375 Expansion of HPV-16 specific T cells in patients with HPV-related cancers treated with bintrafusp alfa

BackgroundThe safety and efficacy of bintrafusp alfa, a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGF-βRII receptor (a TGF-β ‘trap’) fused to a human IgG1 mAb blocking PD-L1, have been demonstrated in patients with human papillomavirus (HPV)-related cancers in an open label, multicenter phase 1 trial (NCT02517398), and an open-label, single center phase 2 trial (NCT03427411). The current study aimed to investigate whether HPV-16-specific T cells are expanded with therapy and associate with the clinical response of patients in these trials. We also present pre-clinical evidence from a mouse model of HPV-associated cancer supporting the combination of bintrafusp alfa with an HPV-16 targeted therapeutic vaccine and an immunostimulatory cytokine.MethodsPeripheral blood mononuclear cells (PBMC) were obtained from 33 patients prior to and 2 weeks after 1 and/or 3 cycles of bintrafusp alfa and evaluated for HPV-16 specific CD4+ and CD8+ T cells. PBMCs were stimulated with 15-mer peptide pools of the HPV-16 E6 and E7 oncoproteins, and T cell responses were assessed for the production of cytokines (TNFa, IFNg, IL-2) and positivity for the degranulation marker CD107a. Multifunctional T cells, positive for >2 measures, were also enumerated. For pre-clinical studies, a syngeneic mouse model of TC-1 carcinoma was treated with bintrafusp alfa alone or in combination with a liposomal-based HPV-16 therapeutic vaccine (PDS 0101) and a tumor targeting immunocytokine (NHS-muIL12) and evaluated for anti-tumor activity and immune responses.ResultsHPV-16 specific T cells were increased after 1 cycle of bintrafusp alfa in a greater proportion of responders (9/14) than non-responders (4/17) (p=0.03). In addition, the magnitude of HPV-16 specific T cells was greater after 1 (p=0.04) and 3 (p<0.0001) cycles of bintrafusp alfa in responders than non-responders. Multifunctional HPV-16-specific T cells were also increased to a greater extent in responders than non-responders. Preclinical studies demonstrated that the combination of bintrafusp alfa with an HPV-16-targeted therapeutic vaccine along with an immunocytokine resulted in maximal anti-tumor activity and T cell responses.ConclusionsAn early increase in HPV-16 specific T cells (after a single administration of bintrafusp alfa, prior to restaging) was associated with clinical activity in patients with HPV-related cancers undergoing bintrafusp alfa therapy. This evidence, and the pre-clinical finding of enhanced antitumor activity observed when combining bintrafusp alfa with an HPV-16 targeted vaccine and an immunostimulatory cytokine have provided the rational for an ongoing study evaluating this combination in patients with advanced HPV-associated malignancies (NCT04287868).Ethics ApprovalAll patients provided written informed consent for participation in a clinical trial that was approved by the Institutional Review Board at the National Cancer Institute (NCT02517398, NCT03427411)

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MHC Class I Presented T Cell Epitopes as Potential Antigens for Therapeutic Vaccine against HBV Chronic Infection

Hepatitis Research and Treatment ◽

10.1155/2014/860562 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 8

Author(s):

Joseph D. Comber ◽

Aykan Karabudak ◽

Vivekananda Shetty ◽

James S. Testa ◽

Xiaofang Huang ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Chronic Infection ◽

Acute Infection ◽

Therapeutic Vaccine ◽

T Cell Responses ◽

Hbv Infection ◽

Mhc I ◽

Cell Responses ◽

Cell Immunity

Approximately 370 million people worldwide are chronically infected with hepatitis B virus (HBV). Despite the success of the prophylactic HBV vaccine, no therapeutic vaccine or other immunotherapy modality is available for treatment of chronically infected individuals. Clearance of HBV depends on robust, sustained CD8+ T activity; however, the limited numbers of therapeutic vaccines tested have not induced such a response. Most of these vaccines have relied on peptide prediction algorithms to identify MHC-I epitopes or characterization of T cell responses during acute infection. Here, we took an immunoproteomic approach to characterize MHC-I restricted epitopes from cells chronically infected with HBV and therefore more likely to represent the true targets of CD8+ T cells during chronic infection. In this study, we identified eight novel MHC-I restricted epitopes derived from a broad range of HBV proteins that were capable of activating CD8+ T cells. Furthermore, five of the eight epitopes were able to bind HLA-A2 and A24 alleles and activated HBV specific T cell responses. These epitopes also have potential as new tools to characterize T cell immunity in chronic HBV infection and may serve as candidate antigens for a therapeutic vaccine against HBV infection.

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HIV-1 Reservoir Dynamics after Vaccination and Antiretroviral Therapy Interruption Are Associated with Dendritic Cell Vaccine-Induced T Cell Responses

Journal of Virology ◽

10.1128/jvi.01062-15 ◽

2015 ◽

Vol 89 (18) ◽

pp. 9189-9199 ◽

Cited By ~ 26

Author(s):

Cristina Andrés ◽

Montserrat Plana ◽

Alberto C. Guardo ◽

Carmen Alvarez-Fernández ◽

Nuria Climent ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Dendritic Cell ◽

Immune Responses ◽

Cd4 T Cells ◽

Therapeutic Vaccine ◽

T Cell Responses ◽

Therapeutic Vaccines ◽

Cell Responses ◽

Hiv 1

ABSTRACTHIV-1-specific immune responses induced by a dendritic cell (DC)-based therapeutic vaccine might have some effect on the viral reservoir. Patients on combination antiretroviral therapy (cART) were randomized to receive DCs pulsed with autologous HIV-1 (n= 24) (DC-HIV-1) or nonpulsed DCs (n= 12) (DC-control). We measured the levels of total and integrated HIV-1 DNA in CD4 T cells isolated from these patients at 6 time points: before any cART; before the first cART interruption, which was at 56 weeks before the first immunization to isolate virus for pulsing DCs; before and after vaccinations (VAC1 and VAC2); and at weeks 12 and 48 after the second cART interruption. The vaccinations did not influence HIV-1 DNA levels in vaccinated subjects. After the cART interruption at week 12 postvaccination, while total HIV-1 DNA increased significantly in both arms, integrated HIV-1 DNA did not change in vaccinees (mean of 1.8 log10to 1.9 copies/106CD4 T cells,P= 0.22) and did increase in controls (mean of 1.8 log10to 2.1 copies/106CD4 T cells,P= 0.02) (P= 0.03 for the difference between groups). However, this lack of increase of integrated HIV-1 DNA observed in the DC-HIV-1 group was transient, and at week 48 after cART interruption, no differences were observed between the groups. The HIV-1-specific T cell responses at the VAC2 time point were inversely correlated with the total and integrated HIV-1 DNA levels after cART interruption in vaccinees (r[Pearson's correlation coefficient] = −0.69,P= 0.002, andr= −0.82,P< 0.0001, respectively). No correlations were found in controls. HIV-1-specific T cell immune responses elicited by DC therapeutic vaccines drive changes in HIV-1 DNA after vaccination and cART interruption. (This study has been registered at ClinicalTrials.gov under registration no. NCT00402142.)IMPORTANCEThere is an intense interest in developing strategies to target HIV-1 reservoirs as they create barriers to curing the disease. The development of therapeutic vaccines aimed at enhancing immune-mediated clearance of virus-producing cells is of high priority. Few therapeutic vaccine clinical trials have investigated the role of therapeutic vaccines as a strategy to safely eliminate or control viral reservoirs. We recently reported that a dendritic cell-based therapeutic vaccine was able to significantly decrease the viral set point in vaccinated patients, with a concomitant increase in HIV-1-specific T cell responses. The HIV-1-specific T cell immune responses elicited by this therapeutic dendritic cell vaccine drove changes in the viral reservoir after vaccinations and significantly delayed the replenishment of integrated HIV-1 DNA after cART interruption. These data help in understanding how an immunization could shift the virus-host balance and are instrumental for better design of strategies to reach a functional cure of HIV-1 infection.

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T cell depletion protects against alveolar destruction due to chronic cigarette smoke exposure in mice

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00152.2012 ◽

2013 ◽

Vol 304 (5) ◽

pp. L312-L323 ◽

Cited By ~ 25

Author(s):

Patricia L. Podolin ◽

Joseph P. Foley ◽

Donald C. Carpenter ◽

Brian J. Bolognese ◽

Gregory A. Logan ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Mouse Model ◽

Cigarette Smoke ◽

T Cell Responses ◽

Smoke Exposure ◽

Cigarette Smoke Exposure ◽

T Cell Depletion ◽

Cell Responses

The role of T cells in chronic obstructive pulmonary disease (COPD) is not well understood. We have previously demonstrated that chronic cigarette smoke exposure can lead to the accumulation of CD4+ and CD8+ T cells in the alveolar airspaces in a mouse model of COPD, implicating these cells in disease pathogenesis. However, whether specific inhibition of T cell responses represents a therapeutic strategy has not been fully investigated. In this study inhibition of T cell responses through specific depleting antibodies, or the T cell immunosuppressant drug cyclosporin A, prevented airspace enlargement and neutrophil infiltration in a mouse model of chronic cigarette smoke exposure. Furthermore, individual inhibition of either CD4+ T helper or CD8+ T cytotoxic cells prevented airspace enlargement to a similar degree, implicating both T cell subsets as critical mediators of the adaptive immune response induced by cigarette smoke exposure. Importantly, T cell depletion resulted in significantly decreased levels of the Th17-associated cytokine IL-17A, and of caspase 3 and caspase 7 gene expression and activity, induced by cigarette smoke exposure. Finally, inhibition of T cell responses in a therapeutic manner also inhibited cigarette smoke-induced airspace enlargement, IL-17A expression, and neutrophil influx in mice. Together these data demonstrate for the first time that therapeutic inhibition of T cell responses may be efficacious in the treatment of COPD. Given that broad immunosuppression may be undesirable in COPD patients, this study provides proof-of-concept for more targeted approaches to inhibiting the role of T cells in emphysema development.

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A phase I study to evaluate safety, immunogenicity and anti-tumor activity of the multi-peptide vaccine IMA901 in renal cell carcinoma patients (RCC)

Journal of Clinical Oncology ◽

10.1200/jco.2007.25.18_suppl.5098 ◽

2007 ◽

Vol 25 (18_suppl) ◽

pp. 5098-5098 ◽

Cited By ~ 1

Author(s):

M. Staehler ◽

A. Stenzl ◽

P. Y. Dietrich ◽

T. Eisen ◽

A. Haferkamp ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Adverse Events ◽

Clinical Benefit ◽

T Cell Responses ◽

Pharmacokinetic Data ◽

Multi Centre Study ◽

Gm Csf ◽

Cell Responses ◽

Anti Tumor Activity

5098 Background: IMA901 is a therapeutic cancer vaccine based on multiple synthetic tumor-associated peptides confirmed to be naturally presented by analysis of primary RCC tissues. IMA901 consists of 9 HLA-class I-binding and 1 HLA class II-binding peptides with the capacity to activate cytotoxic T cells (CD8+ T cells) and T helper cells (CD4+ T cells). Methods: 30 patients with stage III/IV RCC were enrolled in a single arm, multi-centre study. The endpoints were safety, T-cell responses, pharmacokinetics of the intradermal application of GM-CSF and anti-tumor activity according to RECIST. Patients had to be HLA-A*02 positive and received 8 intradermal vaccinations on days 1, 2, 3, 8, 15, 22, 36 and 64 each consisting of 4.5 mg IMA901 and 75 μg GM-CSF. Results: The most prevalent adverse events (AEs) were fatigue, cough and headache. Aseptical lymphadenitis and injection site reactions such as erythema, edema and pruritus were the most frequent possibly drug-related AEs. All possibly drug-related adverse events were mild to moderate. No patient experienced any possibly drug-related serious adverse events or deaths during the study. Pharmacokinetic data provided no evidence for accumulation of GM-CSF upon repeated i.d. administration. 74% of patients showed a vaccine-induced specific T-cell response and 30% of patients responded to multiple peptides contained in IMA901. The overall tumor assessment in patients with measurable disease revealed that 8 patients (35%) demonstrated a clinical benefit (1 PR + 7 SD). Most encouraging, patients who elicited multiple T-cell responses showed a statistically significant higher clinical benefit rate. Conclusions: IMA901 is safe, very well tolerated and immunogenic. Clinically observed tumor growth control in RCC patients may imply anti-tumor activity strongly supported by two patients with tumor regression (1 PR and 1 patient with 27% shrinkage in target lesions). The mode of action is strongly supported by the finding that multiple T-cell responders were significantly more likely to have a clinical benefit. These data clearly support the further development of IMA901. No significant financial relationships to disclose.

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589. Oral Tablet Vaccination Induces Heightened Cross-Reactive CD8 T Cell Responses to SARS-COV-2 in Humans

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.787 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S397-S397

Author(s):

Susan Johnson ◽

Clarissa Martinez ◽

Mario Cortese ◽

Josefina Martinez ◽

Shaily Garg ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Phase 1 ◽

T Cell Responses ◽

Cd8 T Cell ◽

T Cell Response ◽

Vaccine Platform ◽

Open Label ◽

Oral Tablet ◽

Cell Responses

Abstract Background Covid-19 has accelerated global demand for easily distributed vaccines. Furthermore, as variant SARS-CoV-2 strains that circumvent antibody responses emerge, cross-protective vaccines provide substantial public health benefits. Vaxart is developing a shelf stable oral tablet vaccine that incorporates both the spike (S) and the more conserved nucleocapsid (N) proteins. Vaxart’s vaccine platform uses a non-replicating adenovirus and a TLR3 agonist as an adjuvant. Methods In an open-label phase 1 clinical study, 35 healthy subjects received either a single low (1x1010 IU; n=15) or high (5x1010 IU; n=15) dose of the vaccine candidate VXA-CoV2-1 with a small cohort receiving 2 low doses. PBMCs were taken at pre- and 7 days post-vaccination and restimulated with S and N peptides from SARS-CoV-2 or the 4 human endemic coronaviruses (HCoV). Cells were stained for CD4/CD8/CD107a (surface) and IFNγ/TNFα (intracellular). Subjects that received an intramuscular (i.m.) mRNA vaccine had PBMCs taken at the same timepoints and were compared in the same assay. Results The study’s results indicate that the VXA-CoV2-1 tablet was well tolerated. The majority of subjects had an increase in S-specific anti-viral CD8+ T cell responses. 19/26 (73%) subjects had a measurable CD8+ T cell response on day 8 above baseline, on average 1.5-4.6%. In a comparator experiment with the 2 SARS-CoV-2 i.m. mRNA vaccines, VXA-CoV2-1 outperformed other vaccine candidates with a >3.5-fold increase in S specific antiviral CD8 T cell responses. T cell responses specific to the 4 endemic HCoV were increased by 0.6% in subjects given VXA-CoV2-1. Conclusion Here we describe a room temperature stable tablet that induces SARS-CoV-2 S specific CD8 T cells of high magnitude after one dose in humans. Overall, the level of antiviral SARS-CoV-2 specific T cells, particularly IFNg-producing CD8s, induced following oral immunization with VXA-CoV2-1 are of higher magnitude than the mRNA vaccines currently in use against COVID-19. T cell responses against 4 endemic HCoV were also induced. Because T cells may be important in protecting against death and severe infection, these results suggest that VXA-CoV2-1 could be cross-protective against a wide array of emerging pandemic coronaviruses. Disclosures Susan Johnson, PhD, Vaxart (Employee) Clarissa Martinez, MPH, Vaxart (Employee) Mario Cortese, PhD, Vaxart (Employee) Josefina Martinez, n/a, Vaxart (Employee) Shaily Garg, BS, Vaxart (Employee) Nadine Peinovich, MPH, Vaxart (Employee) Emery Dora, n/a, Vaxart (Employee) Sean Tucker, PhD, Vaxart (Employee)

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Protection from viral rebound after therapeutic vaccination with an adjuvanted DNA vaccine is associated with SIV-specific polyfunctional CD8 T cells in the blood and mesenteric lymph nodes

10.1101/2020.09.16.299511 ◽

2020 ◽

Author(s):

Hillary C. Tunggal ◽

Paul V. Munson ◽

Megan A. O’Connor ◽

Nika Hajari ◽

Sandra E. Dross ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Lymph Nodes ◽

Dna Vaccine ◽

Therapeutic Vaccine ◽

T Cell Responses ◽

T Cell Immunity ◽

Viral Rebound ◽

Cell Responses ◽

Cell Immunity

AbstractA therapeutic vaccine that induces lasting control of HIV infection has the potential to eliminate the need for lifelong adherence to antiretroviral therapy (ART). This study investigated the efficacy of a therapeutic DNA vaccine delivered with a novel combination of adjuvants and immunomodulators to augment T cell immunity in the blood and gut-associated lymphoid tissue. In SIV-infected rhesus macaques, a DNA vaccine delivered by intradermal electroporation and expressing SIV Env, Gag, and Pol, and a combination of adjuvant plasmids expressing the catalytic A1 subunit of E. coli heat labile enterotoxin (LTA1), IL-12, IL-33, retinaldehyde dehydrogenase 2 and the immunomodulators soluble PD-1 and soluble CD80, significantly enhanced the breadth and magnitude of Gag-specific IFN-γ T cell responses when compared to controls that were mock vaccinated or received the same DNA vaccine delivered by Gene Gun with a single adjuvant, the E. coli heat labile enterotoxin, LT. Notably, the DNA vaccine and adjuvant combination protected 3/5 animals from viral rebound, compared to only 1/4 mock vaccinated animals and 1/5 animals that received the DNA vaccine and LT. The lower viral burden among controllers during analytical treatment interruption significantly correlated with higher polyfunctional CD8+ T-cells (CD8+ T cells expressing 3 or more effector functions) in both mesenteric lymph nodes and blood measured during ART and analytical treatment interruption. Interestingly, controllers also had lower viral loads during acute infection and ART suggesting that inherent host-viral interactions induced prior to ART initiation likely influenced the response to therapeutic vaccination. These data indicate that gut mucosal immune responses combined with effective ART may play a key role in containing residual virus post-ART and highlight the need for therapeutic vaccines and adjuvants that can restore functional quality of peripheral and mucosal T cell responses before and during ART.Author SummaryHIV has caused significant human disease and mortality since its emergence in the 1980s. Furthermore, although antiretroviral therapy (ART) effectively reduces viral replication, stopping ART leads to increased viral loads and disease progression in most HIV-infected people. A therapeutic vaccine could enable HIV-infected people to control their infection without ART, but none of the vaccines that were tested in clinical trials so far have induced long-lasting control of virus replication. Here, we used the SIV rhesus macaque model to test a therapeutic vaccine consisting of DNA expressing SIV proteins and a novel combination of adjuvants to boost virus-specific immune responses. We found that our vaccine strategy significantly enhanced SIV-specific T cell responses when compared to controls and protected 3/5 animals from viral rebound. We determined that lower levels of virus replication post-ART were associated with enhanced T cell immunity in the gut-draining lymph nodes and blood. Our study highlights the critical role of T cell immunity for control of SIV and HIV replication and demonstrates that a successful therapeutic vaccine for HIV will need to elicit potent T cell responses in both the blood and gut-associated tissues.

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CD4 T cells mediate brain inflammation and neurodegeneration in a mouse model of Parkinson disease

Brain ◽

10.1093/brain/awab103 ◽

2021 ◽

Author(s):

Gregory P Williams ◽

Aubrey M Schonhoff ◽

Asta Jurkuvenaite ◽

Nicole J Gallups ◽

David G Standaert ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Mouse Model ◽

Parkinson Disease ◽

Cd8 T Cells ◽

T Cell Responses ◽

T Cell Response ◽

Brain Inflammation ◽

Cell Responses ◽

Deficient Mice

Abstract α-synuclein (α-syn), a key pathological component of Parkinson disease (PD), has been implicated in the activation of the innate and adaptive immune system. This immune activation includes microgliosis, increased inflammatory cytokines, and the infiltration of T cells into the central nervous system (CNS). More recently, peripherally circulating CD4 and CD8 T cells derived from individuals with PD have been shown to produce Th1/Th2 cytokines in response to α-syn, suggesting there may be a chronic memory T cell response present in PD. To better understand the potential effects of these α-syn associated T cell responses we utilized an α-syn overexpression mouse model, T cell deficient mice, and a combination of immunohistochemistry and flow cytometry. In this study, we found that α-syn overexpression in the midbrain of mice leads to the upregulation of the major histocompatibility complex II (MHCII) protein on CNS myeloid cells as well as the infiltration of IFNγ producing CD4 and CD8 T cells into the CNS. Interestingly, genetic deletion of TCRβ or CD4, as well as the use of the immunosuppressive drug fingolimod, were able to reduce the CNS myeloid MHCII response to α-syn. Furthermore, we observed that CD4 deficient mice were protected from the dopaminergic cell loss observed due to α-syn overexpression. These results suggest that T cell responses associated with α-syn pathology may be damaging to key areas of the CNS in PD and that targeting these T cell responses could be an avenue for disease modifying treatments.

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Single Prime hAd5 Spike (S) + Nucleocapsid (N) Dual Antigen Vaccination of Healthy Volunteers Induces a Ten-Fold Increase in Mean S- and N- T-Cell Responses Equivalent to T-Cell Responses from Patients Previously Infected with SARS-CoV-2

10.1101/2021.04.05.21254940 ◽

2021 ◽

Author(s):

Peter Sieling ◽

Thomas King ◽

Raymond Wong ◽

Andy Nguyen ◽

Kamil Wnuk ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Epitope ◽

T Cell Responses ◽

Fold Increase ◽

Cell Surface Expression ◽

Immune Protection ◽

Open Label ◽

Cell Responses ◽

Vaccine Antigens

ABSTRACTIn response to the need for a safe, efficacious vaccine that provides broad immune protection against SARS-CoV-2 infection, we have developed a dual-antigen COVID-19 vaccine. The vaccine delivers both the viral spike (S) protein modified to increase cell-surface expression (S-Fusion) and the viral nucleocapsid (N) protein with an Enhanced T-cell Stimulation Domain (N-ETSD) to enhance MHC class I and II presentation and T-cell responses. The vaccine antigens are delivered using a human adenovirus serotype 5 (hAd5) platform with E1, E2b, and E3 regions deleted that has been shown in previous cancer vaccine studies to be effective in the presence of pre-existing hAd5 immunity. Here, we demonstrate the hAd5 S-Fusion + N-ETSD (hAd5 S + N) vaccine antigens when expressed by dendritic cells (DCs) of previously SARS-CoV-2-infected patients elicit Th1 dominant activation of autologous patient T cells, indicating the vaccine antigens have the potential for generating immune responses in patients previously infected or vaccinated. We further demonstrate that participants in our open-label Phase 1b study of the dual-antigen hAd5 S + N vaccine generate Th1 dominant S- and N-specific T cells after a single prime subcutaneous injection and that the magnitude of these responses were comparable to those seen for T cells from previously infected patients. We further present our in silico prediction of T-cell epitope HLA binding for both the first-wave SARS-CoV-2 ‘A’ strain and the K417N, E484K, and N501Y S as well as the T201I N variants that suggests T-cell responses to the hAd5 S + N vaccine will retain efficacy against these variants. These findings that the dual-antigen hAd5 S + N vaccine elicits SARS-CoV-2-relevant T-cell responses and that such cell-mediated protection is likely to be sustained against emerging variants supports the testing of this vaccine as a universal booster that would enhance and broaden existing immune protection conferred by currently approved S-based vaccines.

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