scholarly journals Exosome-Mediated mRNA Delivery For SARS-CoV-2 Vaccination

2020 ◽  
Author(s):  
Shang-Jui Tsai ◽  
Chenxu Guo ◽  
Nadia A. Atai ◽  
Stephen J. Gould
Keyword(s):  
Viral Vectors ◽  
Vaccine Development ◽  
Spike Protein ◽  
Interleukin 4 ◽  
Target Cells ◽  
Durable Response ◽  
Elevated Expression ◽  
Cellular Immune

AbstractBackgroundIn less than a year from its zoonotic entry into the human population, SARS-CoV-2 has infected more than 45 million people, caused 1.2 million deaths, and induced widespread societal disruption. Leading SARS-CoV-2 vaccine candidates immunize with the viral spike protein delivered on viral vectors, encoded by injected mRNAs, or as purified protein. Here we describe a different approach to SARS-CoV-2 vaccine development that uses exosomes to deliver mRNAs that encode antigens from multiple SARS-CoV-2 structural proteins.ApproachExosomes were purified and loaded with mRNAs designed to express (i) an artificial fusion protein, LSNME, that contains portions of the viral spike, nucleocapsid, membrane, and envelope proteins, and (ii) a functional form of spike. The resulting combinatorial vaccine, LSNME/SW1, was injected into thirteen weeks-old, male C57BL/6J mice, followed by interrogation of humoral and cellular immune responses to the SARS-CoV-2 nucleocapsid and spike proteins, as well as hematological and histological analysis to interrogate animals for possible adverse effects.ResultsImmunized mice developed CD4+, and CD8+ T-cell reactivities that respond to both the SARS-CoV-2 nucelocapsid protein and the SARS-CoV-2 spike protein. These responses were apparent nearly two months after the conclusion of vaccination, as expected for a durable response to vaccination. In addition, the spike-reactive CD4+ T-cells response was associated with elevated expression of interferon gamma, indicative of a Th1 response, and a lesser induction of interleukin 4, a Th2-associated cytokine. Vaccinated mice showed no sign of altered growth, injection-site hypersensitivity, change in white blood cell profiles, or alterations in organ morphology. Consistent with these results, we also detected moderate but sustained anti-nucleocapsid and anti-spike antibodies in the plasma of vaccinated animals.ConclusionTaken together, these results validate the use of exosomes for delivering functional mRNAs into target cells in vitro and in vivo, and more specifically, establish that the LSNME/SW1 vaccine induced broad immunity to multiple SARS-CoV-2 proteins.

Non-Viral Vectors for Gene Delivery

2018 ◽  
Vol 9 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Aparna Bansal ◽  
Himanshu
Keyword(s):  
Gene Therapy ◽  
Viral Vectors ◽  
Transfection Efficiency ◽  
Gene Transfection ◽  
Expression System ◽  
Target Cells ◽  
Specific Expression ◽  
Naked Dna

Introduction: Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors. Conclusion: To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

scholarly journals A Combined Adjuvant TF–Al Consisting of TFPR1 and Aluminum Hydroxide Augments Strong Humoral and Cellular Immune Responses in Both C57BL/6 and BALB/c Mice

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1408
Author(s):  
Qiao Li ◽  
Zhihua Liu ◽  
Yi Liu ◽  
Chen Liang ◽  
Jiayi Shu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Inbred Mouse ◽  
Effective Vaccine ◽  
Mouse Strains ◽  
Cellular Immune Responses ◽  
Recombinant Hbsag ◽  
Cellular Immune

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.

Identification of a common deletion in the spike protein of SARS-CoV-2

2020 ◽  
Author(s):  
Zhe Liu ◽  
Huanying Zheng ◽  
Runyu Yuan ◽  
Mingyue Li ◽  
Huifang Lin ◽  
...  
Keyword(s):  
Protein Function ◽  
Cleavage Site ◽  
Vaccine Development ◽  
Mechanistic Explanation ◽  
Spike Protein ◽  
Clinical Samples ◽  
Genomic Changes ◽  
And Function

AbstractTwo notable features have been identified in the SARS-CoV-2 genome: (1) the receptor binding domain of SARS-CoV-2; (2) a unique insertion of twelve nucleotide or four amino acids (PRRA) at the S1 and S2 boundary. For the first feature, the similar RBD identified in SARs-like virus from pangolin suggests the RBD in SARS-CoV-2 may already exist in animal host(s) before it transmitted into human. The left puzzle is the history and function of the insertion at S1/S2 boundary, which is uniquely identified in SARS-CoV-2. In this study, we identified two variants from the first Guangdong SARS-CoV-2 cell strain, with deletion mutations on polybasic cleavage site (PRRAR) and its flank sites. More extensive screening indicates the deletion at the flank sites of PRRAR could be detected in 3 of 68 clinical samples and half of 22 in vitro isolated viral strains. These data indicate (1) the deletion of QTQTN, at the flank of polybasic cleavage site, is likely benefit the SARS-CoV-2 replication or infection in vitro but under strong purification selection in vivo since it is rarely identified in clinical samples; (2) there could be a very efficient mechanism for deleting this region from viral genome as the variants losing 23585-23599 is commonly detected after two rounds of cell passage. The mechanistic explanation for this in vitro adaptation and in vivo purification processes (or reverse) that led to such genomic changes in SARS-CoV-2 requires further work. Nonetheless, this study has provided valuable clues to aid further investigation of spike protein function and virus evolution. The deletion mutation identified in vitro isolation should be also noted for current vaccine development.

scholarly journals The Immunogenic and Immunoprotective Activities of Recombinant Chimeric T. gondii Proteins Containing AMA1 Antigen Fragments

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 724
Author(s):  
Justyna Gatkowska ◽  
Katarzyna Dzitko ◽  
Bartłomiej Tomasz Ferra ◽  
Lucyna Holec-Gąsior ◽  
Malwina Kawka ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Chimeric Proteins ◽  
Universal Vaccine ◽  
New Approach ◽  
Partial Protection ◽  
Cellular Immune Responses ◽  
Specific Igg ◽  
Cellular Immune

Toxoplasmosis, one of the most common parasitoses worldwide, is potentially dangerous for individuals with a weakened immune system, but specific immunoprophylaxis intended for humans is still lacking. Thus, efforts have been made to create an efficient universal vaccine for both animals and humans to overcome the shortcomings of currently used treatment methods and protect all hosts against toxoplasmosis. The current work represents a relatively new approach to vaccine development based on recombinant chimeric Toxoplasma gondii antigens. In the present research, three tetravalent chimeric proteins containing different portions of the parasite’s AMA1 antigen—AMA1domainI-SAG2-GRA1-ROP1L (ANSGR), AMA1domainsII,III-SAG2-GRA1-ROP1L (ACSGR) and AMA1fullprotein-SAG2-GRA1-ROP1L (AFSGR)—were tested for their immunogenic and immunoprotective capacities. All tested proteins were immunogenic, as evidenced by the triggering of specific humoral and cellular immune responses in vaccinated C3H/HeOuJ mice, defined by the production of specific IgG (IgG1/IgG2a) antibodies in vivo and synthesis of key Th1/Th2 cytokines by Toxoplasma lysate antigen-stimulated splenocytes in vitro. Although all tested preparations provided partial protection against chronic toxoplasmosis in immunized and T. gondii-challenged mice, the intensity of the generated immunoprotection depended on the fragment of the AMA1 antigen incorporated into the chimeric antigen’s structure.

Stat5a/b contribute to interleukin 7–induced B-cell precursor expansion, but abl- andbcr/abl-induced transformation are independent of Stat5

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2277-2283 ◽  
Author(s):  
Veronika Sexl ◽  
Roland Piekorz ◽  
Richard Moriggl ◽  
Juerg Rohrer ◽  
Michael P. Brown ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Interleukin 4 ◽  
Target Cells ◽  
Interleukin 7 ◽  
And Function ◽  
Deficient Mice

Abstract The cytokines interleukin 7 (IL-7) and interleukin 4 (IL-4) regulate lymphoid differentiation and function and activate the transcription factor Stat5. Using mice deficient for the 2 highly related transcription factors, Stat5a and Stat5b (Stat5a/b−/−), we investigated the role of Stat5 for B-cell differentiation, expansion, and function. Peripheral blood B cells of Stat5-deficient mice are significantly reduced, but no proliferation defects in response to various mitogenic stimuli are found. Also, IgM and IgG1 antibody production and immunoglobulin class switching are not affected. Pre- and pro-B cells of Stat5-deficient animals were found to have reduced responses to IL-7. Pro- and pre-B cells are the target cells of the abloncogene and numerous studies have suggested that Stat5a/b is essential for transformation by derivatives of the Abelson(abl) gene. To assess the role of Stat5a/b in transformation, we have evaluated the ability of variousabl derivatives to transform cells from Stat5a/b-deficient mice in vitro or in vivo. We demonstrate that the absence of Stat5a/b is not essential for the induction of lymphoid or myeloid tumors in vivo or on the ability to transform bone marrow cells in vitro.

scholarly journals The sequence at Spike S1/S2 site enables cleavage by furin and phospho-regulation in SARS-CoV2 but not in SARS-CoV1 or MERS-CoV

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mihkel Örd ◽  
Ilona Faustova ◽  
Mart Loog
Keyword(s):  
Viral Entry ◽  
Spike Protein ◽  
Target Cells ◽  
The Novel ◽  
Novel Coronavirus ◽  
Cleavage Motif ◽  
Left Middle ◽  
Surprising Finding

Abstract The Spike protein of the novel coronavirus SARS-CoV2 contains an insertion 680SPRRAR↓SV687 forming a cleavage motif RxxR for furin-like enzymes at the boundary of S1/S2 subunits. Cleavage at S1/S2 is important for efficient viral entry into target cells. The insertion is absent in other CoV-s of the same clade, including SARS-CoV1 that caused the 2003 outbreak. However, an analogous cleavage motif was present at S1/S2 of the Spike protein of the more distant Middle East Respiratory Syndrome coronavirus MERS-CoV. We show that a crucial third arginine at the left middle position, comprising a motif RRxR is required for furin recognition in vitro, while the general motif RxxR in common with MERS-CoV is not sufficient for cleavage. Further, we describe a surprising finding that the two serines at the edges of the insert SPRRAR↓SV can be efficiently phosphorylated by proline-directed and basophilic protein kinases. Both phosphorylations switch off furin’s ability to cleave the site. Although phospho-regulation of secreted proteins is still poorly understood, further studies, supported by a recent report of ten in vivo phosphorylated sites in the Spike protein of SARS-CoV2, could potentially uncover important novel regulatory mechanisms for SARS-CoV2.

scholarly journals The Role of Escherichia coli Shiga Toxins in STEC Colonization of Cattle

Toxins ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 607 ◽  
Author(s):  
Christian Menge
Keyword(s):  
Escherichia Coli ◽  
Reservoir Host ◽  
Target Cells ◽  
Activation Process ◽  
Shiga Toxins ◽  
E Coli ◽  
Human Infections ◽  
Cellular Immune

Many cattle are persistently colonized with Shiga toxin-producing Escherichia coli (STEC) and represent a major source of human infections with human-pathogenic STEC strains (syn. enterohemorrhagic E. coli (EHEC)). Intervention strategies most effectively protecting humans best aim at the limitation of bovine STEC shedding. Mechanisms enabling STEC to persist in cattle are only partialy understood. Cattle were long believed to resist the detrimental effects of Shiga toxins (Stxs), potent cytotoxins acting as principal virulence factors in the pathogenesis of human EHEC-associated diseases. However, work by different groups, summarized in this review, has provided substantial evidence that different types of target cells for Stxs exist in cattle. Peripheral and intestinal lymphocytes express the Stx receptor globotriaosylceramide (Gb3syn. CD77) in vitro and in vivo in an activation-dependent fashion with Stx-binding isoforms expressed predominantly at early stages of the activation process. Subpopulations of colonic epithelial cells and macrophage-like cells, residing in the bovine mucosa in proximity to STEC colonies, are also targeted by Stxs. STEC-inoculated calves are depressed in mounting appropriate cellular immune responses which can be overcome by vaccination of the animals against Stxs early in life before encountering STEC. Considering Stx target cells and the resulting effects of Stxs in cattle, which significantly differ from effects implicated in human disease, may open promising opportunities to improve existing yet insufficient measures to limit STEC carriage and shedding by the principal reservoir host.

scholarly journals Biochemical evidence of furin specificity and potential for phospho-regulation at Spike protein S1/S2 cleavage site in SARS-CoV2 but not in SARS-CoV1 or MERS-CoV

2020 ◽  
Author(s):  
Mihkel Örd ◽  
Ilona Faustova ◽  
Mart Loog
Keyword(s):  
Viral Entry ◽  
Spike Protein ◽  
Target Cells ◽  
The Novel ◽  
Novel Coronavirus ◽  
Cleavage Motif ◽  
Left Middle ◽  
Surprising Finding

AbstractThe Spike protein of the novel coronavirus SARS-CoV2 contains an insertion 680SPRRAR↓SV687 forming a cleavage motif RxxR for furin-like enzymes at the boundary of S1/S2 subunits. Cleavage at S1/S2 is important for efficient viral entry into target cells. The insertion is absent in other CoV-s of the same clade, including SARS-CoV1 that caused the 2003 outbreak. However, an analogous insertion was present in the Spike protein of the more distant Middle East Respiratory Syndrome coronavirus MERS-CoV. We show that a crucial third arginine at the left middle position, comprising a motif RRxR is required for furin recognition in vitro, while the general motif RxxR in common with MERS-CoV is not sufficient for cleavage. Further, we describe a surprising finding that the two serines at the edges of the insert SPRRAR↓SV can be efficiently phosphorylated by proline-directed and basophilic protein kinases. Both phosphorylations switch off furin’s ability to cleave the site. Although phosphoregulation of secreted proteins is still poorly understood, further studies, supported by a recent report of ten in vivo phosphorylated sites in the Spike protein of SARS-CoV2, could potentially uncover important novel regulatory mechanisms for SARS-CoV2.

Stat5a/b contribute to interleukin 7–induced B-cell precursor expansion, but abl- andbcr/abl-induced transformation are independent of Stat5

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2277-2283 ◽  
Author(s):  
Veronika Sexl ◽  
Roland Piekorz ◽  
Richard Moriggl ◽  
Juerg Rohrer ◽  
Michael P. Brown ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Interleukin 4 ◽  
Target Cells ◽  
Interleukin 7 ◽  
And Function ◽  
Deficient Mice

The cytokines interleukin 7 (IL-7) and interleukin 4 (IL-4) regulate lymphoid differentiation and function and activate the transcription factor Stat5. Using mice deficient for the 2 highly related transcription factors, Stat5a and Stat5b (Stat5a/b−/−), we investigated the role of Stat5 for B-cell differentiation, expansion, and function. Peripheral blood B cells of Stat5-deficient mice are significantly reduced, but no proliferation defects in response to various mitogenic stimuli are found. Also, IgM and IgG1 antibody production and immunoglobulin class switching are not affected. Pre- and pro-B cells of Stat5-deficient animals were found to have reduced responses to IL-7. Pro- and pre-B cells are the target cells of the abloncogene and numerous studies have suggested that Stat5a/b is essential for transformation by derivatives of the Abelson(abl) gene. To assess the role of Stat5a/b in transformation, we have evaluated the ability of variousabl derivatives to transform cells from Stat5a/b-deficient mice in vitro or in vivo. We demonstrate that the absence of Stat5a/b is not essential for the induction of lymphoid or myeloid tumors in vivo or on the ability to transform bone marrow cells in vitro.

scholarly journals Towards the design of multiepitope-based peptide vaccine candidate against SARS-CoV-2

2020 ◽  
Author(s):  
Hasanain Abdulhameed Odhar ◽  
Salam Waheed Ahjel ◽  
Suhad Sami Humadi
Keyword(s):  
Viral Entry ◽  
Simulation Analysis ◽  
Peptide Vaccine ◽  
Spike Protein ◽  
Good Stability ◽  
Target Cells ◽  
Potential Candidate ◽  
Angiotensin Converting Enzyme 2

AbstractCoronavirus disease 2019 is a current pandemic health threat especially for elderly patients with comorbidities. This respiratory disease is caused by a beta coronavirus known as severe acute respiratory syndrome coronavirus 2. The disease can progress into acute respiratory distress syndrome that can be fatal. Currently, no specific drug or vaccine are available to combat this pandemic outbreak. Social distancing and lockdown have been enforced in many places worldwide. The spike protein of coronavirus 2 is essential for viral entry into host target cells via interaction with angiotensin converting enzyme 2. This viral protein is considered a potential target for design and development of a drug or vaccine. Previously, we have reported several potential epitopes on coronavirus 2 spike protein with high antigenicity, low allergenicity and good stability against specified proteases. In the current study, we have constructed and evaluated a peptide vaccine from these potential epitopes by using in silico approach. This construct is predicted to have a protective immunogenicity, low allergenicity and good stability with minor structural flaws in model build. The population coverage of the used T-cells epitopes is believed to be high according to the employed restricted alleles. The vaccine construct can elicit efficient and long-lasting immune response as appeared through simulation analysis. This multiepitope-based peptide vaccine may represent a potential candidate against coronavirus 2. However, further in vitro and in vivo verification are required.

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