Genome-wide assessment of genetic risk loci for childhood acute lymphoblastic leukemia in Japanese patients

Not available.

Deep-learning-based automatic facial bone segmentation using a two-dimensional U-Net

The use of deep learning (DL) in medical imaging is becoming increasingly widespread. Although DL has been used previously for the segmentation of facial bones in computed tomography (CT) images, there are few reports of segmentation involving multiple areas. In this study, a U-Net was used to investigate the automatic segmentation of facial bones into eight areas, with the aim of facilitating virtual surgical planning (VSP) and computer-aided design and manufacturing (CAD/CAM) in maxillofacial surgery. CT data from 50 patients were prepared and used for training, and five-fold cross-validation was performed. The output results generated by the DL model were validated by Dice coefficient and average symmetric surface distance (ASSD). The automatic segmentation was successful in all cases, with a mean± standard deviation Dice coefficient of 0.897 ± 0.077 and ASSD of 1.168 ± 1.962 mm. The accuracy was very high for the mandible (Dice coefficient 0.984, ASSD 0.324 mm) and zygomatic bones (Dice coefficient 0.931, ASSD 0.487 mm), and these could be introduced for VSP and CAD/CAM without any modification. The results for other areas, particularly the teeth, were slightly inferior, with possible reasons being the effects of defects, bonded maxillary and mandibular teeth, and metal artefacts. A limitation of this study is that the data were from a single institution. Hence further research is required to improve the accuracy for some facial areas and to validate the results in larger and more diverse populations.

Rare TCF3 variants associated with pediatric B cell acute lymphoblastic leukemia

Germline genetic variants influence development of pediatric B cell acute lymphoblastic leukemia (B-ALL). Genome-wide association studies (GWAS) have identified several pediatric B-ALL susceptibility loci. IKZF1 and PAX5, transcription factors involved in B cell development, have been reported as susceptibility genes for B-ALL development. Therefore, we hypothesized that rare variants of genes involved in B cell development would be candidate susceptibility loci for pediatric B-ALL. Thus, we sequenced TCF3, a key transcription factor gene involving in B cell development. Saliva DNA from 527 pediatric patients with pediatric B-ALL in remission who were registered with the Tokyo Children's Cancer Study Group (TCCSG) were examined. As a TCF3 gene-based evaluation, the numbers of rare deleterious germline TCF3 sequence variants in patients with pediatric B-ALL were compared with those in cancer-free individuals using data in public databases. As a TCF3 single-variant evaluation, the frequencies of rare deleterious germline TCF3 sequence variants in patients with pediatric B-ALL were also compared with those in control data. TCF3 gene-based analysis revealed significant associations between rare deleterious variants and pediatric B-ALL development. In addition, TCF3 variant-based analysis showed particularly strong association between variant rs372168347 (three in 521 TCCSG and three in the 15780 gnomAD whole genome analysis cohort, p = 0.0006) and pediatric B-ALL development. TCF3 variants are known to influence B cell maturation and may increase the risk of preleukemic clone emergence.

Ultralow-dose binary oncolytic/helper-dependent adenovirus promotes antitumor activity in preclinical and clinical studies

We show that a binary oncolytic/helper-dependent adenovirus (CAdVEC) that both lyses tumor cells and locally expresses the proinflammatory cytokine IL-12 and PD-L1 blocking antibody has potent antitumor activity in humanized mouse models. On the basis of these preclinical studies, we treated four patients with a single intratumoral injection of an ultralow dose of CAdVEC (NCT03740256), representing a dose of oncolytic adenovirus more than 100-fold lower than used in previous trials. While CAdVEC caused no significant toxicities, it repolarized the tumor microenvironment with increased infiltration of CD8 T cells. A single administration of CAdVEC was associated with both locoregional and abscopal effects on metastases and, in combination with systemic administration of immune checkpoint antibodies, induced sustained antitumor responses, including one complete and two partial responses. Hence, in both preclinical and clinical studies, CAdVEC is safe and even at extremely low doses is sufficiently potent to induce significant tumor control through oncolysis and immune repolarization.

Neutrophil S100A9 supports M2 macrophage niche formation in granulomas

Mycobacterium infection gives rise to granulomas predominantly composed of inflammatory M1-like macrophages, with bacteria-permissive M2 macrophages also detected in deep granulomas. Our histological analysis of Mycobacterium bovis bacillus Calmette-Guerin-elicited granulomas in guinea pigs revealed that S100A9-expressing neutrophils bordered a unique M2 niche within the inner circle of concentrically multilayered granulomas. We evaluated the effect of S100A9 on macrophage M2 polarization based on guinea pig studies. S100A9-deficient mouse neutrophils abrogated M2 polarization, which was critically dependent on COX-2 signaling in neutrophils. Mechanistic evidence suggested that nuclear S100A9 interacts with C/EBPβ, which cooperatively activates the Cox-2 promoter and amplifies prostaglandin E2 production, followed by M2 polarization in proximal macrophages. Because the M2 populations in guinea pig granulomas were abolished via treatment with celecoxib, a selective COX-2 inhibitor, we propose the S100A9/Cox-2 axis as a major pathway driving M2 niche formation in granulomas.

Engagement with the TCR induces plasticity in antigenic ligands bound to MHC class I and CD1 molecules

Complementarity-determining regions (CDRs) of αβ T-cell receptors (TCRs) sense peptide-bound MHC (pMHC) complexes via chemical interactions, thereby mediating antigen specificity and MHC restriction. Flexible finger-like movement of CDR loops contributes to the establishment of optimal interactions with pMHCs. In contrast, peptide ligands captured in MHC molecules are considered more static because of the rigid hydrogen-bond network that stabilizes peptide ligands in the antigen-binding groove of MHC molecules. An array of crystal structures delineating pMHC complexes in TCR-docked and TCR-undocked forms is now available, which enables us to assess TCR engagement-induced conformational changes in peptide ligands. In this short review, we overview conformational changes in MHC class I-bound peptide ligands upon TCR docking, followed by those for CD1-bound glycolipid ligands. Finally, we analyze the co-crystal structure of the TCR:lipopeptide-bound MHC class I complex that we recently reported. We argue that TCR engagement-induced conformational changes markedly occur in lipopeptide ligands, which are essential for exposure of a primary T-cell epitope to TCRs. These conformational changes are affected by amino acid residues, such as glycine, that do not interact directly with TCRs. Thus, ligand recognition by specific TCRs involves not only T-cell epitopes but also non-epitopic amino acid residues. In light of their critical function, we propose to refer to these residues as non-epitopic residues affecting ligand plasticity and antigenicity (NR-PA).

A case of crescentic glomerulonephritis induced by afatinib for lung adenocarcinoma

Afatinib is a second-generation, oral, epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). One of the most common adverse effects of affatinib is diarrhea, which may lead to acute kidney injury (AKI) due to severe plasma volume loss; however, no case of glomerular injury directly induced by afatinib has been reported to date. Here, we describe the case of a 53-year-old Japanese male patient with advanced lung adenocarcinoma who twice developed AKI requiring dialysis, once after starting and once after increasing the dose of afatinib. Although serum anti-neutrophil cytoplasmic antibodies were negative, crescentic glomerulonephritis with no immune deposits was confirmed on kidney biopsy. No vasculitis-like signs were observed in other organs, such as lung, skin, or peripheral nerves. Afatinib was considered the cause of glomerular damage and was immediately discontinued; corticosteroids were administered. Renal function gradually recovered thereafter, with serum creatinine levels at ~ 2.3 mg/dL after second-line therapy with bevacizumab and atezolizumab. Several cases of cutaneous leukocytoclastic vasculitis have been reported in patients treated with other EGFR-TKIs; therefore, afatinib-induced vasculitis may lead to crescentic glomerulonephritis. Although afatinib-induced glomerular injury is extremely rare and has an unclear mechanism, renal function and urinary findings need to be closely monitored.

Skin and soft tissue infections in adolescent chronic myeloid leukemia under dasatinib treatment

Although skin complications are common adverse events from tyrosine kinase inhibitors (TKIs) for the treatment of chronic myeloid leukemia (CML), no reports have focused on skin and soft tissue infections (SSTIs) associated with TKI use. We herein present five episodes of SSTIs in three CML patients under dasatinib treatment. All patients were adolescents and had been receiving dasatinib for more than 4 years. In contrast, none of 41 adult CML patients experienced SSTIs in a retrospective analysis. Our findings suggest that long-term dasatinib treatment in adolescent patients may be associated with the increased risk of SSTIs.

Crystal structures of N-myristoylated lipopeptide-bound HLA class I complexes indicate reorganization of B-pocket architecture upon ligand binding

Rhesus monkeys have evolved major histocompatibility complex (MHC)-encoded class I allomorphs such as Mamu-B*098 that are capable of binding N-myristoylated short lipopeptides rather than conventional long peptides; however, it remains unknown whether such antigen-binding molecules exist in other species, including humans. We herein demonstrate that human leukocyte antigen (HLA)-A*24:02 and HLA-C*14:02 proteins, which are known to bind conventional long peptides, also have the potential to bind N-myristoylated short lipopeptides. These HLA class I molecules shared a serine at position 9 (Ser9) with Mamu-B*098, in contrast to most MHC class I molecules that harbor a larger amino acid residue, such as tyrosine, at this position. High resolution X-ray crystallographic analyses of lipopeptide-bound HLA-A*24:02 and HLA-C*14:02 complexes indicated that Ser9 was at the bottom of the B pocket with its small hydroxymethyl side chain directed away from the B-pocket cavity, thereby contributing to the formation of a deep hydrophobic cavity suitable for accommodating the long-chain fatty acid moiety of lipopeptide ligands. Upon peptide binding, however, we found the hydrogen-bond network involving Ser9 was reorganized, and the remodeled B pocket was able to capture the second amino acid residue (P2) of peptide ligands. Apart from the B pocket, virtually no marked alterations were observed for the A and F pockets upon peptide and lipopeptide binding. Thus, we concluded that the structural flexibility of the large B pocket of HLA-A*2402 and HLA-C*1402 primarily accounted for their previously unrecognized capacity to bind such chemically distinct ligands as conventional peptides and N-myristoylated lipopeptides.

Mutated GM-CSF-based CAR-T cells targeting CD116/CD131 complexes exhibit enhanced anti-tumor effects against acute myeloid leukaemia

Objectives

As the prognosis of relapsed/refractory (R/R) acute myeloid leukaemia (AML) remains poor, novel treatment strategies are urgently needed. Clinical trials have shown that chimeric antigen receptor (CAR)‐T cells for AML are more challenging than those targeting CD19 in B‐cell malignancies. We recently developed piggyBac‐modified ligand‐based CAR‐T cells that target CD116/CD131 complexes, also known as the GM‐CSF receptor (GMR), for the treatment of juvenile myelomonocytic leukaemia. This study therefore aimed to develop a novel therapeutic method for R/R AML using GMR CAR‐T cells.

Methods

To further improve the efficacy of the original GMR CAR‐T cells, we have developed novel GMR CAR vectors incorporating a mutated GM‐CSF for the antigen‐binding domain and G4S spacer. All GMR CAR‐T cells were generated using a piggyBac‐based gene transfer system. The anti‐tumor effect of GMR CAR‐T cells was tested in mouse AML xenograft models.

Results

Nearly 80% of the AML cells predominant in myelomonocytic leukaemia were found to express CD116. GMR CAR‐T cells exhibited potent cytotoxic activities against CD116⁺ AML cells in vitro. Furthermore, GMR CAR‐T cells incorporating a G4S spacer significantly improved long‐term in vitro and in vivo anti‐tumor effects. By employing a mutated GM‐CSF at residue 21 (E21K), the anti‐tumor effects of GMR CAR‐T cells were also improved especially in long‐term in vitro settings. Although GMR CAR‐T cells exerted cytotoxic effects on normal monocytes, their lethality on normal neutrophils, T cells, B cells and NK cells was minimal.

Conclusions

GMR CAR‐T cell therapy represents a promising strategy for CD116⁺ R/R AML.

Crystal structure of the ternary complex of TCR, MHC class I and lipopeptides

The covalent conjugation of a 14-carbon fatty acid (myristic acid) to the N-terminal Gly residue, termed N-myristoylation, occurs in some viral proteins to dictate their pathological function. This protein lipidation reaction, however, is monitored by host cytotoxic T lymphocytes that are capable of recognizing N-terminal lipopeptide fragments in the context of major histocompatibility complex (MHC) class I molecules. In a rhesus model of human AIDS, for example, the classical MHC class I allomorph, Mamu-B*05104, was shown to bind SIV Nef-derived 4-mer lipopeptides (myristic acid-Gly-Gly-Ala-Ile; C14nef4) and present them to the CD8+ T-cell line, SN45. These lipopeptides accommodated in MHC class I molecules expose much shorter peptide chains than conventional MHC class I-presented 8-10-mer peptides, and the molecular mechanisms by which αβ T-cell receptors (TCRs) recognize lipopeptides currently remain unclear. An X-ray crystallographic analysis of the SN45 TCR α and β heterodimer in a form that was co-crystallized with the C14nef4-bound Mamu-B*05104 complex indicated that the amide group of the N-myristoylated glycine residue offered a primary T-cell epitope by establishing a sole hydrogen bond between its nitrogen atom and the side chain of Glu at position 101 of CDR3β. Accordingly, the Glu to Ala mutation at this position resulted in the loss of lipopeptide recognition. On the other hand, TCRs were positioned remotely from the peptide portion of C14nef4, and strong interactions were not observed. Thus, these observations provide novel structural insights into lipopeptide recognition by TCRs, which contrast sharply with the general molecular principle of peptide recognition.

[Residual Property of SI-613, a Novel Drug for Osteoarthritis, in Knee Joint]

Osteoarthritis is the most common joint disorder worldwide and one of the leading causes of disability in the elderly. We have reported that the novel sodium hyaluronate derivative chemically linked with diclofenac (DF), diclofenac etalhyaluronate (SI-613), exerted a potent and long-lasting analgesic effect in experimental arthritis models. In this study, we evaluated the properties of residual SI-613 in the knee joint after an intra-articular (IA) administration. After IA administration of fluorescent labeled SI-613 (FA-SI-613) or fluorescent labeled hyaluronic acid (FA-HA) to rabbits, fluorescence intensities in the synovial membrane and cartilage were higher in the FA-SI-613 group until 7 d after administration than in the FA-HA group. After IA administration of radiolabeled SI-613 (¹⁴C-SI-613) to rabbits, the radioactivity remained in the joint cavity and the joint tissues such as synovial membrane and cartilage until 84 d after administration. This residual radioactivity was identified mainly as HA linked with DF, since ¹⁴C-SI-613 was labeled at the benzene ring of DF and since more DF-linked HA oligomer was detected on metabolite analysis than free DF in the synovial membrane and synovial lavage fluid up to 28 d after administration. These results suggested that intra-articularly administered SI-613 remained for a longer time in the joint as HA linked with DF than when HA was administered. Therefore, SI-613 was considered to prolong the pharmacological effects of both HA and DF by remaining in the joint as HA linked with DF.

Transfusion outcome for volume- and plasma-reduced platelet concentrates for pediatric patients

BACKGROUND AND OBJECTIVES

Plasma reduction in platelet concentrate (PC) products has been reported to prevent large volume load and transfusion-related adverse reactions (TRARs). However, volume reduction might be associated with a poor transfusion response because of a deterioration in platelet (PLT) quality. Because PLT quality control and transfusion responses for recently washed PCs using PLT additive solutions are superior, we investigated the clinical safety and transfusion efficacy of volume-reduced washed PCs in pediatric patients.

MATERIALS AND METHODS

We prepared a simplified resuspended PC product (RPC) as a washed PC. Regular RPC (R-RPC) included equivalent volumes of bicarbonate Ringer's solution and anticoagulant citrate dextrose solution A (BRS-A) as the resuspension solution. Half RPC (H-RPC) was prepared by adding a half volume of BRS-A. Twenty-four pediatric patients were scheduled for transfusions with R-RPC and H-RPC up to 4 times. R-RPC was transfused 42 times into 24 patients. H-RPC was transfused 41 times into 23 patients.

RESULTS

Neither product was observed to cause TRARs. Although the calculated PLT recovery for H-RPC was significantly reduced, the posttransfusion corrected count increment (24 h) did not differ. Moreover, similar results were observed for vital signs during transfusion.

CONCLUSION

Volume-reduced washed PC can be transfused without causing TRARs, differences in vital signs, or inferior transfusion responses. Volume-reduced washed PC also provides the advantages of shortened transfusion times and reduced volume loads. Although a standard technique for stable resuspension is necessary, volume-reduced washed PC may be a beneficial option for children, including neonates, or individuals with cardiovascular or renal problems.

Crystal structures of lysophospholipid-bound MHC class I molecules

Newly synthesized major histocompatibility complex (MHC) class I proteins are stabilized in the endoplasmic reticulum (ER) by binding 8-10-mer-long self-peptide antigens that are provided by transporter associated with antigen processing (TAP). These MHC class I:peptide complexes then exit the ER and reach the plasma membrane, serving to sustain the steady-state MHC class I expression on the cell surface. A novel subset of MHC class I molecules that preferentially bind lipid-containing ligands rather than conventional peptides was recently identified. The primate classical MHC class I allomorphs, Mamu-B*098 and Mamu-B*05104, are capable of binding the N-myristoylated 5-mer (C14-Gly-Gly-Ala-Ile-Ser) or 4-mer (C14-Gly-Gly-Ala-Ile) lipopeptides derived from the N-myristoylated SIV Nef protein, respectively, and of activating lipopeptide antigen-specific cytotoxic T lymphocytes. We herein demonstrate that Mamu-B*098 samples lysophosphatidylethanolamine and lysophosphatidylcholine containing up to a C20 fatty acid in the ER. The X-ray crystal structures of Mamu-B*098 and Mamu-B*05104 complexed with lysophospholipids at high resolution revealed that the B and D pockets in the antigen-binding grooves of these MHC class I molecules accommodate these lipids through a monoacylglycerol moiety. Consistent with the capacity to bind cellular lipid ligands, these two MHC class I molecules did not require TAP function for cell-surface expression. Collectively, these results indicate that peptide- and lipopeptide-presenting MHC class I subsets use distinct sources of endogenous ligands.

Thyroid tumor surveillance using ultrasound in childhood cancer survivors

BACKGROUND

The optimal method for thyroid cancer screening in childhood cancer survivors (CCSs) who received radiation involving the thyroid gland is still debated. We describe a case series of ultrasound surveillance for thyroid tumor in CCSs in our institute.

METHODS

We conducted thyroid tumor surveillance for CCSs with a history of radiation therapy involving the thyroid. The basic screening method was palpation. Thyroid ultrasound was also performed for patients who agreed after its benefits and risks were explained to them. We surveyed CCSs who visited the long-term follow-up outpatient clinic in our institution between October 2014 and September 2018.

RESULTS

Of 82 CCSs who visited our institution during the study period, 44 were eligible for inclusion. None had a mass identified by palpation. Thyroid ultrasound was performed in 39 CCSs, and we identified thyroid nodules in 27. Four patients had a nodule with malignant echo features. Two of these cases received biopsies, and one patient was ultimately diagnosed with an early stage thyroid carcinoma.

CONCLUSIONS

Childhood cancer survivors irradiated in the thyroid had a higher prevalence of thyroid nodules than the general population. Ultrasound screening contributed to early detection of impalpable thyroid cancer and enabled us to perform minimal surgery. Thus, ultrasound appears to be a useful option for secondary thyroid cancer screening. The thyroid tumor surveillance modality should be considered according to the individual case, and the patient must receive a clear explanation of the benefits and risks. These results could help doctors consider how to screen for secondary thyroid cancer.

Comparative analysis of graft-versus-host disease prophylaxis with tacrolimus in combination with methylprednisolone or methotrexate after umbilical cord blood transplantation

Post-transplant early immune disorders and engraftment failure/delay are major issues in unrelated umbilical cord blood transplantation (UCBT). We evaluated graft-versus-host disease (GVHD) prophylaxis approaches after UCBT by comparing UCBT outcomes with GVHD prophylaxis using tacrolimus plus methylprednisolone (Tac/mPSL, n = 32) to that with Tac plus methotrexate (Tac/MTX, n = 31) at a single pediatric transplantation center. The 30-day cumulative incidence rates of neutrophil engraftment and median neutrophil engraftment times in the Tac/mPSL and Tac/MTX groups were 70.1% and 90.3% and 19 and 17 days, respectively (p = 0.09). Pre-engraftment immune reactions (PIR) and acute GVHD were improved with Tac/MTX; PIR incidence (p = 0.020) and cumulative incidence of 100-day acute GVHD (grade II-IV, 38.7% vs 68.8%, p = 0.045; grade III-IV, 9.7% vs 34.4%, p = 0.021) were significantly lower in the Tac/MTX group than in the Tac/mPSL group. However, the incidence rates of relapse (p = 0.921) and cytomegalovirus reactivation (p = 0.908), and the estimated overall (p = 0.87) and event-free survival (p = 0.88) were comparable between the two groups. These data indicate that GVHD prophylaxis with Tac/MTX is associated with favorable results, including reduced PIR and acute GVHD incidence after UCBT, without adverse effects.

Identification and Structure of an MHC Class I-Encoded Protein with the Potential to Present N-Myristoylated 4-mer Peptides to T Cells

Similar to host proteins, N-myristoylation occurs for viral proteins to dictate their pathological function. However, this lipid-modifying reaction creates a novel class of "lipopeptide" Ags targeted by host CTLs. The primate MHC class I-encoded protein, Mamu-B*098, was previously shown to bind N-myristoylated 5-mer peptides. Nevertheless, T cells exist that recognize even shorter lipopeptides, and much remains to be elucidated concerning the molecular mechanisms of lipopeptide presentation. We, in this study, demonstrate that the MHC class I allele, Mamu-B*05104, binds the N-myristoylated 4-mer peptide (C14-Gly-Gly-Ala-Ile) derived from the viral Nef protein for its presentation to CTLs. A phylogenetic tree analysis indicates that these classical MHC class I alleles are not closely associated; however, the high-resolution x-ray crystallographic analyses indicate that both molecules share lipid-binding structures defined by the exceptionally large, hydrophobic B pocket to accommodate the acylated glycine (G1) as an anchor. The C-terminal isoleucine (I4) of C14-Gly-Gly-Ala-Ile anchors at the F pocket, which is distinct from that of Mamu-B*098 and is virtually identical to that of the peptide-presenting MHC class I molecule, HLA-B51. The two central amino acid residues (G2 and A3) are only exposed externally for recognition by T cells, and the methyl side chain on A3 constitutes a major T cell epitope, underscoring that the epitopic diversity is highly limited for lipopeptides as compared with that for MHC class I-presented long peptides. These structural features suggest that lipopeptide-presenting MHC class I alleles comprise a distinct MHC class I subset that mediates an alternative pathway for CTL activation.

Ovarian function after allogeneic hematopoietic stem cell transplantation in children and young adults given 8-Gy total body irradiation-based reduced-toxicity myeloablative conditioning

BACKGROUND

The spectrum of late sequelae after hematopoietic stem cell transplantation (HSCT) includes infertility, which is the most frequent complication. Some reports suggested that ovarian function may be better preserved in females undergoing HSCT with reduced-intensity conditioning (RIC) than with conventional myeloablative conditioning (MAC). However, the impact of HSCT after 8-Gy TBI-based reduced-toxicity MAC (RTMAC), whose efficacy is between those of conventional MAC and RIC, on ovarian function remains unclear.

PROCEDURE

A single-center retrospective analysis of data derived from patient information for all the children who underwent transplantation at the Shinshu University Hospital was carried out. Patients who underwent 8-Gy total body irradiation (TBI)-based RTMAC before HSCT were analyzed.

RESULTS

A total of 36% (five of 14) of the patients developed primary ovarian insufficiency (POI) during the observation period, but serum follicle-stimulating hormone levels reduced to normal range with spontaneous menstruation in two, implying the reversal of POI. Furthermore, only one (10%) of the 10 prepubertal patients (71%; 10/14) at the time of HSCT suffered from POI at the last observation, but all three post-pubertal patients developed POI (100%), and two (67%) continued to suffer from POI at the last observation.

CONCLUSIONS

Taken together, 8-Gy TBI-based RTMAC before HSCT may decrease the possibility of POI compared with conventional MAC, especially in prepubertal patients. A longer follow-up will be required to ascertain whether a normal pregnancy and delivery can occur in such patients.

Integration Mapping of piggyBac-Mediated CD19 Chimeric Antigen Receptor T Cells Analyzed by Novel Tagmentation-Assisted PCR

Insertional mutagenesis is an important risk with all genetically modified cell therapies, including chimeric antigen receptor (CAR)-T cell therapy used for hematological malignancies. Here we describe a new tagmentation-assisted PCR (tag-PCR) system that can determine the integration sites of transgenes without using restriction enzyme digestion (which can potentially bias the detection) and allows library preparation in fewer steps than with other methods. Using this system, we compared the integration sites of CD19-specific CAR genes in final T cell products generated by retrovirus-based and lentivirus-based gene transfer and by the piggyBac transposon system. The piggyBac system demonstrated lower preference than the retroviral system for integration near transcriptional start sites and CpG islands and higher preference than the lentiviral system for integration into genomic safe harbors. Integration into or near proto-oncogenes was similar in all three systems. Tag-PCR mapping is a useful technique for assessing the risk of insertional mutagenesis.

Regional evaluation of childhood acute lymphoblastic leukemia genetic susceptibility loci among Japanese

Genome-wide association studies (GWAS) performed mostly in populations of European and Hispanic ancestry have confirmed an inherited genetic basis for childhood acute lymphoblastic leukemia (ALL), but these associations are less clear in other races/ethnicities. DNA samples from ALL patients (aged 0–19 years) previously enrolled onto a Tokyo Children’s Cancer Study Group trial were collected during 2013–2015, and underwent single nucleotide polymorphism (SNP) microarray genotyping resulting in 527 B-cell ALL for analysis. Cases and control data for 3,882 samples from the Nagahama Study Group and Aichi Cancer Center Study were combined, and association analyses across 10 previous GWAS-identified regions were performed after targeted SNP imputation. Linkage disequilibrium (LD) patterns in Japanese and other populations were evaluated using the varLD score based on 1000 Genomes data. Risk associations for ARID5B (rs10821936, OR = 1.84, P = 6 × 10⁻¹⁷) and PIP4K2A (rs7088318, OR = 0.76, P = 2 × 10⁻⁴) directly transferred to Japanese, and the IKZF1 association was detected by an alternate SNP (rs1451367, OR = 1.52, P = 2 × 10⁻⁶). Marked regional LD differences between Japanese and Europeans was observed for most of the remaining loci for which associations did not transfer, including CEBPE, CDKN2A, CDKN2B, and ELK3. This study represents a first step towards characterizing the role of genetic susceptibility in childhood ALL risk in Japanese.

Enhanced Expression of Anti-CD19 Chimeric Antigen Receptor in piggyBac Transposon-Engineered T Cells

Adoptive T cell therapy using chimeric antigen receptor (CAR)-modified T cells is a promising cancer immunotherapy. We previously developed a non-viral method of gene transfer into T cells using a piggyBac transposon system to improve the cost-effectiveness of CAR-T cell therapy. Here, we have further improved our technology by a novel culture strategy to increase the transfection efficiency and to reduce the time of T cell manufacturing. Using a CH2CH3-free CD19-specific CAR transposon vector and combining irradiated activated T cells (ATCs) as feeder cells and virus-specific T cell receptor (TCR) stimulation, we achieved 51.4% ± 14% CAR⁺ T cells and 2.8-fold expansion after 14 culture days. Expanded CD19.CAR-T cells maintained a significant fraction of CD45RA⁺CCR7⁺ T cells and demonstrated potent antitumor activity against CD19⁺ leukemic cells both in vitro and in vivo. Therefore, piggyBac-based gene transfer may provide an alternative to viral gene transfer for CAR-T cell therapy.

Long-term outcomes of transtrochanteric rotational osteotomy for non-traumatic osteonecrosis of the femoral head

AIMS

Transtrochanteric rotational osteotomy (TRO) is performed for young patients with non-traumatic osteonecrosis of the femoral head (ONFH) to preserve the hip. We aimed to investigate the long-term outcomes and the risk factors for failure 15 years after this procedure.

PATIENTS AND METHODS

This study included 95 patients (111 hips) with a mean age of 40 years (21 to 64) who underwent TRO for ONFH. The mean follow-up was 18.2 years (3 to 26). Kaplan-Meier survivorship analyses were performed with conversion to total hip arthroplasty (THA) and radiological failure due to secondary collapse of the femoral head or osteoarthritic changes as the endpoint. Multivariate analyses were performed to assess risk factors for each outcome.

RESULTS

Survival rates at 15 years with conversion to THA and radiological failure as the endpoint were 59% (95% confidence interval (CI) 49 to 67) and 30% (95% CI 22 to 39), respectively. Necrotic type C2 ONFH (lesions extending laterally to the acetabular edge) (hazards ratio (HR) 3.9) and age > 40 years (HR 2.5) were risk factors for conversion to THA. Stage > 3a ONFH (HR 2.0) and age > 40 years (HR 1.9) were risk factors for radiological failure.

CONCLUSION

The 15 year outcomes after TRO for ONFH are unfavorable because osteoarthritic changes occur after five years post-operatively. Cite this article: Bone Joint J 2017;99-B:175-83.

Viral load and ganciclovir (GCV) concentration in cerebrospinal fluid of patients successfully treated with GCV or valGCV for human herpesvirus 6 encephalitis/myelitis following umbilical cord blood transplantation

We describe successful treatment of 3 cases of human herpesvirus 6 (HHV-6) encephalitis/myelitis following cord blood transplantation (CBT). Ganciclovir (GCV) (10 mg/kg/day) reduced HHV-6 load to undetectable levels in cerebrospinal fluid (CSF). Early dose reduction in the presence of HHV-6 detectable in CSF resulted in an increased HHV-6 load. GCV was capably shifted to valganciclovir (VGCV) with an almost equivalent concentration. GCV/VGCV may be effective for HHV-6 encephalitis/myelitis after CBT, although HHV-6 load in CSF should be monitored.

Hypoglycemia During the Temporary Interruption of Parenteral Nutrition Infusion in Pediatric Hematopoietic Stem Cell Transplantation

BACKGROUND

Parenteral nutrition (PN) is required with pediatric procedures such as hematopoietic stem cell transplantation (HSCT). However, risks associated with temporary PN infusion interruption remain unclear.

MATERIALS AND METHODS

We retrospectively analyzed in 22 children undergoing HSCT receiving PN with the same daily routine: temporary PN infusion interruption before breakfast for administering a saline-diluted acyclovir drip. After correcting patients' glucose levels, we examined minimum blood glucose levels between preparative regimen initiation and post-HSCT day 30. Patients were divided into 2 groups according to a minimum glucose cutoff of 60 mg/dL. Patient background characteristics and hypoglycemia risk factors were compared between both groups.

RESULTS

The hypoglycemia group had a significantly lower body surface area, higher glucose infusion rate (GIR), lower cholinesterase levels, and higher zinc levels at the onset of the minimum blood glucose level ( P < .05). Multivariate analyses revealed an association only between higher GIR (≥5 mg/kg/min) and hypoglycemia during the temporary PN infusion interruption. A time course analysis of blood glucose and immunoreactive insulin (IRI) levels in 1 patient revealed a combined high-caloric and saline flush before acyclovir initiation, causing temporary increased IRI, as the etiology for hypoglycemia.

CONCLUSIONS

Particular attention and several precautions are required to prevent complications associated with temporary PN infusion interruption in children with higher GIR.

Lipopeptides: a novel antigen repertoire presented by major histocompatibility complex class I molecules

Post-translationally modified peptides, such as those containing either phosphorylated or O-glycosylated serine/threonine residues, may be presented to cytotoxic T lymphocytes (CTLs) by MHC class I molecules. Most of these modified peptides are captured in the MHC class I groove in a similar manner to that for unmodified peptides. N-Myristoylated 5-mer lipopeptides have recently been identified as a novel chemical class of MHC class I-presented antigens. The rhesus classical MHC class I allele, Mamu-B*098, was found to be capable of binding N-myristoylated lipopeptides and presenting them to CTLs. A high-resolution X-ray crystallographic analysis of the Mamu-B*098:lipopeptide complex revealed that the myristic group as well as conserved C-terminal serine residue of the lipopeptide ligand functioned as anchors, whereas the short stretch of three amino acid residues located in the middle of the lipopeptides was only exposed externally with the potential to interact directly with specific T-cell receptors. Therefore, the modes of lipopeptide-ligand interactions with MHC class I and with T-cell receptors are novel and fundamentally distinct from that for MHC class I-presented peptides. Another lipopeptide-presenting MHC class I allele has now been identified, leading us to the prediction that MHC class I molecules may be separated on a functional basis into two groups: one presenting long peptides and the other presenting short lipopeptides. Since the N-myristoylation of viral proteins is often linked to pathogenesis, CTLs capable of sensing N-myristoylation may serve to control pathogenic viruses, raising the possibility for the development of a new type of lipopeptide vaccine.

Early-onset colorectal cancer in young adult survivors of childhood cancer

We describe the cases of two childhood cancer survivors (CCS) who developed colorectal cancer at 21 and 30 years of age. They had been treated with 30 Gy abdominal irradiation and chemotherapy including platinum and high-dose alkylating agents at age 1 year, and 12 Gy total body irradiation and high-dose cyclophosphamide at age 15 years, respectively. Both had not been screened for colorectal cancer. One patient with advanced cancer died, whereas the other with early cancer was still alive at the time of writing. Two guidelines for long-term follow-up of CCS recommend that CCS who had >30 Gy irradiation receive periodic check-ups at age ≥ 35 years. The present cases suggest that CCS, even with irradiation <30 Gy, should receive earlier check-ups for colorectal cancer. © 2016 Japan Pediatric Society.

Crystal structure of the N-myristoylated lipopeptide-bound MHC class I complex

The covalent conjugation of a 14-carbon saturated fatty acid (myristic acid) to the amino-terminal glycine residue is critical for some viral proteins to function. This protein lipidation modification, termed N-myristoylation, is targeted by host cytotoxic T lymphocytes (CTLs) that specifically recognize N-myristoylated short peptides; however, the molecular mechanisms underlying lipopeptide antigen (Ag) presentation remain elusive. Here we show that a primate major histocompatibility complex (MHC) class I-encoded protein is capable of binding N-myristoylated 5-mer peptides and presenting them to specific CTLs. A high-resolution X-ray crystallographic analysis of the MHC class I:lipopeptide complex reveals an Ag-binding groove that is elaborately constructed to bind N-myristoylated short peptides rather than prototypic 9-mer peptides. The identification of lipopeptide-specific, MHC class I-restricted CTLs indicates that the widely accepted concept of MHC class I-mediated presentation of long peptides to CTLs may need some modifications to incorporate a novel MHC class I function of lipopeptide Ag presentation.

Lipid antigens have been added to the antigenic repertoire in recent years. Here, the authors have identified Mamu-B*098 as a lipopeptide antigen presenting molecule and using structural and biochemical analysis have shown that it has a different antigen binding pocket to previously analysed proteins.

Temozolomide Treatment for Pediatric Refractory Anaplastic Ependymoma with Low MGMT Protein Expression

The benefit of postoperative chemotherapy for anaplastic ependymoma remains unknown. We report two pediatric patients with refractory anaplastic ependymoma treated with temozolomide (TMZ). We did not detect O(6) -methylguanine-DNA methyltransferase (MGMT) promoter methylation in tumor samples; however, MGMT protein expression was low. With TMZ treatment, one patient had a 7-month complete remission; the other, stable disease for 15 months. Three other patients did not respond to TMZ; two had high and one low MGMT expression, and two showed no MGMT promoter methylation. These findings suggest that TMZ may be effective for pediatric refractory anaplastic ependymoma with low MGMT protein expression.

Interleukin-8-producing primary cardiac undifferentiated sarcoma in a child with sustained fever

We report the case of a 12-year-old boy with primary undifferentiated sarcoma of the left atrium. He had sustained fever during the clinical course and multiple lung and brain metastases. Chemotherapy and irradiation were ineffective; he died 41 days after hospitalization. On retrospective analysis, interleukin-8 (IL-8) was elevated; this was supported by immunohistochemistry and gene expression analysis of tumor samples. IL-8 continued to increase with tumor progression accompanied by elevated neutrophil count and C-reactive protein. IL-8 is involved in malignant tumor proliferation, migration, and angiogenesis and may have been related to the clinical condition and prognosis in the present case.

Glycerol monomycolate is a novel ligand for the human, but not mouse macrophage inducible C-type lectin, Mincle

An array of lipidic compounds that constitute the cell wall of mycobacteria is recognized by host receptors. Examples include trehalose dimycolate (TDM), which is a major surface-exposed glycolipid of mycobacteria, that interacts with the macrophage inducible C-type lectin, Mincle, and exerts its highly potent adjuvant functions. Recent evidence has suggested that glycerol monomycolate (GroMM), another mycolate-containing lipid species produced by mycobacteria, can stimulate innate immune cells; however, its specific host receptors have yet to be identified. We here demonstrated that cell transfectants expressing human Mincle (hMincle) reacted to both TDM and GroMM, while those expressing mouse Mincle (mMincle) only reacted to TDM and failed to recognize GroMM. Studies using domain swap chimeras confirmed that the ectodomain of hMincle, but not that of mMincle, interacted with GroMM, and site-directed mutagenesis analyses revealed that short stretches of amino acid residues at positions 174-176 and 195-196 were involved in GroMM recognition. To further substantiate the differential recognition of GroMM by hMincle and mMincle, hMincle transgenic/mMincle knock-out mice (i.e. hMincle(+) mice) were established and compared with non-transgenic mice (i.e. mMincle(+) mice). We showed that macrophages derived from hMincle(+) mice were activated by GroMM and produced inflammatory cytokines, whereas those derived from mMincle(+) mice did not exhibit any reactivity to GroMM. Furthermore, local inflammatory responses were elicited in the GroMM-injected skin of hMincle(+), but not mMincle(+) mice. These results demonstrated that GroMM is a unique ligand for hMincle that is not recognized by mMincle.

Cutting edge: T cells monitor N-myristoylation of the Nef protein in simian immunodeficiency virus-infected monkeys

The use of the host cellular machinery is essential for pathogenic viruses to replicate in host cells. HIV and SIV borrow the host-derived N-myristoyl-transferase and its substrate, myristoyl-CoA, for coupling a saturated C(14) fatty acid (myristic acid) to the N-terminal glycine residue of the Nef protein. This biochemical reaction, referred to as N-myristoylation, assists its targeting to the plasma membrane, thereby supporting the immunosuppressive activity proposed for the Nef protein. In this study, we show that the host immunity is equipped with CTLs capable of sensing N-myristoylation of the Nef protein. A rhesus macaque CD8(+) T cell line was established that specifically recognized N-myristoylated, but not unmodified, peptides of the Nef protein. Furthermore, the population size of N-myristoylated Nef peptide-specific T cells was found to increase significantly in the circulation of SIV-infected monkeys. Thus, these results identify N-myristoylated viral peptides as a novel class of CTL target Ag.

A microbial glycolipid functions as a new class of target antigen for delayed-type hypersensitivity

Delayed-type hypersensitivity (DTH) is marked by high levels of protein antigen-specific T cell responses in sensitized individuals. Recent evidence has revealed a distinct pathway for T cell immunity directed against glycolipid antigens, but DTH to this class of antigen has been undetermined and difficult to prove due to their insolubility in aqueous solutions. Here, glucose monomycolate (GMM), a highly hydrophobic glycolipid of the cell wall of mycobacteria, was dispersed in aqueous solutions in the form of octaarginine-modified liposomes and tested for its ability to elicit cutaneous DTH responses in bacillus Calmette-Guerin (BCG)-immunized guinea pigs. After an intradermal challenge with the GMM liposome, a significant skin induration was observed in BCG-immunized, but not mock-treated, animals. The skin reaction peaked at around 2 days with local infiltration by mononuclear cells, and therefore, the response shared basic features with the classical DTH to protein antigens. Lymph node T cells from BCG-immunized guinea pigs specifically increased IFN-γ transcription in response to the GMM liposome, and this response was completely blocked by antibodies to CD1 lipid antigen-presenting molecules. Finally, whereas the T cells increased transcription of both T helper (Th) 1-type (IFN-γ and TNF-α) and Th2-type (IL-5 and IL-10) cytokines in response to the purified protein derivative or tuberculin, their GMM-specific response was skewed to Th1-type cytokine production known to be critical for protection against tuberculosis. Thus, our study reveals a novel form of DTH with medical implications.

Valproate in children with newly diagnosed idiopathic generalized epilepsy

OBJECTIVES

Sparse information on dose-response characteristics for initial antiepileptic drug monotherapy in children with idiopathic generalized epilepsy (IGE) is available. The aim of this study is to characterize the therapeutic dose of valproate in children with newly diagnosed IGE.

MATERIALS AND METHODS

Effect of initial valproate monotherapy and doses associated with seizure freedom were examined in consecutive children with IGE identified from a New Onset Seizure Clinic.

RESULTS

Of 84 patients identified, 48 (57%) became seizure-free on valproate monotherapy and another 10 patients became seizure-free but discontinued VPA because of adverse effects. The mean dose in seizure-free children was 15.7 mg/kg/day and over 95% of IGE patients will respond below 25 mg/kg/day.

CONCLUSIONS

Half of children became seizure-free on valproate monotherapy and did so at modest doses.

Ganglioside complexes containing GQ1b as targets in Miller Fisher and Guillain-Barre syndromes

BACKGROUND

Serum antibodies to GQ1b are associated with Miller Fisher syndrome (MFS) and Guillain-Barré syndrome (GBS) with ophthalmoplegia. Antibodies to ganglioside complexes (GSCs) have not yet been examined in a large population of patients with MFS or GBS. This study aimed to determine the clinical significance of antibodies to GSCs in MFS and GBS.

METHODS

The study investigated serum anti-GSC antibodies and the clinical features in 64 MFS patients, 53 GBS patients with ophthalmoplegia (GBS-OP(+)) and 53 GBS patients without ophthalmoplegia (GBS-OP(-)).

RESULTS

Thirty patients with MFS (47%), 25 with GBS-OP(+) (47%) and none with GBS-OP(-) had antibodies to GSCs containing GQ1b or GT1a. Patients with MFS and GBS-OP(+) were subdivided according to the antibody reactivities; patients with antibodies specific to GQ1b and/or GT1a (without anti-GSCs antibodies) were placed in Group 1, those with antibodies against GSCs with a total of two sialic acids in the terminal residues, such as GQ1b/GM1, were placed in Group 2, and those with antibodies against GSCs with a total of three sialic acids in the terminal residue, such as GQ1b/GD1a, were placed in Group 3. In MFS, sensory disturbances were infrequent in Group 2 compared with the other groups (p<0.0001). Antibodies specific to GQ1b were observed more often in MFS than in GBS-OP(+) (p = 0.0002).

CONCLUSIONS

IgG antibodies to GSCs containing GQ1b or GT1a were closely associated with the development of ophthalmoplegia in GBS, as well as MFS. Both GQ1b and clustered epitopes of GSCs containing GQ1b or GT1a may be prime target antigens for MFS and GBS-OP(+).

Induction of allergic contact dermatitis by astigmatid mite-derived monoterpene, alpha-acaridial

alpha-Acaridial [2(E)-(4-methyl-3-pentenyl)butenedial] is a novel monoterpene secreted from the house dust mites. Because of its molecular nature of a highly reactive, small lipidic compound, we addressed whether alpha-acaridial might function as a haptenic allergen that induced allergic contact dermatitis. Mice sensitized with alpha-acaridial were challenged by the same antigen on the ear skin. After 2 days, significant ear swelling with a prominent infiltration of CD4(+) T lymphocytes was observed. In vitro, alpha-acaridial exhibited an outstanding ability to quickly interact with and chemically modify a reference protein. Virtually all cysteine residues and a sizable fraction of lysine residues were found to be selectively modified, suggesting that alpha-acaridial could potentially interact with any proteins. Previously, numerous mite-derived proteinaceous allergens have been associated with contact dermatitis. Our study now emphasizes that small lipidic compounds released from mites comprise a new class of mite allergens, and therefore, is of significant medical implications.

Anti-ganglioside complex antibodies associated with severe disability in GBS

Ganglioside complexes (GSCs) are known as target antigens in Guillain-Barré syndrome (GBS). To elucidate the clinical importance of the anti-GSC antibodies in GBS, we investigated serum antibodies to GSCs containing two of the gangliosides, GM1, GD1a, GD1b and GT1b, and analyzed clinical features of anti-GSC-positive GBS patients. Thirty-nine (17%) of 234 GBS patients had IgG anti-GSC antibodies. Anti-GSC-positive GBS had antecedent gastrointestinal infection and lower cranial nerve deficits more frequently than control GBS. The presence of antibody specificity to GD1a/GD1b and/or GD1b/GT1b was significantly associated with severe disability and a requirement for mechanical ventilation.

Anti-ganglioside complex antibodies in Miller Fisher syndrome

BACKGROUND

Some ganglioside complexes (GSCs) are target antigens for serum antibodies in patients with Guillain-Barré syndrome (GBS). Anti-GSC antibodies may be associated with particular clinical features of GBS.

OBJECTIVE

To investigate antibodies to GSCs in the sera of patients with Miller Fisher syndrome (MFS) characterised by elevation of the IgG anti-GQ1b antibody.

RESULTS

In all, 7 of 12 (58%) consecutive patients with MFS were found to have IgG antibodies to GSCs containing GQ1b, of whom 5 had IgG antibodies to GQ1b-GM1 complex (GQ1b/GM1) and 2 had antibodies to GQ1b/GD1a; 4 of 5 patients without sensory symptoms had anti-GQ1b/GM1 antibodies.

CONCLUSIONS

At least three different specificities in MFS-associated antibodies, GQ1b-specific, anti-GQ1b/GM1-positive and anti-GQ1b/GD1a-positive, were observed. In patients with MFS not only GQ1b itself but also clustered epitopes of GSCs, including GQ1b, may be considered to be prime target antigens for serum antibodies. A tendency to escape sensory disturbances is shown by anti-GQ1b/GM1-positive MFS.