Increased Immunogenicity of Full-Length Protein Antigens through Sortase-Mediated Coupling on the PapMV Vaccine Platform

Background: Flexuous rod-shape nanoparticles—made of the coat protein of papaya mosaic virus (PapMV)—provide a promising vaccine platform for the presentation of viral antigens to immune cells. The PapMV nanoparticles can be combined with viral antigens or covalently linked to them. The coupling to PapMV was shown to improve the immune response triggered against peptide antigens (<39 amino acids) but it remains to be tested if large proteins can be coupled to this platform and if the coupling will lead to an immune response improvement. Methods: Two full-length recombinant viral proteins, the influenza nucleoprotein (NP) and the simian immunodeficiency virus group-specific protein antigen (GAG) were coupled to PapMV nanoparticles using sortase A. Mice were immunized with the nanoparticles coupled to the antigens and the immune response directed to the antigens were analyzed by ELISA and ELISPOT. Results: We showed the feasibility of coupling two different full-length proteins (GAG and NP) to the nanoparticle. We also showed that the coupling to PapMV nanoparticles improved significantly the humoral and the cytotoxic T lymphocyte (CTL) immune response to the antigens. Conclusion: This proof of concept demonstrates the versatility and the efficacy of the PapMV vaccine platform in the design of vaccines against viral diseases.

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Modulation of Antigen Display on PapMV Nanoparticles Influences Its Immunogenicity

Vaccines ◽

10.3390/vaccines9010033 ◽

2021 ◽

Vol 9 (1) ◽

pp. 33

Author(s):

Marie-Eve Laliberté-Gagné ◽

Marilène Bolduc ◽

Caroline Garneau ◽

Santa-Mariela Olivera-Ugarte ◽

Pierre Savard ◽

...

Keyword(s):

Immune Response ◽

Influenza A ◽

Matrix Protein ◽

Cell Epitope ◽

Vaccine Antigen ◽

Vaccine Platform ◽

Peptide Antigens ◽

C Terminus ◽

The Impact ◽

Stimulation Of

Background: The papaya mosaic virus (PapMV) vaccine platform is a rod-shaped nanoparticle made of the recombinant PapMV coat protein (CP) self-assembled around a noncoding single-stranded RNA (ssRNA) template. The PapMV nanoparticle induces innate immunity through stimulation of the Toll-like receptors (TLR) 7 and 8. The display of the vaccine antigen at the surface of the nanoparticle, associated with the co-stimulation signal via TLR7/8, ensures a strong stimulation of the immune response, which is ideal for the development of candidate vaccines. In this study, we assess the impact of where the peptide antigen is fused, whether at the surface or at the extremities of the nanoparticles, on the immune response directed to that antigen. Methods: Two different peptides from influenza A virus were used as model antigens. The conserved M2e peptide, derived from the matrix protein 2 was chosen as the B-cell epitope, and a peptide derived from the nucleocapsid was chosen as the cytotoxic T lymphocytes (CTL) epitope. These peptides were coupled at two different positions on the PapMV CP, the N- (PapMV-N) or the C-terminus (PapMV-C), using the transpeptidase activity of Sortase A (SrtA). The immune responses, both humoral and CD8+ T-cell-mediated, directed to the peptide antigens in the two different fusion contexts were analyzed and compared. The impact of coupling density at the surface of the nanoparticle was also investigated. Conclusions: The results demonstrate that coupling of the peptide antigens at the N-terminus (PapMV-N) of the PapMV CP led to an enhanced immune response to the coupled peptide antigens as compared to coupling to the C-terminus. The difference between the two vaccine platforms is linked to the enhanced capacity of the PapMV-N vaccine platform to stimulate TLR7/8. We also demonstrated that the strength of the immune response increases with the density of coupling at the surface of the nanoparticles.

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Novel Protein-Based Pneumococcal Vaccines: Assessing the Use of Distinct Protein Fragments Instead of Full-Length Proteins as Vaccine Antigens

Vaccines ◽

10.3390/vaccines7010009 ◽

2019 ◽

Vol 7 (1) ◽

pp. 9 ◽

Cited By ~ 13

Author(s):

Theano Lagousi ◽

Paraskevi Basdeki ◽

John Routsias ◽

Vana Spoulou

Keyword(s):

Low Cost ◽

Specific Protein ◽

Full Length ◽

Pneumococcal Vaccines ◽

Protein Antigens ◽

Protein Fragments ◽

Humoral And Cellular Immunity ◽

Expression Variability ◽

Efficient Protection ◽

Antigenic Regions

Non-serotype-specific protein-based pneumococcal vaccines have received extensive research focus due to the limitations of polysaccharide-based vaccines. Pneumococcal proteins (PnPs), universally expressed among serotypes, may induce broader immune responses, stimulating humoral and cellular immunity, while being easier to manufacture and less expensive. Such an approach has raised issues mainly associated with sequence/level of expression variability, chemical instability, as well as possible undesirable reactogenicity and autoimmune properties. A step forward employs the identification of highly-conserved antigenic regions within PnPs with the potential to retain the benefits of protein antigens. Besides, their low-cost and stable construction facilitates the combination of several antigenic regions or peptides that may impair different stages of pneumococcal disease offering even wider serotype coverage and more efficient protection. This review discusses the up-to-date progress on PnPs that are currently under clinical evaluation and the challenges for their licensure. Focus is given on the progress on the identification of antigenic regions/peptides within PnPs and their evaluation as vaccine candidates, accessing their potential to overcome the issues associated with full-length protein antigens. Particular mention is given of the use of newer delivery system technologies including conjugation to Toll-like receptors (TLRs) and reformulation into nanoparticles to enhance the poor immunogenicity of such antigens.

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Induction of an Antigen-specific, CD1-restricted Cytotoxic T Lymphocyte Response In vivo

Journal of Experimental Medicine ◽

10.1084/jem.187.3.433 ◽

1998 ◽

Vol 187 (3) ◽

pp. 433-438 ◽

Cited By ~ 41

Author(s):

Delphine J. Lee ◽

Amila Abeyratne ◽

Dennis A. Carson ◽

Maripat Corr

Keyword(s):

T Cell ◽

Cytotoxic T Lymphocyte ◽

Cytolytic Activity ◽

Protein Antigens ◽

Peptide Antigens ◽

Mhc Molecules ◽

Human T Cell ◽

T Cell Lines ◽

Nonpeptide Antigens

The majority of T cell responses are restricted to peptide antigens bound by polymorphic major histocompatibility complex (MHC) molecules. However, peptide antigens can be presented to T cells by murine non-MHC–encoded CD1d (mCD1) molecules, and human T cell lines specific for nonpeptide antigens presented on CD1 isoforms have been identified. It is shown here that antigen-specific, mCD1-restricted lymphocytes can be generated in vivo by immunizing mice with a combination of plasmids encoding chicken ovalbumin, murine CD1d, and costimulatory molecules. Splenocytes from immunized mice have CD1d-restricted, MHC- unrestricted, ovalbumin-specific cytolytic activity that can be inhibited by anti-CD1 antibodies as well as a competing CD1-binding peptide. These results suggest a physiologic role for murine CD1d to present exogenous protein antigens.

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P-369 Immune response to viral antigens produced by transgene of full-length HBV in purebred mice

International Hepatology Communications ◽

10.1016/0928-4346(95)90665-t ◽

1995 ◽

Vol 3 ◽

pp. S129

Author(s):

K HASEGAWA

Keyword(s):

Immune Response ◽

Full Length ◽

Viral Antigens

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Cytolytic Activity of the Human Papillomavirus Type 16 E711-20Epitope-Specific Cytotoxic T Lymphocyte Is Enhanced by Heat Shock Protein 110 inHLA-A*0201Transgenic Mice

Clinical and Vaccine Immunology ◽

10.1128/cvi.00721-12 ◽

2013 ◽

Vol 20 (7) ◽

pp. 1027-1033 ◽

Cited By ~ 6

Author(s):

Zhenzhen Ding ◽

Rongying Ou ◽

Bing Ni ◽

Jun Tang ◽

Yunsheng Xu

Keyword(s):

Immune Response ◽

Human Papillomavirus ◽

Heat Shock ◽

Mouse Model ◽

Cytotoxic T Lymphocyte ◽

Ex Vivo ◽

Human Cancer ◽

Cytolytic Activity ◽

Protein Antigens

ABSTRACTHeat shock proteins (HSPs) have been successfully applied to a broad range of vaccines as biological adjuvants to enhance the immune response. The recently defined HSP110, in particular, exhibits strong protein binding affinity and is capable of enhancing the immunogenicity of protein antigens remarkably more than other HSP family members. In our previous study, we verified that murine HSP110 (mHSP110) significantly enhanced the immune response of a C57BL/6 mouse model to the H-2d-restricted human papillomavirus (HPV) E749-57epitope (short peptide spanning the 49th to 57th amino acid residues in the E7 protein). To determine whether HSP110 similarly enhances the immunogenicity of human epitope peptides, we used theHLA-A2transgenic mouse model to investigate the efficacy of the mHSP110 chaperone molecule as an immunoadjuvant of the human HLA-A2-restricted HPV16 E711-20epitope vaccine. Results showed that mHSP110 efficiently formed a noncovalently bound complex with the E711-20epitope. The mHSP110-E711-20complex induced epitope-specific splenocyte proliferation and E711-20-specific gamma interferon (IFN-γ) secretion. Importantly, cytotoxic T lymphocytes primed by the mHSP110-E711-20complex exerted strong cytolytic effects on target T2cells pulsed with the E711-20peptide or TC-1 cells transfected with theHLA-A2gene. In addition, the mHSP110-E711-20complex elicited strongerex vivoandin vivoantitumor responses than either emulsified complete Freund's adjuvant or HSP70-chaperoned E711-20peptide. These collective data suggest that HSP110 is a promising immunomodulator candidate for peptide-based human cancer vaccines, such as for the HLA-A2-restricted E711-20epitope.

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Immune response to vaccine candidates based on different types of nanoscaffolded RBD domain of the SARS-CoV-2 spike protein

10.1101/2020.08.28.244269 ◽

2020 ◽

Author(s):

Duško Lainšček ◽

Tina Fink ◽

Vida Forstnerič ◽

Iva Hafner-Bratkovič ◽

Sara Orehek ◽

...

Keyword(s):

Immune Response ◽

B Cell ◽

Neutralizing Antibodies ◽

Affinity Maturation ◽

T Cell Response ◽

Spike Protein ◽

Cytotoxic Lymphocytes ◽

Protein Antigens ◽

Vaccine Platform ◽

Suitable Target

AbstractEffective and safe vaccines against SARS-CoV-2 are highly desirable to prevent casualties and societal cost caused by Covid-19 pandemic. The receptor binding domain (RBD) of the surface-exposed spike protein of SARS-CoV-2 represents a suitable target for the induction of neutralizing antibodies upon vaccination. Small protein antigens typically induce weak immune response while particles measuring tens of nanometers are efficiently presented to B cell follicles and subsequently to follicular germinal center B cells in draining lymph nodes, where B cell proliferation and affinity maturation occurs. Here we prepared and analyzed the response to several DNA vaccines based on genetic fusions of RBD to four different scaffolding domains, namely to the foldon peptide, ferritin, lumazine synthase and β-annulus peptide, presenting from 6 to 60 copies of the RBD on each particle. Scaffolding strongly augmented the immune response with production of neutralizing antibodies and T cell response including cytotoxic lymphocytes in mice upon immunization with DNA plasmids. The most potent response was observed for the 24-residue β-annulus peptide scaffold that forms large soluble assemblies, that has the advantage of low immunogenicity in comparison to larger scaffolds. Our results support the advancement of this vaccine platform towards clinical trials.

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Modulation of Antigen Display on PapMV Nanoparticles Influences Its Immunogenicity

10.20944/preprints202012.0327.v1 ◽

2020 ◽

Author(s):

Marie-Eve Laliberté-Gagné ◽

Marilène Bolduc ◽

Caroline Garneau ◽

Santa-Mariela Olivera-Ugarte ◽

Pierre Savard ◽

...

Keyword(s):

Immune Response ◽

Influenza A ◽

Cell Epitope ◽

Vaccine Antigen ◽

Vaccine Platform ◽

Peptide Antigens ◽

C Terminus ◽

The Difference ◽

The Impact ◽

Stimulation Of

Background: The papaya mosaic virus (PapMV) vaccine platform is a rod-shape nanoparticle made of the recombinant PapMV coat protein (CP) self-assembled around a non-coding ssRNA template. The PapMV nanoparticle induces innate immunity through stimulation of the toll-like receptors (TLR) 7 and 8. The display of the vaccine antigen at the surface of the nanoparticle, associated with the co-stimulation signal via TLR7/8, ensures a strong stimulation of the immune response, which is ideal for the development of candidate vaccines. In this study, we assess the impact of where the peptide antigen is fused, either at the surface or at the extremities of the nanoparticles, on the immune response directed to that antigen. Methods: Two different peptides from influenza A virus were used as model antigens. The conserved M2e peptide was chosen as the B-cell epitope, and a peptide derived from the nucleocapsid was chosen as the CTL epitope. These peptides were coupled at two different positions on the PapMV CP, the N- (PapMV-N) or the C-terminus (PapMV-C) using the transpeptidase activity of Sortase A (SrtA). The immune responses, both humoral and CD8+ T cell-mediated, directed to the peptide antigens in the two different fusion contexts were analyzed and compared. The impact of coupling density at the surface of the nanoparticle was also investigated. Conclusions: The results demonstrate that coupling of the peptide antigens at the N-terminus (PapMV-N) of the PapMV CP led to an enhanced immune response to the coupled peptide antigens as compared to coupling to the C-terminus. The difference between the two vaccine platforms is linked to the enhanced capacity of the PapMV-N vaccine platform to stimulate the TLR7/8. We also demonstrated that the strength of the immune response increases with the density of coupling at the surface of the nanoparticles.

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