Adoptive transfer of viral antigen-specific memory T cells can reconstitute antiviral immunity, but in a recent report a majority of virus-specific cytotoxic T-lymphocyte (CTL) lines showed in vitro cross-reactivity against allo-human leukocyte antigen (HLA) molecules as measured by interferon-␥ secretion. We therefore reviewed our clinical experience with adoptive transfer of allogeneic hematopoietic stem cell transplantation donor-derived virus-specific CTLs in 153 recipients, including 73 instances where there was an HLA mismatch. There was no de novo acute graft-versus-host disease after infusion, and incidence of graft-versus-host disease reactivation was low and not significantly different in recipients of matched or mismatched CTL. However, we found that IntroductionAfter stem cell transplantation, there are high morbidity and mortality from viral disease. 1 Such complications are commonest where the donor and recipient are partially human leukocyte antigen (HLA)-mismatched or the donor graft has been depleted of mature T lymphocytes to prevent alloreactivity and graft-versushost disease (GVHD). As a consequence, several investigators have administered donor-derived virus-specific T cells to transplantation recipients to reduce the incidence and severity of posttransplantation viral disease with apparent clinical benefit. 2-9 A recent study by Amir et al, however, suggests that transfer of HLA-mismatched virus-specific cytotoxic T-lymphocytes (CTLs) might risk graftversus-host alloreactions. 10 In that study, T-cell lines reactive against Epstein-Barr virus (EBV), cytomegalovirus, varicella zoster virus, and influenza virus were tested against a panel of HLA-typed target cells and target cells transduced with single HLA molecules. 10 Remarkably, 80% of virus-specific T-cell lines and 45% of virus-specific T-cell clones derived therefrom were crossreactive against allo-HLA molecules, as measured by ␥-interferon secretion. 10 This cross-reactivity was observed in both CD8 ϩ and CD4 ϩ T-cell clones, being directed primarily against HLA class I and II antigens, respectively. These observations raise the concern that virus-specific T cells might mediate graft rejection or GVHD when administered to HLA class I or II mismatched recipients. 10 Notwithstanding the apparently high level of cross-reactivity in the in vitro assays reported by Amir et al,10 there are no data to suggest that cross-reactivity of virus-specific T cells with HLA specificities leads to clinical complications. [3][4][5][6][7][8][9] None of these studies, however, formally dissected responses in recipients who had received HLA partially mismatched virus-specific CTLs, or examined whether the observed lack of any GVHD was simply the result of fortuitous absence of alloreactivity in the administered lines.We now report that, in 73 recipients of virus-specific CTLs from an HLA-mismatched donor, we have not observed GVHD associated with the cell infusion. In 4 patients, the alloreactivity of infused lines was characterized in an in vitro assay ...

Hepatitis-associated aplastic anemia (HAA) is a syndrome of bone marrow failure following an acute attack of seronegative hepatitis. Clinical features and liver histology suggest a central role for an immune-mediated mechanism. To characterize the immune response, we investigated the T-cell repertoire (T-cell receptor [TCR] V ␤ chain subfamily) of intrahepatic lymphocytes in HAA patients by TCR spectratyping. In 6 of 7 HAA liver samples, a broad skewing pattern in the 21 V ␤ subfamilies tested was observed. In total, 62% ؎ 18% of HAA spectratypes showed a skewed pattern, similar to 68% ؎ 18% skewed spectratype patterns in 3 of 4 patients with confirmed viral hepatitis. Additionally, the T-cell repertoire had similarly low levels of complexity. In the peripheral blood lymphocytes (PBLs) of a separate group of HAA patients prior to treatment, 60% ؎ 15% skewed spectratypes were detected, compared with only 18% ؎ 8% skewed spectratypes in healthy controls. After successful immunosuppressive treatment, an apparent reversion to a normal T-cell repertoire with a corresponding significant increase in T-cell repertoire complexity was observed in the HAA samples. In conclusion, our data suggest an antigendriven T-cell expansion in HAA and achievement of a normal T-cell repertoire during recovery from HAA. IntroductionHepatitis-associated aplastic anemia (HAA), the development of hematopoietic failure with bone marrow hypocellularity within 6 months of an episode of hepatitis, is not uncommon, with hepatitis preceding the onset of bone marrow failure in 2% to 5% of aplastic anemia (AA) cases in Europe and the United States. 1 Aplastic anemia is also frequent following orthotopic liver transplantation for non-A, non-B, non-C hepatitis in young patients: 23% to 8% of non-A, non-B, non-C hepatitis patients receiving transplants developed aplastic anemia, compared with fewer than 1% of all liver transplant patients. 2,3 The hepatitis/aplastic anemia syndrome shows a stereotypical pattern; most often affecting young males, the hepatitis generally follows a benign course, but the onset of aplastic anemia 2 to 3 months later can be explosive and is usually fatal if untreated. 4 The presumed infectious cause of the hepatitis is unknown, but most cases are seronegative for known hepatitis viruses, including hepatitis A, B, C, and G (GB virus C[GBV-C]). [5][6][7] We previously reported 10 cases of HAA seen at the National Institutes of Health (NIH) that had evidence of lymphocyte activation; 70% responded to immunosuppression with antithymocyte globulin and cyclosporine. 8 Apart from case reports, the presence of lymphocyte activation, 9,10 and the clinical response to either immunosuppression or bone marrow transplantation, 11 little is known of the immunopathogenesis of this syndrome.The time interval between the occurrence of hepatitis and the onset of bone marrow failure suggests that the initial target organ of the immune response is the liver. For both hepatitis B and hepatitis C infection, large numbers of lymphocytes infilt...

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Adoptive transfer of adult-seropositive, cytomegalovirus (CMV)-specific T-cells can effectively restore antiviral immunity after transplantation. Lack of CMV-specific memory T-cells in blood from CMV-seronegative adult and cord blood (CB) donors restricts the availability of donor-derived virus-specific T-cells for immunoprophylaxis. Here we demonstrate the feasibility of naïve-donor-derived CMV-specific T-cell therapy for transplant recipients. Primed naïve T-cells recognized only atypical epitopes and with a similar avidity to CMV-seropositive-derived T-cells recognizing typical epitopes, but T-cells from CMV-seropositive donors recognizing atypical epitopes had a lower avidity suggesting the loss of high-avidity T-cells over time. Clonotypic analysis revealed T-cells recognizing atypical CMVpp65 epitopes in the peripheral blood of recipients of CB grafts who did not develop CMV. T-cell receptors from atypical epitopes were most common in unmanipulated CB units explaining why these T-cells expanded. When infused to recipients, naïve donor-derived virus specific T-cells that recognized atypical epitopes were associated with prolonged periods of CMV-free survival and complete remission.

Background T-cell large granular lymphocytic leukemia (T-LGL) is a lymphoproliferative disease presenting with immune-mediated cytopenias and characterized by clonal expansion of cytotoxic CD3+CD8+ lymphocytes. Methotrexate, cyclosporine, or cyclophosphamide improve cytopenias in 50% of patients as first therapy, but the activity of an anti-CD52 monoclonal antibody, alemtuzumab, is not defined in T-LGL. Methods Twenty-five consecutive subjects with T-LGL were enrolled from October 2006 to March 2015 at the National Institutes of Health (www.clinicaltrials.gov-NCT00345345). Alemtuzumab was administered at 10 mg/day intravenously for 10 days. The primary endpoint was haematologic response at 3 months. Analysis was intention to treat. Here we report the protocol specified interim benchmark of a phase II clinical trial using alemtuzumab in T-LGL. Findings In this heterogeneous, previously treated cohort, 14/25 (56%; 95% CI, 37–73%) subjects had a haematological response at 3 months. In T-LGL cases not associated with myelodysplasia or marrow transplantation, the response rate was 14/19 (74%; 95% CI, 51–86%). First dose infusion reactions were common which improved with symptomatic therapy. EBV and CMV reactivations were common and subclinical. In only 2 patients pre-emptive anti-CMV therapy was instituted. There were no cases of EBV or CMV disease. Alemtuzumab induced sustained reduction of absolute clonal population of T-cytotoxic lymphocytes, as identified by TCRBV-receptor phenotype, but the abnormal clone serendipitously persisted in responders. STAT3 mutations in the SH2 domain, identified in ten subjects, did not correlate with response. When compared with healthy volunteers, T-LGL subjects showed a distinct plasma cytokine and JAK-STAT signature prior to treatment, but neither correlated to response. Interpretation This is the largest and only prospective cohort of T-LGL subjects treated with alemtuzumab yet reported. The high activity with a single course of a lymphocytotoxic agent in a mainly relapsed and refractory suggests that haematologic response outcomes can be accomplished without the need for continued use of oral immunosuppression. Funding This research was supported by the Intramural Research Program of the NIH, National Heart, Lung, and Blood Institute.

KIT mutations are the most common secondary mutations in inv (16)

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SummaryA growing body of evidence suggests that inflammatory cytokines have a dualistic role in immunity. In this study, we sought to determine the direct effects of interferon-c (IFN-c) on the differentiation and maturation of human peripheral blood monocyte-derived dendritic cells (moDC). Here, we report that following differentiation of monocytes into moDC with granulocyte-macrophage colony-stimulating factor and interleukin-4, IFN-c induces moDC maturation and up-regulates the co-stimulatory markers CD80/CD86/CD95 and MHC Class I, enabling moDC to effectively generate antigen-specific CD4 + and CD8 + T-cell responses for multiple viral and tumour antigens. Early exposure of monocytes to high concentrations of IFN-c during differentiation promotes the formation of macrophages. However, under low concentrations of IFN-c, monocytes continue to differentiate into dendritic cells possessing a unique geneexpression profile, resulting in impairments in subsequent maturation by IFN-c or lipopolysaccharide and an inability to generate effective antigenspecific CD4 + and CD8 + T-cell responses. These findings demonstrate that IFN-c imparts differential programmes on moDC that shape the antigenspecific T-cell responses they induce. Timing and intensity of exposure to IFN-c can therefore determine the functional capacity of moDC.