Co-expression of regulatory B-cell markers, transforming growth factor ß and interleukin-10 as a prognostic factor in diffuse large B-cell lymphoma.

Regulatory B cells (Bregs) suppress antitumor immunity by producing anti-inflammatory cytokines such as transforming growth factor ß (TGF-ß) and interleukin-10 (IL-10) and promoting tumor growth. It is unknown whether diffuse large B-cell lymphoma (DLBCL), a common subtype of B-cell malignancy, exhibits characteristics similar to those of Bregs. This study aimed to clarify the features of DLBCLs carrying Breg markers. In 123 DLBCL cases, we evaluated TGF-ß and IL-10 expression in tumor biopsy samples using immunohistochemical staining and retrospectively analyzed their clinicopathological characteristics. Fifteen cases (12.2 %) classified as Breg-type DLBCL were positive for both TGF-ß and IL-10. Breg-type DLBCL is mainly classified as having activated B cell-like cells of origin. Breg-type DLBCL cases showed significantly worse progression-free survival and overall survival (OS) than other DLBCL cases (P = 0.0016 and P = 0.042, respectively). In multivariate analysis, Breg-type DLBCL significantly affected OS (hazard ratio, 3.13; 95 % confidence interval 1.15-8.55; P = 0.025). Gene expression analysis showed that the expression of follicular dendritic cell-associated genes (FCER2, PIK3CD, FOXO1) was downregulated in Breg-type DLBCLs compared to other DLBCLs. These results suggest that the double expression of Breg markers, TGF-ß and IL-10, in tumor cells indicates a poor prognosis in DLBCL patients. Further studies evaluating genomic abnormalities could confirm the characteristics of Breg-type DLBCL.

Prognostic impact of HLA supertype mismatch in single-unit cord blood transplantation.

The "human leukocyte antigen (HLA) supertype" is a functional classification of HLA alleles, which was defined by structural features and peptide specificities, and has been reportedly associated with the clinical outcomes of viral infections and autoimmune diseases. Although the disparity in each HLA locus was reported to have no clinical significance in single-unit cord blood transplantation (sCBT), the clinical significance of the HLA supertype in sCBT remains unknown. Therefore, we retrospectively analyzed clinical data of 1603 patients who received sCBT in eight institutes in Japan between 2000 and 2017. Each HLA allele was categorized into 19 supertypes, and the prognostic effect of disparities was then assessed. An HLA-B supertype mismatch was identified as a poor prognostic factor (PFS: hazard ratio [HR] = 1.23, p = 0.00044) and was associated with a higher cumulative incidence (CI) of relapse (HR = 1.24, p = 0.013). However, an HLA-B supertype mismatch was not associated with the CI of acute and chronic graft-versus-host-disease. The multivariate analysis for relapse and PFS showed the significance of an HLA-B supertype mismatch independent of allelic mismatches, and other previously reported prognostic factors. HLA-B supertype-matched grafts should be selected in sCBT.

Impact of a third dose of anti-SARS-CoV-2 vaccine in hematopoietic cell transplant recipients: A Japanese multicenter observational study.

This prospective observational study aimed to assess the serological response and safety after the third booster shot of SARS-CoV-2 mRNA vaccines in 292 hematopoietic cell transplant (HCT) recipients. In our patients, mild systemic reactions were present in 10-40% and GVHD aggravation in 1.1%. Overall, clinically relevant response (>250 U/mL) was observed in 93.1% of allogeneic (allo)-HCT recipients and 70.6% of autologous (auto)-HCT recipients, respectively. Of note, detectable antibody response with any titer following the first two doses was a powerful predictor for adequate response after booster shot in both cohorts. For such patients, 98.8% of allo- and 92.3% of auto-HCT recipients obtained clinically relevant response after dose 3. In addition, continued systemic steroid and/or calcineurin inhibitors at the booster shot significantly correlated with serological response. These findings highlighted that booster vaccination efficiently improved serological response without safety concerns and thus recommended for the majority of HCT recipients.

Ferroptosis in the colon epithelial cells as a therapeutic target for ulcerative colitis.

BACKGROUND: Ferroptosis, a type of programmed cell death triggered by oxidative stress, was suspected to play a role in ulcerative colitis. Indigo naturalis is highly effective against ulcerative colitis, but its mechanism is unclear. This study found that indigo naturalis treatment suppressed ferroptosis. METHODS: We analyzed 770 mRNA expressions of patients with ulcerative colitis. Suppression of ferroptosis by indigo naturalis treatment was shown using a cell death assay. Malondialdehyde levels and reactive oxygen species were analyzed in CaCo-2 cells treated with indigo naturalis. Glutathione metabolism was shown by metabolomic analysis. Extraction of the ingredients indigo naturalis from the rectal mucosa was performed using liquid chromatograph-mass spectrometry. RESULTS: Gene expression profiling showed that indigo naturalis treatment increased antioxidant genes in the mucosa of patients with ulcerative colitis. In vitro analysis showed that nuclear factor erythroid-2-related factor 2-related antioxidant gene expression was upregulated by indigo naturalis. Indigo naturalis treatment rendered cells resistant to ferroptosis. Metabolomic analysis suggested that an increase in reduced glutathione by indigo naturalis. The protein expression of CYP1A1 and GPX4 was increased in the rectum by treatment with indigo naturalis. The main ingredients of indigo naturalis, indirubin and indigo inhibited ferroptosis. Indirubin was detected in the rectal mucosa of patients with ulcerative colitis who were treated with indigo naturalis. CONCLUSIONS: Suppression of ferroptosis by indigo naturalis in the intestinal epithelium could be therapeutic target for ulcerative colitis. The main active ingredient of indigo naturalis may be indirubin.

Targeting a mitochondrial E3 ubiquitin ligase complex to overcome AML cell-intrinsic Venetoclax resistance.

To identify molecules/pathways governing Venetoclax (VEN) sensitivity, we performed genome-wide CRISPR/Cas9 screens using a mouse AML line insensitive to VEN-induced mitochondrial apoptosis. Levels of sgRNAs targeting March5, Ube2j2 or Ube2k significantly decreased upon VEN treatment, suggesting synthetic lethal interaction. Depletion of either Ube2j2 or Ube2k sensitized AML cells to VEN only in the presence of March5, suggesting coordinate function of the E2s Ube2j2 and Ube2k with the E3 ligase March5. We next performed CRISPR screens using March5 knockout cells and identified Noxa as a key March5 substrate. Mechanistically, Bax released from Bcl2 upon VEN treatment was entrapped by Mcl1 and Bcl-XL and failed to induce apoptosis in March5 intact AML cells. By contrast, in March5 knockout cells, liberated Bax did not bind to Mcl1, as Noxa likely occupied Mcl1 BH3-binding grooves and efficiently induced mitochondrial apoptosis. We reveal molecular mechanisms underlying AML cell-intrinsic VEN resistance and suggest a novel means to sensitize AML cells to VEN.

RHAMM marks proliferative subpopulation of human colorectal cancer stem cells.

The cancer stem cell (CSC) theory features typically rare self-renewing subpopulations that reconstitute the heterogeneous tumor. Identification of molecules that characterize the features of CSCs is a key imperative for further understanding tumor heterogeneity and for the development of novel therapeutic strategies. However, the use of conventional markers of CSCs is still insufficient for the isolation of bona fide CSCs. We investigated organoids that are miniature forms of tumor tissues by reconstructing cellular diversity to identify specific markers to characterize CSCs in heterogeneous tumors. Here, we report that the receptor for hyaluronan-mediated motility (RHAMM) expresses in a subpopulation of CD44+ conventional human colorectal CSC fraction. Single-cell transcriptomics of organoids highlighted RHAMM-positive proliferative cells that revealed distinct characteristics among the various cell types. Prospectively isolated RHAMM+CD44+ cells from the human colorectal cancer tissues showed highly proliferative characteristics with a self-renewal ability in comparison with the other cancer cells. Furthermore, inhibition of RHAMM strongly suppressed organoid formation in vitro and inhibited tumor growth in vivo. Our findings suggest that RHAMM is a potential therapeutic target because it is a specific marker of the proliferative subpopulation within the conventional CSC fraction.

Anti-dsDNA IgE induces IL-4 production from basophils, potentially involved in B-cell differentiation in systemic lupus erythematosus.

OBJECTIVES: Recently, the involvement of basophils and IgE-type autoantibodies in the pathogenesis of SLE has been elucidated using mouse models; however, few studies have been conducted in humans. In this study, the role of basophils and anti-double-stranded DNA (dsDNA) IgE in SLE was examined using human samples. METHODS: The correlation between disease activity and serum levels of anti-dsDNA IgE in SLE was evaluated using enzyme-linked immunosorbent assay. Cytokines produced by IgE-stimulated basophils from healthy subjects were assessed using RNA sequences. The interaction of basophils and B cells to promote B cell differentiation was investigated using a co-culture system. The ability of basophils from patients with SLE with anti-dsDNA IgE to create cytokines that may be involved in B cell differentiation in response to dsDNA was examined using real-time PCR. RESULTS: Anti-dsDNA IgE levels in the serum of patients with SLE correlated with disease activity. Healthy donor basophils produced IL-3, IL-4 and TGF-ß1 after anti-IgE stimulation. Co-culture of B cells with anti-IgE-stimulated basophils increased plasmablasts which were cancelled by neutralizing IL-4. After encountering the antigen, basophils released IL-4 more quickly than follicular helper T cells. Basophils isolated from patients with anti-dsDNA IgE promoted IL-4 expression by adding dsDNA. CONCLUSIONS: These results suggest that basophils contribute to the pathogenesis of SLE by promoting B cell differentiation via dsDNA-specific IgE in patients similar to the process described in mouse models.

Human acute leukemia uses branched-chain amino acid catabolism to maintain stemness through regulating PRC2 function.

Cancer-specific metabolic activities play a crucial role in the pathogenesis of human malignancies. To investigate human acute leukemia-specific metabolic properties, we comprehensively measured the cellular metabolites within the CD34+ fraction of normal hematopoietic stem progenitor cells (HSPCs), primary human acute myelogenous leukemia (AML), and acute lymphoblastic leukemia (ALL) cells. Here, we show that human leukemia cells are addicted to the branched-chain amino acid (BCAA) metabolism to maintain their stemness, irrespective of myeloid or lymphoid types. Human primary acute leukemias had BCAA transporters for BCAA uptake, cellular BCAA, α-ketoglutarate (α-KG), and cytoplasmic BCAA transaminase-1 (BCAT1) at significantly higher levels than control HSPCs. Isotope-tracing experiments showed that in primary leukemia cells, BCAT1 actively catabolizes BCAA using α-KG into branched-chain α-ketoacids, whose metabolic processes provide leukemia cells with critical substrates for the trichloroacetic acid cycle and the synthesis of nonessential amino acids, both of which reproduce α-KG to maintain its cellular level. In xenogeneic transplantation experiments, deprivation of BCAA from daily diet strongly inhibited expansion, engraftment and self-renewal of human acute leukemia cells. Inhibition of BCAA catabolism in primary AML or ALL cells specifically inactivates the function of the polycomb repressive complex 2, an epigenetic regulator for stem cell signatures, by inhibiting the transcription of PRC components, such as zeste homolog 2 and embryonic ectoderm development. Accordingly, BCAA catabolism plays an important role in the maintenance of stemness in primary human AML and ALL, and molecules related to the BCAA metabolism pathway should be critical targets for acute leukemia treatment.

Successful pseudo-autologous stem cell transplantation for donor-derived Burkitt lymphoma occurring 9 years after allogeneic transplantation.

Donor-derived hematological malignancies have been recognized as rare but serious late complications in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Most cases in the literature were diagnosed as myelodysplastic syndrome or acute leukemia, with very few malignant lymphoma reported. We herein present another case of donor-derived Burkitt lymphoma that occurred 9 years after allo-HSCT under continued administration of immunosuppressants for chronic graft-versus-host disease (GVHD). The patient achieved a partial response after rituximab-combined intensive chemotherapy. To reduce the risk of relapse and to avoid organ toxicities due to repeated chemotherapies, we performed upfront high-dose chemotherapy followed by stem cell rescue using donor-derived CD34+ cells, called pseudo-autologous HSCT (pASCT), and adjusted immunosuppressants appropriately. The patient remained disease-free for 23 months after pASCT without exacerbation of cGVHD. Although the observation period has been relatively short and longer follow-up is needed, pASCT may be a feasible option for donor-derived lymphoma even in patients with active cGVHD.

Lymphoma Microenvironment in DLBCL and PTCL-NOS: the key to uncovering heterogeneity and the potential for stratification.

Diffuse large B-cell lymphoma (DLBCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) are the most common subtypes of mature B cell neoplasm and T/NK cell lymphoma, respectively. They share a commonality in that they are, by definition, highly heterogeneous populations. Recent studies are revealing more about the heterogeneity of these diseases, and at the same time, there is an active debate on how to stratify these heterogeneous diseases and make them useful in clinical practice. The various immune cells and non-cellular components surrounding lymphoma cells, i.e., the lymphoma microenvironment, have been the subject of intense research since the late 2000s, and much knowledge has been accumulated over the past decade. As a result, it has become clear that the lymphoma microenvironment, despite its paucity in tissues, significantly impacts the lymphoma pathogenesis and clinical behavior, such as its prognosis and response to therapy. In this article, we review the role of the lymphoma microenvironment in DLBCL and PTCL-NOS, with particular attention given to its impact on the prognosis and stratification.

Prognostic value of pre-transplantation total metabolic tumor volume on 18fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography in relapsed and refractory aggressive lymphoma.

Relapsed and refractory aggressive lymphoma have a poor prognosis. High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) is effective in chemosensitive patients. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is among the few options for non-chemosensitive patients. 18Fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography (18FDG-PET/CT) is the standard tool for evaluating response to chemotherapy and residual tumor volume. However, accurate assessment of residual tumor volume is not currently being achieved in clinical practice, and its value in prognostic and therapeutic stratification remains unclear. To answer this question, we investigated the efficacy of quantitative indicators, including total metabolic tumor volume (TMTV), in predicting prognosis after auto-HSCT and allo-HSCT. We retrospectively analyzed 39 patients who received auto-HSCT and 28 who received allo-HSCT. In the auto-HSCT group, patients with a higher TMTV had a poor prognosis due to greater risk of relapse. In the allo-HSCT group, patients with a higher TMTV had a lower progression-free survival rate and a significantly higher relapse rate. Neither Deauville score nor other clinical parameters were associated with prognosis in either group. Therefore, pre-transplant TMTV on PET is effective for prognostic prediction and therapeutic decision-making for relapsed or refractory aggressive lymphoma.

Macrophages are primed to transdifferentiate into fibroblasts in malignant ascites and pleural effusions.

Cancer-associated fibroblasts (CAFs) play an important role in cancer progression. However, the origin of CAFs remains unclear. This study shows that macrophages in malignant ascites and pleural effusions (cavity fluid-associated macrophages: CAMs) transdifferentiate into fibroblast-like cells. CAMs obtained from gastrointestinal cancer patients were sorted by flow cytometry and cultured in vitro. CD45+CD14+ CAMs transdifferentiated into CD45-CD90+ fibroblast-like cells that exhibited spindle shapes. Then, cDNA microarray analysis showed that the CD45-CD90+ fibroblast-like cells (macrophage-derived CAFs: MDCAFs) had a fibroblast-specific gene expression signature and produced growth factors for epithelial cell proliferation. Human colon cancer cells transplanted into immunodeficient mice with MDCAFs formed larger tumors than cancer cells alone. Gene ontology analyses showed the involvement of TGFß signaling and cell-matrix adhesion in MDCAFs, and transdifferentiation of CAMs into MDCAFs was canceled by inhibiting TGFß and cell adhesion. Furthermore, the acquired genetic alterations in hematopoietic stem cells (HSCs) were shared in CAMs and MDCAFs. Taken together, CAMs could be a source of CAFs and might originate from HSCs. We propose the transdifferentiation process of CAMs into MDCAFs as a new therapeutic target for fibrosis associated with gastrointestinal cancer.

A germinal center-associated microenvironmental signature reflects malignant phenotype and outcome of DLBCL.

Diffuse large B-cell lymphoma (DLBCL) is the most common B-cell malignancy, with varying prognosis after the gold standard rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Several prognostic models have been established by focusing primarily on characteristics of lymphoma cells themselves, including cell-of-origin (COO), genomic alterations, and gene/protein expressions. However, the prognostic impact of the lymphoma microenvironment and its association with characteristics of lymphoma cells are not fully understood. Using the nCounter-based gene expression profiling of untreated DLBCL tissues, we assess the clinical impact of lymphoma microenvironment on the clinical outcomes and pathophysiological, molecular signatures in DLBCL. The presence of normal germinal center (GC)-microenvironmental cells, including follicular T cells, macrophage/dendritic cells, and stromal cells in lymphoma tissue indicates a positive therapeutic response. Our prognostic model, based on quantitation of transcripts from distinct GC-microenvironmental cell markers, clearly identified patients with graded prognosis independently of existing prognostic models. We observed increased incidences of genomic alterations and aberrant gene expression associated with poor prognosis in DLBCL tissues lacking GC-microenvironmental cells relative to those containing these cells. These data suggest that the loss of GC-associated microenvironmental signature dictates clinical outcomes of DLBCL patients reflecting the accumulation of "unfavorable" molecular signatures.

Targeting leukemia-specific dependence on the de novo purine synthesis pathway.

Acute myeloid leukemia (AML) is a devastating disease, and clinical outcomes are still far from satisfactory. Here, to identify novel targets for AML therapy, we performed a genome-wide CRISPR/Cas9 screen using AML cell lines, followed by a second screen in vivo. We show that PAICS, an enzyme involved in de novo purine biosynthesis, is a potential target for AML therapy. AML cells expressing shRNA-PAICS exhibited a proliferative disadvantage, indicating a toxic effect of shRNA-PAICS. Treatment of human AML cells with a PAICS inhibitor suppressed their proliferation by inhibiting DNA synthesis and promoting apoptosis and had anti-leukemic effects in AML PDX models. Furthermore, CRISPR/Cas9 screens using AML cells in the presence of the inhibitor revealed genes mediating resistance or synthetic lethal to PAICS inhibition. Our findings identify PAICS as a novel therapeutic target for AML and further define components of de novo purine synthesis pathway and its downstream effectors essential for AML cell survival.

Ustekinumab Improves Active Crohn's Disease by Suppressing the T Helper 17 Pathway.

BACKGROUND: Ustekinumab (UST), an antibody targeting the p40 subunit of interleukin (IL)-12 and IL-23, is effective in treating Crohn's disease (CD). To clarify the mechanism of UST, we investigated T-cell differentiation in CD patients treated with UST. METHODS: Twenty-seven patients with active CD were enrolled in this study. Seventeen patients were treated with UST, and 10 patients were treated with anti-tumor necrosis factor (TNF)-alpha therapy. The changes in the proportions of T-cell subsets after these therapies were analyzed by flow cytometry. Comprehensive gene expression changes in the colonic mucosa were also evaluated. RESULTS: The frequency of T helper (Th) 17 cells was significantly decreased in the peripheral blood of patients with active CD after UST therapy. Anti-TNF therapy had a minimal effect on Th17 cells but increased the proportion of regulatory T cells. Enrichment analysis showed the expression of genes involved in the Th17 differentiation pathway was downregulated in the colonic mucosa after UST but not anti-TNF therapy. There were no common differentially expressed genes between CD patients treated with UST and anti-TNF therapy, suggesting a clear difference in their mechanism of action. CONCLUSION: In patients with active CD, UST therapy suppressed Th17 cell differentiation both in the peripheral blood and colonic tissues.

Autoimmune manifestations associated with myelodysplastic syndrome predict a poor prognosis.

ABSTRACT: We evaluated the clinical characteristics of autoimmune manifestations (AIMs) associated with myelodysplastic syndrome (MDS) to elucidate whether AIMs impacted MDS outcomes in Japan.This retrospective study including 61 patients who received a new diagnosis of MDS between January 2008 and December 2015 was conducted by the review of electronic medical records for the presence of AIMs within a 1-year period prior to or following the diagnosis of MDS.AIMs were identified in 12 of the 61 (20.0%) patients with MDS. The neutrophil counts and C-reactive protein levels in peripheral blood were significantly elevated in patients with AIMs, and the survival was shorter in those with AIMs compared to those without AIMs. Multivariate analysis demonstrated that the presence of AIMs and higher-risk disease according to the International Prognositic Scoring System (IPSS) were independent risk factors for increased mortality (hazard ratio, 4.76 and 4.79, respectively).This retrospective study revealed that the prognosis was poor in patients with MDS-associated AIMs. The treatment of MDS using the current algorithms is based on prognostic scoring systems such as IPSS. Treatment strategies for patients with MDS-associated AIMs should be reconsidered, even in those with low-risk MDS according to the IPSS.

Type 1 helper T cells generate CXCL9/10-producing T-bet+ effector B cells potentially involved in the pathogenesis of rheumatoid arthritis.

Efficacy of B-cell depletion therapy highlights the antibody-independent effector functions of B cells in rheumatoid arthritis (RA). Given type 1 helper T (Th1) cells abundant in synovial fluid (SF) of RA, we have determined whether Th1 cells could generate novel effector B cells. Microarray and qPCR analysis identified CXCL9/10 transcripts as highly expressed genes upon BCR/CD40/IFN-γ stimulation. Activated Th1 cells promoted the generation of CXCL9/10-producing T-bet+ B cells. Expression of CXCL9/10 was most pronounced in CXCR3+ switched memory B cells. Compared with peripheral blood, SFRA enriched highly activated Th1 cells that coexisted with abundant CXCL9/10-producing T-bet+ B cells. Intriguingly, anti-IFN-γ antibody and JAK inhibitors significantly abrogated the generation of CXCL9/10-producing T-bet+ B cells. B cell derived CXCL9/10 significantly facilitated the migration of CD4+ T cells. These findings suggest that Th1 cells generate the novel CXCL9/10-producing T-bet+ effector B cells that could be an ideal pathogenic B cell target for RA therapy.