Severe and fatal viral infections remain common after hematopoietic stem cell transplantation. Adoptive transfer of cytotoxic T lymphocytes (CTLs) specific for Epstein-Barr virus (EBV), cytomegalovirus (CMV), and adenoviral antigens can treat infections that are impervious to conventional therapies, but broader implementation and extension to additional viruses is limited by competition between virus-derived antigens and time-consuming and laborious manufacturing procedures. We now describe a system that rapidly generates a single preparation of polyclonal (CD4(+) and CD8(+)) CTLs that is consistently specific for 15 immunodominant and subdominant antigens derived from 7 viruses (EBV, CMV, Adenovirus (Adv), BK, human herpes virus (HHV)-6, respiratory syncytial virus (RSV), and Influenza) that commonly cause post-transplant morbidity and mortality. CTLs can be rapidly produced (10 days) by a single stimulation of donor peripheral blood mononuclear cells (PBMCs) with a peptide mixture spanning the target antigens in the presence of the potent prosurvival cytokines interleukin-4 (IL4) and IL7. This approach reduces the impact of antigenic competition with a consequent increase in the antigenic repertoire and frequency of virus-specific T cells. Our approach can be readily introduced into clinical practice and should be a cost-effective alternative to common antiviral prophylactic agents for allogeneic hematopoietic stem cell transplant (HSCT) recipients.
Of 11 children with juvenile myelomonocytic leukemia (JMML) carrying RAS mutations (8 with NRAS mutations, 3 with KRAS2 mutations), 5 had a profound elevation in either or both the white blood cells and spleen size at diagnosis. Three patients had no or modest hepatosplenomegaly and mild leukocytosis at presentation but subsequently showed a marked increase in spleen size with or without hematologic exacerbation, for which nonintensive chemotherapy was initiated. The other three patients with NRAS or KRAS2 glycine to serine substitution received no chemotherapy, but hematologic improvement has been observed during a 2-to 4-year follow up. In the third group, all hematopoietic cell lineages analyzed had the RAS mutations at the time of hematologic improvement, whereas DNA ob- IntroductionSomatic point mutations of the RAS genes at codons 12, 13, and 61 (NRAS and KRAS2) are found in approximately 20% of patients with juvenile myelomonocytic leukemia (JMML). 1,2 Other patients show inactivation of NF1 or PTPN11 mutations. [3][4][5] Although most patients with JMML die from progressive disease unless treated with hematopoietic stem cell transplantation, there are a few patients who have been reported to spontaneously recover without intervention. 6,7 Some of these children have JMML associated with Noonan syndrome, but others do not. So far, the individual prognosis in JMML-carrying specific genetic aberrations remains unclear. We report the clinical course in 11 patients with RAS mutations. Materials and methodsThis study was approved by the Institutional Review Board of Shinshu University. Informed consent was obtained from the guardians of the patients following institutional guidelines. Cell preparationWe used peripheral blood (PB) or bone marrow (BM) mononuclear cells (MNCs) that had been frozen with liquid nitrogen. CD3-and CD56-positive PB cells were separated immunomagnetically. 8 Ninety-nine percent of the isolated cells were CD3-or CD56-positive according to a flow cytometric analysis. Clonal cell cultureTwenty thousand PB or BM MNCs were plated in a dish containing methylcellulose medium supplemented with or without 0.01 to 10 ng/mL of granulocyte-macrophage colony-stimulating factor (GM-CSF). 9 To examine the clonal derivation of myeloid and erythroid lineages, 2000 CD34 ϩ PB cells harvested immunomagnetically were cultured in methylcellulose medium supplemented with GM-CSF, stem cell factor, interleukin 3, and erythropoietin. Twelve days after incubation in 5% CO 2 , GM colonies, erythroid colonies, and mixed colonies were individually lifted and prepared as single cell suspensions. Sequence analyses were then performed on individual colonyconstituent cells. Detection of NRAS and KRAS2 mutationsDNA was extracted from PB or BM MNCs and nails. Exon 1 (codons 12 and 13) and exon 2 (codon 61) of NRAS and KRAS2 genes were amplified by polymerase chain reaction (PCR) using primer pairs described previously. 10,11 The PCR products were subjected to direct sequencing from both directions on an automatic DNA se...
The success of adoptively transferred tumor-directed T cells requires them to survive and expand in vivo. Most tumors, however, employ immune evasion mechanisms, including the production of inhibitory cytokines that limit in vivo T-cell persistence and effector function. To protect tumor-directed T cells from such negative influences, we generated a chimeric cytokine receptor in which the interleukin (IL) 4 receptor exodomain was fused to the IL7 receptor endodomain. We thereby inverted the effects of tumor-derived IL4 so that the proliferation and activation of tumor directed cytotoxic T cells was enhanced rather than inhibited in the tumor microenvironment, resulting in superior antitumor activity. These transgenic T cells were only activated in the tumor environment since triggering required exposure to both tumor antigen (signal 1) and tumor-derived IL4 (signal 2). This selectivity supports future clinical adaptation.
Epstein-Barr virus (EBV) is the pathogen that most commonly triggers infection-associated hemophagocytic lymphohistiocytosis (HLH) and ectopically infects CD8(+) T cells in EBV-associated HLH (EBV-HLH). We recently described an EBV-HLH patient who had a clonally expanded population of EBV-infected CD8(+) T cells with CD5 down-regulation. To determine whether this finding could serve as a useful marker for EBV-HLH, we investigated 5 additional patients. We found a significant increase in the subpopulation of CD8(+) T cells with CD5 down-regulation and bright human leukocyte antigen (HLA)-DR expression in all patients with EBV-HLH but not in patients with infectious mononucleosis or in control subjects. Such T cells were frequently found to be larger cells that stained positive for a specific T cell receptor VB. We also demonstrated that those cells were the major cellular target of EBV, and their numbers progressively declined in parallel with the serum ferritin levels. All together, our findings reveal the immunophenotypic characteristics of EBV-infected CD8(+) T cells and may provide a valuable tool for the diagnosis of EBV-HLH.
M-sol-R-PCs were found to be effective in preventing ATRs without loss of transfusion efficiency in children; however, its efficacy should be further evaluated in prospective clinical trials.
These results suggest that leucocytes or mediators from leucocytes are underlying cause of ATRs in addition to FNHTRs in children. Furthermore, particular characteristics of patients would be other risk factors for ATRs.
BackgroundDiamond-Blackfan anemia is a rare, clinically heterogeneous, congenital red cell aplasia: 40% of patients have congenital abnormalities. Recent studies have shown that in western countries, the disease is associated with heterozygous mutations in the ribosomal protein (RP) genes in about 50% of patients. There have been no studies to determine the incidence of these mutations in Asian patients with Diamond-Blackfan anemia. Design and MethodsWe screened 49 Japanese patients with Diamond-Blackfan anemia (45 probands) for mutations in the six known genes associated with Diamond-Blackfan anemia: RPS19, RPS24, RPS17, RPL5, RPL11, and RPL35A. RPS14 was also examined due to its implied involvement in 5q-syndrome. ResultsMutations in RPS19, RPL5, RPL11 and RPS17 were identified in five, four, two and one of the probands, respectively. In total, 12 (27%) of the Japanese Diamond-Blackfan anemia patients had mutations in ribosomal protein genes. No mutations were detected in RPS14, RPS24 or RPL35A. All patients with RPS19 and RPL5 mutations had physical abnormalities. Remarkably, cleft palate was seen in two patients with RPL5 mutations, and thumb anomalies were seen in six patients with an RPS19 or RPL5 mutation. In contrast, a small-for-date phenotype was seen in five patients without an RPL5 mutation. ConclusionsWe observed a slightly lower frequency of mutations in the ribosomal protein genes in patients with Diamond-Blackfan anemia compared to the frequency reported in western countries. Genotype-phenotype data suggest an association between anomalies and RPS19 mutations, and a negative association between small-for-date phenotype and RPL5 mutations.Key words: protein genes, Diamond-Blackfan anemia, RPL5 mutation. DiamondBlackfan anemia. Haematologica 2010;95(8):1293-1299. doi:10.3324/haematol.2009 This is an open-access paper. Citation: Konno Y, Toki T, Tandai S, Xu G, Wang RN, Terui K, Ohga S, Hara T, Hama A, Kojima S, Hasegawa D, Kosaka Y, Yanagisawa R, Koike K, Kanai R, Imai T, Hongo T, Park M-J, Sugita K, and Ito E. Mutations in the ribosomal protein genes in Japanese patients with Mutations in the ribosomal protein genes in Japanese patients with Diamond-Blackfan anemia
Background aims To develop a treatment option for Philadelphia chromosome—positive acute lymphoblastic leukemia (Ph+ALL) resistant to tyrosine kinase inhibitors (TKIs), we evaluated the anti-leukemic activity of T cells non-virally engineered to express a CD19-specific chimeric antigen receptor (CAR). Methods A CD19.CAR gene was delivered into mononuclear cells from 10 mL of blood of healthy donors through the use of piggyBac-transposons and the 4-D Nucleofector System. Nucleofected cells were stimulated with CD3/CD28 antibodies, magnetically selected for the CD19.CAR, and cultured in interleukin-15–containing serum-free medium with autologous feeder cells for 21 days. To evaluate their cytotoxic potency, we co-cultured CAR T cells with seven Ph+ALL cell lines including three TKI-resistant (T315I–mutated) lines at an effector-to-target ratio of 1:5 or lower without cytokines. Results We obtained ~ 1.3 × 108 CART cells (CD4+, 25.4%; CD8+, 71.3%), co-expressing CD45RA and CCR7 up to ~80%. After 7-day co-culture, CAR T cells eradicated all tumor cells at the 1:5 and 1:10 ratios and substantially reduced tumor cell numbers at the 1:50 ratio. Kinetic analysis revealed up to 37-fold proliferation of CART cells during a 20-day culture period in the presence of tumor cells. On exposure to tumor cells, CAR T cells transiently and reproducibly upregulated the expression of transgene as well as tumor necrosis factor–related apoptosis-inducing ligand and interleukin-2. Conclusions We generated a clinically relevant number of CAR T cells from 10 mL of blood through the use of piggyBac-transposons, a 4D-Nulcleofector, and serum/xeno/tumor cell/virus-free culture system. CAR T cells exhibited marked cytotoxicity against Ph+ALL regardless of T315I mutation. PiggyBac-mediated CD19-specific T-cell therapy may provide an effective, inexpensive and safe option for drug-resistant Ph+ALL.
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