Kenneth G. Lucas

The detection of CMV pp65 and IE1 in glioblastoma multiforme.

Glioblastoma multiforme (GBM) is a highly lethal brain tumor affecting children and adults, with the majority of affected individuals dying from their disease by 2 years following diagnosis. Other groups have reported the association of cytomegalovirus (CMV) with GBM, and we sought to confirm these findings in a large series of patients with primary GBM from our institution. Immunohistochemical analysis of paraffin embedded tissue sections was performed on 49 newly diagnosed GBM tumors, the largest series reported to date. We confirmed the presence of CMV pp65 on 25/49 (51%) and of IE1 on 8/49 (16%) of these tumors. While pp65 and IE1 are generally found in the nucleus of cells that are permissibly infected by CMV, GBM in this series had mostly cytoplasmic staining, with only 16% having nuclear staining for one or both of these antigens. We infected GBM cell lines with a laboratory strain of CMV, and found that most of the staining was cytoplasmic, with some perinuclear localization of IE1. To test the potential for CMV infected GBM cells to be recognized by CMV pp65 and IE1 specific cytotoxic T lymphocytes (CTL), we used CMV infected GBM cell lines in cytotoxicity assays with human leukocyte antigen partially matched CMV CTL. Lysis of CMV infected GBM tumor cells was accentuated by pre-treating these cell lines with either the demethylating agent decitabine or interferon-γ, both of which were shown to increase MHC Class I and II expression on tumor cells in vitro. These studies confirm the presence of CMV pp65 or IE1 on approximately half of GBM, with the possibility that CMV positive tumor cells can be recognized by CMV pp65/IE1 specific T cells.

Complete Remission Following Decitabine/Dendritic Cell Vaccine for Relapsed Neuroblastoma

Patients with relapsed stage 4 neuroblastoma have an extremely poor long-term prognosis, making the investigation of new agents of interest. We report the outcome of the first patient treated in a phase 1 study for relapsed neuroblastoma, using the chemotherapy agent decitabine to upregulate cancer testis antigen expression, followed by a dendritic cell vaccine targeting the cancer testis antigens MAGE-A1, MAGE-A3, and NY-ESO-1. Our patient had persistent tumor in his bone marrow after completion of standard therapy for neuroblastoma, including multiagent chemotherapy, tumor resection, stem cell transplantation, radiation therapy, and anti-GD2 monoclonal antibodies. His marrow disease persisted despite chemotherapy, which was given while the vaccine was being produced. After 3 cycles of decitabine and vaccine, this patient achieved a complete remission and is now 1 year from his last treatment, with no evidence of tumor in his bone marrow or other sites. This patient was noted to have an increase in MAGE-A3–specific T cells. This is the first report combining demethylating chemotherapy to enhance tumor antigen expression followed by a cancer antigen vaccine.

Adoptive Immunotherapy with CMV Specific Cytotoxic T Lymphocytes for Stem Cell Transplant Patients with Refractory CMV Infections

Adoptive immunotherapy with cytomegalovirus (CMV)-specific cytotoxic T lymphocytes (CTL) is an effective strategy for preventing and treating viral reactivation after allogeneic stem cell transplantation (SCT). We have shown previously that CMV CTL can be generated in 1 to 2 weeks by stimulating donor lymphocytes with peptide mixes derived from full-length pp65 and IE1. We conducted a multi-institutional study of CMV-specific CTL for patients with persistent or anti–viral-resistant CMV infections after allogeneic SCT, to determine the safety, feasibility, and immunologic effects of this approach. We were successful in stimulating CTL from 10/10 donors with pooled CMV overlapping peptide mixes. Five of the 7 subjects who met infusion criteria had new onset CMV-specific CTL activity detected within 4 to 6 weeks after infusion. Of the 2 subjects who did not have immunologic responses after infusion, 1 received CTL with a low viability after thawing, and the other patient received cyclosporine A and systemic corticosteroids at the time of the infusion, achieving only a low, transient increase (10%) in pp65-specific activity. There was no graft-versus-host disease attributable to these infusions. These findings indicate that the infusion of CTL stimulated over 1 to 2 weeks with overlapping CMV peptides can result in virus-specific immune reconstitution in SCT recipients, without exacerbations of graft-versus-host disease.

Allogeneic stem cell transplantation in a patient with relapsed Ewing sarcoma

Ewing sarcoma (ES) can express tumor antigens which can be recognized by T cells, making allogeneic stem cell transplant (SCT) a potential option for those patients with refractory disease. A 6‐year old with multifocal ES developed a recurrence of pulmonary metastases and underwent an allogeneic bone marrow transplant from her human leukocyte antigen (HLA) 10/10 matched mother. During a taper of her immunosuppression, she developed grade 1 skin and oral graft versus host disease (GVHD). CT scans performed 9 months post‐transplant revealed a marked decrease in the size of her pulmonary lesions compared to scans 2 months post‐transplant. This case highlights the possibility of treating patients with refractory metastatic ES with allogeneic SCT. Pediatr Blood Cancer 2008;51:142–144.

Expansion of Cytomegalovirus pp65 and IE-1 Specific Cytotoxic T Lymphocytes for Cytomegalovirus-Specific Immunotherapy Following Allogeneic Stem Cell Transplantation

Adoptive immunotherapy with antigen-specific cytotoxic T lymphocytes (CTLs) has proven effective in restoring cellular immunity to cytomegalovirus (CMV) and preventing viral reactivation after allogeneic stem cell transplantation (SCT). In an effort to develop a cost-effective, relatively rapid method of CMV CTL expansion, we investigated the use of a pool of overlapping CMV peptides. Because the possibility exists of vaccinating CMV-seronegative donors, and these individuals may have T cell responses predominantly against IE-1, commercially available peptide mixes for pp65 as well as IE-1 were used to stimulate CTLs from 10 seropositive donors. Of these 10 donors, 4 responded to pp65 only, 1 did not respond to either pp65 or IE-1, 4 responded to both pp65 and IE-1, and 1 responded to IE-1 only. These CMV- specific T cells included a mixture of CD4(+) and CD8(+) effectors, and specific cytotoxicity correlated with interferon-gamma production. The costs associated with a 28-day maintenance course of intravenous ganciclovir, cidofovir, foscarnet, and valganciclovir, as well as the preparation and shipping a single dose of CTLs, were determined. The price of generating CMV CTLs using this method was comparable to or less expensive than a 28-day maintenance course for these agents, not including the costs associated with drug administration, supportive care, and the treatment of drug-related complications. Considering the relative ease, low cost, and the fact that CTL administration can result in CMV-specific immune reconstitution, this option should be considered for patients with CMV reactivation or for prophylaxis in patients at high risk for infection.

Rapid generation of CMV pp65-specific T cells for immunotherapy.

Adoptive immunotherapy with cytomegalovirus (CMV)-specific cytotoxic T lymphocytes (CTL) has been shown to be an effective means of restoring cellular immunity to this virus and preventing CMV infection after allogeneic stem cell transplantation. Problems with current strategies include requirements for generating dendritic cells or other antigen presenting cells for stimulating CTL and the time needed for cell culture. The adherent cell fraction of peripheral blood mononuclear cells from 6 CMV seropositive donors were pulsed with pooled CMV pp65 peptides and incubated with nonadherent peripheral blood lymphocytes. CTL lacking specific cytotoxicity to pp65 were restimulated at day 10 of culture using peptide pulsed adherent cells. Of the 6 CMV seropositive donors tested, 5 had specific cytotoxicity to CMV pp65 (range 31% to 75%), with no alloreactivity. The resulting pp65-specific CTL consisted of a mixture of CD4+ and CD8+ cells, with 1% to 29% of CD8 cells and 0.5% to 10% CD4 cells making interferon-γ (IFN-γ) in response to pp65. The donor from whom we could not detect CMV-specific cytotoxicity had detectable CD4 and CD8+ CMV pp65 CTL by intracellular cytokine analysis for IFN-γ. Using this simplified strategy for expanding CMV pp65 CTL, adoptive immunotherapy with pp65-specific CTL could be made available in a more timely manner for patients who have persistent or therapy refractory CMV infections.

Cancer testis antigen and immunotherapy.

The identification of cancer testis (CT) antigens has been an important advance in determining potential targets for cancer immunotherapy. Multiple previous studies have shown that CT antigen vaccines, using both peptides and dendritic cell vaccines, can elicit clinical and immunologic responses in several different tumors. This review details the expression of melanoma antigen family A, 1 (MAGE-A1), melanoma antigen family A, 3 (MAGE-A3), and New York esophageal squamous cell carcinoma-1 (NY-ESO-1) in various malignancies, and presents our current understanding of CT antigen based immunotherapy.

Epstein Barr virus induced lymphoma in a child with IPEX syndrome.

IPEX syndrome (immune deficiency, polyendocrinopathy, enteropathy, X‐linked) is a disorder or regulatory T cell (Treg) function which can result in early death due to infection or complications related to autoimmunity. Therapeutic options for these patients can include allogeneic stem cell transplantation (SCT) or the use of immunosuppressive regimens to control the manifestations of autoimmunity. We report a patient with IPEX syndrome who was managed with rapamycin and subsequently developed EBV induced lymphoma. Pediatr Blood Cancer 2008;50:1056–1057.

Infusion of cytomegalovirus specific cytotoxic T lymphocytes from a sero-negative donor can facilitate resolution of infection and immune reconstitution.

We report a stem cell transplant patient with a therapy-refractory cytomegalovirus (CMV) infection who received CMV-specific T cells from his sero-negative stem cell donor. This donor received the Towne strain CMV vaccine, and T cells were expanded using monocytes pulsed with pp65 overlapping peptides. CMV DNA decreased after the CTL infusion, and CMV-specific cytotoxicity increased. This strategy could be implemented in similar situations or with persistent viremia post-transplant.

Immunotherapy for Epstein – Barr Virus-Associated Tumors

Epstein-Barr Virus (EBV) is associated with a number of tumors, including lymphomas in solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients, patients with the acquired immunodeficiency syndrome (AIDS), Burkitts lymphoma, as well as a subset of patients with nasopharyngeal carcinoma (NPC) and Hodgkins disease (HD). The types of latent EBV infections vary in these tumors, which influences the EBV antigens expressed and ultimately the immunogenicity of tumor cells. Not all EBV associated malignancies are directly related to altered cellular immunity, as is the case with EBV induced lymphoproliferations in immunocompromised patients. Treatment strategies have ranged from restoration of normal cellular immunity, which is generally successful in SOT and HSCT patients, anti-B cell monoclonal antibodies, and conventional chemotherapy and radiation. The fact that these tumors express EBV antigens for which many individuals have high circulating levels of protective cytotoxic T lymphocytes (CTL) has lead to investigation into the applicability of adoptive transfer of EBV specific T cells. Initial success with adoptive immunotherapy for HSCT and SOT patients has lead to current studies examining the feasibility and efficacy of this strategy for other EBV associated tumors, such as NPC and HD. We will review the pathogenesis of these disorders, current therapies, and future investigations aimed at targeting EBV antigen expression on these tumors.