Autologous Epstein-Barr virus (EBV)-specific cytotoxic T cells for the treatment of persistent active EBV infection

Constitutive Interleukin-7 Cytokine Signaling Enhances the Persistence of Epstein-Barr Virus-Specific T-Cells

The efficacy of therapeutic T-cells is limited by a lack of positive signals and excess inhibitory signaling in tumor microenvironments. We previously showed that a constitutively active IL7 receptor (C7R) enhanced the persistence, expansion, and anti-tumor activity of T-cells expressing chimeric antigen receptors (CARs), and C7R-modified GD2.CAR T-cells are currently undergoing clinical trials. To determine if the C7R could also enhance the activity of T-cells recognizing tumors via their native T-cell receptors (TCRs), we evaluated its effects in Epstein-Barr virus (EBV)-specific T-cells (EBVSTs) that have produced clinical benefits in patients with EBV-associated malignancies. EBVSTs were generated by stimulation of peripheral blood T-cells with overlapping peptide libraries spanning the EBV lymphoma antigens, LMP1, LMP2, and EBNA 1, followed by retroviral vector transduction to express the C7R. The C7R increased STAT5 signaling in EBVSTs and enhanced their expansion over 30 days of culture in the presence or absence of exogenous cytokines. C7R-EBVSTs maintained EBV antigen specificity but were dependent on TCR stimulation for continued expansion. C7R-EBVSTs produced more rapid lymphoma control in a murine xenograft model than unmodified EBVSTs and persisted for longer. The findings have led to a clinical trial, evaluating C7R-EBVSTs for the treatment of refractory or relapsed EBV-positive lymphoma (NCT04664179).

Epstein‒Barr virus-associated cellular immunotherapy

Epstein‒Barr virus (EBV) is a human herpes virus that is saliva-transmissible and universally asymptomatic. It has been confirmed that more than 90% of the population is latently infected with EBV for life. EBV can cause a variety of related cancers, such as nasopharyngeal carcinoma, diffuse large B-cell lymphoma, and Burkitt lymphoma. Currently, many clinical studies have demonstrated that EBV-specific cytotoxic T lymphocytes and other cell therapies can be safely and effectively transfused to prevent and treat some diseases caused by EBV. This review will mainly focus on discussing EBV-specific cytotoxic T lymphocytes and will touch on therapeutic EBV vaccines and chimeric antigen receptor T-cell therapy briefly.

Delivering co-stimulatory tumor necrosis factor receptor agonism for cancer immunotherapy: past, current and future perspectives

The tumor necrosis factor superfamily (TNFSF) and their receptors (TNFRSF) are important regulators of the immune system, mediating proliferation, survival, differentiation, and function of immune cells. As a result, their targeting for immunotherapy is attractive, although to date, under-exploited. In this review we discuss the importance of co-stimulatory members of the TNFRSF in optimal immune response generation, the rationale behind targeting these receptors for immunotherapy, the success of targeting them in pre-clinical studies and the challenges in translating this success into the clinic. The efficacy and limitations of the currently available agents are discussed alongside the development of next generation immunostimulatory agents designed to overcome current issues, and capitalize on this receptor class to deliver potent, durable and safe drugs for patients.

Reconstitution of EBV-directed T cell immunity by adoptive transfer of peptide-stimulated T cells in a patient after allogeneic stem cell transplantation for AITL

Reconstitution of the T cell repertoire after allogeneic stem cell transplantation is a long and often incomplete process. As a result, reactivation of Epstein-Barr virus (EBV) is a frequent complication that may be treated by adoptive transfer of donor-derived EBV-specific T cells. We generated donor-derived EBV-specific T cells by stimulation with peptides representing defined epitopes covering multiple HLA restrictions. T cells were adoptively transferred to a patient who had developed persisting high titers of EBV after allogeneic stem cell transplantation for angioimmunoblastic T-cell lymphoma (AITL). T cell receptor beta (TCRβ) deep sequencing showed that the T cell repertoire of the patient early after transplantation (day 60) was strongly reduced and only very low numbers of EBV-specific T cells were detectable. Manufacturing and in vitro expansion of donor-derived EBV-specific T cells resulted in enrichment of EBV epitope-specific, HLA-restricted T cells. Monitoring of T cell clonotypes at a molecular level after adoptive transfer revealed that the dominant TCR sequences from peptide-stimulated T cells persisted long-term and established an EBV-specific TCR clonotype repertoire in the host, with many of the EBV-specific TCRs present in the donor. This reconstituted repertoire was associated with immunological control of EBV and with lack of further AITL relapse.

A characteristic feature of all herpesviruses is their persistence in the host’s body after primary infection. Hence, the host’s immune system is confronted with the problem to control these viruses life-long. When the immune system is severely compromised, for example after stem cell transplantation from a foreign (allogeneic) donor, these viruses can reappear, as they persist in the host’s body life-long after primary infection. Epstein-Barr virus (EBV) is a herpesvirus that can cause life-threatening complications after stem cell transplantation and only reinforcement of the host’s immune system can reestablish control over the virus. Here we show that ex vivo manufactured EBV-specific T cells can reestablish long-term control of EBV and that these cells persist in the host’s body over months. These results give us a better understanding of viral immune reconstitution post-transplant and of clinically-relevant T cell populations against EBV.

Characterizing EBV-associated lymphoproliferative diseases and the role of myeloid-derived suppressor cells

Chronic active Epstein-Barr virus (CAEBV) typically presents as persistent infectious mononucleosis-like disease and/or hemophagocytic lymphohistocytosis (HLH), reflecting ectopic Epstein-Barr virus (EBV) infection and lymphoproliferation of T and/or NK cells. Clinical behavior ranges from indolent, stable disease through to rapidly progressive, life-threatening disease. Although it is thought the chronicity and/or progression reflect an escape from immune control, very little is known about the phenotype and function of the infected cells vs coresident noninfected population, nor about the mechanisms that could underpin their evasion of host immune surveillance. To investigate these questions, we developed a multicolor flow cytometry technique combining phenotypic and functional marker staining with in situ hybridization for the EBV-encoded RNAs (EBERs) expressed in every infected cell. This allows the identification, phenotyping, and functional comparison of infected (EBERPOS) and noninfected (EBERNEG) lymphocyte subset(s) in patients' blood samples ex vivo. We have characterized CAEBV and HLH cases with monoclonal populations of discrete EBV-activated T-cell subsets, in some cases accompanied by EBV-activated NK-cell subsets, with longitudinal data on the infected cells' progression despite standard steroid-based therapy. Given that cytotoxic CD8+ T cells with relevant EBV antigen specificity were detectable in the blood of the best studied patient, we searched for means whereby host surveillance might be impaired. This revealed a unique feature in almost every patient with CAEBV studied: the presence of large numbers of myeloid-derived suppressor cells that exhibited robust inhibition of T-cell growth. We suggest that their influence is likely to explain the host's failure to contain EBV-positive T/NK-cell proliferation.

Case Report: Pediatric Chronic Active Epstein-Barr Virus Infection With Giant Sinus of Valsalva Aneurysms and Aorta and Its Branch Dilations

Chronic active Epstein-Barr virus infection (CAEBV), which often manifests as persistent infectious mononucleosis-like symptoms and can involve multiple organs, is a prolonged or reactivated status of primary EBV infection. Cardiovascular damage is one of the rare but severe complications correlated with poor prognosis among all CAEBV patients. Few published articles have demonstrated systemic arterial lesions involving branches of the aorta as cardiovascular complications. Herein, we report a rare pediatric case of CAEBV associated with giant sinus of Valsalva aneurysms and aorta and its branch dilations.

The Identity Card of T Cells-Clinical Utility of T-cell Receptor Repertoire Analysis in Transplantation

There is a clear medical need to change the current strategy of "one-size-fits-all" immunosuppression for controlling transplant rejection to precision medicine and targeted immune intervention. As T cells play a key role in both undesired graft rejection and protection, a better understanding of the fate and function of both alloreactive graft-deteriorating T cells and those protecting to infections is required. The T-cell receptor (TCR) is the individual identity card of each T cell clone and can help to follow single specificities. In this context, tracking of lymphocytes with certain specificity in blood and tissue in clinical follow up is of especial importance. After overcoming technical limitations of the past, novel molecular technologies opened new avenues of diagnostics. Using advantages of next generation sequencing, a method was established for T-cell tracing by detection of variable TCR region as identifiers of individual lymphocyte clones. The current review describes principles of laboratory and computational methods of TCR repertoire analysis, and gives an overview on applications for the basic understanding of transplant biology and immune monitoring. The review also delineates methodological pitfalls and challenges. With the outlook on prediction of antigens in immune-mediated processes including those of unknown causative pathogens, monitoring the fate and function of individual T cell clones, and the adoptive transfer of protective effector or regulatory T cells, this review highlights the current and future capability of TCR repertoire analysis.

A case of abdominal-pelvic infiltrative lesion of chronic active Epstein–Barr virus infection

Epstein–Barr virus (EBV) belongs to a subfamily of herpesviruses, also known as human herpesvirus type 4. EBV is widely distributed in the population, with a high infection rate of 90%. EBV infects mainly B lymphocytes, stimulates cell proliferation and transformation and even causes cancer. In recent years, it has been found that it can also infect T lymphocytes, epithelial cells and natural killer (NK) cells and can cause related diseases. EBV infection can cause a variety of clinical symptoms and clinical manifestations, which brings some confusion to clinical diagnosis and easily leads to missed diagnosis and misdiagnosis. In this article, we report a case of EBV-induced severe abdominal and pelvic infection, which eventually led to death.

Comprehensive Characterization of a Next-Generation Antiviral T-Cell Product and Feasibility for Application in Immunosuppressed Transplant Patients

Viral infections have a major impact on morbidity and mortality of immunosuppressed solid organ transplant (SOT) patients because of missing or failure of adequate pharmacologic antiviral treatment. Adoptive antiviral T-cell therapy (AVTT), regenerating disturbed endogenous T-cell immunity, emerged as an attractive alternative approach to combat severe viral complications in immunocompromised patients. AVTT is successful in patients after hematopoietic stem cell transplantation where T-cell products (TCPs) are manufactured from healthy donors. In contrast, in the SOT setting TCPs are derived from/applied back to immunosuppressed patients. We and others demonstrated feasibility of TCP generation from SOT patients and first clinical proof-of-concept trials revealing promising data. However, the initial efficacy is frequently lost long-term, because of limited survival of transferred short-lived T-cells indicating a need for next-generation TCPs. Our recent data suggest that Rapamycin treatment during TCP manufacture, conferring partial inhibition of mTOR, might improve its composition. The aim of this study was to confirm these promising observations in a setting closer to clinical challenges and to deeply characterize the next-generation TCPs. Using cytomegalovirus (CMV) as model, our next-generation Rapamycin-treated (Rapa-)TCP showed consistently increased proportions of CD4⁺ T-cells as well as CD4⁺ and CD8⁺ central-memory T-cells (T_CM). In addition, Rapamycin sustained T-cell function despite withdrawal of Rapamycin, showed superior T-cell viability and resistance to apoptosis, stable metabolism upon activation, preferential expansion of T_CM, partial conversion of other memory T-cell subsets to T_CM and increased clonal diversity. On transcriptome level, we observed a gene expression profile denoting long-lived early memory T-cells with potent effector functions. Furthermore, we successfully applied the novel protocol for the generation of Rapa-TCPs to 19/19 SOT patients in a comparative study, irrespective of their history of CMV reactivation. Moreover, comparison of paired TCPs generated before/after transplantation did not reveal inferiority of the latter despite exposition to maintenance immunosuppression post-SOT. Our data imply that the Rapa-TCPs, exhibiting longevity and sustained T-cell memory, are a reasonable treatment option for SOT patients. Based on our success to manufacture Rapa-TCPs from SOT patients under maintenance immunosuppression, now, we seek ultimate clinical proof of efficacy in a clinical study.

Serological Assessment of 18 Pathogens and Risk of AIDS-Associated Non-Hodgkin Lymphoma

BACKGROUND

HIV infection is associated with increased susceptibility to common pathogens, which may trigger chronic antigenic stimulation and hyperactivation of B cells, events known to precede the development of AIDS-associated non-Hodgkin lymphoma (AIDS-NHL).

METHODS

To explore whether cumulative exposure to infectious agents contributes to AIDS-NHL risk, we tested sera from 199 AIDS-NHL patients (pre-NHL, average lead time 3.9 years) and 199 matched HIV-infected controls from the Multicenter AIDS Cohort Study, for anti-IgG responses to 18 pathogens using multiplex serology. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression models.

RESULTS

We found no association between cumulative exposure to infectious agents and AIDS-NHL risk (OR 1.01, 95% CI: 0.91 to 1.12). However, seropositivity for trichodysplasia spinulosa polyomavirus (TSPyV), defined as presence of antibodies to TSPyV capsid protein VP1, was significantly associated with a 1.6-fold increase in AIDS-NHL risk (OR 1.62, 95% CI: 1.02 to 2.57). High Epstein-Barr virus (EBV) anti-VCA p18 antibody levels closer to the time of AIDS-NHL diagnosis (<4 years) were associated with a 2.6-fold increase in AIDS-NHL risk (OR 2.59, 95% CI: 1.17 to 5.74). In addition, high EBV anti-EBNA-1 and anti-ZEBRA antibody levels were associated with 2.1-fold (OR 0.47, 95% CI: 0.26 to 0.85) and 1.6-fold (OR 0.57, 95% CI: 0.35 to 0.93) decreased risk of AIDS-NHL, respectively.

CONCLUSIONS

Our results do not support the hypothesis that cumulative exposure to infectious agents contributes to AIDS-NHL development. However, the observed associations with respect to TSPyV seropositivity and EBV antigen antibody levels offer additional insights into the pathogenesis of AIDS-NHL.

Chronic active EBV infection associated with NK cell lymphoma and hemophagocytic lymphohistiocytosis in a 27-year-old woman: A case report

RATIONALE

Chronic active Epstein-Barr virus infection (CAEBV) is a common infectious disease that often affects multiple organs or systems. However, it is liable to be neglected and misdiagnosed owing to its insidious onset, lack of specific findings in the early phase, and a general lack of awareness among clinicians. PATIENT CONCERNS:: a 27-year-old woman case has been described who was initially misdiagnosed as drug-induced liver injury due to onset presentation of mild splenomegaly, recurrent liver dysfunction, and disputable pathological evidence of liver biopsy.

DIAGNOSES

CAEBV complicated with natural killer (NK) cell lymphoma and hemophagocytic lymphohistiocytosis (HLH) was diagnosed by in situ hybridization of liver tissue section with EBV-encoded RNA -1 probe and flow cytometry of bone marrow.

INTERVENTIONS

After admission, the patient received symptomatic treatment and antiviral therapy (combination of acyclovir and foscarnet sodium) as well as adjuvant treatment (thymosin alpha 1 and methylprednisolone); later, the patient received etoposide and dexamethasone for diagnosis of EBV associated HLH. Subsequently, the disease progressed to NK cell lymphoma and the patient received the revised EPOCH chemotherapy regimen [etoposide (100 mg/d, d1-5), dexamethasone (7.5 mg/d, d1-5; 5 mg/d, d6-14), cyclophosphamide (0.8 g/d, d1-2), and pegaspargase (3750 u/d, tid, d1-2)].

OUTCOMES

Although the patient received a series of therapies and other comprehensive measures, finally she died of gastrointestinal hemorrhage and multiple organ failure.

LESSONS

Liver is one of the main target organs of EBV infection. In the clinical setting of unexplained fever and liver injury, it is necessary to be aware of CAEBV, as well as its fatal complication such as EBV associated NK cell lymphoma and HLH.

Spleen Tyrosine Kinase Inhibitor TAK-659 Prevents Splenomegaly and Tumor Development in a Murine Model of Epstein-Barr Virus-Associated Lymphoma

The novel SYK and FLT3 inhibitor TAK-659 prevents the enlargement of spleen and tumor development in a mouse model of EBV-associated lymphoma by counteracting the activation of cellular kinase SYK through the viral LMP2A gene by inducing cell death in tumor cells but not in nontumor cells. These findings indicate that TAK-659 may be a very effective nontoxic therapeutic molecule especially for EBV-positive hematologic malignancies.

Epstein-Barr virus (EBV) is associated with several B and epithelial cell cancers. EBV-encoded latent membrane protein 2A (LMP2A) contributes to cellular transformation by mimicking B cell receptor signaling. LMP2A/MYC double transgenic mice develop splenomegaly and B cell lymphoma much faster than MYC transgenic mice do. In this study, we explored the potential therapeutic efficacy of a novel spleen tyrosine kinase (SYK) and FLT3 inhibitor TAK-659 for development of a treatment option for EBV-associated malignancies. In our transgenic model, TAK-659 treatment totally abrogated splenomegaly and tumor development in LMP2A/MYC mice in both pretumor and tumor cell transfer experiments. TAK-659 treatment killed tumor cells, but not host cells within the spleen and tumors. Furthermore, TAK-659 treatment abrogated metastasis of tumor cells into bone marrow. Our data also show that TAK-659 inhibits SYK phosphorylation and induces apoptosis in LMP2A/MYC tumor cells at low nanomolar concentrations. Therefore, TAK-659 may provide an effective therapeutic option for treatment of LMP2A-positive EBV-associated malignancies and should be explored further in clinical trials.

IMPORTANCE The novel SYK and FLT3 inhibitor TAK-659 prevents the enlargement of spleen and tumor development in a mouse model of EBV-associated lymphoma by counteracting the activation of cellular kinase SYK through the viral LMP2A gene by inducing cell death in tumor cells but not in nontumor cells. These findings indicate that TAK-659 may be a very effective nontoxic therapeutic molecule especially for EBV-positive hematologic malignancies.

The clinical characteristics and the features of immunophenotype of peripheral lymphocytes of adult onset chronic active Epstein-Barr virus disease at a Tertiary Care Hospital in Beijing

Chronic active Epstein-Barr virus (CAEBV) infection is a rare disease with high mortality. Most of CAEBV patients have been reported from Japan and are pediatric cases.The goal was to describe the clinical characteristics and the immunophenotypic features of peripheral lymphocytes in adult onset CAEBV patients.We retrospectively reviewed and analyzed all adult onset CAEBV cases admitted to Peking Union Medical College Hospital (PUMCH) between 2012 and 2016. Demographic, clinical, laboratory data, and the immunophentyping data of peripheral lymphocytes were collected.There were 28 adult onset CAEBV patients. The median age was 45 (range, 20-81). Most of the patients presented with fever; splenomegaly; lymphadenopathy and hepatitis. Unlike pediatric cases reported, the manifestations of cardiovascular diseases in our patients were pulmonary arterial hypertension, decreased cardiac function and aorta vasculitis. Prevalence of interstitial pneumonitis in our patients were comparatively higher and prevalence of hypersensitivity to mosquito bites were comparatively lower than that reported by Japan. In this study, CAEBV patients had decreased B cell, NK cell, CD4 cell and CD8 cell counts. The prevalence of low level of B cells, NK cells, CD4 cells was relatively higher than reported ever.Chinese adult onset CAEBV patients have different clinical characteristics and are featured by an immunosuppression status as demonstrated by decreased B cell, NK cell, CD4 cell and CD8 cell.

Specific Adoptive T-Cell Therapy for Viral and Fungal Infections

Despite advances in anti-infective agents, viral and fungal infections after hematopoietic stem cell transplantation (HSCT) continue to cause life-threatening complications that limit the success of HSCT. Early adoptive T-cell immunotherapy studies showed that administration of allogeneic virus-specific cytotoxic T lymphocytes (vCTL) can prevent and control viral infections and reconstitute antiviral immunity to cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Advances in immunobiology, in vitro culture technology, and current good manufacturing practice (cGMP) have provided opportunities for advancing adoptive cell therapy for viral infections: (1) T cells have been expanded targeting multiple pathogens; (2) vCTL production no longer requires viral infection or viral vector transduction of antigen-presenting cells (APCs); (3) the source of lymphocytes is no longer restricted to donors who are immune to the pathogens; (4) naive T cells have been redirected with chimeric antigen receptor T cells (CARTs) or armed with bispecific antibody-armed T cells (BATs) to mediate vCTL activity; (5) these technologies could be combined to targeted multiple viral or fungal pathogens; and (6) pathogen-specific T-cell products manufactured from third parties and banked for “off-the-shelf” use post-HSCT may soon become a reality.

Hematopoietic Stem Cell Transplantation for the Treatment of Epstein-Barr Virus-Associated T- or NK-Cell Lymphoproliferative Diseases and Associated Disorders

Chronic active Epstein-Barr virus infection (CAEBV) is a prototype of EBV-associated T- and/or NK-cell (EBV⁺ T/NK-cell) lymphoproliferative disorders. Most subtypes of these are lethal. We established a unified treatment strategy composed of step 1 (immunochemotherapy: steroids, cyclosporine A, and etoposide), step 2 (multi-drug block chemotherapy), and step 3 (allogeneic hematopoietic stem cell transplantation; HSCT) for CAEBV and its related diseases. Allogeneic HSCT is the only cure for CAEBV with few exceptions. Primary-EBV infection-associated hemophagocytic lymphohistiocytosis (primary-EBV HLH) is also an EBV⁺ T/NK-cell lymphoproliferation. The nature of EBV⁺ T/NK cells in CAEBV and those in primary-EBV HLH differ. In primary-EBV HLH, most patients need step 1 only and some require step 2 for the successful induction of apoptosis in EBV-infected T cells; however, some exceptional patients require HSCT. We herein present our single institutional experience of CAEBV and primary-EBV HLH, together with that of post-transplant EBV⁺ T/NK-cell lymphoproliferative disease. We also discuss some practical points on HCST with a review of the literature.

The spread of EBV to ectopic lymphoid aggregates may be the final common pathway in the pathogenesis of ME/CFS

According to the hypothesis presented here, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) develops over 3 steps: Step 1 is characterized by the aggregation of lymphoid cells in dorsal root ganglia or other nervous structures. The cause of this formation of ectopic lymphoid aggregates may be an acute infection, asymptomatic reactivations of a common neurotropic virus, exposure to a neurotoxin, or physical injury to peripheral nerves. In step 2, Epstein-Barr virus (EBV)-infected lymphocytes or monocytes bring EBV from the circulation to one or several of these lymphoid aggregates, whereupon cell-to-cell transmission of EBV and proliferation of latently EBV-infected lymphocytes lead to the presence of many EBV-infected cells in the lymphoid aggregates. The EBV-infected cells in the aggregates ignite an inflammation in the surrounding nervous tissue. This local inflammation elicits, in turn, a wave of glial cell activation that spreads from the EBV-infected area to parts of the nervous system that are not EBV-infected, disturbing the neuron-glial interaction in both the peripheral - and central nervous system. In step 3, immune cell exhaustion contributes to a consolidation of the pathological processes. There might be a cure: Infusions of autologous EBV-specific T-lymphocytes can perhaps remove the EBV-infected cells from the nervous system.

How we treat chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus infection (CAEBV) is a prototype of the EBV-associated T- or NK-cell lymphoproliferative diseases, which also include hypersensitivity to mosquito bites and severe-type hydroavacciniforme. The manifestations of CAEBV are often self-limiting with minimum supportive care or only prednisolone and cyclosporine A with or without etoposide. However, allogeneic hematopoietic stem cell transplantation (HSCT) is the only cure, without which patients with CAEBV die within several years. A severe hypercytokinemia and hemophagocytic syndrome, which may occur suddenly, often results in a fatal clinical course. At out institute, we have established a 3-step strategy, including allogeneic HSCT, for the treatment of CAEBV. Seventy-nine patients with CAEBV and related diseases have been treated to date. The 3-year overall survival rate (3y-OS) is currently 87.3 ± 4.2% after planned allogeneic HSCT. However, 3y-OS in patients with uncontrolled active disease is only 16.7 ± 10.8%. To maximize survival rates with minimized late sequelae, we recommend earlier initiation and completion of the 3-step treatment without watchful waiting. We present six illustrative and difficult cases (including severe hypercytokinemia or emergent HSCT) and discuss them together with 73 residual cases.

Inherited CD70 deficiency in humans reveals a critical role for the CD70-CD27 pathway in immunity to Epstein-Barr virus infection

Izawa et al. identify the first patient with CD70 deficiency suffering from recurrent EBV-induced B cell proliferations including Hodgkin’s lymphoma. Expression of CD70 on B cells is necessary to induce proliferation of EBV-specific T cells.

Epstein-Barr virus (EBV) infection in humans is a major trigger of malignant and nonmalignant B cell proliferations. CD27 is a co-stimulatory molecule of T cells, and inherited CD27 deficiency is characterized by high susceptibility to EBV infection, though the underlying pathological mechanisms have not yet been identified. In this study, we report a patient suffering from recurrent EBV-induced B cell proliferations including Hodgkin’s lymphoma because of a deficiency in CD70, the ligand of CD27. We show that EBV-specific T lymphocytes did not expand properly when stimulated with CD70-deficient EBV-infected B cells, whereas expression of CD70 in B cells restored expansion, indicating that CD70 on B cells but not on T cells is required for efficient proliferation of T cells. CD70 was found to be up-regulated on B cells when activated and during EBV infection. The proliferation of T cells triggered by CD70-expressing B cells was dependent on CD27 and CD3 on T cells. Importantly, CD27-deficient T cells failed to proliferate when stimulated with CD70-expressing B cells. Thus, the CD70–CD27 pathway appears to be a crucial component of EBV-specific T cell immunity and more generally for the immune surveillance of B cells and may be a target for immunotherapy of B cell malignancies.

Achievement of disease control with donor-derived EB virus-specific cytotoxic T cells after allogeneic peripheral blood stem cell transplantation for aggressive NK-cell leukemia

Aggressive NK-cell leukemia (ANKL) is characterized by systemic infiltration of Epstein-Barr virus (EBV)-associated natural killer cells and poor prognosis. We report a case of ANKL in which EBV-specific cytotoxic T lymphocytes (CTLs) were induced. A 41-year-old male suffered from fever, pancytopenia, and hepatosplenomegaly. The number of abnormal large granular lymphocytes in the bone marrow was increased and the cells were positive for CD56 and EBV-encoded small nuclear RNAs. The patient was diagnosed with ANKL and achieved a complete response following intensive chemotherapy. He then underwent allogeneic peripheral blood stem cell transplantation from his sister. Conditioning therapy consisted of total body irradiation and cyclophosphamide. Graft-versus-host disease prophylaxis consisted of cyclosporine and methotrexate. On day 31, complete donor chimerism was achieved and no acute graft-versus-host disease developed. The ANKL relapsed on day 80, and cyclosporine was rapidly tapered and chemotherapy was started. During hematopoietic recovery, the number of atypical lymphocytes increased, but they were donor-derived EBV-specific CTLs. The patient achieved a partial response and EBV viral load decreased to normal range. Unfortunately, ANKL worsen again when the CTLs disappeared from his blood. This is the first case report of ANKL in which induced EBV-specific CTLs may have contributed to disease control.

Generating Peripheral Blood Derived Lymphocytes Reacting Against Autologous Primary AML Blasts

Expanding on our prior studies with cord blood T cells, we hypothesized that primary acute myeloid leukemia (AML)-reactive autologous T cells could be generated ex vivo under immunomodulatory conditions. We purified AML and T cells from 8 newly diagnosed high-risk patients. After 2 weeks expansion, T cells were stimulated with interferon-γ-treated autologous AML weekly × 3, interleukin-15, and agonistic anti-CD28 antibody. Cytotoxic T cells and ELISpot assays tested functionality; reverse transcriptase quantitative polymerase chain reaction tested AML and T-cell gene expression profiles. On the basis of combined positive ELIspot and cytotoxic T cells assays, T cells reactive against AML were generated in 5 of 8 patients. Treg proportion declined after cocultures in reactive T-cell samples. AML-reactive T cells displayed an activated gene expression profile. "Resistant" AML blasts displayed genes associated with immunosuppressive myeloid-derived suppressor cells. We discuss our approach to creating primary AML-reactive autologous T cell and limitations that require further work. Our study provides a platform for future research targeting on generating autologous leukemia-reactive T cells.

A Case Report of NK-Cell Lymphoproliferative Disease With a Wide Involvement of Digestive Tract Develop Into Epstein-Barr Virus Associated NK/T Cell Lymphoma in an Immunocompetent Patient

Epstein-Barr virus (EBV) plays an important role in various diseases. EBV-associated lymphoproliferative disease (LPD) is a rare disease with a canceration tendency. It is difficult to differentiate LPD with involvement of digestive tract from Crohn disease due to similar clinical and endoscopic manifestations. We present a case report of multiple ulcers with esophagus, small bowel and the entire colon involved, proved to be NK-Cell LPD, developed into EBV-associated NK/T Cell lymphoma, in an immunocompetent man who was initially misdiagnosed as Crohn disease.This report underscores that intestinal ulcers should be cautiously diagnosed, for it sometimes could be a precancerous lesion.

Treatment of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis: Study protocol of a prospective pilot study

In this manuscript, a number of debatable issues related to the diagnosis and treatment of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis (EBV-HLH) will be addressed. Considering the heterogeneous nature of EBV-HLH, diagnostic efforts are required to clarify the precise nature of the disease at diagnosis, the number of EBV genome copies in peripheral blood, and localization of the EBV genome in lymphoid cells (B, T, or natural killer cells). Although the majority of cases of EBV-HLH develop without evidence of immunodeficiency, some cases have been found to be associated with chronic active EBV infection, genetic diseases such as X-linked lymphoproliferative disease (XLP, type 1, or type 2), or familial HLH (FHL, types 2-5). Due to such background heterogeneity, the therapeutic results of EBV-HLH have also been found to vary. Patients have been found to respond to corticosteroids alone or an etoposide-containing regimen, whereas other patients require hematopoietic stem cell transplantation. Thus, decision-making for optimal treatment of EBV-HLH and its eventual outcome requires evaluation in consideration of the precise nature of the disease. A protocol for a pilot study on the treatment of patients with EBV-HLH is presented here.

Immune control of oncogenic γ-herpesviruses

Human γ-herpesviruses contain Epstein Barr virus (EBV), the first human tumor virus that was identified in man, and Kaposi Sarcoma associated herpesvirus (KSHV), one of the most recently identified human oncogenic pathogens. Both of these have co-evolved with humans to cause tumors only in a minority of infected individuals, despite their exquisite ability to establish persistent infections. In this review we will summarize the fine-tuned balance between immune responses, immune escape and cellular transformation by these viruses, which results in life-long persistent, but asymptomatic infection with immune control in most virus carriers. A detailed understanding of this balance is required to immunotherapeutically reinstall it in patients that suffer from EBV and KSHV associated malignancies.

A heart breaking case of rapidly developing severe hemophagocytic syndrome secondary to chronic active EBV infection; a case report and review of the literature

Epstein-Barr virus (EBV, HHV-4) is a gamma Herpesvirus with a 90% >seroprevalence in adults. Reactivations in non-immuno compromised individuals usually cause mild or no symptoms at all. Rarely, host immunity-virus balance is interrupted, resulting in a chronic active EBV infection. The following case illustrates the rapid development of severe hemophagocytic syndrome during chronic active EBV infection in a 73 year old woman who presented with lower extremity pain and edema, splenomegaly and abnormal liver enzymes. A diagnosis of chronic active EBV infection was made following an extensive investigation and the patient died secondary to rapidly progressive hemophagocytic syndrome.

Epstein Barr virus-associated lymphoproliferative diseases: the virus as a therapeutic target

Epstein Barr virus (EBV)-associated lymphoproliferative diseases (LPDs) express all EBV latent antigens (type III latency) in immunodeficient patients and limited antigens (type I and II latencies) in immunocompetent patients. Post-transplantation lymphoproliferative disease (PTLD) is the prototype exhibiting type III EBV latency. Although EBV antigens are highly immunogenic, PTLD cell proliferation remains unchecked because of the underlying immunosuppression. The restoration of anti-EBV immunity by EBV-specific T cells of either autologous or allogeneic origin has been shown to be safe and effective in PTLDs. Cellular therapy can be improved by establishing a bank of human leukocyte antigen-characterized allogeneic EBV-specific T cells. In EBV+ LPDs exhibiting type I and II latencies, the use of EBV-specific T cells is more limited, although the safety and efficacy of this therapy have also been demonstrated. The therapeutic role of EBV-specific T cells in EBV+ LPDs needs to be critically reappraised with the advent of monoclonal antibodies and other targeted therapy. Another strategy involves the use of epigenetic approaches to induce EBV to undergo lytic proliferation when expression of the viral thymidine kinase renders host tumor cells susceptible to the cytotoxic effects of ganciclovir. Finally, the prophylactic use of antiviral drugs to prevent EBV reactivation may decrease the occurrence of EBV+ LPDs.

Adapted treatment of Epstein-Barr virus infection to prevent posttransplant lymphoproliferative disorder after heart transplantation

Up to 35% of posttransplant lymphoproliferative disorder (PTLD) cases occur within 1 year of transplantation, and over 50% are associated with Epstein-Barr virus (EBV). EBV primary infection and reactivation are PTLD predictive factors, but there is no consensus for their treatment. We conducted a prospective single-center study on 299 consecutive heart-transplant patients treated with the same immunosuppressive regimen and monitored by repetitive EBV viral-load measurements and endomyocardial biopsies to detect graft rejection. Immunosuppression was tapered on EBV reactivation with EBV viral loads >10(5) copies/mL or primary infection. In the absence of response at 1 month or a viral load >10(6) copies/mL, patients received one rituximab infusion (375 mg/m(2) ). All patients responded to treatment without increased graft rejection. One primary infection case developed a possible PTLD, which completely responded to diminution of immunosuppression, and one patient, whose EBV load was unevaluable, died of respiratory complications secondary to PTLD. Compared with a historical cohort of 820 patients, PTLD incidence was decreased (p = 0.033) by a per-protocol analysis. This is the largest study on EBV primary infection/reactivation treatment, the first using rituximab following solid organ transplantation to prevent PTLD and the first to demonstrate an acceptable tolerability profile in this setting.

Impact of T cell selection methods in the success of clinical adoptive immunotherapy

Chemotherapy and/or radiotherapy regular regimens used for conditioning of recipients of hematopoietic stem cell transplantation (SCT) induce a period of transient profound immunosuppression. The onset of a competent immunological response, such as the appearance of viral-specific T cells, is associated with a lower incidence of viral infections after haematopoietic transplantation. The rapid development of immunodominant peptide virus screening together with advances in the design of genetic and non-genetic viral- and tumoural-specific cellular selection strategies have opened new strategies for cellular immunotherapy in oncologic recipients who are highly sensitive to viral infections. However, the rapid development of cellular immunotherapy in SCT has disclosed the role of the T cell selection method in the modulation of functional cell activity and of in vivo secondary effects triggered following immunotherapy.

EBV associated lymphomas in 2008 WHO classification

Epstein-Barr virus (EBV) is a ubiquitous γ-herpes virus that asymptomatically infects more than 90% of the world's population. The exact mechanism of EBV in oncogenesis is an area of active debate. However, EBV has been implicated in the pathogenesis of several kinds of lymphomas and lymphoproliferative disorders, including B-, T- and NK-cell derived. Subsequent studies have proven that the EBV gene expression product plays an activating and/or promoting role on lymphomagenesis, and paves the way for novel cellular therapies of EBV-associated lymphomas. This review concentrates on the pathology, morphology, treatment and prognosis of EBV-associated lymphomas in the 2008 WHO classification of tumors of hematopoietic and lymphoma tissues.

The changing immune system in sepsis: is individualized immuno-modulatory therapy the answer?

Sepsis remains the leading cause of death in most intensive care units. Advances in understanding the immune response to sepsis provide the opportunity to develop more effective therapies. The immune response in sepsis can be characterized by a cytokine-mediated hyper-inflammatory phase, which most patients survive, and a subsequent immune-suppressive phase. Patients fail to eradicate invading pathogens and are susceptible to opportunistic organisms in the hypo-inflammatory phase. Many mechanisms are responsible for sepsis-induced immuno-suppression, including apoptotic depletion of immune cells, increased T regulatory and myeloid-derived suppressor cells, and cellular exhaustion. Currently in clinical trial for sepsis are granulocyte macrophage colony stimulating factor and interferon gamma, immune-therapeutic agents that boost patient immunity. Immuno-adjuvants with promise in clinically relevant animal models of sepsis include anti-programmed cell death-1 and interleukin-7. The future of immune therapy in sepsis will necessitate identification of the immunologic phase using clinical and laboratory parameters as well as biomarkers of innate and adaptive immunity.

Clinical Implications of T Cell Receptor Repertoire Analysis after Allogeneic Stem Cell Transplantation

Stem cell transplantation (SCT) constitutes a major challenge to the immune system. Long-term impairment of immunity against various common infectious stimuli leads to increased susceptibility to infectious diseases; in contrast, an immune response against the recipient may cause the devastating graft-versus-host disease (GvHD). Recovery of the immune system (both qualitative and quantitative) after SCT is perhaps the most important factor in determining the clinical outcome. Consequently, immune reconstitution has been extensively studied using different approaches, including quantitative analysis of immune cells as well as their phenotypic characterization. Analysis of diversity and clonality is an important tool in determining competence of the immune system, assuming that a broad diversity assures efficient response to different stimuli and clonal dominance reflects ongoing, potentially relevant immune responses. Detailed analysis of the immune repertoire through the flow cytometric and molecular study of the T cell receptor repertoire has been applied to gain quantitative and qualitative insights about the T cell immune competence and responsiveness. After SCT, a contraction of the T cell pool and a reduction in T cell receptor diversity is clearly associated with clinical immunodeficiency. Reconstitution of the immune system is often characterized by dominance of oligoclonal T cell populations, reflecting specific antigen-driven immune responses. Detailed characterization of T lymphocytes by T cell receptor analysis is possible, and may lead to the identification of individual clones involved in specific immune reactions, such as alloresponses in GvHD, the closely related graft-versus-leukemia effect and opportunistic viral agents such as CMV or EBV.

Clinicopathologic features of chronic active Epstein-Barr virus hepatitis

AIM: To investigate the clinicopathologic features of chronic active Epstein-Barr virus hepatitis (CAEBVH) as well as its diagnosis, differential diagnosis, treatment and prognosis.

METHODS: We presented the clinical manifestations, histopathological characteristics, diagnosis, treatment and prognosis of two cases of CAEBVH. A literature review was also performed to summarize the characteristics of this clinical entity.

RESULTS: Of two young male patients, one presented with intermittent fever, jaundice, hepatosplenomegaly and abnormal liver function, the other had abnormal liver biochemical tests and symptoms including edema of lower limbs, yellowish urine, fatigue, splenomegaly, and central nervous system symptoms. Histopathologic examination of liver biopsies revealed varying degrees of macrovesicular steatosis and fibrosis, scattered lobular necrosis, beaded sinusoidal lymphocytic infiltration, portal inflammation and interface activity. Electron microscopic investigation showed chronic hepatitis along with steatosis of liver cells and fibrosis. No mylinoid body, special lysosome, glycogen storage or hepatitis B surface antigens were found. In situ hybridization (ISH) for EBV early RNA (EBER) showed EBER-positive nuclei of lymphocytes. Both patients ended in death. The course was 2 years and 4 mo for case 1 and 13 years and 5 mo for case 2.

CONCLUSION: CAEBVH has no specific clinical features, which makes it easy to reach a misdiagnosis. Pathologic features include macrovesicular steatosis, fibrosis, beaded sinusoidal lymphocytes infiltration, scattered lobular necrosis, interface activity and portal inflammation. EBER-positive nuclei of lymphocytes can be detected by ISH. This disease has a poor prognosis and early diagnosis is pivotal for appropriate clinical management.

Mg2+ regulates cytotoxic functions of NK and CD8 T cells in chronic EBV infection through NKG2D

The magnesium transporter 1 (MAGT1) is a critical regulator of basal intracellular free magnesium (Mg(2+)) concentrations. Individuals with genetic deficiencies in MAGT1 have high levels of Epstein-Barr virus (EBV) and a predisposition to lymphoma. We show that decreased intracellular free Mg(2+) causes defective expression of the natural killer activating receptor NKG2D in natural killer (NK) and CD8(+) T cells and impairs cytolytic responses against EBV. Notably, magnesium supplementation in MAGT1-deficient patients restores intracellular free Mg(2+) and NKG2D while concurrently reducing EBV-infected cells in vivo, demonstrating a link between NKG2D cytolytic activity and EBV antiviral immunity in humans. Moreover, these findings reveal a specific molecular function of free basal intracellular Mg(2+) in eukaryotic cells.

Phenotypic and functional attributes of lentivirus-modified CD19-specific human CD8+ central memory T cells manufactured at clinical scale

A key determinant of the therapeutic potency of adoptive T-cell transfer is the extent to which infused cells can persist and expand in vivo. Ex vivo propagated virus-specific and chimeric antigen receptor (CAR)-redirected antitumor CD8 effector T cells derived from CD45RA(-) CD62L(+) central memory (TCM) precursors engraft long-term and reconstitute functional memory after adoptive transfer. Here, we describe a clinical scale, closed system, immunomagnetic selection method to isolate CD8(+) T(CM) from peripheral blood mononuclear cells (PBMC). This method uses the CliniMACS device to first deplete CD14(+), CD45RA(+), and CD4(+) cells from PBMC, and then to positively select CD62L(+) cells. The average purity and yield of CD8(+) CD45RA(-) CD62L TCM obtained in full-scale qualification runs were 70% and 0.4% (of input PBMC), respectively. These CD8(+) T(CM) are responsive to anti-CD3/CD28 bead stimulation, and can be efficiently transduced with CAR encoding lentiviral vectors, and undergo sustained expansion in interleukin (IL)-2/IL-15 over 3-6 weeks. The resulting CD8(+) T(CM)-derived effectors are polyclonal, retain expression of CD62L and CD28, exhibit CAR-redirected antitumor effector function, and are capable of huIL-15-dependent in vivo homeostatic engraftment after transfer to immunodeficient NOD/Scid IL-2RgCnull mice. Adoptive therapy using purified T(CM) cells is now the subject of a Food and Drug Administration-authorized clinical trial for the treatment of CD19(+) B-cell malignancies, and 3 clinical cell products expressing a CD19-specific CAR for IND #14645 have already been successfully generated from lymphoma patients using this manufacturing platform.

Quantification of Epstein-Barr virus DNA is helpful for evaluation of chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus infection (CAEBV) presents with chronic or recurrent infectious mononucleosis-like symptoms, such as low-grade fever, liver dysfunction, lymphadenopathy, and hepatosplenomegaly. Immunological methods are useful for the diagnosis of viral infections. However, CAEBV patients do not necessarily have high titers of Epstein-Barr virus (EBV)-specific antibodies. Hosts that are immunocompromised after hematopoietic stem cell transplantations sometimes suffer from systemic EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and EBV-positive lymphoma. Patients with EBV-associated diseases are often diagnosed by analyses of bone marrow. Cytomegalovirus (CMV) can cause serious pneumonia or retinitis in immunocompromised hosts. In order to noninvasively understand the clinical status of patients with EBV-associated diseases, we conducted real-time polymerase chain reaction (PCR) methods in their peripheral blood in order to quantify EBV and CMV DNA levels, which reflect viral activity. Here, we describe a 30-year-old Japanese female patient with CAEBV. The patient had repeated fever, fatigue, and liver dysfunction. The histopathological results of liver biopsies were positive for EBV-encoded RNA-1. Acute hepatitis was associated with the EBV infection. The whole-blood EBV DNA levels were high and above 1.0 × 10⁷ copies/mL. After immunosuppressive and antiviral therapies, EBV DNA levels lowered. However, she had to receive bone marrow transplantation because of her EBV-HLH. As the number of lymphocytes increased in the post-transplantation period, EBV DNA levels gradually increased again. The simultaneous detection of CMV DNA was more sensitive than the CMV antigenemia test that is often used to diagnose CMV infections. Unfortunately, the patient died due to a fungal infection. Observing EBV DNA levels closely with real-time quantitative PCR methods is helpful for evaluating the changes in the clinical course.

CD27 deficiency is associated with combined immunodeficiency and persistent symptomatic EBV viremia

BACKGROUND

CD27 is a lymphocyte costimulatory molecule that regulates T-cell, natural killer (NK) cell, B-cell, and plasma cell function, survival, and differentiation. On the basis of its function and expression pattern, we considered CD27 a candidate gene in patients with hypogammaglobulinemia.

OBJECTIVE

We sought to describe the clinical and immunologic phenotypes of patients with genetic CD27 deficiency.

METHODS

A molecular and extended immunologic analysis was performed on 2 patients lacking CD27 expression.

RESULTS

We identified 2 brothers with a homozygous mutation in CD27 leading to absence of CD27 expression. Both patients had persistent symptomatic EBV viremia. The index patient was hypogammaglobulinemic, and immunoglobulin replacement therapy was initiated. His brother had aplastic anemia in the course of his EBV infection and died from fulminant gram-positive bacterial sepsis. Immunologically, lack of CD27 expression was associated with impaired T cell-dependent B-cell responses and T-cell dysfunction.

CONCLUSION

Our findings identify a role for CD27 in human subjects and suggest that this deficiency can explain particular cases of persistent symptomatic EBV viremia with hypogammaglobulinemia and impaired T cell-dependent antibody generation.

[Chronic active Epstein-Barr virus infection]

The ubiquitous Epstein-Barr virus (EBV), which establishes latency after primary infection, does not cause any symptomatic diseases as long as cellular immunity is intact. In apparently immunocompetent individuals, a chronic infection can develop, and this has been called as chronic active EBV infection (CAEBV). CAEBV is characterized by chronic or recurrent infectious mononucleosis-like symptoms, such as fever, extensive lymphadenopathy, and, hepatosplenomegaly. This disease is rare but severe with high morbidity and mortality. Recently, its pathophysiology is not an infection but a clonal expansion of EBV-infected T or natural killer NK cells. In this review, I discuss our current understanding of the pathogenesis of CAEBV and summarize its clinical features, therapies, and prognosis.

EBV-associated T/NK-cell lymphoproliferative diseases in nonimmunocompromised hosts: prospective analysis of 108 cases

EBV-associated T/NK-cell lymphoproliferative disease (T/NK-LPD) is defined as a systemic illness characterized by clonal proliferation of EBV-infected T or NK cells. We prospectively enrolled 108 nonimmunocompromised patients with this disease (50 men and 58 women; median onset age, 8 years; age range, 1-50 years) evidenced by expansion of EBV(+) T/NK cells in the peripheral blood; these were of the T-cell type in 64 cases and of the NK-cell type in 44, and were clinically categorized into 4 groups: 80 cases of chronic active EBV disease, 15 of EBV-associated hemophagocytic lymphohistiocytosis, 9 of severe mosquito bite allergy, and 4 of hydroa vacciniforme. These clinical profiles were closely linked with the EBV(+) cell immunophenotypes. In a median follow-up period of 46 months, 47 patients (44%) died of severe organ complications. During the follow-up, 13 patients developed overt lymphoma or leukemia characterized by extranodal NK/T-cell lymphoma and aggressive NK-cell leukemia. Fifty-nine received hematopoietic stem cell transplantation, 66% of whom survived. Age at onset of disease (≥ 8 years) and liver dysfunction were risk factors for mortality, whereas patients who received transplantation had a better prognosis. These data depict clinical characteristics of systemic EBV(+) T/NK-LPD and provide insight into the diagnostic and therapeutic approaches for distinct disease.

Adverse events following infusion of T cells for adoptive immunotherapy: a 10-year experience

BACKGROUND AIMS

The Food and Drug Administration (FDA) currently recommends at least 4 h of recipient monitoring after T cell infusions to detect early infusion reactions. Recent catastrophic reactions to 'first-in-man' biologic agents have emphasized the importance of this rule for initial studies of new products. The value of such monitoring for better established agents is less obvious.

METHODS

We reviewed infusion-related adverse events (AE) following administration of ex vivo-expanded T cell products (antigen-specific cytotoxic T lymphocytes, allodepleted T cells, and genetically modified T cells) on investigational new drug (IND) studies in our center.

RESULTS

From 1998 to 2008, we infused 381 T cell products to 180 recipients, enrolled on 18 studies, receiving T cells targeting malignancies or post-transplant viral infections. There were no grade 3-4 infusion reactions during initial monitoring or 24-h follow-up. Twenty-four mild (grade 1-2) AE occurred in 21 infusions either during or immediately following infusion (up to 6 h), most commonly nausea and vomiting (10/24, 41.6%), probably because of the dimethyl sulfoxide cryoprotectant, and hypotension (20.8%), attributable to diphenhydramine pre-medication. Twenty-two additional non-severe events were reported within 24 h of infusion, most commonly culture-negative fever, chills and nausea. An increased risk of adverse events was associated with age [incidence rate ratio (IRR) 0.98; 95% confidence interval (CI) 0.96-1.00, P = 0.05], while an increased risk of immediate infusion-related events was higher in patients reporting allergies (IRR 2.72, 95% CI 1.00-7.40, P = 0.05); sex, disease type and T cell source (allogeneic or autologous) had no effect on frequency of adverse events.

CONCLUSIONS

Infusion of these T cell products was safe in the outpatient setting and associated with no severe reactions, so monitoring for 1 h after infusion is probably sufficient. As many of the AE were attributable to diphenhydramine premedication, a lower dose (0.25 mg/kg) should be selected.

Characterization and treatment of chronic active Epstein-Barr virus disease: a 28-year experience in the United States

Chronic active EBV disease (CAEBV) is a lymphoproliferative disorder characterized by markedly elevated levels of antibody to EBV or EBV DNA in the blood and EBV RNA or protein in lymphocytes in tissues. We present our experience with CAEBV during the last 28 years, including the first 8 cases treated with hematopoietic stem cell transplantation in the United States. Most cases of CAEBV have been reported from Japan. Unlike CAEBV in Japan, where EBV is nearly always found in T or natural killer (NK) cells in tissues, EBV was usually detected in B cells in tissues from our patients. Most patients presented with lymphadenopathy and splenomegaly; fever, hepatitis, and pancytopenia were common. Most patients died of infection or progressive lymphoproliferation. Unlike cases reported from Japan, our patients often showed a progressive loss of B cells and hypogammaglobulinemia. Although patients with CAEBV from Japan have normal or increased numbers of NK cells, many of our patients had reduced NK-cell numbers. Although immunosuppressive agents, rituximab, autologous cytotoxic T cells, or cytotoxic chemotherapy often resulted in short-term remissions, they were not curative. Hematopoietic stem cell transplantation was often curative for CAEBV, even in patients with active lymphoproliferative disease that was unresponsive to chemotherapy. These studies are registered at http://www.clinicaltrials.gov as NCT00032513 for CAEBV, NCT00062868 and NCT00058812 for EBV-specific T-cell studies, and NCT00578539 for the hematopoietic stem cell transplantation protocol.

Immunotherapy for EBV-associated malignancies

Since 1995 to date, more than 250 patients with EBV-related diseases received virus-specific CTL. Cell therapy proved to be safe and effective, and achieved some complete remissions also in patients who failed all previous standard treatments. The first clinical results with EBV-specific CTL were obtained for both prophylaxis and treatment of post-transplant lymphoproliferative disease arising in stem cell transplant or solid organ transplant recipients. Based on such encouraging results, the same approach was then extended to other EBV-related diseases, namely Hodgkin's lymphoma, nasopharyngeal carcinoma, and chronic active infection. Nowadays, the modification of the CTL generation protocols and the introduction of new specificities into EBV-specific CTL lines by chimeric antigen receptor transfer allow targeting other viral infections and also non-EBV related malignancies. Aim of this review is to summarize clinical results obtained thus far in adoptive cell therapy approaches with EBV-specific CTL. Moreover, by analyzing ongoing clinical trials, we also provide some insights on the potential future of a successful and paradigmatic history.

High-avidity cytotoxic T lymphocytes specific for a new PRAME-derived peptide can target leukemic and leukemic-precursor cells

The cancer testis antigen (CTA) preferentially expressed antigen of melanoma (PRAME) is overexpressed by many hematologic malignancies, but is absent on normal tissues, including hematopoietic progenitor cells, and may therefore be an appropriate candidate for T cell-mediated immunotherapy. Because it is likely that an effective antitumor response will require high-avidity, PRAME-specific cytotoxic T lymphocytes (CTLs), we attempted to generate such CTLs using professional and artificial antigen-presenting cells loaded with a peptide library spanning the entire PRAME protein and consisting of 125 synthetic pentadecapeptides overlapping by 11 amino acids. We successfully generated polyclonal, PRAME-specific CTL lines and elicited high-avidity CTLs, with a high proportion of cells recognizing a previously uninvestigated HLA-A*02-restricted epitope, P435-9mer (NLTHVLYPV). These PRAME-CTLs could be generated both from normal donors and from subjects with PRAME(+) hematologic malignancies. The cytotoxic activity of our PRAME-specific CTLs was directed not only against leukemic blasts, but also against leukemic progenitor cells as assessed by colony-forming-inhibition assays, which have been implicated in leukemia relapse. These PRAME-directed CTLs did not affect normal hematopoietic progenitors, indicating that this approach may be of value for immunotherapy of PRAME(+) hematologic malignancies.

Immunotherapy and vaccination after transplant: the present, the future

Vaccination and adoptive immunotherapy for herpes virus infections has become an attractive option for the control of a virus family that negatively affects transplantation. In the future, enhanced ability to select antigen-specific T cells without significant in vitro manipulation should provide new opportunities for refining and enhancing adoptive immunotherapeutic approaches. This article focuses on advances in the area of vaccinology for some of these infections and in the use of adoptive immunotherapy. At present, many of these approaches in transplant recipients have focused on infections such as human cytomegalovirus, but the opportunity to use these examples as proof of concept for other infections is discussed.

Epstein-Barr virus: Silent companion or causative agent of chronic liver disease?

The Epstein-Barr virus (EBV) has an important and multifaceted role in liver pathology. As a member of the herpes virus family, EBV establishes a persistent infection in more than 90% of adults. Besides acute hepatitis during primary infection, many clinical syndromes of interest for the hepatologist are associated with EBV infection. The role of EBV in the evolution of chronic hepatitis from hepatotropic viruses is considered. Chronic EBV-associated hepatitis is suspected in immunocompetent adults with compatible serology, suggestive histology and detection of the viral genome in the liver and/or increase of specific circulating cytotoxic T-lymphocytes. EBV is the main cause of post-transplant lymphoproliferative disorders which occur in up to 30% of cases. EBV-driven lymphoproliferative diseases are also recognized in non-immunocompromised patients and liver is involved in up to a third of the cases. Directly implicated in the pathogenesis of different tumors, EBV has a disputable role in hepatocellular carcinoma carcinogenesis. Further research is required in order to establish or reject the role of EBV in human liver cancer. This paper attempts to discuss the range of EBV-associated chronic liver diseases in immunocompetent patients, from mild, self-limiting mononuclear hepatitis to liver cancer.

Immunotherapy and vaccination after transplant: the present, the future

Vaccination and adoptive immunotherapy for herpes virus infections has become an attractive option for the control of a virus family that negatively affects transplantation. In the future, enhanced ability to select antigen-specific T cells without significant in vitro manipulation should provide new opportunities for refining and enhancing adoptive immunotherapeutic approaches. This article focuses on advances in the area of vaccinology for some of these infections and in the use of adoptive immunotherapy. At present, many of these approaches in transplant recipients have focused on infections such as human cytomegalovirus, but the opportunity to use these examples as proof of concept for other infections is discussed.

The interplay between Epstein-Barr virus and the immune system: a rationale for adoptive cell therapy of EBV-related disorders

The Epstein-Barr virus has evolved a plethora of strategies to evade immune system recognition and to establish latent infection in memory B cells, where the virus resides lifelong without any consequence in the majority of individuals. However, some imbalances in the equilibrium between the inherent virus transforming properties and the host immune system can lead to the development of different tumors, such as lymphoproliferative disorders, Hodgkin's lymphoma, Burkitt's lymphoma, and nasopharyngeal carcinoma. The expression of viral antigens in malignant cells makes them suitable targets for immunotherapeutic approaches, which are mainly based on the ex vivo expansion of EBV-specific T cells. Indeed, the infusion of virus-specific cytotoxic T lymphocytes has proved not only to be safe and effective, but also capable of restoring or inducing a protective anti-virus immunity, which is lacking, albeit to a different extent, in every EBV-driven malignancy. The purpose of this review is to summarize the results of adoptive immunotherapy approaches for EBV-related malignancies, with particular emphasis on the immunological and virological aspects linked to the clinical responses obtained. Data collected confirm the clinical relevance of the use of EBV-specific cytotoxic T lymphocytes in the field of adoptive immunotherapy and suggest the increasing importance of this approach also against other tumors, concurrent with the increasing knowledge of the intimate and continuous interplay between the virus and the host immune system.