scholarly journals Induction of Specific T-Cell Responses, Opsonizing Antibodies, and Protection against Plasmodium chabaudi adami Infection in Mice Vaccinated with Genomic Expression Libraries Expressed in Targeted and Secretory DNA Vectors

2003 ◽  
Vol 71 (8) ◽  
pp. 4506-4515 ◽  
Author(s):  
A. Rainczuk ◽  
T. Scorza ◽  
P. M. Smooker ◽  
T. W. Spithill
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Genomic Library ◽  
Protective Efficacy ◽  
T Cell Responses ◽  
Interleukin 4 ◽  
Plasmodium Chabaudi ◽  
Lethal Challenge ◽  
Cell Responses ◽  
Expression Libraries

ABSTRACT It has been proposed that a multivalent malaria vaccine is necessary to mimic the naturally acquired resistance to this disease observed in humans. A major experimental challenge is to identify the optimal components to be used in such a multivalent vaccine. Expression library immunization (ELI) is a method for screening genomes of a pathogen to identify novel combinations of vaccine sequences. Here we describe immune responses associated with, and the protective efficacy of, genomic Plasmodium chabaudi adami DS expression libraries constructed in VR1020 (secretory), monocyte chemotactic protein-3 (chemoattractant), and cytotoxic T lymphocyte antigen 4 (lymph node-targeting) DNA vaccine vectors. With splenocytes from vaccinated mice, specific T-cell responses, as well as gamma interferon and interleukin-4 production, were observed after stimulation with P. chabaudi adami-infected erythrocytes, demonstrating the specificity of genomic library vaccination for two of the three libraries constructed. Sera obtained from mice vaccinated with genomic libraries promoted the opsonization of P. chabaudi adami-infected erythrocytes by murine macrophages in vitro, further demonstrating the induction of malaria-specific immune responses following ELI. Over three vaccine trials using biolistic delivery of the three libraries, protection after lethal challenge with P. chabaudi adami DS ranged from 33 to 50%. These results show that protective epitopes or antigens are expressed within the libraries and that ELI induces responses specific to P. chabaudi adami malaria. This study further demonstrates that ELI is a suitable approach for screening the malaria genome to identify the components of multivalent vaccines.

scholarly journals Regulation of DNA-Raised Immune Responses by Cotransfected Interferon Regulatory Factors

2002 ◽  
Vol 76 (13) ◽  
pp. 6652-6659 ◽  
Author(s):  
Shin Sasaki ◽  
Rama Rao Amara ◽  
Wen-Shuz Yeow ◽  
Paula M. Pitha ◽  
Harriet L. Robinson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Interleukin 4 ◽  
Good Activity ◽  
Gene Gun ◽  
Cell Responses

ABSTRACT Interferon regulatory factor 1 (IRF-1), IRF-3, and IRF-7 have been tested as genetic adjuvants for influenza virus hemagglutinin (HA) and nucleoprotein vaccine DNAs. Cotransfection of HA with IRF-3 and IRF-7 increased CD4 T-cell responses by 2- to 4-fold and CD8 T-cell responses by more than 10-fold. Following intramuscular deliveries of DNA, both CD4 and CD8 T cells were biased towards type 1 immune responses and the production of gamma interferon. Following gene gun bombardments of DNA, both were biased towards type 2 immune responses and the production of interleukin-4. The biases of the T-cell responses towards type 1 or type 2 were stronger for immunizations with IRF-3 as an adjuvant than for immunizations with IRF-7 as an adjuvant. Moderate adjuvant effects for antibody were observed. The isotypes of the antibody responses reflected the method of DNA delivery; intramuscular deliveries of DNA predominantly raised immunoglobulin G2a (IgG2a), whereas gene gun deliveries of DNA predominantly raised IgG1. These biases were enhanced by the codelivered IRFs. Overall, under the conditions of our experiments, IRF-3 had good activity for T cells, IRF-7 had good activity for both antibody and T cells, and IRF-1 had good activity for antibody.

scholarly journals 413 GEN-009, a personalized neoantigen vaccine, elicits robust immune responses in individuals with advanced or metastatic solid tumors

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A438-A438
Author(s):  
Mara Shainheit ◽  
Devin Champagne ◽  
Gabriella Santone ◽  
Syukri Shukor ◽  
Ece Bicak ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Solid Tumors ◽  
Ex Vivo ◽  
T Cell Responses ◽  
Checkpoint Blockade ◽  
T Cell Subsets ◽  
Cell Responses

BackgroundATLASTM is a cell-based bioassay that utilizes a cancer patient‘s own monocyte-derived dendritic cells and CD4+ and CD8+ T cells to screen their mutanome and identify neoantigens that elicit robust anti-tumor T cell responses, as well as, deleterious InhibigensTM.1 GEN-009, a personalized vaccine comprised of 4–20 ATLAS-identified neoantigens combined with Hiltonol®, harnesses the power of neoantigen-specific T cells to treat individuals with solid tumors. The safety and efficacy of GEN-009 is being assessed in a phase 1/2a clinical trial (NCT03633110).MethodsA cohort of 15 adults with solid tumors were enrolled in the study. During the screening period, patients received standard of care PD-1-based immunotherapies appropriate for their tumor type. Subsequently, patients were immunized with GEN-009 with additional doses administered at 3, 6, 12, and 24 weeks. Peripheral blood mononuclear cells (PBMCs) were collected at baseline, pre-vaccination (D1), as well as 29, 50, 92, and 176 days post first dose. Vaccine-induced immunogenicity and persistence were assessed by quantifying neoantigen-specific T cell responses in ex vivo and in vitro stimulation dual-analyte fluorospot assays. Polyfunctionality of neoantigen-specific T cells was evaluated by intracellular cytokine staining. Additionally, potential correlations between the ATLAS-identified profile and vaccine-induced immunogenicity were assessed.ResultsGEN-009 augmented T cell responses in 100% of evaluated patients, attributable to vaccine and not checkpoint blockade. Furthermore, neoantigen-induced secretion of IFNγ and/or TNFα by PBMCs, CD4+, and CD8+ T cells was observed in all patients. Responses were primarily from polyfunctional TEM cells and detectable in both CD4+ and CD8+ T cell subsets. Some patients had evidence of epitope spreading. Unique response patterns were observed for each patient with no apparent relationship between tumor types and time to emergence, magnitude or persistence of response. Ex vivo vaccine-induced immune responses were observed as early as 1 month, and in some cases, persisted for 176 days. Clinical efficacy possibly attributable to GEN-009 was observed in several patients, but no correlation has yet been identified with neoantigen number or magnitude of immune response.ConclusionsATLAS empirically identifies stimulatory neoantigens using the patient‘s own immune cells. GEN-009, which is comprised of personalized, ATLAS-identified neoantigens, elicits early, long-lasting and polyfunctional neoantigen-specific CD4+ and CD8+ T cell responses in individuals with advanced cancer. Several patients achieved clinical responses that were possibly attributable to vaccine; efforts are underway to explore T cell correlates of protection. These data support that GEN-009, in combination with checkpoint blockade, represents a unique approach to treat solid tumors.AcknowledgementsWe are grateful to the patients and their families who consented to participate in the GEN-009-101 clinical trial.Trial RegistrationNCT03633110Ethics ApprovalThis study was approved by Western Institutional Review Board, approval number 1-1078861-1. All subjects contributing samples provided signed individual informed consent.ReferenceDeVault V, Starobinets H, Adhikari S, Singh S, Rinaldi S, Classon B, Flechtner J, Lam H. Inhibigens, personal neoantigens that drive suppressive T cell responses, abrogate protection of therapeutic anti-tumor vaccines. J. Immunol 2020; 204(1 Supplement):91.15.

scholarly journals Neutrophil subtypes shape HIV-specific CD8 T-cell responses after vaccinia virus infection

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mauro Di Pilato ◽  
Miguel Palomino-Segura ◽  
Ernesto Mejías-Pérez ◽  
Carmen E. Gómez ◽  
Andrea Rubio-Ponce ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Adaptive Immune System ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Adaptive Immune

AbstractNeutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.

scholarly journals Innate cell microenvironments in lymph nodes shape the generation of T cell responses during type I inflammation

2021 ◽  
Vol 6 (56) ◽  
pp. eabb9435
Author(s):  
Joseph M. Leal ◽  
Jessica Y. Huang ◽  
Karan Kohli ◽  
Caleb Stoltzfus ◽  
Miranda R. Lyons-Cohen ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Critical Role ◽  
Myeloid Cell ◽  
T Cell Responses ◽  
Type I ◽  
Cell Responses ◽  
Inflammatory Monocytes ◽  
Cell Effector

Microanatomical organization of innate immune cells within lymph nodes (LNs) is critical for the generation of adaptive responses. In particular, steady-state LN-resident dendritic cells (Res cDCs) are strategically localized to intercept lymph-draining antigens. Whether myeloid cell organization changes during inflammation and how that might affect the generation of immune responses are unknown. Here, we report that during type I, but not type II, inflammation after adjuvant immunization or viral infection, antigen-presenting Res cDCs undergo CCR7-dependent intranodal repositioning from the LN periphery into the T cell zone (TZ) to elicit T cell priming. Concurrently, inflammatory monocytes infiltrate the LNs via local blood vessels, enter the TZ, and cooperate with Res cDCs by providing polarizing cytokines to optimize T cell effector differentiation. Monocyte infiltration is nonuniform across LNs, generating distinct microenvironments with varied local innate cell composition. These spatial microdomains are associated with divergent early T cell effector programming, indicating that innate microenvironments within LNs play a critical role in regulating the quality and heterogeneity of T cell responses. Together, our findings reveal that dynamic modulation of innate cell microenvironments during type I inflammation leads to optimized generation of adaptive immune responses to vaccines and infections.

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

2017 ◽  
Vol 214 (9) ◽  
pp. 2563-2572 ◽  
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.

scholarly journals Optimized Adenovirus-Antibody Complexes Stimulate Strong Cellular and Humoral Immune Responses against an Encoded Antigen in Naïve Mice and Those with Preexisting Immunity

2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
T Cell Responses ◽  
Transduction Efficiency ◽  
Virus Antibody ◽  
Cell Responses

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.

scholarly journals Immunogenicity of mRNA-1273, BNT162b2 and Ad26.COV2.S COVID-19 vaccines

2021 ◽  
Author(s):  
Vivek Naranbhai ◽  
Wilfredo F Garcia-Beltran ◽  
Christhian Berrios Mairena ◽  
Julia Cara Thierauf ◽  
Christina Catherine Chang ◽  
...  
Keyword(s):  
Single Dose ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Control Groups ◽  
Neutralization Titer ◽  
Cell Responses ◽  
Effectiveness Studies ◽  
Prior Infection ◽  
Repeat Sampling

Background: Understanding variation in immunogenicity may help rationalize use of existing SARS-CoV-2 vaccines. Methods: We compared immune responses in ambulatory adults vaccinated with mRNA-1273 , BNT-162b2 or Ad26.COV2.S in Massachusetts, USA between February and May 2021. Control groups were pre-pandemic controls (n=1220) and individuals without (n=112) or with prior SARS-CoV-2 infection (n=130) sampled in mid-2020. We measured total anti-spike IgG/M/A antibodies (Roche Elecsys Anti-SARS-COV-2 S assay), anti-receptor-binding-domain (RBD) antibodies; neutralization of SARS-CoV-2 pseudovirus; and T-cell responses. Findings In individuals with prior infection, all vaccines were associated with higher antibody concentrations and neutralization than those in convalescent individuals, even after a single dose. In individuals without prior infection, a single dose of either mRNA vaccine yielded comparable concentrations and neutralization to convalescent unvaccinated individuals, and Ad26.COV2.S yielded lower antibody concentrations and neutralization titers. The second dose of either mRNA vaccine boosted responses. At a median of 24 days after vaccination, two of 21 (9.5%) Ad26.COV2.S recipients had a neutralization titer higher than pre-pandemic controls; repeat sampling at a median 66 days after vaccination found most (11/15 (73%) remained negative. Antibody concentrations and neutralization titers increased similarly after the first dose of either vaccine, and even further in recipients of a second dose of vaccine. T-cell responses were higher in mRNA1273 and BNT162b2 than Ad26.COV2.S recipients. Interpretation SARS-CoV-2 vaccines vary significantly in immunogenicity in individuals without prior infection. If confirmed in effectiveness studies, public health policy may need to be tailored to each vaccine, or even individual responses.

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

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.

scholarly journals Negligible impact of SARS-CoV-2 variants on CD4+ and CD8+ T cell reactivity in COVID-19 exposed donors and vaccinees.

2021 ◽  
Author(s):  
Alison Tarke ◽  
John Sidney ◽  
Nils Methot ◽  
Yun Zhang ◽  
Jennifer M Dan ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Comprehensive Analysis ◽  
T Cell Epitopes ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Adaptive Immune ◽  
T Cell Reactivity

The emergence of SARS-CoV-2 variants highlighted the need to better understand adaptive immune responses to this virus. It is important to address whether also CD4+ and CD8+ T cell responses are affected, because of the role they play in disease resolution and modulation of COVID-19 disease severity. Here we performed a comprehensive analysis of SARS-CoV-2-specific CD4+ and CD8+ T cell responses from COVID-19 convalescent subjects recognizing the ancestral strain, compared to variant lineages B.1.1.7, B.1.351, P.1, and CAL.20C as well as recipients of the Moderna (mRNA-1273) or Pfizer/BioNTech (BNT162b2) COVID-19 vaccines. Similarly, we demonstrate that the sequences of the vast majority of SARS-CoV-2 T cell epitopes are not affected by the mutations found in the variants analyzed. Overall, the results demonstrate that CD4+ and CD8+ T cell responses in convalescent COVID-19 subjects or COVID-19 mRNA vaccinees are not substantially affected by mutations found in the SARS-CoV-2 variants.

Long term results from a phase 1 trial of GEN-009, a personalized neoantigen vaccine, combined with PD-1 inhibition in advanced solid tumors.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2613-2613
Author(s):  
Maura L. Gillison ◽  
Mark M. Awad ◽  
Przemyslaw Twardowski ◽  
Ammar Sukari ◽  
Melissa Lynne Johnson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Solid Tumors ◽  
Salvage Therapy ◽  
Ex Vivo ◽  
T Cell Responses ◽  
Long Term Results ◽  
Advanced Solid Tumors ◽  
Cell Responses

2613 Background: GEN-009 is an adjuvanted personalized cancer vaccine containing up to 20 neoantigens selected by ATLAS, an ex vivo bioassay screening autologous T cells for immune responses against both neoantigens as well as Inhibigens. Inhibigen-specific T cells suppress immunity and have been shown to accelerate tumor progression in mice and are avoided in GEN-009. In cohort A, all patients immunized in the adjuvant setting with GEN-009 monotherapy developed immune responses. Nearly all (99%) of selected peptides were immunogenic: ex vivo CD4+ and CD8+ fluorospot responses specific for 51% and 41% of immunized peptides, respectively. Seven of 8 patients continue without progression with a median follow up of 18 months. Methods: GEN-009 is being evaluated in patients (pts) with advanced cancer who received standard-of-care (SOC) PD-1 inhibitor as monotherapy or in combination therapy during vaccine manufacturing. Five vaccine doses were administered over 24 weeks in combination with a PD-1 CPI. Patients who progressed prior to vaccination received alternative salvage therapy followed by GEN-009 in combination. Peripheral T cell responses were measured by fluorospot assays in ex vivo and in vitro stimulation. Results: 15 pts received GEN-009 in combination with a PD-1 inhibitor; 1 patient received GEN-009 monotherapy. Median number of neoantigens per vaccine was 14 (5-18). GEN-009-related adverse events were limited to vaccine injection site reactions and mild myalgias or fatigue. Longitudinal evaluation of ex vivo T cell responses revealed that sequential vaccination with GEN-009 had an overall additive effect on the robustness of IFNγ secretion and responses were persistent for at least 6 months in some patients. Epitope spread was detected in CPI sensitive patients, but not in CPI refractory patients receiving salvage therapy. Three patients who responded to PD-1 inhibition followed by disease stabilization then demonstrated further reduction after GEN-009 vaccination that could represent vaccine effect. Eight of 9 CPI responsive patients are progression-free from 3 to 10 months after first vaccine dose. Four of 7 CPI refractory patients have experienced unexpected prolonged stable disease after vaccination of up to 8 months after vaccination. 2 of 2 patients with available samples lost all evidence of circulating tumor DNA including non-targeted neoantigens. Conclusions: Vaccination with GEN-009 in combination with anti-PD-1 CPI in patients with advanced solid tumors shows little additive toxicity. Preliminary data demonstrate induction of broad neoantigen-specific immune responses and epitope spreading in the presence of PD-1 CPI. Broad immunity against tumor specific targets and encouraging patient outcomes support further study. Clinical trial information: NCT03633110.

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