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Carlos A Ramos,
Neeharika Narala,
Gayatri M Vyas,
Ann M Leen,
Ulrike Gerdemann,
Erich M Sturgis,
Matthew L Anderson,
Barbara Savoldo,
Helen E Heslop,
Malcolm K Brenner,
Cliona M Rooney
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ABSTRACT: Vaccines prevent human papillomavirus (HPV)-associated cancer but, although these tumors express foreign, viral antigens (E6 and E7 proteins), they have little benefit in established malignancies, likely due to negative environmental cues that block tumor recognition and induce T-cell anergy in vivo. We postulated that we could identify mechanisms by which ex vivo stimulation of T cells could reactivate and expand tumor-directed T-cell lines from HPV cancer patients for subsequent adoptive immunotherapy. A total of 68 patients with HPV-associated cancers were studied. Peripheral blood T cells were stimulated with monocyte-derived dendritic cells loaded with pepmixes [peptide libraries of 15-mers overlapping by 11 amino acids (aa)] spanning E6/E7, in the presence or absence of specific accessory cytokines. The resulting T-cell lines were further expanded with pepmix-loaded activated B-cell blasts. Interferon-γ release and cytotoxic responses to E6/E7 were assessed. We successfully reactivated and expanded (>1200-fold) E6-specific/E7-specific T cells from 8/16 cervical and 33/52 oropharyngeal cancer patients. The presence of the cytokines interleukin (IL)-6, IL-7, IL-12, and IL-15 is critical for this process. These T-cell lines possess the desirable characteristics of polyclonality, multiple T-cell subset representation (including the memory compartment) and a TH1 bias, and may eliminate E6/E7 targets. In conclusion, we have shown it is possible to robustly generate HPV16 E6/E7-directed T-cell lines from patients with HPV16-associated cancers. Because our technique is scalable and good-manufacturing procedures-compliant, these lines could be used for adoptive cellular immunotherapy of patients with HPV16 cancers.
Journal of immunotherapy (Hagerstown, Md.: 1997) 11/2012; · 3.20 Impact Factor
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Ulrike Gerdemann,
Laura Keukens,
Jacqueline M Keirnan,
Usha L Katari,
Chinh T Q Nguyen,
Anne P de Pagter, Carlos A Ramos,
Alana Kennedy-Nasser,
Stephen M Gottschalk,
Helen E Heslop,
Malcolm K Brenner,
Cliona M Rooney,
Ann M Leen
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ABSTRACT: Human herpesvirus (HHV) 6 causes substantial morbidity and mortality in the immunocompromised host and has no approved therapy. Adoptive transfer of virus specific T cells has proven safe and apparently effective as prophylaxis and treatment of other virus infections in immunocompromised patients; however, extension to subjects with HHV6 has been hindered by the paucity of information on targets of cellular immunity. We now characterize the cellular immune response from 20 donors against five major HHV6B antigens predicted to be immunogenic and define a hierarchy of immunodominance of antigens based on the frequency of responding donors and the magnitude of the T cell response. We identified specific epitopes within these antigens and expanded the HHV6 reactive T cells using a GMP-compliant protocol. The expanded population comprised both CD4+ and CD8+ T cells that were able to produce multiple effector cytokines and kill both peptide-loaded and HHV6B wild type virus-infected target cells. Thus, we conclude that adoptive T cell immunotherapy for HHV6 is a practical objective, and that the peptide and epitope tools we describe will allow such cells to be prepared, administered and monitored in human subjects.
Blood 11/2012; · 9.90 Impact Factor
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American Journal of Hematology 07/2011; 86(11):961-2. · 4.67 Impact Factor
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ABSTRACT: INTRODUCTION: Chimeric antigen receptors (CARs) usually combine the antigen binding site of a monoclonal antibody with the signal activating machinery of a T cell, freeing antigen recognition from MHC restriction and thus breaking one of the barriers to more widespread application of cellular therapy. Similar to treatment strategies employing monoclonal antibodies, T cells expressing CARs are highly targeted, but additionally offer the potential benefits of active trafficking to tumor sites, in vivo expansion and long-term persistence. Furthermore, gene transfer allows the introduction of countermeasures to tumor immune evasion and of safety mechanisms. AREAS COVERED: The basic structure of so-called first and later generation CARs and their potential advantages over other immune therapy systems. How these molecules can be grafted into immune cells (including retroviral and non-retroviral transduction methods) and strategies to improve the in vivo persistence and function of immune cells expressing CARs. Examples of tumor-associated antigens that have been targeted in preclinical models and clinical experience with these modified cells. Safety issues surrounding CAR gene transfer into T cells and potential solutions to them. EXPERT OPINION: Because of recent advances in immunology, genetics and cell processing, CAR-modified T cells will likely play an increasing role in the cellular therapy of cancer, chronic infections and autoimmune disorders.
Expert opinion on biological therapy 04/2011; 11(7):855-73. · 3.22 Impact Factor
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Carlos A Ramos,
Rima M Saliba,
Leandro de Pádua Silva,
Ola Khorshid,
Elizabeth J Shpall,
Sergio Giralt,
Poliana A Patah,
Chitra M Hosing,
Uday R Popat,
Gabriela Rondon,
Yago Nieto,
Richard E Champlin,
Marcos de Lima
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ABSTRACT: Serologic evidence of resolved hepatitis B virus (HBV) infection has been associated with reactivation of hepatitis after allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the true impact of this finding is unknown. We conducted a retrospective matched-control analysis of the outcomes of 76 patients with positive HBV core antibody (HBcAb) and negative HBV surface antigen (HBsAg) at the time of allo-HSCT for hematologic or solid malignancies. Control patients (matched controls), with negative serology for HBV and other viral hepatitides, were matched by age, diagnosis, disease risk, intensity of conditioning regimen, and donor type. In addition, the HBcAb-positive patients and all seronegative patients (all controls, n = 1858) undergoing transplantation during the same period were compared to adjust for other confounding effects. Patient characteristics and baseline hepatic function studies were similar in the HBcAb-positive and matched control groups. The cumulative incidence of hepatitis B reactivation (defined as the emergence of HBsAg in serum) was 11.6% at 3 years. There were no significant differences in overall survival, relapse, nonrelapse mortality, and incidence of acute graft-versus-host disease between the HBcAb-positive and control groups. Our data suggest that seropositivity for HBcAb and seronegativity for HBsAg at the time of transplantation does not seem to adversely affect outcome after allo-HSCT.
Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 05/2010; 16(5):686-94. · 3.15 Impact Factor
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Ulrike Gerdemann,
Anne S Christin,
Juan F Vera, Carlos A Ramos,
Yuriko Fujita,
Hao Liu,
Dagmar Dilloo,
Helen E Heslop,
Malcolm K Brenner,
Cliona M Rooney,
Ann M Leen
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ABSTRACT: Viral infections cause morbidity and mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. To prevent and treat these, we have produced and infused cytotoxic T lymphocytes (CTLs) with specificity for Epstein-Barr virus (EBV), cytomegalovirus (CMV), and adenovirus (Adv), and shown that small numbers of infused cells proliferate in vivo and protect against all three viruses. Despite these encouraging results, broader implementation of this approach is limited by the need for infectious virus material (EBV), expensive production of clinical grade adenoviral vectors, and a prolonged (8-12 weeks) period of manufacture. There is also competition between virus-derived antigens within antigen-presenting cells (APCs), limiting extension to additional agents. We now describe an approach that uses DNA nucleofection of dendritic cells (DCs) with DNA plasmids that encode a range of immunodominant and subdominant viral antigens from CMV, EBV, BK, and Adv. Within 10 days, this methodology provides multivirus-reactive CTLs that lack alloreactivity. We further demonstrate that nucleofected DC stimulation can be combined with interferon-gamma (IFN-gamma) capture technology to produce even more rapid multivirus-CTL products for treatment of acute infection. These CTL generation procedures should increase the feasibility and applicability of T-cell therapy.
Molecular Therapy 08/2009; 17(9):1616-25. · 6.87 Impact Factor
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Carlos A Ramos,
Rima M Saliba,
Leandro de Pádua,
Ola Khorshid,
Elizabeth J Shpall,
Sergio Giralt,
Poliana A Patah,
Chitra M Hosing,
Uday R Popat,
Gabriela Rondon,
Issa F Khouri,
Yago L Nieto,
Richard E Champlin,
Marcos de Lima
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ABSTRACT: Because hepatitis C virus infection causes hepatic and immunological dysfunction, we hypothesized that seropositivity for this virus could be associated with increased non-relapse mortality after allogeneic hematopoietic stem cell transplantation.
We performed a case-control study of the outcomes of patients who were hepatitis C virus seropositive at the time of allogeneic hematopoietic stem cell transplantation (N=31). Patients positive for hepatitis C virus were considered candidates for stem cell transplantation only if they had no significant evidence of hepatic dysfunction. Matched controls (N=31) were seronegative for viral hepatitides and were paired according to age, diagnosis, disease stage, conditioning regimen and donor type. We also compared the hepatitis C virus seropositive patients to all seronegative patients (all controls, N=1800) transplanted during the same period, to adjust for other confounding effects.
The median age of the seropositive patients was 49 (range 26-72); 15 had acute myeloid leukemia/myelodysplastic syndrome, 6 had chronic myeloid leukemia/myeloproliferative disease, 6 non-Hodgkin's lymphoma, 2 myeloma, 1 acute lymphocytic leukemia and 1 Hodgkin's lymphoma; 61% had poor risk disease; 68% had related donors; 68% received reduced intensity conditioning; 7 patients had mildly abnormal alanine transaminase levels (all less than three times the upper limit of normal) and 1 patient had minimally elevated bilirubin. These characteristics were similar to those of the matched control group. Median overall survival was 3, 18 and 20 months, and 1-year survival was 29%, 56% and 56%, in the hepatitis C virus, matched and all controls groups, respectively (hazard ratio for death 3.1, 95% confidence interval 1.9-5.6, p<0.001 in multivariate analysis). Non-relapse mortality at 1 year was 43%, 24% and 23%, respectively (hazard ratio 3.3, 95% confidence interval 1.8-7.1, p<0.01). Disease progression and graft-versus-host disease rates were comparable.
Hepatitis C virus seropositivity is a significant risk factor for non-relapse mortality after allogeneic hematopoietic stem cell transplantation even in patients with normal or minimally abnormal liver function tests.
Haematologica 01/2009; 94(2):249-57. · 6.42 Impact Factor
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ABSTRACT: Hematopoietic stem cells replenish all the cells of the blood throughout the lifetime of an animal. Although thousands of stem cells reside in the bone marrow, only a few contribute to blood production at any given time. Nothing is known about the differences between individual stem cells that dictate their particular state of activation readiness. To examine such differences between individual stem cells, we determined the global gene expression profile of 12 single stem cells using microarrays. We showed that at least half of the genetic expression variability between 12 single cells profiled was due to biological variation in 44% of the genes analyzed. We also identified specific genes with high biological variance that are candidates for influencing the state of readiness of individual hematopoietic stem cells, and confirmed the variability of a subset of these genes using single-cell real-time PCR. Because apparent variation of some genes is likely due to technical factors, we estimated the degree of biological versus technical variation for each gene using identical RNA samples containing an RNA amount equivalent to that of single cells. This enabled us to identify a large cohort of genes with low technical variability whose expression can be reliably measured on the arrays at the single-cell level. These data have established that gene expression of individual stem cells varies widely, despite extremely high phenotypic homogeneity. Some of this variation is in key regulators of stem cell activity, which could account for the differential responses of particular stem cells to exogenous stimuli. The capacity to accurately interrogate individual cells for global gene expression will facilitate a systems approach to biological processes at a single-cell level.
PLoS Genetics 10/2006; 2(9):e159. · 8.69 Impact Factor
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Teresa V Bowman,
Andrew J McCooey,
Akil A Merchant, Carlos A Ramos,
Patricia Fonseca,
Alan Poindexter,
Steven B Bradfute,
Daniela M Oliveira,
Rahshaana Green,
Yayun Zheng,
Kathyjo A Jackson,
Stuart M Chambers,
Shannon L McKinney-Freeman,
Kevin G Norwood,
Gretchen Darlington,
Preethi H Gunaratne,
David Steffen,
Margaret A Goodell
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ABSTRACT: Hematopoietic stem cells (HSCs) maintain tissue homeostasis by rapidly responding to environmental changes. Although this function is well understood, the molecular mechanisms governing this characteristic are largely unknown. We used a sequenced-based strategy to explore the role of both transcriptional and post-transcriptional regulation in HSC biology. We characterized the gene expression differences between HSCs, both quiescent and proliferating, and their differentiated progeny. This analysis revealed a large fraction of sequence tags aligned to intronic sequences, which we showed were derived from unspliced transcripts. A comparison of the biological properties of the observed spliced versus unspliced transcripts in HSCs showed that the unspliced transcripts were enriched in genes involved in DNA binding and RNA processing. In addition, levels of unspliced message decreased in a transcript-specific fashion after HSC activation in vivo. This change in unspliced transcript level coordinated with increases in gene expression of splicing machinery components. Combined, these results suggest that post-transcriptional regulation is important in HSC activation in vivo.
Stem Cells 04/2006; 24(3):662-70. · 7.78 Impact Factor
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ABSTRACT: Stem cells resident in adult tissues are principally quiescent, yet harbor enormous capacity for proliferation to achieve self renewal and to replenish their tissue constituents. Although a single hematopoietic stem cell (HSC) can generate sufficient primitive progeny to repopulate many recipients, little is known about the molecular mechanisms that maintain their potency or regulate their self renewal. Here we have examined the gene expression changes that occur over a time course when HSCs are induced to proliferate and return to quiescence in vivo. These data were compared to data representing differences between naturally proliferating fetal HSCs and their quiescent adult counterparts. Bioinformatic strategies were used to group time-ordered gene expression profiles generated from microarrays into signatures of quiescent and dividing stem cells. A novel method for calculating statistically significant enrichments in Gene Ontology groupings for our gene lists revealed elemental subgroups within the signatures that underlie HSC behavior, and allowed us to build a molecular model of the HSC activation cycle. Initially, quiescent HSCs evince a state of readiness. The proliferative signal induces a preparative state, which is followed by active proliferation divisible into early and late phases. Re-induction of quiescence involves changes in migratory molecule expression, prior to reestablishment of homeostasis. We also identified two genes that increase in both gene and protein expression during activation, and potentially represent new markers for proliferating stem cells. These data will be of use in attempts to recapitulate the HSC self renewal process for therapeutic expansion of stem cells, and our model may correlate with acquisition of self renewal characteristics by cancer stem cells.
PLoS Biology 11/2004; 2(10):e301. · 11.45 Impact Factor
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BioTechniques 04/2003; 34(3):572-8, 580-4, 586-91. · 2.67 Impact Factor
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BioTechniques 02/2003; 34(1):160-2. · 2.67 Impact Factor
