Dual-Antigen COVID-19 Vaccine Subcutaneous Prime Delivery With Oral Boosts Protects NHP Against SARS-CoV-2 Challenge

We have developed a dual-antigen COVID-19 vaccine incorporating genes for a modified SARS-CoV-2 spike protein (S-Fusion) and the viral nucleocapsid (N) protein with an Enhanced T-cell Stimulation Domain (N-ETSD) to increase the potential for MHC class II responses. The vaccine antigens are delivered by a human adenovirus serotype 5 platform, hAd5 [E1-, E2b-, E3-], previously demonstrated to be effective in the presence of Ad immunity. Vaccination of rhesus macaques with the hAd5 S-Fusion + N-ETSD vaccine by subcutaneous prime injection followed by two oral boosts elicited neutralizing anti-S IgG and T helper cell 1-biased T-cell responses to both S and N that protected the upper and lower respiratory tracts from high titer (1 x 106 TCID50) SARS-CoV-2 challenge. Notably, viral replication was inhibited within 24 hours of challenge in both lung and nasal passages, becoming undetectable within 7 days post-challenge.

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The Dual-Antigen Ad5 COVID-19 Vaccine Delivered as an Intranasal Plus Subcutaneous Prime Elicits Th1 Dominant T-Cell and Humoral Responses in CD-1 Mice

10.1101/2021.03.22.436476 ◽

2021 ◽

Author(s):

Adrian Rice ◽

Mohit Verma ◽

Annie Shin ◽

Lise Zakin ◽

Peter Sieling ◽

...

Keyword(s):

T Cell ◽

Oral Delivery ◽

Surface Display ◽

T Cell Responses ◽

Human Adenovirus ◽

Cell Surface Display ◽

Mhc I ◽

Cell Responses ◽

Serotype 5 ◽

Humoral Responses

In response to the need for an efficacious, thermally-stable COVID-19 vaccine that can elicit both humoral and cell-mediated T-cell responses, we have developed a dual-antigen human adenovirus serotype 5 (hAd5) COVID-19 vaccine in formulations suitable for subcutaneous (SC), intranasal (IN), or oral delivery. The vaccine expresses both the SARS-CoV-2 spike (S) and nucleocapsid (N) proteins using an hAd5 platform with E1, E2b, and E3 sequences deleted; hAd5(E1-, E2b-, E3-); that is effective even in the presence of hAd5 immunity. In the vaccine, S is modified (S-Fusion) for enhanced cell surface display to elicit humoral responses and N is modified with an Enhanced T-cell Stimulation Domain (N-ETSD) to direct N to the endosomal/lysosomal pathway to increase MHC I and II presentation. Initial studies using subcutaneous (SC) prime and SC boost vaccination of CD-1 mice demonstrated that the hAd5 S-Fusion + N-ETSD vaccine elicits T-helper cell 1 (Th1) dominant T-cell and humoral responses to both S and N. We then compared SC to IN prime vaccination with either an SC or IN boost post-SC prime and an IN boost after IN prime. These studies reveal that IN prime/IN boost is as effective at generating Th1 dominant humoral responses to both S and N as the other combinations, but that the SC prime with either an IN or SC boost elicits greater T cell responses. In a third study to assess the power of the two routes of delivery when used together, we used a combined SC plus IN prime with or without a boost and found the combined prime alone to be as effective as the combined prime with either an SC or IN boost in generating both humoral and T-cell responses. The findings here in CD-1 mice demonstrate that combined SC and IN prime-only delivery has the potential to provide broad immunity, including mucosal immunity, against SARS-CoV-2 and supports further testing of this delivery approach in additional animal models and clinical trials.

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A Novel Adenovirus Type 6 (Ad6)-Based Hepatitis C Virus Vector That Overcomes Preexisting Anti-Ad5 Immunity and Induces Potent and Broad Cellular Immune Responses in Rhesus Macaques

Journal of Virology ◽

10.1128/jvi.80.4.1688-1699.2006 ◽

2006 ◽

Vol 80 (4) ◽

pp. 1688-1699 ◽

Cited By ~ 63

Author(s):

Stefania Capone ◽

Annalisa Meola ◽

Bruno Bruni Ercole ◽

Alessandra Vitelli ◽

Monica Pezzanera ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

T Cell ◽

Rhesus Macaques ◽

T Cell Responses ◽

T Cell Response ◽

Cell Mediated Immunity ◽

Cell Responses ◽

Wide Range ◽

Serotype 5

ABSTRACT Success in resolving hepatitis C virus (HCV) infection has been correlated to vigorous, multispecific, and sustained CD8+ T-cell response in humans and chimpanzees. The efficacy of inducing T-cell-mediated immunity by recombinant serotype 5 adenovirus vector has been proven in many animal models of infectious diseases, but its immunogenicity can be negatively influenced by preexisting immunity against the vector itself. To evaluate the less prevalent adenovirus serotype 6 (Ad6) as an alternative vector for and HCV vaccine development, we have generated serotype 5 and 6 adenoviral vectors directing expression of the nonstructural region of HCV (MRKAd5-NSmut and MRKAd6-NSmut). Immunogenicity studies in mice showed that the two vectors induced comparable T-cell responses but that only MRKAd6-NSmut was not suppressed in the presence of anti-Ad5 immunity. In contrast, preexisting anti-Ad5 immunity dramatically blunted the immunogenicity of the serotype 5-based HCV vector. Furthermore, MRKAd6-NSmut showed equivalent potency, breadth, and longevity of HCV-specific T-cell responses in rhesus macaques as the corresponding Ad5-based vector over a wide range of doses and was capable of boosting DNA-primed animals even if administered at low doses. These data support the use of the MRKAd6-NSmut for anti-HCV immunotherapy and, more generally, for the Ad6 serotype as a better genetic vaccine vehicle than Ad5.

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Effect of Preexisting Immunity to Adenovirus Human Serotype 5 Antigens on the Immune Responses of Nonhuman Primates to Vaccine Regimens Based on Human- or Chimpanzee-Derived Adenovirus Vectors

Journal of Virology ◽

10.1128/jvi.02497-06 ◽

2007 ◽

Vol 81 (12) ◽

pp. 6594-6604 ◽

Cited By ~ 130

Author(s):

Kimberly McCoy ◽

Nia Tatsis ◽

Birgit Korioth-Schmitz ◽

Marcio O. Lasaro ◽

Scott E. Hensley ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Mononuclear Cells ◽

Rhesus Macaques ◽

T Cell Responses ◽

Cell Responses ◽

Significant Difference ◽

Immunodeficiency Virus ◽

Serotype 5 ◽

Adenovirus Vectors

ABSTRACT In this study we compared a prime-boost regimen with two serologically distinct replication-defective adenovirus (Ad) vectors derived from chimpanzee serotypes C68 and C1 expressing Gag, Pol, gp140, and Nef of human immunodeficiency virus type 1 with a regimen in which replication-defective Ad vectors of the human serotype 5 (AdHu5) were given twice. Experiments were conducted in rhesus macaques that had or had not been preexposed to antigens of AdHu5. There was no significant difference in T-cell responses tested from peripheral blood of the different groups, although responses were overall highest in nonpreexposed animals immunized with the chimpanzee Ad vectors. Preexisting immunity to AdHu5 completely inhibited induction of transgene product-specific antibodies by the AdHu5 vectors without affecting antibody responses to the chimpanzee vectors. Upon euthanasia, T-cell responses were tested from a number of tissues. Preexisting immunity to AdHu5, commonly found in humans, changed the homing pattern of vaccine-induced T cells. In AdHu5-preexposed animals vaccinated with the chimpanzee Ad vectors, frequencies of transgene-specific T cells were higher in spleens than in blood, and in most preexposed animals vaccinated either with AdHu5 vectors or chimpanzee adenovirus vectors, frequencies of such T cells were exceptionally high in livers. The latter results indicate that analysis of T-cell responses solely from blood mononuclear cells of vaccine recipients may not suffice to compare the potencies of different vaccine regimens.

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Intranasal plus subcutaneous prime vaccination with a dual antigen COVID-19 vaccine elicits T-cell and antibody responses in mice

Scientific Reports ◽

10.1038/s41598-021-94364-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adrian Rice ◽

Mohit Verma ◽

Annie Shin ◽

Lise Zakin ◽

Peter Sieling ◽

...

Keyword(s):

T Cell ◽

T Cell Responses ◽

Human Adenovirus ◽

Wild Type ◽

T Helper ◽

Cell Responses ◽

Antigen Vaccine ◽

Serotype 5 ◽

Humoral Responses ◽

Delivery Approach

AbstractWe have developed a COVID-19 vaccine, hAd5 S-Fusion + N-ETSD, that expresses SARS-CoV-2 spike (S) and nucleocapsid (N) proteins with modifications to increase immune responses delivered using a human adenovirus serotype 5 (hAd5) platform. Here, we demonstrate subcutaneous (SC) prime and SC boost vaccination of CD-1 mice with this dual-antigen vaccine elicits T-helper cell 1 (Th1) biased T-cell and humoral responses to both S and N that are greater than those seen with hAd5 S wild type delivering only unmodified S. We then compared SC to intranasal (IN) prime vaccination with SC or IN boosts and show that an IN prime with an IN boost is as effective at generating Th1 biased humoral responses as the other combinations tested, but an SC prime with an IN or SC boost elicits greater T cell responses. Finally, we used a combined SC plus IN (SC + IN) prime with or without a boost and found the SC + IN prime alone to be as effective in generating humoral and T-cell responses as the SC + IN prime with a boost. The finding that SC + IN prime-only delivery has the potential to provide broad immunity—including mucosal immunity—against SARS-CoV-2 supports further testing of this vaccine and delivery approach in animal models of viral challenge.

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Faculty Opinions recommendation of Peptide-MHC class II dimers as therapeutics to modulate antigen-specific T cell responses in autoimmune diabetes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1016402.200705 ◽

2003 ◽

Author(s):

Matthias von Herrath

Keyword(s):

T Cell ◽

Mhc Class Ii ◽

Autoimmune Diabetes ◽

T Cell Responses ◽

Class Ii ◽

Cell Responses

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Faculty Opinions recommendation of Durable protection of rhesus macaques immunized with a replicating adenovirus-SIV multigene prime/protein boost vaccine regimen against a second SIVmac251 rectal challenge: role of SIV-specific CD8+ T cell responses.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1047136.498191 ◽

2006 ◽

Author(s):

Kendall Smith

Keyword(s):

T Cell ◽

Rhesus Macaques ◽

T Cell Responses ◽

Cd8 T Cell ◽

Vaccine Regimen ◽

Cell Responses ◽

Protein Boost ◽

Boost Vaccine

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Faculty Opinions recommendation of Cutting edge: Conditional MHC class II expression reveals a limited role for B cell antigen presentation in primary and secondary CD4 T cell responses.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718020496.793480946 ◽

2013 ◽

Author(s):

Tim Manser

Keyword(s):

T Cell ◽

B Cell ◽

Antigen Presentation ◽

Mhc Class Ii ◽

T Cell Responses ◽

Class Ii ◽

Cutting Edge ◽

Cd4 T Cell ◽

Cell Antigen ◽

Cell Responses

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Human adenovirus-specific CD8+ T-cell responses are not inhibited by E3-19K in the presence of gamma interferon.

Journal of Virology ◽

10.1128/jvi.70.9.6314-6322.1996 ◽

1996 ◽

Vol 70 (9) ◽

pp. 6314-6322 ◽

Cited By ~ 42

Author(s):

P Flomenberg ◽

V Piaskowski ◽

R L Truitt ◽

J T Casper

Keyword(s):

T Cell ◽

T Cell Responses ◽

Human Adenovirus ◽

Cd8 T Cell ◽

Gamma Interferon ◽

Cell Responses

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Novel Recombinant Mycobacterium bovis BCG, Ovine Atadenovirus, and Modified Vaccinia Virus Ankara Vaccines Combine To Induce Robust Human Immunodeficiency Virus-Specific CD4 and CD8 T-Cell Responses in Rhesus Macaques

Journal of Virology ◽

10.1128/jvi.02607-09 ◽

2010 ◽

Vol 84 (12) ◽

pp. 5898-5908 ◽

Cited By ~ 19

Author(s):

Maximillian Rosario ◽

Richard Hopkins ◽

John Fulkerson ◽

Nicola Borthwick ◽

Máire F. Quigley ◽

...

Keyword(s):

T Cell ◽

Vaccinia Virus ◽

Mycobacterium Bovis ◽

Ex Vivo ◽

Rhesus Macaques ◽

T Cell Responses ◽

Cd8 T Cell ◽

Cell Responses ◽

Modified Vaccinia Virus Ankara ◽

Hiv 1

ABSTRACT Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity against tuberculosis, is the most widely used vaccine in the world. Due to its persistence and immunogenicity, BCG has been proposed as a vector for vaccines against other infections, including HIV-1. BCG has a very good safety record, although it can cause disseminated disease in immunocompromised individuals. Here, we constructed a recombinant BCG vector expressing HIV-1 clade A-derived immunogen HIVA using the recently described safer and more immunogenic BCG strain AERAS-401 as the parental mycobacterium. Using routine ex vivo T-cell assays, BCG.HIVA401 as a stand-alone vaccine induced undetectable and weak CD8 T-cell responses in BALB/c mice and rhesus macaques, respectively. However, when BCG.HIVA401 was used as a priming component in heterologous vaccination regimens together with recombinant modified vaccinia virus Ankara-vectored MVA.HIVA and ovine atadenovirus-vectored OAdV.HIVA vaccines, robust HIV-1-specific T-cell responses were elicited. These high-frequency T-cell responses were broadly directed and capable of proliferation in response to recall antigen. Furthermore, multiple antigen-specific T-cell clonotypes were efficiently recruited into the memory pool. These desirable features are thought to be associated with good control of HIV-1 infection. In addition, strong and persistent T-cell responses specific for the BCG-derived purified protein derivative (PPD) antigen were induced. This work is the first demonstration of immunogenicity for two novel vaccine vectors and the corresponding candidate HIV-1 vaccines BCG.HIVA401 and OAdV.HIVA in nonhuman primates. These results strongly support their further exploration.

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