Adoptive T-cell therapy for malignancies using redirected T cells genetically engineered by tumor antigen-specific T-cell receptor (TCR) gene transfer is associated with mispairing between introduced and endogenous TCR chains with unknown specificity. Therefore, deterioration of antitumor reactivity and serious autoimmune reactivity are major concerns. To address this problem, we have recently established a novel retroviral vector system encoding siRNAs for endogenous TCR genes (siTCR vector). In this study, to test the clinical application of siTCR gene therapy for human leukemia, we examined in detail the efficacy and safety of WT1-siTCR-transduced T cells. Compared with conventional WT1-TCR (WT1-coTCR) gene-transduced T cells, these cells showed significant enhancement of antileukemia reactivity resulting from stronger expression of the introduced WT1-specific TCR with inhibition of endogenous TCRs. Notably, WT1-siTCR gene-transduced T cells were remarkably expandable after repetitive stimulation with WT1 peptide in vitro, without any deterioration of antigen specificity. WT1-siTCR gene-transduced T cells from IntroductionRecent identification of various tumor-associated antigens has encouraged the clinical development of cell-mediated immunotherapy for leukemia targeting leukemia-associated antigens. 1,2 Among various kinds of immunotherapy, adoptive tumor-specific T-cell therapy using ex vivo expansion of autologous tumorresponsive T cells seems to be an attractive option. Indeed, patients with advanced metastatic melanoma have been treated successfully with melanoma-specific T cells obtained from tumor-infiltrating T cells. [3][4][5] Although adoptive transfer of tumor-specific tumorinfiltrating T cells is a promising strategy, its general application for therapy would appear to be unlikely because of the complex procedures and difficulties involved in the timely preparation of sufficient numbers of tumor-specific cytotoxic T lymphocytes (CTLs) with adequate therapeutic quality. 6,7 To address these problems, an innovative approach involving substituting redirected T cells using predefined tumor antigen-specific T-cell receptor (TCR) gene transfer has been developed. In recent clinical trials, melanoma antigen-specific TCR gene-transferred T cells have been used for treatment of patients with advanced melanoma. 8,9 However, the clinical efficacy of TCR gene-engineered T cells is still not satisfactory, and serious autoimmune responses have been observed in some melanoma patients. In addition, adoptive immunotherapy using tumor antigen-specific TCR gene-transferred T cells targeting malignancies other than melanoma still remains in its infancy. Therefore, the development of TCR gene-immunotherapy targeting universal tumor-associated antigens is essential to popularize this strategy for cancer treatment.Wilms tumor gene product 1 (WT1) is one of the zinc-finger transcriptional regulators that is abundantly expressed in the vast majority of acute leukemias, but not in normal cells. 10,11 In addition, the exp...

Background-The measurement of serum concentrations of cardiac troponin T (TnT) is a simple, useful method to detect myocyte injury that may be repeated multiple times to follow patients without interobserver variability. Methods and Results-Multiple measurements of TnT with a second-generation assay were performed in 60 patients with dilated cardiomyopathy confirmed by coronary angiography and endomyocardial biopsy between April 1996 and December 1999. Three evolutionary patterns of TnT concentrations were identified. Thirty-three patients had concentrations of TnT Ͻ0.02 ng/mL throughout the follow-up period (group 1). The remaining 27 patients had high initial serum concentrations of TnT (Ն0.02 ng/mL). In 10 of these 27 patients, TnT decreased to Ͻ0.02 ng/mL during follow-up (group 2), whereas 17 had persistently high serum TnT concentrations despite being conventionally treated for chronic congestive heart failure (group 3). Although the initial echocardiographic left ventricular diastolic dimension (LVDd) and left ventricular ejection fraction (LVEF) were not significantly different among the 3 groups, follow-up echocardiography showed significantly decreased LVDd and increased LVEF in group 1 (each PϽ0.01) and group 2 (each PϽ0.05) compared with increased LVDd and decreased LVEF in group 3 (each PϽ0.05). The cardiac event-free rate was significantly lower in group 3 than in groups 1 and 2 (each PϽ0.001), and the survival rate was lower in group 3 than in group 1 (PϽ0.05). Conclusions-Persistently increased

Deficiency of X-linked inhibitor of apoptosis (XIAP) caused by XIAP/BIRC4 gene mutations is an inherited immune defect recognized as X-linked lymphoproliferative syndrome type 2. This disease is mainly observed in patients with hemophagocytic lymphohistiocytosis (HLH) often associated with Epstein-Barr virus infection. We described nine Japanese patients from six unrelated families with XIAP deficiency and studied XIAP protein expression, XIAP gene analysis, invariant natural killer T (iNKT) cell counts, and the cytotoxic activity of CD8(+) alloantigen-specific cytotoxic T lymphocytes. Of the nine patients, eight patients presented with symptoms in infancy or early childhood. Five patients presented with recurrent HLH, one of whom had severe HLH and died after cord blood transplantation. One patient presented with colitis, as did another patient's maternal uncle, who died of colitis at 4 years of age prior to diagnosis with XIAP deficiency. Interestingly, a 17-year-old patient was asymptomatic, while his younger brother suffered from recurrent HLH and EBV infection. Seven out of eight patients showed decreased XIAP protein expression. iNKT cells from patients with XIAP deficiency were significantly decreased as compared with age-matched healthy controls. These results in our Japanese cohort are compatible with previous studies, confirming the clinical characteristics of XIAP deficiency.

Breeding the Y chromosome from certain Mus musculus domesticus strains onto the inbred laboratory mouse strain, C57BL/6J (B6), results in hermaphroditic progeny. This strain-dependent sex reversal suggests that there may be significant allelic variation in the murine sex determining gene, Sry. We have analysed the Sry genes from several domesticus-type Y chromosomes and show that they encode smaller proteins than the molossinus-type alleles SryB6 and Sry129. We have also identified a polymorphic stretch of trinucleotide repeats that is unique to strains causing sex reversal and show that specific changes in the predicted polyglutamine amino acid sequence at this site are associated with different degrees of sex reversal.