Adjuvant Peptide Pulsed Dendritic Cell Vaccination in Addition to T Cell Adoptive Immunotherapy for Cytomegalovirus Infection in Allogeneic Hematopoietic Stem Cell Transplantation Recipients.

Adoptive cellular immunotherapy has been shown to be effective in the management of cytomegalovirus (CMV) reactivation and disease. Whether adjuvant dendritic cell (DC) vaccination will provide additional benefit in prophylaxis or treatment of CMV in hematoietic cell transplantation (HSCT) recipients is unknown. In this study, we administered prophylactic CMV-peptide specific T cell infusions, followed by 2 doses of intradermal CMV peptide-pulsed DC vaccine, to 4 HSCT recipients. There were no immediate adverse events associated with T cell infusion or DC vaccinations. One of the 4 patients developed grade III acute gut graft-versus-host disease. Immune reconstitution against CMV was detected in all 4 patients. Patients receiving CMV peptide-specific T cells and DC vaccination had peak immune reconstitution at least 10 days after the second DC vaccination. In summary, combining DC vaccine with T cell infusion appears feasible, although further study is required to ascertain its safety and efficacy in augmenting the effects of infusing donor-derived CMV-specific T cells.

Dealing with the spiralling price of medicines: issues and solutions.

Escalating cost of medicines is rapidly becoming a serious threat to patients and health systems. This trend has been documented to impact patient outcomes adversely. As clinicians and tax payers, it is our responsibility to be aware of the potential detrimental effects spiralling costs have on our patients, our community and our health system and to mitigate these effects by exposing this issue to our respective professional societies, representatives of the pharmaceutical companies that we interact with, government regulatory bodies and to patients who we are caring for. Only through understanding and constructive actions will we be able to provide the best quality of care to our patients and continue to enjoy universal healthcare in our country.

Herpes simplex virus type 1 (HSV-1) specific T-cell generation from HLA-A1- and HLA-A2-positive donors for adoptive immunotherapy.

BACKGROUND AIMS: Herpes simplex virus (HSV) reactivation and infection is common in patients undergoing hematopoietic stem cell transplant (HSCT) and requires routine antiviral prophylaxis. Drug-resistant strains are increasingly common, and effective alternative therapy is currently unavailable. We generated and characterized HSV-1-specific T cells for use in adoptive cellular immunotherapy following allogeneic stem cell transplantation. METHODS: Peripheral blood mononuclear cells from HLA-A1 and HLA-A2 HSV-seropositive hereditary hemochromatosis donors were used as the antigen source. Three HLA-A1 and four HLA-A2 specific epitopes were used for stimulation of T cells. Cells were stimulated with antigen-pulsed dendritic cells and cultured for 21 days in medium with interleukin (IL)-2. Cultured cells were phenotyped and tested for cytokine production, proliferation and cytotoxicity. RESULTS: There was a 5.3-fold expansion in total cell numbers over 21 days of culture, with 35% of T cells being CD8 positive. Thirty-five percent, 21% and 5% of CD8 cells secreted interferon-γ, tumor necrosis factor-α and IL-2 upon HSV antigen re-stimulation. More than 50% of antigen-specific T cells secreted multiple cytokines. Cultured T cells proliferated upon antigen re-stimulation and lysed HSV-1 peptide and virus-infected targets. CONCLUSIONS: It is feasible to generate functional HSV-1 specific T cells from the blood of HLA-A1 and HLA-A2 HSV-seropositive donors using specific peptides. The utility of these cells in preventing and treating HSV-1 reactivation in allogeneic HSCT will need to be tested clinically.

Donor-derived CMV-specific T cells reduce the requirement for CMV-directed pharmacotherapy after allogeneic stem cell transplantation.

We investigated the use of adoptively transferred donor-derived cytomegalovirus (CMV) specific cytotoxic T lymphocytes (CTL) as immune reconstitution postallogeneic transplant in a phase 2 study. Fifty patients were infused with a single dose of 2 × 10(7)cells/m(2) after day 28 post-transplant. Twenty-six patients reactivated CMV posttransplant (only 5 post-CTL infusion) and 9 required therapy with ganciclovir or foscarnet (only 1 post-CTL infusion). There was 1 case of fatal CMV disease, attributable to high levels of antithymocyte globulin at the time of T cell infusion. We compared the patients in the phase 2 study with a group of contemporaneous controls also treated at the trial centers. There was no increase in acute or chronic graft-versus-host disease attributable to CTL infusion; overall and progression-free survival were similar in both groups. There was a reduction in the percentage of patients who required CMV directed antiviral therapy (17% vs 36%, P = .01) and in the total number of treatment days in the cohort receiving CTL (3.4 days vs 8.9 days, P = .03) without a reduction in CMV reactivation rates. We postulate that adoptively transferred cells are able to expand in response to viral antigen, limit viral replication, and prevent progression to tissue infection. This study was registered on the Australian Clinical Trial Registry as #ACTRN12605000213640 and #ACTRN12607000224426.

Addition of varicella zoster virus-specific T cells to cytomegalovirus, Epstein-Barr virus and adenovirus tri-specific T cells as adoptive immunotherapy in patients undergoing allogeneic hematopoietic stem cell transplantation.

BACKGROUND AIMS: Virus-specific T-cell immunotherapy is emerging as a promising management strategy for virus infections in patients after hematopoietic stem cell transplant (HSCT). Here we present outcomes of 10 adult patients who received multi-virus-specific T cells prophylactically after HSCT. METHODS: Donor-derived cytomegalovirus (CMV)-, Epstein-Barr virus (EBV)-, adenoviral- and varicella zoster virus (VZV)-specific T cells were generated in a single culture and administered to HSCT patients at a dose of 2 × 10(7)/m(2) virus-specific T cells at a median of 63 days post-transplant. Patients were monitored for 12 months for evidence of viral reactivation and graft-versus-host disease. RESULTS: There was no acute infusion-related toxicity. Six patients developed CMV reactivation after T-cell infusion with a median peak CMV DNA titer of 600 copies per milliliter, and 1 received CMV-specific pharmacotherapy post-infusion. No EBV, adenoviral or VZV reactivation or disease was reported. Using interferon-γ Elispot analysis on post-infusion samples, we identified anti-viral immunity against all viruses including VZV. Three patients (30%) developed grade II-IV acute graft-versus-host disease. CONCLUSIONS: This is the first description of the use of a multi-virus-specific T-cell product containing cells specific for VZV after allogeneic HSCT. The T-cell product appears safe in the setting of HSCT and confirms our previous findings regarding CMV control and treatment. A larger study with longer follow-up is required to determine the efficacy of VZV-specific T cells given prophylactically in controlling episodes of herpes zoster and disseminated varicella infection after cessation of prophylactic anti-viral treatment.

In vitro generation of influenza-specific polyfunctional CD4+ T cells suitable for adoptive immunotherapy.

BACKGROUND AIMS: Influenza viruses cause potentially fatal respiratory infections in stem cell transplant patients. Specific T cells provide long-lived host adaptive immunity to influenza viruses, and the potential for generating such cells for clinical use was investigated. METHODS: The inactivated influenza vaccine (Fluvax) approved for human use was used as the antigen source. Monocyte-derived dendritic cells pulsed with Fluvax were used to stimulate autologous peripheral blood mononuclear cells (PBMC) on days 0 and 7. Cells were expanded with interleukin (IL)-2 from day 7 onwards. Cell numbers and phenotype were assessed on day 21. The presence of influenza virus-specific cells was assessed by cytokine production and proliferative responses following restimulation with influenza antigens. RESULTS: Over 21 days of culture, a mean fold increase of 26.3 in cell number was observed (n = 7). Cultures were predominantly effector and central memory CD4+ cells, and expressed a phenotype characteristic of activated antigen-specific cells capable of B-cell helper function. Cytotoxic CD4+ and CD8+ cells specific for influenza and a high percentage of CD4+ cells specific for each of three influenza viruses targeted by Fluvax (H1N1, H3N2 and Brisbane viruses) were generated. In addition, T cells expanded when restimulated with antigens derived from influenza viruses. CONCLUSIONS: We have demonstrated a clinically usable method for producing influenza virus-specific T cells that yield high numbers of highly reactive CD4+ cells suitable for adoptive immunotherapy. We propose that reconstructing host immunity through adoptive transfer of influenza virus-specific T cells will reduce the frequency of influenza-related deaths in the period of severe immune suppression that follows stem cell transplantation.