Development of a Novel CD26-Targeted Chimeric Antigen Receptor T-Cell Therapy for CD26-Expressing T-Cell Malignancies.

Chimeric-antigen-receptor (CAR) T-cell therapy for CD19-expressing B-cell malignancies is already widely adopted in clinical practice. On the other hand, the development of CAR-T-cell therapy for T-cell malignancies is in its nascent stage. One of the potential targets is CD26, to which we have developed and evaluated the efficacy and safety of the humanized monoclonal antibody YS110. We generated second (CD28) and third (CD28/4-1BB) generation CD26-targeted CAR-T-cells (CD26-2G/3G) using YS110 as the single-chain variable fragment. When co-cultured with CD26-overexpressing target cells, CD26-2G/3G strongly expressed the activation marker CD69 and secreted IFNgamma. In vitro studies targeting the T-cell leukemia cell line HSB2 showed that CD26-2G/3G exhibited significant anti-leukemia effects with the secretion of granzymeB, TNFα, and IL-8, with 3G being superior to 2G. CD26-2G/3G was also highly effective against T-cell lymphoma cells derived from patients. In an in vivo mouse model in which a T-cell lymphoma cell line, KARPAS299, was transplanted subcutaneously, CD26-3G inhibited tumor growth, whereas 2G had no effect. Furthermore, in a systemic dissemination model in which HSB2 was administered intravenously, CD26-3G inhibited tumor growth more potently than 2G, resulting in greater survival benefit. The third-generation CD26-targeted CAR-T-cell therapy may be a promising treatment modality for T-cell malignancies.

DPP8 Selective Inhibitor Tominostat as a Novel and Broad-Spectrum Anticancer Agent against Hematological Malignancies.

DPP8/9 inhibition induces either pyroptotic or apoptotic cell death in hematological malignancies. We previously reported that treatment with the DPP8/9 inhibitor 1G244 resulted in apoptotic cell death in myeloma, and our current study further evaluates the mechanism of action of 1G244 in different blood cancer cell lines. Specifically, 1G244 inhibited DPP9 to induce GSDMD-mediated-pyroptosis at low concentrations and inhibited DPP8 to cause caspase-3-mediated-apoptosis at high concentrations. HCK expression is necessary to induce susceptibility to pyroptosis but does not participate in the induction of apoptosis. To further characterize this DPP8-dependent broad-spectrum apoptosis induction effect, we evaluated the potential antineoplastic role for an analog of 1G244 with higher DPP8 selectivity, tominostat (also known as 12 m). In vitro studies demonstrated that the cytotoxic effect of 1G244 at high concentrations was enhanced in tominostat. Meanwhile, in vivo work showed tominostat exhibited antitumor activity that was more effective on a cell line sensitive to 1G244, and at higher doses, it was also effective on a cell line resistant to 1G244. Importantly, the weight loss morbidity associated with increasing doses of 1G244 was not observed with tominostat. These results suggest the possible development of novel drugs with antineoplastic activity against selected hematological malignancies by refining and increasing the DPP8 selectivity of tominostat.

High incidence of disseminated intravascular coagulation and acute cerebral infarction in acute myeloid leukemia with cup-like nuclei.

In this study, we examined a cohort of Japanese patients with acute myeloid leukemia (AML) with cup-like nuclei. In particular, we attempted to provide a detailed definition of the clinical features of AML with cup-like nuclei. The clinical records of patients diagnosed with de novo AML were collected retrospectively. We showed that approximately 23% of all patients with AML diagnosed during the study period had AML with cup-like nuclei. All three cup-like AML cases had FLT3-ITD mutations. In addition, we reported a high incidence of disseminated intravascular coagulation and acute cerebral infarction in patients with AML with cup-like nuclei. Our results show that AML with cup-like nuclei may be more common than expected. Due to these unique characteristics, recognition of this morphology is recommended.

Development of Acute Adult T-cell Leukemia Following PD-1 Blockade Therapy for Lung Cancer.

Immune checkpoint inhibitors (ICIs) are widely used for the treatment of various cancers. However, paradoxical exacerbation of neoplasms, referred to as "hyperprogressive disease," has been reported in a proportion of patients treated with anti-programmed cell death-1 (PD-1)/PD-1 ligand (PD-L1) blockade. We herein report a case of acute adult T-cell leukemia (ATL) that developed shortly after the administration of nivolumab, a PD-1 inhibitor, to treat non-small-cell lung cancer. There were no signs of ATL before the administration of nivolumab, and seropositivity for human T-cell leukemia virus type-1 (HTLV-1) was confirmed after the development of acute ATL. We speculate that nivolumab likely contributed to the development of acute ATL.

Humanized anti-IL-26 monoclonal antibody as a novel targeted therapy for chronic graft-versus-host disease.

IL-26 is a Th17 cytokine, with its gene being absent in rodents. To characterize the in vivo immunological effects of IL-26 in chronic systemic inflammation, we used human IL26 transgenic (hIL-26Tg) mice and human umbilical cord blood mononuclear cells (hCBMC) in mouse allogeneic-graft-versus-host disease (GVHD) and chronic xenogeneic-GVHD model, respectively. Transfer of bone marrow and spleen T cells from hIL-26Tg mice into B10.BR mice resulted in GVHD progression, with clinical signs of tissue damage in multiple organs. IL-26 markedly increased neutrophil levels both in the GVHD-target tissues and peripheral blood. Expression levels of Th17 cytokines in hIL-26Tg mice-derived donor CD4 T cells were significantly increased, whereas IL-26 did not affect cytotoxic function of donor CD8 T cells. In addition, granulocyte-colony stimulating factor, IL-1ß, and IL-6 levels were particularly enhanced in hIL-26Tg mice. We also developed a humanized neutralizing anti-IL-26 monoclonal antibody (mAb) for therapeutic use, and its administration after onset of chronic xenogeneic-GVHD mitigated weight loss and prolonged survival, with preservation of graft-versus-leukemia effect. Taken together, our data elucidate the in vivo immunological effects of IL-26 in chronic GVHD models and suggest that a humanized anti-IL-26 mAb may be a potential therapeutic agent for the treatment of chronic GVHD.

Adult paroxysmal cold hemoglobinuria following mRNA COVID-19 vaccination.

Paroxysmal cold hemoglobinuria (PCH) is an extremely rare subtype of autoimmune hemolytic anemia (AIHA) in adults. PCH is caused by the biphasic Donath-Landsteiner (DL) antibody which fixes complement to red blood cells at low temperatures and dissociates at warmer temperatures, leading to complement-mediated intravascular hemolysis. Autoimmune hematological disorders including AIHA and immune thrombocytopenia have been reported to develop following the mRNA COVID-19 vaccination. However, PCH developing subsequent to mRNA vaccination has never been reported. We report a 59-year-old male who developed PCH approximately a month after his second mRNA COVID-19 vaccination.

Two autopsy cases of pulmonary leukemic infiltration mimicking severe pneumonia in patients with acute myeloid leukemia.

Although a previous autopsy series demonstrated that pulmonary leukemic infiltration (PLI) is a major pulmonary complication in patients with acute myeloid leukemia (AML), an antemortem diagnosis of PLI is rare. Diverse pulmonary complications cause acute respiratory failure (ARF) in patients with AML undergoing chemotherapy. This article reports two elderly patients with AML who presented with ARF due to PLI mimicking severe pneumonia during induction chemotherapy. Accurate antemortem diagnosis of PLI was almost impossible without pathological examination since the clinical course was not typical of PLI. We recommend considering PLI in patients with AML who have an unknown etiology of ARF.

Primary Skeletal Muscle Peripheral T-cell Lymphoma: An Autopsy Case Report and Review of the Literature.

Primary skeletal muscle lymphoma is extremely uncommon, and there have only been eight previous case reports on primary skeletal muscle peripheral T-cell lymphoma, not otherwise specified (PSM-PTCL, NOS). We herein report an autopsy case of a 71-year-old woman with PSM-PTCL, NOS, who had a 24-year history of systemic sclerosis treated with immunosuppressive drugs. A post-mortem examination revealed infiltration of lymphoma cells positive for T-cell markers, cytotoxic markers, and p53. This case was considered to be one of other iatrogenic immunodeficiency-associated lymphoproliferative disorder (OIIA-LPD). This is the first case categorized under both PSM-PTCL, NOS, and OIIA-LPD.

IL-26 mediates epidermal growth factor receptor-tyrosine kinase inhibitor resistance through endoplasmic reticulum stress signaling pathway in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) has a poor prognosis compared to other breast cancer subtypes. Although epidermal growth factor receptor (EGFR) is overexpressed in TNBC, clinical trials with EGFR inhibitors including tyrosine kinase inhibitors (EGFR-TKI) in TNBC have heretofore been unsuccessful. To develop effective EGFR-targeted therapy for TNBC, the precise mechanisms of EGFR-TKI resistance in TNBC need to be elucidated. In this study, to understand the molecular mechanisms involved in the differences in EGFR-TKI efficacy on TNBC between human and mouse, we focused on the effect of IL-26, which is absent in mice. In vitro analysis showed that IL-26 activated AKT and JNK signaling of bypass pathway of EGFR-TKI in both murine and human TNBC cells. We next investigated the mechanisms involved in IL-26-mediated EGFR-TKI resistance in TNBC. We identified EphA3 as a novel functional receptor for IL-26 in TNBC. IL-26 induced dephosphorylation and downmodulation of EphA3 in TNBC, which resulted in increased phosphorylation of AKT and JNK against EGFR-TKI-induced endoplasmic reticulum (ER) stress, leading to tumor growth. Meanwhile, the blockade of IL-26 overcame EGFR-TKI resistance in TNBC. Since the gene encoding IL-26 is absent in mice, we utilized human IL-26 transgenic (hIL-26Tg) mice as a tumor-bearing murine model to characterize the role of IL-26 in the differential effect of EGFR-TKI in human and mice and to confirm our in vitro findings. Our findings indicate that IL-26 activates the bypass pathway of EGFR-TKI, while blockade of IL-26 overcomes EGFR-TKI resistance in TNBC via enhancement of ER stress signaling. Our work provides novel insights into the mechanisms of EGFR-TKI resistance in TNBC via interaction of IL-26 with its newly identified receptor EphA3, while also suggesting IL-26 as a possible therapeutic target in TNBC.

Hemophagocytic lymphohistiocytosis associated with Epstein-Barr virus-positive diffuse large B-cell lymphoma, NOS of bone marrow-liver-spleen type: an autopsy case report.

Lymphoma-associated hemophagocytic lymphohistiocytosis (HLH) has a significantly poor prognosis among secondary HLH. We describe the rare case of a 74-year-old female with secondary HLH presenting with a rapidly fatal course. Post-mortem examination revealed Epstein-Barr virus (EBV) -positive diffuse large B-cell lymphoma (DLBCL). We were unable to make a definite antemortem diagnosis because the patient did not exhibit lymphadenopathy and bone marrow biopsy demonstrated hemophagocytosis without evidence of lymphoma. She died of multiple organ failure on the twelfth day of hospitalization despite a temporary response to steroids. Autopsy revealed diffuse lymphoma cell infiltration of the bone marrow, liver and spleen, suggesting "bone marrow-liver-spleen" (BLS)-type large B-cell lymphoma (LBCL). BLS-type LBCL is a rare and clinically aggressive lymphoma, usually associated with fever, cytopenia and HLH. The disease has a high mortality rate due to the delay in diagnosis and a highly aggressive clinical course. Further studies are required to improve our understanding of this rare extranodal DLBCL.

[Microgranular-type acute promyelocytic leukemia with weak myeloperoxidase staining: difficulty of morphological diagnosis].

The 2017 World Health Organization (WHO) classification states that acute promyelocytic leukemia (APL) always presents with strong myeloperoxidase staining. However, we herein report of a 40-year-old woman with the microgranular variant of acute promyelocytic leukemia presenting with weak myeloperoxidase (MPO) staining. The leukemic cells were morphologically similar to monocytic cells, showing distorted-shaped nuclei and weak MPO staining. However, flow cytometry revealed positivity of CD2, CD34, and human leucocyte antigen-DR (HLA-DR) and pointed toward a diagnosis of APL. PML-RARA mRNA detection finally led the patient to a definitive diagnosis. The patient achieved complete remission by induction chemotherapy including tretinoin, cytarabine and idarubicin, and no differentiation syndrome was observed.

DPP8 is a novel therapeutic target for multiple myeloma.

Dipeptidyl peptidases (DPPs) are proteolytic enzymes that are ideal therapeutic targets in human diseases. Indeed, DPP4 inhibitors are widely used in clinical practice as anti-diabetic agents. In this paper, we show that DPP4 inhibitors also induced cell death in multiple human myeloma cells. Among five DPP4 inhibitors, only two of them, vildagliptin and saxagliptin, exhibited apparent cytotoxic effects on myeloma cell lines, without any difference in suppression of DPP4 activity. As these two DPP4 inhibitors are known to have off-target effects against DPP8/9, we employed the specific DPP8/9 inhibitor 1G244. 1G244 demonstrated anti-myeloma effects on several cell lines and CD138+ cells from patients as well as in murine xenograft model. Through siRNA silencing approach, we further confirmed that DPP8 but not DPP9 is a key molecule in inducing cell death induced by DPP8/9 inhibition. In fact, the expression of DPP8 in CD38+ cells from myeloma patients was higher than that of healthy volunteers. DPP8/9 inhibition induced apoptosis, as evidenced by activated form of PARP, caspases-3 and was suppressed by the pan-caspase inhibitor Z-VAD-FMK. Taken together, these results indicate that DPP8 is a novel therapeutic target for myeloma treatment.

[Rapidly fatal streptococcal toxic shock syndrome due to Streptococcus agalactiae in a patient with chronic myeloid leukemia and cirrhosis].

A 72-year-old woman with chronic myeloid leukemia (CML) and cirrhosis complicated with blood blisters on her right upper arm and ascites was admitted. She presented with shock vital on admission. Initial gram staining of blood cultures showed gram-positive cocci in chains, suggesting streptococcal toxic shock syndrome (STSS). Amputation of the right upper arm was performed owing to necrotizing fasciitis. Despite continued antibiotic therapy and systemic management, the blood blisters rapidly spread to the skin of the whole body, and she died 41 h after admission. Blood and fluid cultures from the blisters showed group B streptococci. Reports of patients with leukemia complicated with STSS are rare, and all cases have followed fatal courses. Particularly in this case, various risk factors, such as neutropenia due to tyrosine kinase inhibitor, neutrophil dysfunction due to cirrhosis, and elderly CML, overlapped. In the future, we believe that the lives of patients with leukemia complicated with STSS may be saved by establishing treatment methods and determining the detailed pathogenesis of STSS.

A novel role for CD26/dipeptidyl peptidase IV as a therapeutic target.

CD26 is a 110 kDa surface glycoprotein with intrinsic dipeptidyl peptidase IV activity that is expressed on numerous cell types and has a multitude of biological functions. The role of CD26 in immune regulation has been extensively characterized, with recent findings elucidating its linkage with signaling pathways and structures involved in T-lymphocyte activation as well as antigen presenting cell-T-cell interaction. In this paper, we will review emerging data on CD26-mediated immune regulation suggesting that CD26 may be an appropriate therapeutic target for the treatment of selected immune disorders as well as Middle East respiratory syndrome coronavirus. Moreover, we have had a long-standing interest in the role of CD26 in cancer biology and its suitability as a novel therapeutic target in selected neoplasms. We reported robust in vivo data on the anti-tumor activity of anti-CD26 monoclonal antibody in mouse xenograft models. We herein review significant novel findings and the early clinical development of a CD26-targeted therapy in selected immune disorders and cancers, advances that can lead to a more hopeful future for patients with these intractable diseases.

Role of IL-26+CD26+CD4 T Cells in Pulmonary Chronic Graft-Versus-Host Disease and Treatment with Caveolin-1-Ig Fc Conjugate.

Obliterative bronchiolitis is the primary noninfectious pulmonary complication after allogeneic hematopoietic cell transplantation and the only pathognomonic manifestation of pulmonary chronic graft-versus-host disease (cGVHD). In our recent study, we identified a novel effect of IL-26, which is absent in rodents, on transplant related-obliterative bronchiolitis. Sublethally irradiated NOD/Shi-scidIL2rγnull mice transplanted with human umbilical cord blood gradually exhibited obliterative bronchiolitis with increased collagen deposition and predominant infiltration with human IL-26+CD26+CD4 T cells. Moreover, we showed that IL-26 increased collagen synthesis in fibroblasts in vitro and that collagen contents were increased in a murine GVHD model using IL26 transgenic mice. In vitro analysis demonstrated a significant increase in IL-26 production by CD4 T cells following CD26 costimulation, while immunoglobulin Fc domain fused with the N-terminal of caveolin-1, the ligand for CD26, (Cav-Ig) effectively inhibited production of IL-26. Administration of Cav-Ig before or after onset of GVHD impeded the development of clinical and histologic features of GVHD without interrupting engraftment of donor-derived human cells, with preservation of the graft-versus-leukemia effect. We concluded that cGVHD of the lungs is caused in part by IL-26+CD26+CD4 T cells, and that treatment with Cav-Ig could be beneficial for cGVHD prevention and therapy.

Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains.

CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis.

Online reporting system for transfusion-related adverse events to enhance recipient haemovigilance in Japan: a pilot study.

BACKGROUND: A surveillance system for transfusion-related adverse reactions and infectious diseases in Japan was started at a national level in 1993, but current reporting of events in recipients is performed on a voluntary basis. A reporting system which can collect information on all transfusion-related events in recipients is required in Japan. METHODS: We have developed an online reporting system for transfusion-related events and performed a pilot study in 12 hospitals from 2007 to 2010. RESULTS: The overall incidence of adverse events per transfusion bag was 1.47%. Platelet concentrates gave rise to statistically more adverse events (4.16%) than red blood cells (0.66%) and fresh-frozen plasma (0.93%). In addition, we found that the incidence of adverse events varied between hospitals according to their size and patient characteristics. CONCLUSION: This online reporting system is useful for collection and analysis of actual adverse events in recipients of blood transfusions and may contribute to enhancement of the existing surveillance system for recipients in Japan.

Stage IV intramucosal gastric marginal zone B cell lymphoma of mucosa-associated lymphoid tissue type.

A 45-year-old woman with no symptoms underwent upper gastrointestinal endoscopy. A discolored area was noted at the greater curvature of the gastric upper body. Endoscopic ultrasonography demonstrated thickening of the second sonographic layer indicating that the depth of invasion was confined to the mucosa. A urea breath test and anti-Helicobacter pylori antibody test were negative. A computed tomography scan showed a consolidation at the right lung. Gastric biopsy and transbronchial lung biopsy (TBLB) demonstrated a monotonous proliferation of atypical small lymphocytes. A diagnosis of gastric marginal zone B cell lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma) was made. The clinical stage was stage IV. A genetic analysis showed rearrangement of the joining region of the immunoglobulin heavy chain gene and identical clones in both lesions. An API2-MALT1 fusion gene was detected in the gastric lesion. After H. pylori eradication treatment, combination treatment with rituximab plus CHOP (R-CHOP) was performed; 6 months later an endoscopy revealed complete disappearance of the lesion. Multiple gastric biopsies showed no infiltrating atypical lymphocytes. Similarly, the lesion in the lung showed complete remission (CR) on CT and TBLB. This report shows that a gastric MALT lymphoma located in the mucosa and disseminated to the lung maintained CR by R-CHOP.