Li Z, Moore AR, Zheng H
… +21 more, Karunamurthy J, Bhagrath A, Li J, Young D, Jurado LF, Couto K, Kulle A, Park H, Kwak A, Belur V, Talbot S, Divangahi M, DiGiandomenico A, Rogers A, Cohen TS, Ehrlicher AJ, Mandl JN, Wang J, Dufour A, Khatri P, Thanabalasuriar A
The hyperinflammatory syndromes in critically ill patients, including trauma, sepsis, and acute lung injury, are characterized by dysregulated neutrophil responses that contribute to tissue damage and poor outcomes. Usin...The hyperinflammatory syndromes in critically ill patients, including trauma, sepsis, and acute lung injury, are characterized by dysregulated neutrophil responses that contribute to tissue damage and poor outcomes. Using murine models of cytokine storm induced by trauma and lung injury, we identified transforming growth factor β (TGFβ) as a central regulator of immune checkpoint in neutrophils. TGFβ signaling modulates neutrophil activation and upregulates the expression of programmed death-ligand 1 (PDL1). Disruption of TGFβ signaling during hyperinflammation restores the migratory capacity of neutrophils but leads to excessive activation, severe pulmonary tissue damage, and increased susceptibility to spontaneous bacterial infection in the lung. Mechanistically, PDL1 expression alters neutrophil behavior within lung capillaries, promoting intravascular clustering and restricting tissue infiltration. Targeted deletion of PDL1 in neutrophils reverses hyperinflammation-induced clustering, restores effective trafficking to infectious foci, and enhances host-protective immune function while limiting pathological neutrophil hyperactivation. These findings define a TGFβ-PDL1 regulatory axis that restrains the pathogenicity of neutrophils during hyperinflammation, revealing a checkpoint mechanism that balances host defense and tissue integrity.
The use of chimeric antigen receptor (CAR) T cell therapy is increasing in adult B-cell acute lymphoblastic leukemia (B-ALL), with three commercially available CD19 CAR T cell products. Several key clinical questions rel...The use of chimeric antigen receptor (CAR) T cell therapy is increasing in adult B-cell acute lymphoblastic leukemia (B-ALL), with three commercially available CD19 CAR T cell products. Several key clinical questions related to best practices for CAR T cell administration in this population exist, and limited prospective randomized trials have been conducted to fill these knowledge gaps. Thus, to help guide clinical practice, we conducted a modified Delphi study to develop and validate consensus recommendations on the administration of commercially available CAR T cell therapy for adults with B-ALL. Consensus panelists (n= 9) included Principal Investigators (PIs) from Real World Outcomes Collaborative of CAR T Cell Therapy in Adult ALL (ROCCA) consortium sites and were selected based on expertise and CAR T center volume. Final panel consensus recommendations were distributed for rating by the remaining PIs from ROCCA consortium sites, which served as the validation group (n=27). Consensus topics included patient selection, bridging and pre-CAR T leukemia staging, lymphodepletion and CAR T treatment setting, specific toxicity prevention and management, post-CAR T response assessment and disease monitoring, and the role of consolidation and/or maintenance therapies following CAR T cell therapy. Initially, 58 recommendation statements were evaluated for consensus. After two panel meetings, a total of 34 statements achieved consensus rating among the expert panel. After rating by the validation group, all but one recommendation statement continued to meet consensus, for a total of 33 consensus recommendation statements on the administration of CAR T cell therapy in adult B-ALL.
Montanaro A, Monica G, Zamponi R
… +23 more, D'Antuono A, Andreani A, Andrei P, Su A, Ciringione A, Sammarelli G, Todaro G, Rosati R, La Starza R, Mecucci C, Elia L, Gherli A, Vento F, Simoncini E, Lorusso B, Lagastra CAM, Giaimo M, Pagliaro L, Marchesini M, Jimenez CR, Quaini F, Stegmaier K, Roti G
Driver mutations in T-cell acute leukemia (T-ALL) rarely affect druggable kinases. However, these kinases can be aberrantly activated or repressed as secondary oncogenic events. Thus, integrating unbiased phosphoproteomi...Driver mutations in T-cell acute leukemia (T-ALL) rarely affect druggable kinases. However, these kinases can be aberrantly activated or repressed as secondary oncogenic events. Thus, integrating unbiased phosphoproteomics with genomic approaches may offer novel opportunities for target discovery and therapeutic interventions. In our study, we identified WNK1 as a potential target in T-ALL by pairing a list of vulnerable kinases with data from a phosphoproteomic screen of T-ALL cell lines. We subsequently validated WNK1 by loss-of-function-based studies and tested WNK inhibitors in several in vitro and in vivo T-ALL models and clinical T-ALL samples. We showed that therapeutic WNK1 repression promotes polyploidy, resulting in cell proliferation arrest, and morphometric changes, such as incomplete cell division or chromosome segregation through altered mitotic spindle assembly and abscission defects. Furthermore, we found that WNK1 is overexpressed in the TAL1/2-related subgroup, but not in normal thymus or lymph nodes, suggesting a potential translational area for clinical exploitation in poor-prognosis T-ALL carrying PTEN mutations and del(6q). Our work also reports a functional contribution of WNK1 in the leukemia establishment and progression. Structurally WNK1 is an atypical serine/threonine kinase that diverge from canonical kinases by lacking the conserved lysine in subdomain II, instead featuring a cysteine in subdomain I, which is critical for ATP-binding. This unusual structural configuration creates a distinct ATP-binding pocket with limited sequence similarity to conventional kinases, offering a unique opportunity to develop highly selective small-molecules. Targeting this atypical ATP-domain could thus provide a therapeutic advantage and broaden the treatment landscape for T-ALL.
The transcription factor GATA1 has pleiotropic hematopoietic functions, particularly in erythroid and megakaryocytic ontogeny. While mechanistic investigations have uncovered many facets of GATA1 biology, how GATA1 co-re...The transcription factor GATA1 has pleiotropic hematopoietic functions, particularly in erythroid and megakaryocytic ontogeny. While mechanistic investigations have uncovered many facets of GATA1 biology, how GATA1 co-regulates divergent cell fates remains incompletely characterized. We previously described that loss of Stag2, a member of the cohesin complex and a recurrent mutational target in myelodysplastic syndrome (MDS) and myeloid leukemia of Down Syndrome, results in altered chromatin accessibility, transcription factor function, and cell differentiation. Hence, we hypothesized that chromatin accessibility determines GATA1 cistrome specificity and lineage fate decisions. To understand the connection between chromatin accessibility and GATA1, we comprehensively studied erythropoiesis in Stag2∆ mice. Defects in Stag2-deficient hematopoiesis included reduced numbers of erythroid progenitors (EryPs), impaired terminal erythroid differentiation, increased number of MkPs, and increased megakaryocytes. RNA- and ATAC-sequencing of EryPs revealed altered patterns of Gata1 target gene expression with altered accessibility in conjunction with loss of expression of erythroid targets and gain of megakaryocyte targets. Despite unchanged Gata1 expression, Gata1 occupancy was reprogrammed from erythroid to megakaryocyte targets with Fli1 motifs enriched at Stag2∆ Gata1 binding sites. Functionally, we observed that Stag2-deficient EryPs have diminished erythroid output and augmented megakaryocyte output in orthogonal differentiation assays, which was partially reversed with Fli1 knockdown. Human models and primary MDS patients recapitulated the essential phenotypic and molecular features of our in vivo murine MDS model. Collectively, this study establishes chromatin accessibility as a determinant of transcription factor binding specificity, revealing an accessibility-driven Gata1 retargeting mechanism underlying MDS dyserythropoiesis.
Wang Y, Astafiev SV, Yu J
… +15 more, Fellah S, Reis M, Chen V, Mirro AE, Ying C, Guilliams K, Fields ME, King AA, Chen Y, Campbell RA, Di Paola J, Cruchaga C, Lee JM, An H, Ford AL
Sickle cell disease (SCD) causes brain injury and cognitive disability. Systemic inflammation and endothelial injury are central to SCD pathophysiology, yet the relationship between systemic drivers of blood-brain barrie...Sickle cell disease (SCD) causes brain injury and cognitive disability. Systemic inflammation and endothelial injury are central to SCD pathophysiology, yet the relationship between systemic drivers of blood-brain barrier (BBB) disruption and brain injury remains understudied. This cross-sectional study assessed whole-brain and regional BBB permeability (Ktrans) using dynamic contrast-enhanced magnetic resonance imaging in 37 adults with SCD in steady-state and 37 non-SCD adults. Cerebral oxygen extraction fraction (OEF) and white matter mean diffusivity (MD) measured tissue hypoxia and microstructural injury, respectively. The SCD cohort showed elevated Ktrans compared with controls (3.6 x10-4min-1 vs. 2.58x10-4min-1, 95% CI median difference [0.36, 1.30]x10-4min-1, P< 0.001), indicating BBB disruption. In SCD, white matter Ktrans was associated with MD (β [95% Cl]: 6.25 [1.72, 10.77], P=0.008), independent of OEF (β [95% Cl]: 0.22 [0.09, 0.35]) and silent cerebral infarcts (β [95% Cl]: 0.01 [0.00, 0.02]). The interaction (P=0.037) between Ktrans and OEF on MD suggested a combined, deleterious effect of BBB disruption and hypoxia on microstructural injury. High-throughput plasma proteomics followed by differential expression analysis, and weighted gene correlation network analysis in a subset of 61 participants revealed 79 proteins associated with BBB permeability belonged to iron homeostasis, response to hypoxia, immune dysregulation, extracellular matrix degradation, lipoprotein homeostasis, and arginine-proline metabolism pathways. All pathways were independently associated with microstructural injury. BBB permeability is a mediator of brain injury for all pathways except extracellular matrix degradation. Targeting specific systemic pathways to protect the BBB may represent a therapeutic approach to preserve brain health in SCD.
Sickle cell disease (SCD) is a hereditary hemoglobinopathy characterized by persistent pain. The mechanisms underlying pain in SCD are poorly understood and opioids remain the primary treatment, despite their severe side...Sickle cell disease (SCD) is a hereditary hemoglobinopathy characterized by persistent pain. The mechanisms underlying pain in SCD are poorly understood and opioids remain the primary treatment, despite their severe side effects. Here we investigated the contribution of lysophosphatidic acid (LPA), an endogenous pronociceptive lipid mediator, to chronic pain in SCD using humanized transgenic homozygous Berkeley mice that express >99% human sickle hemoglobin (HbSS mice) and control HbAA mice that express normal human hemoglobin A. Hyperalgesia in HbSS mice was associated with an increase in both plasma level of LPA and expression of LPAR1 mRNA in L1-L5 dorsal root ganglion (DRG). Blocking LPA synthesis with BI-2545 or blocking LPA1 receptor (LPA1R) function with siRNA or the LPA1R antagonist, AM966, reversed mechanical and heat hyperalgesia in HbSS mice. LPA also produced acute mechanical and heat hyperalgesia in HbAA mice, which resulted from the sensitization of C-fiber nociceptors. In HbSS mice, hyperalgesia was associated with sensitization of nociceptive DRG neurons. Nociceptors from hyperalgesic HbSS mice had lower rheobase, more positive resting membrane potential and higher frequency of action potential. Although no changes were found in the values of inward currents in nociceptors of HbSS mice compared to HbAA mice, outward-inactivating and non-inactivating currents were reduced, indicating the importance of potassium channels to sensitization in SCD. All these parameters were normalized by pretreatment of HbSS mice with LPA1R siRNA. Our results suggest that LPA signaling may be a promising target for treating pain in SCD.
Boissel N, Huguet F, Leguay TT
… +31 more, Hunault M, Kim R, Hicheri Y, Passet M, Chevallier P, Balsat M, Pastoret C, Delabesse E, Maury S, Thiebaut-Bertrand A, Van Obbergh F, Cluzeau T, Escoffre M, Straetmans N, Konopacki J, Belhabri A, Villate A, Pasquier F, Vaida I, Sanhes L, Blum S, Alexis M, Lamarque M, Farnault L, Berthon C, Lheritier V, Ifrah N, Graux C, Chalandon Y, Clappier E, Dombret H
Intensified chemotherapy regimens have improved outcomes in adults with Philadelphia chromosome (Ph)-negative B-cell acute lymphoblastic leukemia (B-ALL), yet relapse remains a major cause of treatment failure and death....Intensified chemotherapy regimens have improved outcomes in adults with Philadelphia chromosome (Ph)-negative B-cell acute lymphoblastic leukemia (B-ALL), yet relapse remains a major cause of treatment failure and death. Blinatumomab, a CD19×CD3 bispecific T-cell engager, has demonstrated marked activity in relapsed, measurable residual disease (MRD)-positive B-ALL, and in frontline consolidation for MRD-negative patients. The phase 2 GRAALL-2014/B-QUEST sub-study (NCT02617004) evaluated the integration of blinatumomab into consolidation and maintenance therapy for adults with high-risk (HR) B-ALL treated within the GRAALL-2014/B trial. Between 2015 and 2020, 489 adults aged 18-59 years with newly diagnosed Ph-negative B-ALL were enrolled, among them 259 were classified as HR (presence of KMT2A-r, IKZF1 deletion, or end-of-induction MRD≥10-4). Ninety-four HR patients enrolled in QUEST (2018-2020) received up to five 28-day cycles of blinatumomab integrated into consolidation and maintenance. Ninety HR patients treated before QUEST activation without blinatumomab served as controls in a post hoc analysis. Baseline characteristics were comparable. Blinatumomab consolidation significantly improved MRD clearance, reduced relapse, and prolonged survival. At 5 years, cumulative incidence of relapse, disease-free survival (DFS), and overall survival were 23%, 68%, and 79% versus 49% (p=0.001), 42% (p=0.001), and 60% (p=0.03) in controls. Outcome benefit generally favored blinatumomab across subgroups, although not reaching significance in KMT2A-rearranged cases. Very high-risk patients eligible for alloHSCT derived overall benefit. However, no clear additional DFS advantage was observed among those ultimately transplanted. These findings support frontline integration of blinatumomab and warrant prospective evaluation of transplantation strategies in this setting.
T cell exhaustion has been shown to be a key resistance mechanism to efficacy of T cell engagers (TCE) in multiple myeloma (MM). Mezigdomide, a potent cereblon E3 ligase modulator that targets IKZF1 and IKZF3 simultaneou...T cell exhaustion has been shown to be a key resistance mechanism to efficacy of T cell engagers (TCE) in multiple myeloma (MM). Mezigdomide, a potent cereblon E3 ligase modulator that targets IKZF1 and IKZF3 simultaneously for proteasomal degradation, has been shown to modulate T cell activity in MM patients. We explored the possibility that targeting IKZF1/IKZF3 could address T cell exhaustion and restore functionality. We conducted extensive transcriptomic and epigenetic profiling on ex vivo generated exhausted T cells, using their autologous activated T cells as a comparison. Our study reveals that IKZF1 and IKZF3 are critical regulators contributing to the development and maintenance of T cell exhaustion. They regulate transcription by directly binding to promoters and enhancers, both proximal and distal, thereby altering transcriptional potential. Increased IKZF1 binding to exhaustion genes after multiple T cell stimulations results in enhancement of transcription, while binding to cytokine genes results in transcription repression. Mezigdomide treatment in exhausted T cells results in decreased expression of exhaustion-related markers, increased proinflammatory cytokine expression, and enhanced target cell killing with Alnuctamab, a B-cell maturation antigen (BCMA) targeting TCE. This study provides crucial mechanistic insights into the roles of IKZF1/IKZF3 in T cell exhaustion, supporting the rationale for combining mezigdomide with TCEs to enhance therapeutic outcomes in MM.
Kastritis E, Palladini G, Minnema MC
… +42 more, Wechalekar AD, Jaccard A, Lee HC, Sanchorawala V, Mollee P, Lu J, Schönland SO, Gatt ME, Suzuki K, Kim K, Cibeira MT, Bhutani M, Beksac M, Libby EN, Valent J, Hungria V, Rosenzweig MA, Bumma N, Huart A, Dimopoulos MA, Bhutani D, Waxman A, Goodman S, Zonder JA, Lam S, Song KW, Hansen T, Manier S, Roeloffzen WWH, Jamroziak K, Kwok F, Shimazaki C, Kim JS, Crusoé EQ, Tran N, Wang J, Chen Y, Vasey SY, Schecter JM, Vermeulen J, Comenzo R, Merlini G
In the primary analysis of ANDROMEDA, addition of subcutaneous daratumumab to bortezomib/cyclophosphamide/dexamethasone (D-VCd) significantly improved hematologic complete response (CR) rate versus VCd, establishing D-VC...In the primary analysis of ANDROMEDA, addition of subcutaneous daratumumab to bortezomib/cyclophosphamide/dexamethasone (D-VCd) significantly improved hematologic complete response (CR) rate versus VCd, establishing D-VCd as the only approved therapy for light-chain (AL) amyloidosis. We present results from the preplanned final analysis. In this phase 3 trial, we randomly assigned 388 patients with newly diagnosed AL amyloidosis to six cycles of VCd alone (control group) or with subcutaneous daratumumab (D-VCd) followed by single-agent daratumumab every 4 weeks for up to 24 total cycles. The primary endpoint was hematologic CR. The updated hematologic CR rate was 59.5% for D-VCd versus 19.2% for VCd (odds ratio, 6.03; 95% confidence interval [CI], 3.80-9.58; P<0.0001). Median time to hematologic CR was shorter with D-VCd (67.5 days [range, 8.0-879.0]) versus VCd (85.0 days [range, 14.0-617.0]). With a median follow-up of 61.4 months, significant improvement was observed with D-VCd versus VCd in major organ deterioration-progression-free survival (hazard ratio, 0.44; 95% CI, 0.31-0.63; P<0.0001) and overall survival (hazard ratio, 0.62; 95% CI, 0.42-0.90; P=0.0121). Cardiac and renal response rates were 2-3 times higher with D-VCd versus VCd. Achieving hematologic or cardiac CR was associated with improved major organ deterioration-progression-free survival and overall survival. Adverse events were consistent with the known safety profiles for VCd and daratumumab. Adding daratumumab to VCd resulted in deeper and more rapid hematologic responses and recovery of organ function, translating to statistically significant improvement in both overall survival and major organ deterioration-progression-free survival in newly diagnosed AL amyloidosis. ClinicalTrials.gov NCT03201965.
Hematopoietic stem cells (HSCs) and multipotent progenitors (MPPs) are sustained by networks of transcription factors and epigenetic regulators that prime lineage-specific programs yet maintain multipotency. Two epigenet...Hematopoietic stem cells (HSCs) and multipotent progenitors (MPPs) are sustained by networks of transcription factors and epigenetic regulators that prime lineage-specific programs yet maintain multipotency. Two epigenetic regulators, MLL3 and MLL4, play important but distinct roles in maintaining this balance. MLL3 promotes HSC differentiation, whereas MLL4 opposes differentiation. These activities are essential for both normal homeostasis and leukemia suppression, yet it is not clear how MLL3 and MLL4 regulate HSC and MPP gene expression to control HSC/MPP fate decisions. To resolve these mechanisms, we performed an extensive series of single cell genomic studies after conditionally deleting Mll3, Mll4 or both genes together. Mll3 deletion had only limited effects on HSC/MPP enhancer networks at steady state, whereas Mll4 deletion led to precocious activation of myeloid enhancers. Surprisingly, compound Mll3/4 deletion eliminated all myeloid, erythroid and megakaryocytic potential within the hematopoietic hierarchy and caused all progenitors to rapidly default to a B-cell-like identity. These changes were accompanied by widespread inactivation of HSC/MPP enhancers and superenhancers, and ectopic activation of B-cell superenhancers. Disabling MLL3/4 histone methyltransferase activity did not recapitulate the pervasive changes in cell identity that were observed when MLL3 and MLL4 were fully inactivated, indicating that MLL3 and MLL4 activate HSC/MPP enhancers independently from their enzymatic activities. Our findings show that HSC/MPP multipotency requires sustained tension between MLL3/4-dependent enhancers that maintain myeloid, erythroid and megakaryocyte potential, and MLL3/4-independent enhancers that prime B-cell identity. MLL3 and MLL4 therefore serve as critical linchpins of multilineage hematopoiesis.
T-cell engaging bispecific antibodies (BsAbs) have transformed the treatment landscape for multiple hematologic malignancies and are under investigation in the frontline setting, within combination regimens, and for non-...T-cell engaging bispecific antibodies (BsAbs) have transformed the treatment landscape for multiple hematologic malignancies and are under investigation in the frontline setting, within combination regimens, and for non-malignant diseases. However, their increasing use has revealed new patterns of immune suppression and infectious complications that differ from other treatment modalities including chimeric antigen receptor T-cell therapy. Notably, infections are frequent and represent the principal cause of non-relapse mortality. These risks with repeated BsAb dosing arise from multifactorial mechanisms, including B-cell or plasma-cell aplasia, hypogammaglobulinemia, and early cytopenias. Additional contributors such as T-cell exhaustion, cytokine-directed immune modulation, and disease-related immunodeficiency further compound infection risk. The result is a dynamic and cumulative impairment of host immunity that evolves over the course of therapy. In this "How I Treat" article, we provide a practical, phase-based framework for preventing and managing infections in patients receiving BsAbs for non-Hodgkin lymphoma or multiple myeloma. Our review includes pre-treatment evaluation, the period of active therapy, and long-term follow-up. Using representative cases, we highlight strategies for infectious disease screening, antimicrobial prophylaxis, immunoglobulin supplementation, vaccination, and other supportive care practices. Our aim is to equip clinicians with an evidence-informed and pragmatic framework for mitigating BsAb-related infection risks.
Arginine methylation catalyzed by protein arginine methyltransferases (PRMTs) is required for cancer cell proliferation, but whether PRMTs mediate resistance to therapy remains elusive. Here, we have performed loss-of-fu...Arginine methylation catalyzed by protein arginine methyltransferases (PRMTs) is required for cancer cell proliferation, but whether PRMTs mediate resistance to therapy remains elusive. Here, we have performed loss-of-function screens in venetoclax-resistant (VEN-R) AML patient-derived xenograft (PDX) cells and found that PRMT9 plays a critical role in promoting VEN resistance. Specifically, VEN-R AML samples exhibited high levels of PRMT9, and PRMT9 inhibition re-sensitized the AML cells to VEN treatment. In preclinical resistant models, genetic ablation of PRMT9 synergized with VEN to eradicate AML cells. Consistently, pharmacologic inhibition of PRMT9 combined with VEN yielded similar effects in VEN-R AML mouse models. Mechanistically, PRMT9 ablation disrupted RNA splicing by inducing exon-skipping of mRNA encoding ALG13, an UDP-N-Acetylglucosaminyltransferase subunit, downregulating expression of a VEN-efflux transporter encoded by the adenosine triphosphate binding cassette subfamily C member 1 (ABCC1) gene. PRMT9 inhibition also suppressed protein synthesis, downregulating short-lived oncoproteins, such as MCL1. These findings establish a connection between PRMT9-mediated arginine methylation and poor VEN responsiveness, also demonstrate that targeting PRMT9 may represent a viable strategy to overcome VEN resistance.