immune responses. The results show that the rabies virus vector-based vaccine can induce remarkably earlier antibody response and higher levels of cellular immunity than the GEM particles vector. However, the GEM particles vector-based vaccine candidate can induce remarkably higher antibody response, even at a very low dose of 1 µg. These results indicate that vaccines constructed using different vaccine vector platforms for the same pathogen have different rates and trends in humoral and cellular immune responses in the same animal model. This discovery not only provides more alternative vaccine development platforms for MERS-CoV vaccine development, but also provides a theoretical basis for our future selection of vaccine vector platforms for other specific pathogens.


1996 ◽  
Vol 42 (3) ◽  
pp. 193-199 ◽  
Author(s):  
Graham Pawelec ◽  
Arnika Rehbein ◽  
Elke Schlotz ◽  
Paul da Silva

2019 ◽  
Vol 20 (18) ◽  
pp. 4323 ◽  
Author(s):  
Salvo Danilo Lombardo ◽  
Emanuela Mazzon ◽  
Maria Sofia Basile ◽  
Giorgia Campo ◽  
Federica Corsico ◽  
...  

Tetraspanins are a conserved family of proteins involved in a number of biological processes including, cell–cell interactions, fertility, cancer metastasis and immune responses. It has previously been shown that TSPAN32 knockout mice have normal hemopoiesis and B-cell responses, but hyperproliferative T cells. Here, we show that TSPAN32 is expressed at higher levels in the lymphoid lineage as compared to myeloid cells. In vitro activation of T helper cells via anti-CD3/CD28 is associated with a significant downregulation of TSPAN32. Interestingly, engagement of CD3 is sufficient to modulate TSPAN32 expression, and its effect is potentiated by costimulation with anti-CD28, but not anti-CTLA4, -ICOS nor -PD1. Accordingly, we measured the transcriptomic levels of TSPAN32 in polarized T cells under Th1 and Th2 conditions and TSPAN32 resulted significantly reduced as compared with unstimulated cells. On the other hand, in Treg cells, TSPAN32 underwent minor changes upon activation. The in vitro data were finally translated into the context of multiple sclerosis (MS). Encephalitogenic T cells from Myelin Oligodendrocyte Glycoprotein (MOG)-Induced Experimental Autoimmune Encephalomyelitis (EAE) mice showed significantly lower levels of TSPAN32 and increased levels of CD9, CD53, CD82 and CD151. Similarly, in vitro-activated circulating CD4 T cells from MS patients showed lower levels of TSPAN32 as compared with cells from healthy donors. Overall, these data suggest an immunoregulatory role for TSPAN32 in T helper immune response and may represent a target of future immunoregulatory therapies for T cell-mediated autoimmune diseases.


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