Establishment of ganglioside GD2-expressing extranodal NK/T-cell lymphoma cell line with scRNA-seq analysis.

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKL), is characterized by Epstein-Barr virus infection and poor prognosis. We established a novel cell line, ENKL-J1, from bone marrow cells of an ENKL patient. We found that ENKL-J1 cells express the ganglioside GD2 (GD2) and that GD2-directed chimeric antigen receptor T cells exhibit cytotoxicity against ENKL-J1 cells, indicating that GD2 would be a suitable target of GD2-expressing ENKL cells. Targeted next-generation sequencing revealed TP53 and TET2 variants in ENKL-J1 cells. Furthermore, single-cell RNA sequencing in ENKL-J1 cells showed high gene-expression levels in the oncogenic signaling pathways JAK-STAT, NF-κB, and MAPK. Genes related to multidrug resistance (ABCC1), tumor suppression (ATG5, CRYBG1, FOXO3, TP53, MGA), anti-apoptosis (BCL2, BCL2L1), immune checkpoints (CD274, CD47), and epigenetic regulation (DDX3X, EZH2, HDAC2/3) also were expressed at high levels. The molecular targeting agents eprenetapopt, tazemetostat, and vorinostat efficiently induced apoptosis in ENKL-J1 cells in vitro. Furthermore, GD2-directed chimeric antigen receptor T cells showed cytotoxicity against ENKL-J1 cells in vivo. These findings not only contribute to understanding the molecular and genomic characteristics of ENKL; they also suggest new treatment options for patients with advanced or relapsed ENKL.

iPSC-derived hypoimmunogenic tissue resident memory T cells mediate robust anti-tumor activity against cervical cancer.

Functionally rejuvenated human papilloma virus-specific cytotoxic T lymphocytes (HPV-rejTs) generated from induced pluripotent stem cells robustly suppress cervical cancer. However, autologous rejT generation is time consuming, leading to difficulty in treating patients with advanced cancer. Although use of allogeneic HPV-rejTs can obviate this, the major obstacle is rejection by the patient immune system. To overcome this, we develop HLA-A24&-E dual integrated HPV-rejTs after erasing HLA class I antigens. These rejTs effectively suppress recipient immune rejection while maintaining more robust cytotoxicity than original cytotoxic T lymphocytes. Single-cell RNA sequencing performed to gain deeper insights reveal that HPV-rejTs are highly enriched with tissue resident memory T cells, which enhance cytotoxicity against cervical cancer through TGFßR signaling, with increased CD103 expression. Genes associated with the immunological synapse also are upregulated, suggesting that these features promote stronger activation of T cell receptor (TCR) and increased TCR-mediated target cell death. We believe that our work will contribute to feasible "off-the-shelf" T cell therapy with robust anti-cervical cancer effects.

Advances in Allogeneic Cancer Cell Therapy and Future Perspectives on "Off-the-Shelf" T Cell Therapy Using iPSC Technology and Gene Editing.

The concept of allogeneic cell therapy was first presented over 60 years ago with hematopoietic stem cell transplantation. However, complications such as graft versus host disease (GVHD) and regimen-related toxicities remained as major obstacles. To maximize the effect of graft versus leukemia, while minimizing the effect of GVHD, donor lymphocyte infusion was utilized. This idea, which was used against viral infections, postulated that adoptive transfer of virus-specific cytotoxic T lymphocytes could reconstitute specific immunity and eliminate virus infected cells and led to the idea of banking third party cytotoxic T cells (CTLs). T cell exhaustion sometimes became a problem and difficulty arose in creating robust CTLs. However, the introduction of induced pluripotent stem cells (iPSCs) lessens such problems, and by using iPSC technology, unlimited numbers of allogeneic rejuvenated CTLs with robust and proliferative cytotoxic activity can be created. Despite this revolutionary concept, several concerns still exist, such as immunorejection by recipient cells and safety issues of gene editing. In this review, we describe approaches to a feasible "off-the-shelf" therapy that can be distributed rapidly worldwide. We also offer perspectives on the future of allogeneic cell cancer immunotherapy.

Vitamin B6 deficiency as a cause of polyneuropathy in POEMS syndrome: rapid recovery with supplementation in two cases.

BACKGROUND: The etiology of POEMS syndrome and its associated polyneuropathy have not been fully elucidated. The clinical picture of POEMS-associated polyneuropathy and nutritional polyneuropathy due to vitamin B6 (VB6) deficiency are strikingly similar, both being typically sensorimotor, symmetrical, stocking and glove distribution, and more severe in the lower extremities. CASE PRESENTATION: We report two consecutive POEMS patients with VB6 deficiency who showed unusual rapid and drastic recovery of polyneuropathies within 6-8 weeks after oral VB6 supplementation. Case 1 was supplemented with VB6 from time of autologous stem cell transplantation. Polyneuropathy began to improve within one week, and he became walker-free and could walk unaided with a cane within 6 weeks. Case 2 was supplemented with VB6 from time of stem cell harvest, and he became cane-free and his gait almost normalized within two months. Nerve conduction studies were also confirmatory of neurologic recovery in both cases. CONCLUSIONS: Objective physical improvement of POEMS-associated polyneuropathy has been reported to typically require approximately a year after autologous stem cell transplantation, and together with our observations of VB6 deficiency and supplementations leading to accelerated recoveries of polyneuropathy, VB6 deficiency most probably contributes to POEMS-associated polyneuropathy. VB6 acts as a coenzyme in approximately 150 biochemical reactions. VB6 has been reported to inhibit the hypoxia-inducible factor/vascular endothelial growth factor (VEGF) pathway, and VEGF levels are known to corollate with disease activity of POEMS syndrome. Therefore, VB6 deficiency may contribute not only to POEMS-associated polyneuropathy, but also to the etiology of POEMS syndrome itself.

Long-term spontaneous regression of Stage IV diffuse large B-cell lymphoma.

Diffuse large B cell lymphoma (DLBCL) is an aggressive disorder accounting for >30% of all lymphomas. Its prognosis is poor due to a high relapse rate. Spontaneous regression (SR) in DLBCL is rare, with only a few reported cases. Moreover, almost all of these were low-grade lymphomas with an average SR duration of 13 mo. As the cause of SR is unknown, there are many theories such as trauma, infection, medication, and an antitumor immune response. We present a patient with progressive DLBCL who demonstrated SR for >42 mo. Although treatment for lymphoma usually starts soon after diagnosis, insights into SR of lymphomas may lead to new treatment strategies.

High-grade Primary Central Nervous System Lymphomatoid Granulomatosis: Successful Rituximab Monotherapy.

The primary central nervous system (CNS) presentation of lymphomatoid granulomatosis (LYG) is rare, and no standard therapy for LYG with primary CNS symptoms exists. CNS-LYG patients usually survive for only less than a year from diagnosis. This is the first report of high-grade primary CNS-LYG with monoclonality that was successfully treated with rituximab monotherapy, resulting in a durable remission for more than 1 year in a 66-year-old woman with pemphigus vulgaris who was also on immunosuppressive therapy.

Trigenic ADH5/ALDH2/ADGRV1 mutations in myelodysplasia with Usher syndrome.

Trio-next generation sequencing is useful to identify undiagnosed inherited diseases. We have attended a patient with trigenic ADH5/ALDH2/ADGRV1 pathogenic variants, which caused two distinct diseases, myelodysplastic syndrome and Usher syndrome. Whole genome sequencing of peripheral blood from the patient and his parents were applied to identify disease-causing genes. Sanger sequencing was performed to validate the identified ADH5/ALDH2/ADGRV1 variants. Our results identified disease-associated variants in ADGRV1 (disease inheritance autosomal recessive) and in ADH5 (disease inheritance also autosomal recessive) and a variant in ALDH2 (disease inheritance autosomal dominant). Although the variants identified in ADH5 and ALDH2 have been reported, their co-existence in association with disease-causing variation in a third gene has not. They broaden the spectrum of ADGRV1 in Usher syndrome. Findings on next generation sequencing guided rapid and accurate diagnosis, resulting in patient-tailored therapeutic intervention.

iPSC-Derived Neoantigen-Specific CTL Therapy for Ewing Sarcoma.

The prognosis of Ewing sarcoma caused by EWS/FLI1 fusion is poor, especially after metastasis. Although therapy with CTLs targeted against altered EWS/FLI1 sequences at the gene break/fusion site may be effective, CTLs generated from peripheral blood are often exhausted because of continuous exposure to tumor antigens. We addressed this by generating induced pluripotent stem cell (iPSC)-derived functionally rejuvenated CTLs (rejT) directed against the neoantigen encoded by the EWS/FLI1 fusion gene. In this study, we examined the antitumor effects of EWS/FLI1-rejTs against Ewing sarcoma. The altered amino acid sequence at the break/fusion point of EWS/FLI1, when presented as a neoantigen, evokes an immune response that targets EWS/FLI1 + sarcoma. Although the frequency of generated EWS/FLI1-specific CTLs was only 0.003%, we successfully established CTL clones from a healthy donor. We established iPSCs from a EWS/FLI1-specific CTL clone and redifferentiated them into EWS/FLI1-specific rejTs. To evaluate cytotoxicity, we cocultured EWS/FLI1-rejTs with Ewing sarcoma cell lines. EWS/FLI1-rejTs rapidly and continuously suppressed the proliferation of Ewing sarcoma for >40 hours. Using a Ewing sarcoma xenograft mouse model, we verified the antitumor effect of EWS/FLI1-rejTs via imaging, and EWS/FLI1-rejTs conferred a statistically significant survival advantage. "Off-the-shelf" therapy is less destructive and disruptive than chemotherapy, and radiation is always desirable, particularly in adolescents, whom Ewing sarcoma most often affects. Thus, EWS/FLI1-rejTs targeting a Ewing sarcoma neoantigen could be a promising new therapeutic tool.

Diallyl trisulfide induces apoptosis by suppressing NF-κB signaling through destabilization of TRAF6 in primary effusion lymphoma.

The allyl sulfides, including diallyl sulfide (DAS), diallyl disulfide (DAD), and diallyl trisulfide (DAT), contained in garlic and members of the Allium family, have a variety of pharmacological activities. Therefore, allyl sulfides have been evaluated as potential novel chemotherapeutic agents. Here, we found that DAT inhibited nuclear factor-κB (NF-κB) signaling and induced apoptosis in primary effusion lymphoma (PEL), a subtype of non-Hodgkin's B-cell lymphoma caused by Kaposi's sarcoma-associated herpesvirus (KSHV). We examined the cytotoxic effects of DAS, DAD and DAT on PEL cells. DAT significantly reduced the viability of PEL cells compared with uninfected B-lymphoma cells, and induced the apoptosis of PEL cells by activating caspase-9. DAT induced stabilization of IκBα, and suppressed NF-κB transcriptional activity in PEL cells. We examined the mechanism underlying DAT-mediated IκBα stabilization. The results indicated that DAT stabilized IκBα by inhibiting the phosphorylation of IκBα by the IκB kinase (IKK) complex. Furthermore, DAT induced proteasomal degradation of TRAF6, and DAT suppressed IKKß-phosphorylation through downregulation of TRAF6. It is known that activation of NF-κB is essential for survival of PEL cells. In fact, the NF-κB inhibitor BAY11-7082 induced apoptosis in PEL cells. In addition, DAT suppressed the production of progeny virus from PEL cells. The administration of DAT suppressed the development of PEL cells and ascites in SCID mice xenografted with PEL cells. These findings provide evidence that DAT has antitumor activity against PEL cells in vitro and in vivo, suggesting it to be a novel therapeutic agent for the treatment of PEL.

Breather-breather interactions in sine-Gordon systems using collective coordinate approach.

We investigate the interaction between breathers in sine-Gordon systems using a collective coordinate approach. Focusing on the in-phase or out-of-phase oscillation mode of two identical breathers, we derive a simple ordinary differential equation for the collective coordinate: the separation between the centers of mass of the two breathers R. Analytic solutions of this equation can reproduce quantitatively the results of a direct numerical simulation of the sine-Gordon equation over the whole parameter range. The interaction between the two breathers is attractive (repulsive) for the in-phase (out-of-phase) oscillation mode with an asymptotic exponential dependence on R. We find that the interaction within the innermost kink-antikink (kink-kink) pair for the in-phase (out-of-phase) case plays the most significant role in determining the sign and the strength of the effective breather-breather interaction. We also find an internal oscillation mode of the in-phase oscillating breather pair and obtain an analytic expression for the angular frequency of the mode.