Dose Effects of Recombinant Adenovirus Immunization in Rodents

Recombinant adenovirus type 5 (rAd) has been used as a vaccine platform against many infectious diseases and has been shown to be an effective vaccine vector. The dose of the vaccine varies significantly from study to study, making it very difficult to compare immune responses and vaccine efficacy. This study determined the immune correlates induced by serial dilutions of rAd vaccines delivered intramuscularly (IM) and intranasally (IN) to mice and rats. When immunized IM, mice had substantially higher antibody responses at the higher vaccine doses, whereas, the IN immunized mice showed a lower response to the higher rAd vaccine doses. Rats did not show dose-dependent antibody responses to increasing vaccine doses. The IM immunized mice and rats also showed significant dose-dependent T cell responses to the rAd vaccine. However, the T cell immunity plateaued in both mice and rats at 109 and 1010 vp/animal, respectively. Additionally, the highest dose of vaccine in mice and rats did not improve the T cell responses. A final vaccine analysis using a lethal influenza virus challenge showed that despite the differences in the immune responses observed in the mice, the mice had very similar patterns of protection. This indicates that rAd vaccines induced dose-dependent immune responses, especially in IM immunized animals, and that immune correlates are not as predictive of protection as initially thought.

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Durability of immune responses to the BNT162b2 mRNA vaccine

10.1101/2021.09.30.462488 ◽

2021 ◽

Author(s):

Mehul Suthar ◽

Prabhu S Arunachalam ◽

Mengyun Hu ◽

Noah Reis ◽

Meera Trisal ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Significant Proportion ◽

T Cell Responses ◽

Primary Vaccination ◽

Antibody Responses ◽

Booster Immunization ◽

Cell Responses ◽

Cell Immunity ◽

Antibody Titers

The development of the highly efficacious mRNA vaccines in less than a year since the emergence of SARS-CoV-2 represents a landmark in vaccinology. However, reports of waning vaccine efficacy, coupled with the emergence of variants of concern that are resistant to antibody neutralization, have raised concerns about the potential lack of durability of immunity to vaccination. We recently reported findings from a comprehensive analysis of innate and adaptive immune responses in 56 healthy volunteers who received two doses of the BNT162b2 vaccination. Here, we analyzed antibody responses to the homologous Wu strain as well as several variants of concern, including the emerging Mu (B.1.621) variant, and T cell responses in a subset of these volunteers at six months (day 210 post-primary vaccination) after the second dose. Our data demonstrate a substantial waning of antibody responses and T cell immunity to SARS-CoV-2 and its variants, at 6 months following the second immunization with the BNT162b2 vaccine. Notably, a significant proportion of vaccinees have neutralizing titers below the detection limit, and suggest a 3rd booster immunization might be warranted to enhance the antibody titers and T cell responses.

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Marburg virus survivor immune responses are Th1 skewed with limited neutralizing antibody responses

Journal of Experimental Medicine ◽

10.1084/jem.20170161 ◽

2017 ◽

Vol 214 (9) ◽

pp. 2563-2572 ◽

Cited By ~ 9

Author(s):

Spencer W. Stonier ◽

Andrew S. Herbert ◽

Ana I. Kuehne ◽

Ariel Sobarzo ◽

Polina Habibulin ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Ebola Virus ◽

T Cell Responses ◽

Neutralizing Antibody ◽

Cd8 T Cell ◽

Marburg Virus ◽

Antibody Responses ◽

Cd4 T Cell ◽

Cell Responses

Until recently, immune responses in filovirus survivors remained poorly understood. Early studies revealed IgM and IgG responses to infection with various filoviruses, but recent outbreaks have greatly expanded our understanding of filovirus immune responses. Immune responses in survivors of Ebola virus (EBOV) and Sudan virus (SUDV) infections have provided the most insight, with T cell responses as well as detailed antibody responses having been characterized. Immune responses to Marburg virus (MARV), however, remain almost entirely uncharacterized. We report that immune responses in MARV survivors share characteristics with EBOV and SUDV infections but have some distinct differences. MARV survivors developed multivariate CD4+ T cell responses but limited CD8+ T cell responses, more in keeping with SUDV survivors than EBOV survivors. In stark contrast to SUDV survivors, rare neutralizing antibody responses in MARV survivors diminished rapidly after the outbreak. These results warrant serious consideration for any vaccine or therapeutic that seeks to be broadly protective, as different filoviruses may require different immune responses to achieve immunity.

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Robust SARS-CoV-2-specific T-cell immunity is maintained at 6 months following primary infection

10.21203/rs.3.rs-101480/v1 ◽

2020 ◽

Author(s):

Jianmin Zuo ◽

Alex Dowell ◽

Hayden Pearce ◽

Kriti Verma ◽

Heather Long ◽

...

Keyword(s):

Immune Response ◽

T Cell ◽

Immune Responses ◽

Antibody Level ◽

Primary Infection ◽

Natural Infection ◽

T Cell Responses ◽

Symptomatic Infection ◽

Cell Responses ◽

Cell Immunity

Abstract The immune response to SARS-CoV-2 is critical in both controlling primary infection and preventing re-infection. However, there is concern that immune responses following natural infection may not be sustained and that this may predispose to recurrent infection. We analysed the magnitude and phenotype of the SARS-CoV-2 cellular immune response in 100 donors at six months following primary infection and related this to the profile of antibody level against spike, nucleoprotein and RBD over the previous six months. T-cell immune responses to SARS-CoV-2 were present by ELISPOT or ICS analysis in all donors and are characterised by predominant CD4+ T cell responses with strong IL-2 cytokine expression. Median T-cell responses were 50% higher in donors who had experienced an initial symptomatic infection indicating that the severity of primary infection establishes a ‘setpoint’ for cellular immunity that lasts for at least 6 months. The T-cell responses to both spike and nucleoprotein/membrane proteins were strongly correlated with the peak antibody level against each protein. The rate of decline in antibody level varied between individuals and higher levels of nucleoprotein-specific T cells were associated with preservation of NP-specific antibody level although no such correlation was observed in relation to spike-specific responses. In conclusion, our data are reassuring that functional SARS-CoV-2-specific T-cell responses are retained at six months following infection although the magnitude of this response is related to the clinical features of primary infection.

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Systems Vaccinology for a Live Attenuated Tularemia Vaccine Reveals Unique Transcriptional Signatures That Predict Humoral and Cellular Immune Responses

Vaccines ◽

10.3390/vaccines8010004 ◽

2019 ◽

Vol 8 (1) ◽

pp. 4 ◽

Cited By ~ 9

Author(s):

Muktha S. Natrajan ◽

Nadine Rouphael ◽

Lilin Lai ◽

Dmitri Kazmin ◽

Travis L. Jensen ◽

...

Keyword(s):

Gene Expression ◽

T Cell ◽

Immune Responses ◽

T Cell Responses ◽

Innate Immune ◽

Antibody Responses ◽

Cytokine Signaling ◽

Cell Responses ◽

Viral Vaccine ◽

Tularemia Vaccine

Background: Tularemia is a potential biological weapon due to its high infectivity and ease of dissemination. This study aimed to characterize the innate and adaptive responses induced by two different lots of a live attenuated tularemia vaccine and compare them to other well-characterized viral vaccine immune responses. Methods: Microarray analyses were performed on human peripheral blood mononuclear cells (PBMCs) to determine changes in transcriptional activity that correlated with changes detected by cellular phenotyping, cytokine signaling, and serological assays. Transcriptional profiles after tularemia vaccination were compared with yellow fever [YF-17D], inactivated [TIV], and live attenuated [LAIV] influenza. Results: Tularemia vaccine lots produced strong innate immune responses by Day 2 after vaccination, with an increase in monocytes, NK cells, and cytokine signaling. T cell responses peaked at Day 14. Changes in gene expression, including upregulation of STAT1, GBP1, and IFIT2, predicted tularemia-specific antibody responses. Changes in CCL20 expression positively correlated with peak CD8+ T cell responses, but negatively correlated with peak CD4+ T cell activation. Tularemia vaccines elicited gene expression signatures similar to other replicating vaccines, inducing early upregulation of interferon-inducible genes. Conclusions: A systems vaccinology approach identified that tularemia vaccines induce a strong innate immune response early after vaccination, similar to the response seen after well-studied viral vaccines, and produce unique transcriptional signatures that are strongly correlated to the induction of T cell and antibody responses.

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Priming with Recombinant BCG Expressing HTI Enhances the Magnitude and Breadth of the T-Cell Immune Responses Elicited by MVA.HTI in BALB/c Mice

Vaccines ◽

10.3390/vaccines8040678 ◽

2020 ◽

Vol 8 (4) ◽

pp. 678

Author(s):

Narcís Saubi ◽

Athina Kilpeläinen ◽

Yoshiki Eto ◽

Chun-Wei Chen ◽

Àlex Olvera ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

T Cell Responses ◽

Vaccine Platform ◽

Cell Responses ◽

Total Magnitude ◽

T Cell Immune Responses ◽

Ifn Γ ◽

Hiv 1 ◽

Recombinant Bcg

The use of Mycobacterium bovis bacillus Calmette–Guérin (BCG) as a live vaccine vehicle is a promising approach for HIV-1-specific T-cell induction. In this study, we used recombinant BCG expressing HIVACAT T-cell immunogen (HTI), BCG.HTI2auxo.int. BALB/c mice immunization with BCG.HTI2auxo.int prime and MVA.HTI boost was safe and induced HIV-1-specific T-cell responses. Two weeks after boost, T-cell responses were assessed by IFN-γ ELISpot. The highest total magnitude of IFN-γ spot-forming cells (SFC)/106 splenocytes was observed in BCG.HTI2auxo.int primed mice compared to mice receiving MVA.HTI alone or mice primed with BCGwt, although the differences between the vaccination regimens only reached trends. In order to evaluate the differences in the breadth of the T-cell immune responses, we examined the number of reactive peptide pools per mouse. Interestingly, both BCG.HTI2auxo.int and BCGwt primed mice recognized an average of four peptide pools per mouse. However, the variation was higher in BCG.HTI2auxo.int primed mice with one mouse recognizing 11 peptide pools and three mice recognizing few or no peptide pools. The recognition profile appeared to be more spread out for BCG.HTI2auxo.int primed mice and mice only receiving MVA.HTI. Here, we describe a useful vaccine platform for priming protective responses against HIV-1/TB and other prevalent infectious diseases.

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Impact of Recombinant Adenovirus Serotype 35 Priming versus Boosting of a Plasmodium falciparum Protein: Characterization of T- and B-Cell Responses to Liver-Stage Antigen 1

Infection and Immunity ◽

10.1128/iai.01614-07 ◽

2008 ◽

Vol 76 (4) ◽

pp. 1709-1718 ◽

Cited By ~ 19

Author(s):

Ariane Rodríguez ◽

Jaap Goudsmit ◽

Arjen Companjen ◽

Ratna Mintardjo ◽

Gert Gillissen ◽

...

Keyword(s):

Immune Response ◽

T Cell ◽

Recombinant Adenovirus ◽

Antibody Responses ◽

T Cell Immunity ◽

Adenovirus Serotype ◽

Liver Stage ◽

Cell Responses ◽

Cell Immunity ◽

Ifn Γ

ABSTRACT Prime-boost vaccination regimens with heterologous antigen delivery systems have indicated that redirection of the immune response is feasible. We showed earlier that T-cell responses to circumsporozoite (CS) protein improved significantly when the protein is primed with recombinant adenovirus serotype 35 coding for CS (rAd35.CS). The current study was designed to answer the question whether such an effect can be extended to liver-stage antigens (LSA) of Plasmodium falciparum such as LSA-1. Studies with mice have demonstrated that the LSA-1 protein induces strong antibody response but a weak T-cell immunity. We first identified T-cell epitopes in LSA-1 by use of intracellular gamma interferon (IFN-γ) staining and confirmed these epitopes by means of enzyme-linked immunospot assay and pentamer staining. We show that a single immunization with rAd35.LSA-1 induced a strong antigen-specific IFN-γ CD8+ T-cell response but no measurable antibody response. In contrast, vaccinations with the adjuvanted recombinant LSA-1 protein induced remarkably low cellular responses but strong antibody responses. Finally, both priming and boosting of the adjuvanted protein by rAd35 resulted in enhanced T-cell responses without impairing the level of antibody responses induced by the protein immunizations alone. Furthermore, the incorporation of rAd35 in the vaccination schedule led to a skewing of LSA-1-specific antibody responses toward a Th1-type immune response. Our results show the ability of rAd35 to induce potent T-cell immunity in combination with protein in a prime-boost schedule without impairing the B-cell response.

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Robust Stimulation of Humoral and Cellular Immune Responses following Vaccination with Antigen-Loaded β-Glucan Particles

mBio ◽

10.1128/mbio.00164-10 ◽

2010 ◽

Vol 1 (3) ◽

Cited By ~ 87

Author(s):

Haibin Huang ◽

Gary R. Ostroff ◽

Chrono K. Lee ◽

Charles A. Specht ◽

Stuart M. Levitz

Keyword(s):

T Cell ◽

Immune Responses ◽

Elispot Assay ◽

Cellular Response ◽

T Cell Responses ◽

Minor Role ◽

Mouse Bone Marrow ◽

Antigen Delivery ◽

Vaccine Platform ◽

Cell Responses

ABSTRACTβ-Glucan particles (GPs) are purifiedSaccharomyces cerevisiaecell walls treated so that they are primarily β1,3-d-glucans and free of mannans and proteins. GPs are phagocytosed by dendritic cells (DCs) via the Dectin-1 receptor, and this interaction stimulates proinflammatory cytokine secretion by DCs. As the hollow, porous GP structure allows for high antigen loading, we hypothesized that antigen-loaded GPs could be exploited as a receptor-targeted vaccine delivery system. Ovalbumin (OVA) was electrostatically complexed inside the hollow GP shells (GP-OVA). Incubation of C57BL/6J mouse bone marrow-derived DCs with GP-OVA resulted in phagocytosis, upregulation of maturation markers, and rapid proteolysis of OVA. Compared with free OVA, GP-OVA was >100-fold more potent at stimulating the proliferation of OVA-reactive transgenic CD8+OT-I and CD4+OT-II T cells, as measured byin vitro[3H]thymidine incorporation using DCs as antigen-presenting cells. Next, immune responses in C57BL/6J mice following subcutaneous immunizations with GP-OVA were compared with those in C57BL/6J mice following subcutaneous immunizations with OVA absorbed onto the adjuvant alum (Alum/OVA). Vaccination with GP-OVA stimulated substantially higher antigen-specific CD4+T-cell lymphoproliferative and enzyme-linked immunospot (ELISPOT) responses than that with Alum/OVA. Moreover, the T-cell responses induced by GP-OVA were Th1 biased (determined by gamma interferon [IFN-γ] ELISPOT assay) and Th17 biased (determined by interleukin-17a [IL-17a] ELISPOT assay). Finally, both the GP-OVA and Alum/OVA formulations induced strong secretions of IgG1 subclass anti-OVA antibodies, although only GP-OVA induced secretion of Th1-associated IgG2c antibodies. Thus, the GP-based vaccine platform combines adjuvanticity and antigen delivery to induce strong humoral and Th1- and Th17-biased CD4+T-cell responses.IMPORTANCEMost licensed vaccines work by promoting protective antibody responses. However, for many infectious diseases, antibody-mediated protection appears to play a relatively minor role, and vaccination has met with limited success. While live-attenuated organisms generally elicit T-cell responses, their use in vaccines is limited by the potential for causing disease. Thus, there is an urgent need for new vaccine platforms that deliver antigens in such a manner as to promote strong T-cell-mediated responses. Here we designed a novel vaccine platform consisting of yeast-derived β-glucan particles (GPs) that combines antigen delivery and adjuvant activity. GPs loaded with the model antigen ovalbumin (OVA) stimulated robust humoral and T-cell responses in mice. In addition, the cellular response was Th1 and Th17 biased. This work has implications for the design of vaccines that stimulate biased T-cell responses as well as for understanding how immunity to fungal pathogens develops.

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P03.01 High immunogenic VLP-based vaccines elicit new T cell specificities against melanoma neoantigens in mice

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-itoc8.24 ◽

2021 ◽

Vol 9 (Suppl 1) ◽

pp. A13.1-A13

Author(s):

C Aguilar-Gurrieri ◽

A Barajas ◽

A Pons-Grifols ◽

I Varela ◽

P Amengual-Rigo ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Therapeutic Vaccine ◽

T Cell Responses ◽

Advisory Board ◽

Tumor Control ◽

Vaccine Platform ◽

Anchor Residue ◽

Synonymous Mutations ◽

Cell Responses

BackgroundNeoantigens’ (neoAg) identification, which determines T-cell responses against tumors, has fostered the development of personalized vaccines with promising results. While the ranking of the most immunogenic neoAg can be addressed using predictive techniques, their formulation as vaccines needs to be improved. To maximize their therapeutic potential, optimal neoAg-based vaccines should be manufactured in a superb delivery platform that enhances robust new immune responses, able to bypass thymic tolerance and the humoral immunosuppressive microenvironment. These novel T cell responses generated at the periphery will not be exhausted, opposite to TILs. We aim to develop a highly immunogenic vaccine platform, based on engineered HIV-derived Virus-Like Particles (VLP) expressing approximately 2500 copies of each selected neoAg. We tested different neoAgs loaded VLPs (neoVLP) in a melanoma mouse model to evaluate their capability to generate new immunogenic specificities.Material and MethodsSpecific non-synonymous mutations from B16F10 cells were identified, selected and used to generate a list of prioritized peptides. NeoAgs were classified as: Tier1, acquiring a mutation that creates an anchor residue to the MHC-I, not present in the WT peptide; Tier2, acquiring a mutation in a position that largely impacts contact with the TCR respect to WT; and Tier3, acquiring a mutation in the TCR contact region but inducing a less drastic change than in Tier2. Frame shift (FS) mutations, expected to be highly immunogenic, were also included.Thirteen to fifteen selected neoAgs from each group were loaded on highly immunogenic neoVLPs. Their immunogenicity was evaluated in C57bl/6 mice by immunization with a neoVLP-coding plasmid DNA (prime) and purified neoVLPs as soluble particles (boost). Splenocytes were used to evaluate neoAg-specific T cell responses.ResultsWe have successfully generated and purified neoVLPs, exposing neoAgs from all groups by transient transfection of Expi293 cells. Protein integrity and VLP morphology were confirmed by western blot and cryo-EM. When used for immunization assays, neoVLPs, containing neoAgs from Tier2, Tier3 and FS groups, were capable of generating humoral responses against viral proteins and T cell responses against neoAgs present in the neoVLP. B16F10 inoculated animals, but not vaccinated, did not develop detectable T cell responses against neoAgs present in any tested neoVLP, suggesting that the vaccination with neoVLPs promoted new specificities against selected neoAgs that might contribute to tumor control and eradication.ConclusionOur data show that the neoVLPs promote the generation of new antitumor-specific immune responses against selected neoepitopes, suggesting that neoVLPs vaccination could be an alternative to current therapeutic vaccine approaches and a promising candidate for future personalized immunotherapy.Disclosure InformationC. Aguilar-Gurrieri: None. A. Barajas: None. A. Pons-Grifols: None. I. Varela: None. P. Amengual-Rigo: None. R. Farriol: None. M. Vazquez: None. R. Lepore: None. C. Anjos-Souza: None. J. Blanco-Heredia: None. L. de Mattos-Arruda: None. V. Guallar: None. A. Valencia: None. B. Clotet: F. Consultant/Advisory Board; Significant; Albajuna Therapeutics. J. Carrillo: Other; Significant; Albajuna Therapeutics. J. Blanco: F. Consultant/Advisory Board; Significant; Albajuna Therapeutics.

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Immune Responses in Macaques to a Prototype Recombinant Adenovirus Live Oral Human Papillomavirus 16 Vaccine

Clinical and Vaccine Immunology ◽

10.1128/cvi.00197-14 ◽

2014 ◽

Vol 21 (9) ◽

pp. 1224-1231 ◽

Cited By ~ 5

Author(s):

Michael G. Berg ◽

Robert J. Adams ◽

Ratish Gambhira ◽

Mark C. Siracusa ◽

Alan L. Scott ◽

...

Keyword(s):

Human Papillomavirus ◽

T Cell ◽

Neutralizing Antibodies ◽

Cellular Response ◽

Recombinant Adenovirus ◽

T Cell Responses ◽

Transcriptional Unit ◽

Human Papillomavirus 16 ◽

Cell Responses ◽

Cell Immunity

ABSTRACTImmunization with human papillomavirus (HPV) L1 virus-like particles (VLPs) prevents infection with HPV. However, the expense and logistical demands of current VLP vaccines will limit their widespread use in resource-limited settings, where most HPV-induced cervical cancer occurs. Live oral adenovirus vaccines have properties that are well-suited for use in such settings. We have described a live recombinant adenovirus vaccine prototype that produces abundant HPV16 L1 protein from the adenovirus major late transcriptional unit and directs the assembly of HPV16 VLPs in tissue culture. Recombinant-derived VLPs potently elicit neutralizing antibodies in mice. Here, we characterize the immune response to the recombinant after dual oral and intranasal immunization of pigtail macaques, in which the virus replicates as it would in immunized humans. The immunization of macaques induced vigorous humoral responses to adenovirus capsid and nonstructural proteins, although, surprisingly, not against HPV L1. In contrast, immunization elicited strong T-cell responses to HPV VLPs as well as adenovirus virions. T-cell responses arose immediately after the primary immunization and were boosted by a second immunization with recombinant virus. T-cell immunity contributes to protection against a wide variety of pathogens, including many viruses. The induction of a strong cellular response by the recombinant indicates that live adenovirus recombinants have potential as vaccines for those agents. These studies encourage and will inform the continued development of viable recombinant adenovirus vaccines.

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Heterogenous Cellular and Humoral Immune Trajectories after SARS-CoV-2 Infection: Compensatory Responses in a Population-Based Cohort

10.1101/2021.12.15.21267776 ◽

2021 ◽

Author(s):

Dominik Menges ◽

Kyra D Zens ◽

Tala Ballouz ◽

Nicole Caduff ◽

Daniel Llanas-Cornejo ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Disease Severity ◽

Cell Subset ◽

T Cell Responses ◽

Population Based ◽

Antibody Responses ◽

Igg Antibody ◽

Cell Responses ◽

Over Time

To better understand the development of immunity against SARS-CoV-2 over time, we evaluated humoral and cellular responses a population-based cohort of SARS-CoV-2-infected individuals covering the full spectrum of COVID-19 up to 217 days after diagnosis. We characterized anti-Spike (S)-IgA and -IgG antibody responses in 431 individuals and found that about 85% develop and maintain anti-S-IgG responses over time. In a subsample of 64 participants selected for a detailed characterization of immune responses, we additionally evaluated anti-Nucleocapsid (N)-IgG antibodies and T cell responses specific to viral Membrane (M), N, and S proteins. Most participants had detectable T cell responses to at least one of the four peptide pools analyzed, which were more frequent than antibody seropositivity. We found a moderate correlation between antibody and T cell responses, which declined over time and suggests important variability in response patterns between individuals. The heterogeneity of immune trajectories was further analyzed using cluster analyses taking into account joint antibody and T cell responses over time. We identified five distinct immune trajectory patterns, which were characterized by specific antibody, T cell and T cell subset patterns along with disease severity and demographic factors. Higher age, male sex, higher disease severity and being a non-smoker was significantly associated with stronger immune responses. Overall, the results highlight that there is a consistent and maintained antibody response among most SARS-CoV-2-infected individuals, while T cell responses appear to be more heterogenous but potentially compensatory among those with low antibody responses.

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