Allogeneic stem cell transplantation after reduced-intensity conditioning in lymphoid malignancies

IL-22 promoted CD3+ T cell infiltration by IL-22R induced STAT3 phosphorylation in murine acute graft versus host disease target organs after allogeneic bone marrow transplantation

Graft versus host disease (GVHD) is a life threatening complication of bone marrow stem cell transplantation, in which considerable numbers of proinflammatory cytokines secreted by allo-reactive donor T cells are involved. We and other previous studies have found that interleukin-22 (IL-22) was able to aggravate the target organs damage of GVHD. However, the mechanism and the signal pathway of IL-22 in murine acute GVHD was not clear. Here, we observed that compared with GVHD group, more serious pathological damage and more CD3(+) T cells infiltrated in GVHD target organs were detected in the mice injected with IL-22. Meanwhile, transcription factor T-bet, RORγt and AhR respectively associated with Th1, Th17 and Th22 cells changed in varying degrees in different GVHD target organs. Furthermore, the increased expression of IL-22R and its downstream protein P-STAT3 were detected in GVHD mice with IL-22 treated. These results suggested that the pathological role of IL-22 in GVHD target organs contribute to exogenous injected IL-22 as well as secreted IL-22 from the infiltrated allo-reactive effector T cells. In addition, the IL-22R-STAT3 pathway may play important role in GVHD tissue injury and target this way may yield new approaches for reduction of GVHD.

Haematopoietic SCT for children and adolescents with relapsed and refractory Hodgkin's lymphoma

Despite the generally excellent prognosis of children and adolescents with Hodgkin's lymphoma (HL), approximately 15% of patients relapse. Salvage therapy options include further chemo-radiotherapy and autologous or allogeneic haematopoietic SCT (HSCT). Autologous HSCT following high-dose chemotherapy, the standard treatment for adult patients with relapsed HL, is also effective in paediatric patients, but randomized trials showing its superiority to conventional therapy are lacking. Although patients with late relapse (>12 months after completion of therapy) may be cured with conventional therapy, those with progressive disease or early relapse (3-12 months) are considered candidates for autologous HSCT. According to patient selection criteria, overall and disease-free survival rates after autologous HSCT are 43-95% and 31-70%, respectively. Short time to relapse and refractory disease at the time of autologous HSCT remain the most important risk factors. Data on allogeneic HSCT in children with HL are scarce. Broader use has been hampered for a long time mainly by high non-relapse mortality, offsetting the advantage of a graft-vs-lymphoma effect. Data suggest that young patients with recurring disease following autologous HSCT, as well as some patients with multiple relapses and selected patients with refractory lymphoma, might benefit from allogeneic HSCT, but relapse remains the major challenge.

Current treatment strategies of the German Hodgkin Study Group (GHSG)

Hodgkin's Lymphoma (HL) has developed to one of the best curable human cancers and overall about 80% of patients experience long-term disease free survival. Therefore, current treatment strategies aim at further improving treatment outcome, thereby trying to by minimize therapy-induced complications, such as infertility, cardiopulmonary toxicity, and secondary malignancies. Ongoing trials investigate a reduction of chemotherapy in terms of dose or cycles given, and the application of lower radiation doses and smaller radiation fields. For patients with a specific high-risk profile, new approaches with more intense drug combinations are currently being investigated. Moreover, the advent of effective salvage high-dose therapy for relapsed disease and a better understanding of prognostic factors have further improved the management of HL. Here, we summarize current strategies of the German Hodgkin Study Group (GHSG) in diagnostics and treatment of primary and relapsed HL, together with recent approaches for specific subgroups of HL patients.

UTY-specific TCR-transfer generates potential graft-versus-leukaemia effector T cells

Immunotherapeutic approaches that target antigens that are differentially recognized on haematopoietic and non-haematopoietic cells may specifically enhance the graft-versus-leukaemia (GVL) effect of donor lymphocyte infusion. In this study, we have characterized a new HLA-B*5201-restricted epitope of the UTY gene. Unusually, presentation of this epitope was restricted to lymphoblasts. As a result, a T cell clone specific to this epitope recognized normal and malignant male B and T lymphoblasts, while showing little reactivity towards male HLA-B*5201+ fibroblasts. Transfer of its T cell receptor (TCR) into donor T cells led to the generation of large numbers of T cells, which acquired the specificity of the original clone, its avidity and the differential pattern of reactivity towards lymphoblasts and fibroblasts. Remarkably, the specific response of TCR-transferred T cells was significantly higher than that of the original clone. This is the first demonstration of the possibility to preserve the specific pattern of a T cell response to a differentially expressed antigen after TCR-transfer and to augment the amplitude of this response concomitantly. These results indicate that it may be feasible to enhance the GVL effect of donor lymphocyte infusions in lymphoproliferative malignancies by the transfer of TCRs specific to epitopes that are differentially recognized on lymphoblasts.

Identification of a 40S Ribosomal Protein S4–Derived H-Y Epitope Able to Elicit a Lymphoblast-Specific Cytotoxic T Lymphocyte Response

PURPOSE

The superior graft-versus-leukemia (GVL) effect of the female-to-male stem cell transplantation is partially independent from the concomitant graft-versus-host reactivity. However, the antigenic basis of this selective GVL response remains enigmatic, because no H-Y antigens with hematopoietic-restricted expression were identified. In this study, we report a novel H-Y epitope that is preferentially recognized on activated proliferating lymphocytes.

EXPERIMENTAL DESIGN

We generated a CTL clone YKIII.8 that showed reactivity toward male B*5201+ CD40-activated B cells, EBV-lymphoblastoid cell lines, and phytohemagglutinin-activated T-cell blasts but little or no reactivity toward fibroblasts, CD14+ cells, or unstimulated B and T cells. The antigen recognized by YKIII.8 was identified by screening of a cDNA expression library, and its pattern of expression was investigated.

RESULTS

cDNA of the male isoform of 40S ribosomal protein S4 was found to encode the antigenic peptide TIRYPDPVI, which was recognized by YKIII.8. Western blot analysis showed that rapidly proliferating cells overexpress the RPS4 protein in comparison with nonrecognized cell subsets. Retroviral transfer of YKIII.8 T-cell receptor resulted in preservation of the lymphoblast-specific reactivity pattern.

CONCLUSION

Our findings suggest that CTL specific to certain epitopes of ubiquitously expressed H-Y antigens may specifically target lymphoblasts, contributing to the selective GVL effect of female-to-male stem cell transplantation.