Immune activation alters cellular and humoral responses to yellow fever 17D vaccine

• Text
• PDF

Abstract

Background. Defining the parameters that modulate vaccine responses in African populations will be imperative to design effective vaccines for protection against HIV, malaria, tuberculosis, and dengue virus infections. This study aimed to evaluate the contribution of the patient-specific immune microenvironment to the response to the licensed yellow fever vaccine 17D (YF-17D) in an African cohort.

Methods. We compared responses to YF-17D in 50 volunteers in Entebbe, Uganda, and 50 volunteers in Lausanne, Switzerland. We measured the CD8⁺ T cell and B cell responses induced by YF-17D and correlated them with immune parameters analyzed by flow cytometry prior to vaccination.

Results. We showed that YF-17D–induced CD8⁺ T cell and B cell responses were substantially lower in immunized individuals from Entebbe compared with immunized individuals from Lausanne. The impaired vaccine response in the Entebbe cohort associated with reduced YF-17D replication. Prior to vaccination, we observed higher frequencies of exhausted and activated NK cells, differentiated T and B cell subsets and proinflammatory monocytes, suggesting an activated immune microenvironment in the Entebbe volunteers. Interestingly, activation of CD8⁺ T cells and B cells as well as proinflammatory monocytes at baseline negatively correlated with YF-17D–neutralizing antibody titers after vaccination. Additionally, memory T and B cell responses in preimmunized volunteers exhibited reduced persistence in the Entebbe cohort but were boosted by a second vaccination.

Conclusion. Together, these results demonstrate that an activated immune microenvironment prior to vaccination impedes efficacy of the YF-17D vaccine in an African cohort and suggest that vaccine regimens may need to be boosted in African populations to achieve efficient immunity.

Trial registration. Registration is not required for observational studies.

Funding. This study was funded by Canada’s Global Health Research Initiative, Defense Threat Reduction Agency, National Institute of Allergy and Infectious Diseases, Bill & Melinda Gates Foundation, and United States Agency for International Development.

Authors

Enoch Muyanja, Aloysius Ssemaganda, Pearline NGauv, Rafael Cubas, Helene Perrin, Divya Srinivasan, Glenda Canderan, Benton Lawson, Jakub Kopycinski, Amanda S. Graham, Dawne K. Rowe, Michaela J. Smith, Sharon Isern, Scott Michael, Guido Silvestri, Thomas H. Vanderford, Erika Castro, Giuseppe Pantaleo, Joel Singer, Jill Gillmour, Noah Kiwanuka, Annet Nanvubya, Claudia Schmidt, Josephine Birungi, Josephine Cox, Elias K. Haddad, Pontiano Kaleebu, Patricia Fast, Rafick-Pierre Sekaly, Lydie Trautmann

Sympathetic activity–associated periodic repolarization dynamics predict mortality following myocardial infarction

• Text
• PDF

Abstract

Background. Enhanced sympathetic activity at the ventricular myocardium can destabilize repolarization, increasing the risk of death. Sympathetic activity is known to cluster in low-frequency bursts; therefore, we hypothesized that sympathetic activity induces periodic low-frequency changes of repolarization. We developed a technique to assess the sympathetic effect on repolarization and identified periodic components in the low-frequency spectral range (≤0.1 Hz), which we termed periodic repolarization dynamics (PRD).

Methods. We investigated the physiological properties of PRD in multiple experimental studies, including a swine model of steady-state ventilation (n = 7) and human studies involving fixed atrial pacing (n = 10), passive head-up tilt testing (n = 11), low-intensity exercise testing (n = 11), and beta blockade (n = 10). We tested the prognostic power of PRD in 908 survivors of acute myocardial infarction (MI). Finally, we tested the predictive values of PRD and T-wave alternans (TWA) in 2,965 patients undergoing clinically indicated exercise testing.

Results. PRD was not related to underlying respiratory activity (P < 0.001) or heart-rate variability (P = 0.002). Furthermore, PRD was enhanced by activation of the sympathetic nervous system, and pharmacological blockade of sympathetic nervous system activity suppressed PRD (P ≤ 0.005 for both). Increased PRD was the strongest single risk predictor of 5-year total mortality (hazard ratio 4.75, 95% CI 2.94–7.66; P < 0.001) after acute MI. In patients undergoing exercise testing, the predictive value of PRD was strong and complementary to that of TWA.

Conclusion. We have described and identified low-frequency rhythmic modulations of repolarization that are associated with sympathetic activity. Increased PRD can be used as a predictor of mortality in survivors of acute MI and patients undergoing exercise testing.

Trial registration. ClinicalTrials.gov NCT00196274.

Funding. This study was funded by Angewandte Klinische Forschung, University of Tübingen (252-1-0).

Authors

Konstantinos D. Rizas, Tuomo Nieminen, Petra Barthel, Christine S. Zürn, Mika Kähönen, Jari Viik, Terho Lehtimäki, Kjell Nikus, Christian Eick, Tim O. Greiner, Hans P. Wendel, Peter Seizer, Jürgen Schreieck, Meinrad Gawaz, Georg Schmidt, Axel Bauer

Transport properties of pancreatic cancer describe gemcitabine delivery and response

• Text
• PDF

Abstract

Background. The therapeutic resistance of pancreatic ductal adenocarcinoma (PDAC) is partly ascribed to ineffective delivery of chemotherapy to cancer cells. We hypothesized that physical properties at vascular, extracellular, and cellular scales influence delivery of and response to gemcitabine-based therapy.

Methods. We developed a method to measure mass transport properties during routine contrast-enhanced CT scans of individual human PDAC tumors. Additionally, we evaluated gemcitabine infusion during PDAC resection in 12 patients, measuring gemcitabine incorporation into tumor DNA and correlating its uptake with human equilibrative nucleoside transporter (hENT1) levels, stromal reaction, and CT-derived mass transport properties. We also studied associations between CT-derived transport properties and clinical outcomes in patients who received preoperative gemcitabine-based chemoradiotherapy for resectable PDAC.

Results. Transport modeling of 176 CT scans illustrated striking differences in transport properties between normal pancreas and tumor, with a wide array of enhancement profiles. Reflecting the interpatient differences in contrast enhancement, resected tumors exhibited dramatic differences in gemcitabine DNA incorporation, despite similar intravascular pharmacokinetics. Gemcitabine incorporation into tumor DNA was inversely related to CT-derived transport parameters and PDAC stromal score, after accounting for hENT1 levels. Moreover, stromal score directly correlated with CT-derived parameters. Among 110 patients who received preoperative gemcitabine-based chemoradiotherapy, CT-derived parameters correlated with pathological response and survival.

Conclusion. Gemcitabine incorporation into tumor DNA is highly variable and correlates with multiscale transport properties that can be derived from routine CT scans. Furthermore, pretherapy CT-derived properties correlate with clinically relevant endpoints.

Trial registration. Clinicaltrials.gov NCT01276613.

Funding. Lustgarten Foundation (989161), Department of Defense (W81XWH-09-1-0212), NIH (U54CA151668, KCA088084).

Authors

Eugene J. Koay, Mark J. Truty, Vittorio Cristini, Ryan M. Thomas, Rong Chen, Deyali Chatterjee, Ya’an Kang, Priya R. Bhosale, Eric P. Tamm, Christopher H. Crane, Milind Javle, Matthew H. Katz, Vijaya N. Gottumukkala, Marc A. Rozner, Haifa Shen, Jeffery E. Lee, Huamin Wang, Yuling Chen, William Plunkett, James L. Abbruzzese, Robert A. Wolff, Gauri R. Varadhachary, Mauro Ferrari, Jason B. Fleming

Randomized trial of the anti-FGF23 antibody KRN23 in X-linked hypophosphatemia

• Text
• PDF

Abstract

Background. X-linked hypophosphatemia (XLH) is the most common heritable form of rickets and osteomalacia. XLH-associated mutations in phosphate-regulating endopeptidase (PHEX) result in elevated serum FGF23, decreased renal phosphate reabsorption, and low serum concentrations of phosphate (inorganic phosphorus, Pi) and 1,25-dihydroxyvitamin D [1,25(OH)₂D]. KRN23 is a human anti-FGF23 antibody developed as a potential treatment for XLH. Here, we have assessed the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of KRN23 following a single i.v. or s.c. dose of KRN23 in adults with XLH.

Methods. Thirty-eight XLH patients were randomized to receive a single dose of KRN23 (0.003–0.3 mg/kg i.v. or 0.1–1 mg/kg s.c.) or placebo. PK, PD, immunogenicity, safety, and tolerability were assessed for up to 50 days.

Results. KRN23 significantly increased the maximum renal tubular threshold for phosphate reabsorption (TmP/GFR), serum Pi, and 1,25(OH)₂D compared with that of placebo (P < 0.01). The maximum serum Pi concentration occurred later following s.c. dosing (8–15 days) compared with that seen with i.v. dosing (0.5–4 days). The effect duration was dose related and persisted longer in patients who received s.c. administration. Changes from baseline in TmP/GFR, serum Pi, and serum 1,25(OH)₂D correlated with serum KRN23 concentrations. The mean t_1/2 of KRN23 was 8–12 days after i.v. administration and 13–19 days after s.c. administration. Patients did not exhibit increased nephrocalcinosis or develop hypercalciuria, hypercalcemia, anti-KRN23 antibodies, or elevated serum parathyroid hormone (PTH) or creatinine.

Conclusion. KRN23 increased TmP/GFR, serum Pi, and serum 1,25(OH)₂D. The positive effect of KR23 on serum Pi and its favorable safety profile suggest utility for KRN23 in XLH patients.

Trial registration. Clinicaltrials.gov NCT00830674.

Funding. Kyowa Hakko Kirin Pharma, Inc.

Authors

Thomas O. Carpenter, Erik A. Imel, Mary D. Ruppe, Thomas J. Weber, Mark A. Klausner, Margaret M. Wooddell, Tetsuyoshi Kawakami, Takahiro Ito, Xiaoping Zhang, Jeffrey Humphrey, Karl L. Insogna, Munro Peacock

Autologous CLL cell vaccination early after transplant induces leukemia-specific T cells

• Text
• PDF

Abstract

Background: Patients with advanced hematologic malignancies remain at risk for relapse following reduced-intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (allo-HSCT). We conducted a prospective clinical trial to test whether vaccination with whole leukemia cells early after transplantation facilitates the expansion of leukemia-reactive T cells and thereby enhances antitumor immunity.

Methods: We enrolled 22 patients with advanced chronic lymphocytic leukemia (CLL), 18 of whom received up to 6 vaccines initiated between days 30 and 45 after transplantation. Each vaccine consisted of irradiated autologous tumor cells admixed with GM-CSF–secreting bystander cells. Serial patient PBMC samples following transplantation were collected, and the impact of vaccination on T cell activity was evaluated.

Results: At a median follow-up of 2.9 (range, 1–4) years, the estimated 2-year progression-free and overall survival rates of vaccinated subjects were 82% (95% CI, 54%–94%) and 88% (95% CI, 59%–97%), respectively. Although vaccination only had a modest impact on recovering T cell numbers, CD8⁺ T cells from vaccinated patients consistently reacted against autologous tumor, but not alloantigen-bearing recipient cells with increased secretion of the effector cytokine IFN-γ, unlike T cells from nonvaccinated CLL patients undergoing allo-HSCT. Further analysis confirmed that 17% (range, 13%–33%) of CD8⁺ T cell clones isolated from 4 vaccinated patients by limiting dilution of bulk tumor-reactive T cells solely reacted against CLL-associated antigens.

Conclusion: Our studies suggest that autologous tumor cell vaccination is an effective strategy to advance long-term leukemia control following allo-HSCT.

Trial registration: Clinicaltrials.gov NCT00442130.

Funding: NCI (5R21CA115043-2), NHLBI (5R01HL103532-03), and Leukemia and Lymphoma Society Translational Research Program.

Authors

Ute E. Burkhardt, Ursula Hainz, Kristen Stevenson, Natalie R. Goldstein, Mildred Pasek, Masayasu Naito, Di Wu, Vincent T. Ho, Anselmo Alonso, Naa Norkor Hammond, Jessica Wong, Quinlan L. Sievers, Ana Brusic, Sean M. McDonough, Wanyong Zeng, Ann Perrin, Jennifer R. Brown, Christine M. Canning, John Koreth, Corey Cutler, Philippe Armand, Donna Neuberg, Jeng-Shin Lee, Joseph H. Antin, Richard C. Mulligan, Tetsuro Sasada, Jerome Ritz, Robert J. Soiffer, Glenn Dranoff, Edwin P. Alyea, Catherine J. Wu